FN Thomson Reuters Web of Science™ VR 1.0 PT J AU Lahvis, MA Baehr, AL AF Lahvis, MA Baehr, AL TI Estimation of rates of aerobic hydrocarbon biodegradation by simulation of gas transport in the unsaturated zone SO WATER RESOURCES RESEARCH LA English DT Article AB The distribution of oxygen and carbon dioxide gases in the unsaturated zone provides a geochemical signature of aerobic hydrocarbon degradation at petroleum product spill sites. The fluxes of these gases are proportional to the rate of aerobic biodegradation and are quantified by calibrating a mathematical transport model to the oxygen and carbon dioxide gas concentration data. Reaction stoichiometry is assumed to convert the gas fluxes to a corresponding rate of hydrocarbon degradation. The method is applied at a gasoline spill site in Galloway Township, New Jersey, to determine the rate of aerobic degradation of hydrocarbons associated with passive and bioventing remediation field experiments. At the site, microbial degradation of hydrocarbons near the water table limits the migration of hydrocarbon solutes in groundwater and prevents hydrocarbon volatilization into the unsaturated zone. In the passive remediation experiment a site-wide degradation rate estimate of 34,400 g yr(-1) (11.7 gal. yr(-1)) of hydrocarbon was obtained by model calibration to carbon dioxide gas concentration data collected in December 1989. In the bioventing experiment, degradation rate estimates of 46.0 and 47.9 g m(-2) yr(-1) (1.45 x 10(-3) and 1.51 x 10(-3) gal. ft.(-2) yr(-1)) of hydrocarbon were obtained by model calibration to oxygen and carbon dioxide gas concentration data, respectively. Method application was successful in quantifying the significance of a naturally occurring process that can effectively contribute to plume stabilization. RP Lahvis, MA (reprint author), US GEOL SURVEY,810 BEAR TAVERN RD,SUITE 206,W TRENTON,NJ 08628, USA. NR 29 TC 41 Z9 42 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUL PY 1996 VL 32 IS 7 BP 2231 EP 2249 DI 10.1029/96WR00805 PG 19 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UV613 UT WOS:A1996UV61300030 ER PT J AU Evans, HT Weakley, TJR Jameson, GB AF Evans, HT Weakley, TJR Jameson, GB TI Crystal structures of [NEt(3)H](5)[XCo(II)W(11)O(39)]center dot 3H(2)O (X=P or As) SO JOURNAL OF THE CHEMICAL SOCIETY-DALTON TRANSACTIONS LA English DT Article AB The orthorhombic crystal structures of [NEt(3)H](5)[XCo(II)W(11)O(39)]. 3H(2)O for X=P and As have been determined with data collected at room temperature, and for X=P at -degrees 100C, using Mo-K alpha radiation. For the latter the space group is Pna2(1), a=21.670(11), b=14.805(4), c=20.393(5) Angstrom and Z=4. The structure consists of chains of alpha-Keggin-type molecules joined by W-O-Co links aligned in the a-axis direction. The Co/W occupancy at the link is disordered, with 61% Co on one side and 39% on the other. Further probable disorder, by lamellar merohedral twinning on (001) and by misorientation of the triethylammonium ions, has obscured the ethyl groups and the water molecules. In polarized light the crystals are-deep wine-red normal to the chains (in the b direction), but-nearly colourless in the a and c directions. The structure of the arsenate is similar to that of the phosphate. C1 UNIV OREGON,DEPT CHEM,EUGENE,OR 97403. GEORGETOWN UNIV,DEPT CHEM,WASHINGTON,DC 20057. RP Evans, HT (reprint author), US GEOL SURVEY,NATL CTR 959,RESTON,VA 22092, USA. NR 14 TC 51 Z9 51 U1 2 U2 5 PU ROYAL SOC CHEMISTRY PI CAMBRIDGE PA THOMAS GRAHAM HOUSE, SCIENCE PARK MILTON ROAD, CAMBRIDGE, CAMBS, ENGLAND CB4 4WF SN 0300-9246 J9 J CHEM SOC DALTON JI J. Chem. Soc.-Dalton Trans. PD JUN 21 PY 1996 IS 12 BP 2537 EP 2540 DI 10.1039/dt9960002537 PG 4 WC Chemistry, Inorganic & Nuclear SC Chemistry GA UU187 UT WOS:A1996UU18700020 ER PT J AU Wiemer, S Benoit, JP AF Wiemer, S Benoit, JP TI Mapping the b-value anomaly at 100 km depth in the Alaska and New Zealand subduction zones SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID MAGNITUDE AB A positive anomaly in the frequency-magnitude distribution (b-value) is detected at approximately 90-100 km depth in two subduction zones. The b-value in this anomalous zone is 40% higher than in adjacent volumes. We use regional catalogs with a magnitude of completeness of 2.6 (Central Alaska and Cook Inlet), 2.0 (Shumagin Islands), and 3.5 (New Zealand). To resolve the b-value as a function of space in more detail, we project all earthquakes onto planes perpendicular to the strike of the slab. These cross-section views of the b-value distribution locate the high b-value anomalies at a depth of 90-100 km, on the upper surface of the Wadati-Benioff Zone. At these depths, slab dehydration may increase pore pressure, thus lowering the effective stress and increasing the b-value. Increased pore pressure would also lower the liquidus in the overlying asthenosphere, giving rise to the volcanism that occurs directly above this zone. C1 UNIV ALASKA, ALASKA VOLCANO OBSERV, FAIRBANKS, AK 99775 USA. RP Wiemer, S (reprint author), UNIV ALASKA, INST GEOPHYS, FAIRBANKS, AK 99775 USA. RI Wiemer, Stefan/E-5033-2015 NR 25 TC 90 Z9 92 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0094-8276 EI 1944-8007 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD JUN 15 PY 1996 VL 23 IS 13 BP 1557 EP 1560 DI 10.1029/96GL01233 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UT009 UT WOS:A1996UT00900003 ER PT J AU Jaffe, BE Rubin, DM AF Jaffe, BE Rubin, DM TI Using nonlinear forecasting to learn the magnitude and phasing of time-varying sediment suspension in the surf zone SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SUSPENDED SEDIMENT; NEARSHORE ENVIRONMENT; COMBINED WAVE; TRANSPORT; CURRENTS; BOTTOM; SYSTEM; SERIES; BEACH AB The time-dependent response of sediment suspension to flow velocity was explored by modeling field measurements collected in the surf zone during a large storm. Linear and nonlinear models were created and tested using flow velocity as input and suspended-sediment concentration as output. A sequence of past velocities (velocity history), as well as velocity from the same instant as the suspended-sediment concentration, was used as input; this velocity history length was allowed to vary. The models also allowed for a lag between input (instantaneous velocity or end of velocity sequence) and output (suspended-sediment concentration). Predictions of concentration from instantaneous velocity or instantaneous velocity raised to a power (up to 8) using linear models were poor (correlation coefficients between predicted and observed concentrations were less than 0.10). Allowing a lag between velocity and concentration improved linear models (correlation coefficient of 0.30), with optimum lag time increasing with elevation above the seabed (from 1.5 s at 13 cm to 8.5 s at 60 cm). These lags are largely due to the time for an observed flow event to effect the bed and mix sediment upward. Using a velocity history further improved linear models (correlation coefficient of 0.43). The best linear model used 12.5 s of velocity history (approximately one wave period) to predict concentration. Nonlinear models gave better predictions than linear models, and, as with linear models, nonlinear models using a velocity history performed better than models using only instantaneous velocity as input. Including a lag time between the velocity and concentration also improved the predictions. The best model (correlation coefficient of 0.58) used 3 s (approximately a quarter wave period) of the cross-shore velocity squared, starting at 4.5 s before the observed concentration, to predict concentration. Using a velocity history increases the performance of the models by specifying a more complete description of the dynamical forcing of the flow (including accelerations and wave phase and shape) responsible for sediment suspension. Incorporating such a velocity history and a lag time into the formulation of the forcing for time-dependent models for sediment suspension in the surf zone will greatly increase our ability to predict suspended-sediment transport. RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 999, MENLO PK, CA 94025 USA. RI Jaffe, Bruce/A-9979-2012 OI Jaffe, Bruce/0000-0002-8816-5920 NR 51 TC 21 Z9 21 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD JUN 15 PY 1996 VL 101 IS C6 BP 14283 EP 14296 DI 10.1029/96JC00495 PG 14 WC Oceanography SC Oceanography GA UR422 UT WOS:A1996UR42200021 ER PT J AU Amelin, YV Neymark, LA Ritsk, EY Nemchin, AA AF Amelin, YV Neymark, LA Ritsk, EY Nemchin, AA TI Enriched Nd-Sr-Pb isotopic signatures in the Dovyren layered intrusion (eastern Siberia, Russia), evidence for source contamination by ancient upper-crustal material SO CHEMICAL GEOLOGY LA English DT Article ID MAFIC MAGMA CHAMBERS; TRACE-ELEMENT; CONTINENTAL-CRUST; LITHOSPHERIC MANTLE; FLOOD BASALTS; MAJOR-ELEMENT; SOUTH-AFRICA; EVOLUTION; CONSTRAINTS; XENOLITHS AB Major- and trace-element concentrations and Nd-, Sr- and Pb-isotopic ratios are reported for the Dovyren layered mafic-ultramafic intrusion in the northern Baikal region, eastern Siberia. Sm-Nd internal isochrons for an olivine gabbro from the layered series and a gabbronorite from a sill at the bottom of the Dovyren intrusion yield ages of 673 +/- 22 and 707 +/- 40 Ma, respectively. Initial isotopic ratios: Sr-87/Sr-86 (673) from 0.7101 to 0.7135, epsilon(Nd)(673 Ma) from -16.3 to -14.1, Pb-206/Pb-204 from 16.80 to 17.14, Pb-207/Pb-204 from 15.477 to 15.501 and Pb-208/Pb-204 from 37.17 to 37.59, are similar to those of late Archean-early Proterozoic upper continental crust, but do not appear to be a result of wallrock assimilation in the magma chamber. These isotopic features, as well as high K, Rb and LREE and low Ti concentrations in the calculated composition of the Dovyren parental magma, may be explained by subduction of sediments derived from upper continental crust into depleted mantle and subsequent melting of the metasomatized peridotite. C1 ROYAL ONTARIO MUSEUM,GEOCHRONOL LAB,TORONTO,ON M5S 2C6,CANADA. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. CURTIN UNIV TECHNOL,SCH APPL GEOL,PERTH,WA 6001,AUSTRALIA. RP Amelin, YV (reprint author), RUSSIAN ACAD SCI,INST PRECAMBRIAN GEOL & GEOCHRONOL,MAKAROVA EMB 2,ST PETERSBURG 199034,RUSSIA. NR 80 TC 39 Z9 44 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD JUN 14 PY 1996 VL 129 IS 1-2 BP 39 EP 69 DI 10.1016/0009-2541(95)00135-2 PG 31 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UW369 UT WOS:A1996UW36900003 ER PT J AU Koepenick, KW Brantley, SL Thompson, JM Rowe, GL Nyblade, AA Moshy, C AF Koepenick, KW Brantley, SL Thompson, JM Rowe, GL Nyblade, AA Moshy, C TI Volatile emissions from the crater and flank of Oldoinyo Lengai volcano, Tanzania SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MOUNT ST-HELENS; CARBON-DIOXIDE; ISOTOPIC COMPOSITION; AUGUSTINE VOLCANO; SOIL-ATMOSPHERE; MAGMATIC GAS; TEMPERATURE; INDICATORS; EQUILIBRIA; ERUPTION AB As a comparison to airborne infrared (IR) flux measurements, ground-based sampling of fumarole and soil gases was used to characterize the quiescent degassing of CO2 from Oldoniyo Lengai volcano. Aerial and ground-based measurements are in good agreement: similar to 75% of the aerially measured CO2 flux at Lengai (0.05-0.06 x 10(12) mol yr(-1) or 6000-7200 tonnes CO2 d(-1)) can be attributed to seven large crater vents. In contrast to Etna and Vulcano Island, where 15-50% of the total CO2 flux emanates diffusely through the volcanic flanks, diffuse emissions were measured only within 500 m of the crater rim at Lengai, contributing < 2% of the total flux. The lack of extensive flank emissions may reflect the dimensions of the magma chamber and/or the lack of a shallow fluid flow system. Thermodynamic restoration of fumarole analyses shows that,eases are the most CO2-rich and H2O-poor reported for any volcano; containing 64-74% CO2, 24-34% H2O, 0.88-1.0% H-2, 0.1-0.4% CO and < 0.1% H2S, HCl, HF, and CH4. Volatile emissions of S, Cl, and F at Oldoiyno Lengai are estimated as 4.5, 1.5; and 1.0 x 10(7) mol yr(-1), respectively. Accuracy of the airborne technique was also assessed by measuring the C emission rate from a coal-burning power plant. CO2 fluxes were measured within +/-10% near the plant; however, poor resolution at increased distances caused an underestimation of the flux by a factor of 2. The relatively large CO2 fluxes measured for alkaline volcanoes such as Oldoinyo Lengai or Etna may indicate that midplate volcanoes represent a large, yet relatively unknown, natural source of CO2. C1 MINIST WATER ENERGY & MINERALS, DODOMA, TANZANIA. US GEOL SURVEY, DIV WATER RESOURCES, COLUMBUS, OH 43212 USA. US GEOL SURVEY, CASCADES VOLCANO OBSERV, VANCOUVER, WA 98661 USA. PENN STATE UNIV, DEPT GEOSCI, UNIVERSITY PK, PA 16802 USA. RP Koepenick, KW (reprint author), ICF KAISER ENGINEERS INC, 1301 CONTINENTAL DR, SUITE 101, ABINGDON, MD 21009 USA. NR 59 TC 42 Z9 43 U1 0 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1996 VL 101 IS B6 BP 13819 EP 13830 DI 10.1029/96JB00173 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ014 UT WOS:A1996UQ01400019 ER PT J AU Boatwright, J Cocco, M AF Boatwright, J Cocco, M TI Frictional constraints on crustal faulting SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID STATE-DEPENDENT FRICTION; 1984 MORGAN-HILL; SINGLE DEGREE; STRESS DROP; ROCK FRICTION; EARTHQUAKE; SLIP; RUPTURE; CALIFORNIA; MOTION AB We consider how variations in fault frictional properties affect the phenomenology of earthquake faulting. In particular, we propose that lateral variations in fault friction produce the marked heterogeneity of slip observed in large earthquakes. We model these variations using a rate- and state-dependent friction law, where we differentiate velocity-weakening behavior into tyro fields: the strong seismic field is very velocity weakening and the weak seismic held is slightly velocity weakening. Similarly, we differentiate velocity-strengthening behavior into two fields: the compliant field is slightly velocity strengthening and the viscous field is very velocity strengthening. The strong seismic field comprises the seismic slip concentrations, or asperities. The two ''intermediate'' fields, weak seismic and compliant, have frictional velocity dependences that are close to velocity neutral: these fields modulate both the tectonic loading and the dynamic rupture process. During the interseismic period, the weak seismic and compliant regions slip aseismically, while the strong seismic regions remain locked, evolving into stress concentrations that fail only in main shocks. The weak seismic areas exhibit most of the interseismic activity and aftershocks but can also creep seismically. This ''mixed'' frictional behavior can be obtained from a sufficiently heterogenous distribution of the critical slip distance. The model also provides a mechanism for rupture arrest: dynamic rupture fronts decelerate as they penetrate into unloaded complaint or weak seismic areas, producing broad areas of accelerated afterslip. Aftershocks occur on both. the weak seismic and compliant areas around a fault, but most of the stress is diffused through aseismic slip. Rapid afterslip on these peripheral areas can also produce aftershocks within the main shock rupture area by reloading weak fault areas that slipped in the main shock and then healed. We test this frictional model by comparing the seismicity and the coseismic slip for the 1966 Parkfield, 1979 Coyote Lake, and 1984 Morgan Hill earthquakes. The interevent seismicity and aftershocks appear to occur on fault areas outside the regions of significant slip: these regions are interpreted as either weak seismic or compliant, depending on whether or not they manifest interevent seismicity. C1 IST NAZL GEOFIS, I-00143 ROME, ITALY. RP Boatwright, J (reprint author), US GEOL SURVEY, MS 977, 345 MIDDLEFIELD RD, MENLO PK, CA 94025 USA. RI Cocco, Massimo/G-6872-2012 NR 51 TC 117 Z9 121 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JUN 10 PY 1996 VL 101 IS B6 BP 13895 EP 13909 DI 10.1029/96JB00405 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ014 UT WOS:A1996UQ01400024 ER PT J AU MacZura, G Moody, KJ Anderson, EM Kunka, MK AF MacZura, G Moody, KJ Anderson, EM Kunka, MK TI Annual minerals review SO AMERICAN CERAMIC SOCIETY BULLETIN LA English DT Article C1 ADV REFRACTORY TECHNOL INC,BUFFALO,NY 14207. F&S INT INC,NEW YORK,NY 10158. OLD HICKORY CLAY CO,HICKORY,KY 42051. TAM CERAM INC,NIAGARA FALLS,NY 14305. BASSTECH INT,ENGLEWOOD,NJ 07631. US GEOL SURVEY,RESTON,VA 22092. C E MINERALS,KING OF PRUSSIA,PA 19406. AMER MINERAL INC,KING OF PRUSSIA,PA. EAGLE ZINC CO,NEW YORK,NY 10112. ST GOBAIN NORTON INC CERAM CORP,WORCESTER,MA 01615. BOULDER SCI CO,BOULDER,CO. KENTUCKY TENNESSEE CLAY CO,MAYFIELD,KY 42066. GWALIA CONSOLIDATED LTD,PERTH,WA 6872,AUSTRALIA. UNIMIN CORP,NEW CANAAN,CT 06840. RT VANDERBILT CO INC,NORWALK,CT 06856. US BUR MINES,WASHINGTON,DC 20241. US BORAX INC,VALENCIA,CA 91355. LEHIGH PORTLAND CEMENT CO,ALLENTOWN,PA 18195. ASBURY GRAPHITE MILLS INC,ASBURY PK,NJ 08802. SEAFORTH MINERAL & ORE CO INC,CAVE IN ROCK,IL 62919. BAKER REFRACTORIES,YORK,PA. AS OLIVIN,AAHEIM,NORWAY. RP MacZura, G (reprint author), ALCOA,IND CHEM DIV,6100 FAIRVIEW RD,SUITE 610,CHARLOTTE,NC 28210, USA. NR 21 TC 1 Z9 1 U1 0 U2 1 PU AMER CERAMIC SOC PI WESTERVILLE PA 735 CERAMIC PLACE, PO BOX 6136, WESTERVILLE, OH 43081-6136 SN 0002-7812 J9 AM CERAM SOC BULL JI Am. Ceram. Soc. Bull. PD JUN PY 1996 VL 75 IS 6 BP 93 EP & PG 59 WC Materials Science, Ceramics SC Materials Science GA UQ187 UT WOS:A1996UQ18700005 ER PT J AU Seitz, JC Pasteris, JD Chou, IM AF Seitz, JC Pasteris, JD Chou, IM TI Raman spectroscopic characterization of gas mixtures .2. Quantitative composition and pressure determination of the CO2-CH4 system SO AMERICAN JOURNAL OF SCIENCE LA English DT Article ID O-H-N; FLUID INCLUSIONS; MICROPROBE SPECTROSCOPY; DENSITY; MICROTHERMOMETRY; SCATTERING; METHANE; CH4 AB Raman spectral parameters were determined for the nu(1) band of CH4 and the nu(1) and 2 nu(2) bands (Fermi diad) of CO2 in pure CO2 and CO2-CH4 mixtures at pressures up to 700 bars and room temperature, Peak position, area, height, and width were investigated as functions of pressure and composition, The peak positions of the CH4 and CO2 bands shift to lower relative wavenumbers as fluid pressure is increased, The peak position of the lower-wavenumber member of the Fermi diad for CO2 is sensitive to fluid composition, whereas the peak positions of the CH4 band and the upper Fermi diad member for CO2 are relatively insensitive in the CO2-CH4 system, The magnitude of the shifts in each of the three peak positions (as a function of pressure) is sufficient to be useful as a monitor of fluid pressure, The relative molar proportions in a CO2-CH4 mixture may be determined from the peak areas: the ratio of the peak areas of the CH4 band and the CO2 upper Fermi diad member is very sensitive to composition, whereas above about 100 bars, it is Insensitive to pressure, Likewise, the peak height ratio is very sensitive to composition but also to fluid pressure, The individual peak widths of CO2 and CH4, as well as the ratios of the widths of the CH4 peak to the CO2 peaks are a sensitive function of pressure and, to a lesser extent, composition, Thus, upon determination of fluid composition, the peak width ratios may be used as a monitor of fluid pressure, The application of these spectral parameters to a suite of natural CO2-CH4 inclusions has yielded internally-consistent, quantitative determinations of the fluid composition and density. C1 WASHINGTON UNIV,DEPT EARTH & PLANETARY SCI,ST LOUIS,MO 63130. US GEOL SURVEY,RESTON,VA 22092. RP Seitz, JC (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,BLDG 4500S,OAK RIDGE,TN 37831, USA. NR 26 TC 46 Z9 53 U1 1 U2 14 PU KLINE GEOLOGY LABORATORY PI NEW HAVEN PA YALE UNIV, NEW HAVEN, CT 06520 SN 0002-9599 J9 AM J SCI JI Am. J. Sci. PD JUN PY 1996 VL 296 IS 6 BP 577 EP 600 PG 24 WC Geosciences, Multidisciplinary SC Geology GA UU522 UT WOS:A1996UU52200001 ER PT J AU Wintsch, RP Kunk, MJ Epstein, JB AF Wintsch, RP Kunk, MJ Epstein, JB TI Ar-40/Ar-39 whole-rock data constraints on Acadian diagenesis and Alleghanian cleavage in the Martinsburg Formation, eastern Pennsylvania SO AMERICAN JOURNAL OF SCIENCE LA English DT Article ID FISSION-TRACK ANALYSIS; DELAWARE-WATER-GAP; SLATY CLEAVAGE; LEHIGH-GAP; ARGILLACEOUS SEDIMENT; BURIAL METAMORPHISM; APPALACHIAN BASIN; ISOTOPIC DATA; GLARUS ALPS; NEW-JERSEY AB A comparison of Ar-40/Ar-39 age spectra of whole-rock mudstone and slate samples from the Ordovician Martinsburg Formation at Lehigh Gap, Pennsylvania, and stratigraphic and thermal constraints support an Alleghanian age for regional slaty cleavage and a late Acadian age for diagenesis in these rocks. Age spectra from mudstones have a sigmoidal shape, with slopes that climb steeply from apparent Mesozoic ages to intermediate saddle regions with Devonian apparent ages, and then climb steeply again to Late Proterozoic apparent ages. The steps with these oldest apparent ages are interpreted to be dominated by Late Proterozoic detrital muscovite. The saddle region of the mudstone samples gives very Late Silurian to earliest Devonian ages, which are maximum ages of diagenetic micas and which eliminate a Taconic age for the cleavage. The ages of the saddle regions of the slate samples containing cleavage-forming muscovite is 390 analyses were acquired from 32 polished thin sections. Concentrations of trace elements in the tourmalines vary widely, from < 40 to 3,770 ppm Mn, < 4 to 1,800 ppm Ni, < 2 to 1,430 ppm Cu, < 9 to 4,160 ppm Zn, 3 to 305 ppm Ga, < 6 to 1,345 ppm Sr, < 10 to 745 ppm Sn, < 49 to 510 ppm Ba, and < 3 to 4,115 ppm Pb. Individual grains and growth zones are relatively homogeneous, suggesting that these trace elements are contained within the crystal structure of the tourmaline, and are not present in inclusions. The highest base metal contents are in ore-related tourmaline samples from Kidd Creek (Ontario), Broken Hill (Australia), and Sazare (Japan). Tourmaline data from these and many other massive sulfide deposits cluster by sample and display broadly linear trends on Zn vs. Fe plots, suggesting chemical control by temperature and hydrothermal and/or metamorphic fluid-mineral equilibria. Significant Ni occurs only in samples from the Kidd Creek Cu-Zn-Pb-Ag deposit, which is associated with a large footwall ultramafic body. An overall antithetic relationship between Zn and Ni probably reflects fluid source controls. Mn is correlated with Fe in tourmalines from barren associations, and possibly in some tourmalines associated with sulfide vein deposits. Sn increases systematically with Fe content irrespective of association; the highest values are found in schorls from granites. Other trace elements are generally uncorrelated with major element concentrations (e.g., Sr-Ca). Base metal proportions in the tourmalines show systematic patterns on ternary Cu-Pb-Zn diagrams that correlate well with the major commodity metals in the associated massive sulfide deposits. For example, data for tourmalines from Cu-Zn deposits (e.g., Ming mine, Newfoundland) Fall mainly on the Cu-Zn join, whereas those from W-Zn deposits (e.g., Broken Hill, Australia) plot on the Pb-Zn join; no data fall on the Cu-Pb join, consistent with the lack of this metal association in massive sulfide deposits. The systematic relationship between base metal proportions in the tourmalines and the metallogeny of the host massive sulfide deposits indicates that the analyzed tourmalines retain a strong chemical signature of their original hydrothermal formation, in spite of variable metamorphic recrystallization. Such trace element patterns in massive sulfide tourmalines may be useful in mineral exploration, specifically for the evaluation of tourmaline concentrations in rocks, soils, and stream sediments. C1 MACQUARIE UNIV,SCH EARTH SCI,KEY CTR GEOCHEM EVOLUT & METALLOGENY CONTINENTS,SYDNEY,NSW 2109,AUSTRALIA. US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP Griffin, WL (reprint author), CSIRO,POB 136,51 DELHI RD,N RYDE,NSW 2113,AUSTRALIA. RI Ryan, Chris/A-6032-2011; GAU, geochemist/H-1985-2016; Griffin, William/F-7713-2011; OI Ryan, Chris/0000-0003-2891-3912; Griffin, William L/0000-0002-0980-2566 NR 70 TC 28 Z9 31 U1 0 U2 1 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD JUN-JUL PY 1996 VL 91 IS 4 BP 657 EP 675 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VX607 UT WOS:A1996VX60700001 ER PT J AU Paillet, FL Pedler, WH AF Paillet, FL Pedler, WH TI Integrated borehole logging methods for wellhead protection applications SO ENGINEERING GEOLOGY LA English DT Article ID POROUS-MEDIA; PERMEABILITY AB Modeling of ground water infiltration and movement in the wellhead area is a critical part of an effective wellhead protection program. Such models depend on an accurate description of the aquifer in the wellhead area so that reliable estimates of contaminant travel times can be used in defining a protection area. Geophysical and hydraulic measurements in boreholes provide one of the most important methods for obtaining the data needed to specify wellhead protection measures. Most effective characterization of aquifers in the wellhead vicinity results when a variety of geophysical and hydraulic measurements are made where geophysical measurements can be calibrated in terms of hydraulic variables, and where measurements are made at somewhat different scales of investigation. The application of multiple geophysical measurements to ground water flow in the wellhead area is illustrated by examples in alluvial, fractured sedimentary, and fractured crystalline rock aquifers. Data obtained from a single test well are useful, but cannot indicate how conductive elements in the aquifer are connected to form large-scale flow paths. Geophysical and hydraulic measurements made in arrays of observation boreholes can provide information about such large-scale flow paths, and are especially useful in specifying aquifer properties in wellhead protection studies. RP Paillet, FL (reprint author), US GEOL SURVEY,POB 25046,MS 403,DENVER,CO 80225, USA. NR 23 TC 17 Z9 20 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0013-7952 J9 ENG GEOL JI Eng. Geol. PD JUN PY 1996 VL 42 IS 2-3 BP 155 EP 165 DI 10.1016/0013-7952(95)00077-1 PG 11 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA UX730 UT WOS:A1996UX73000005 ER PT J AU Bradley, PM Chapelle, FH AF Bradley, PM Chapelle, FH TI Anaerobic mineralization of vinyl chloride in Fe(III)-reducing, aquifer sediments SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID REDUCTIVE DECHLORINATION; METHANOGENIC CONDITIONS; TETRACHLOROETHYLENE; BIOTRANSFORMATION; TRICHLOROETHYLENE; BIODEGRADATION AB Within anaerobic aquifer systems, reductive dehalogenation of polychlorinated ethenes commonly results in the accumulation of vinyl chloride, which is highly toxic and carcinogenic to humans. Anaerobic reduction of vinyl chloride is considered to be slow and incomplete. Here, we provide the first evidence for anaerobic oxidation of vinyl chloride under Fe(III)-reducing conditions. Addition of chelated Fe(III) (as Fe-EDTA) to anaerobic aquifer microcosms resulted in mineralization of up to 34% of [1,2-C-14]vinyl chloride within 84 h. The results indicate that vinyl chloride can be mineralized under anaerobic, Fe(III)-reducing conditions and that the bioavailability of Fe(III) is an important factor affecting the rates of mineralization. RP Bradley, PM (reprint author), US GEOL SURVEY,720 GRACERN RD,SUITE 129,COLUMBIA,SC 29210, USA. NR 27 TC 93 Z9 94 U1 0 U2 8 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN PY 1996 VL 30 IS 6 BP 2084 EP 2086 DI 10.1021/es950926k PG 3 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UM991 UT WOS:A1996UM99100062 ER PT J AU Hurley, JP Shafer, MM Cowell, SE Overdier, JT Hughes, PE Armstrong, DE AF Hurley, JP Shafer, MM Cowell, SE Overdier, JT Hughes, PE Armstrong, DE TI Trace metal assessment of Lake Michigan tributaries using low-level techniques SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MERCURY; STORAGE; WATERS C1 UNIV WISCONSIN,WATER CHEM PROGRAM,MADISON,WI 53706. US GEOL SURVEY,MADISON,WI 53719. RP Hurley, JP (reprint author), WISCONSIN DEPT NAT RESOURCES,BUR RES,1350 FEMRITE DR,MONONA,WI 53716, USA. RI Hurley, James/A-9216-2010 NR 22 TC 59 Z9 59 U1 2 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JUN PY 1996 VL 30 IS 6 BP 2093 EP 2098 DI 10.1021/es9509543 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UM991 UT WOS:A1996UM99100064 ER PT J AU Paveglio, FL Kilbride, KM Grue, CE Simenstad, CA Fresh, KL AF Paveglio, FL Kilbride, KM Grue, CE Simenstad, CA Fresh, KL TI Use of Rodeo(R) and X-77(R) spreader to control smooth cordgrass (Spartina alterniflora) in a southwestern Washington estuary .1. Environmental fate SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE glyphosate; aminomethylphosphonic acid; nonylphenol polyethoxylates; estuary; Spartina alterniflora ID AMINOMETHYLPHOSPHONIC ACID; ALKYLPHENOL ETHOXYLATES; FOREST PONDS; COHO SALMON; GLYPHOSATE; SOIL; TRANSLOCATION; DISSIPATION; METABOLISM; ADSORPTION AB A I-ha plot with smooth cordgrass (Spartina alterniflora) at three locations in Willapa Bay, a southwestern Washington estuary, was aerially treated with 4.7 L/ha Rodeo(R) and 0.9 L/ha X-77(R) Spreader to determine the fate of the herbicide formulation. Rates of spray deposit on filter pads placed over treated intertidal mudflats did not differ among locations for glyphosate and aminomethylphosphonic acid (AMPA); however, deposit rates for nonylphenol polyethoxylates (NPEO) did differ among locations. Glyphosate concentrations in sediment cores from treated mudflats declined 51 to 72% during 119 days posttreatment (DPT); NPEO concentrations in sediment declined (42%) between spray day and 14 DPT. The highest concentrations of glyphosate, AMPA, and NPEO in seawater were found in off-site samples collected from the leading edge of the first high tide after application. Glyphosate and AMPA concentrations in depth-integrated seawater samples declined 73 and 42%, respectively, between the first high tide immediately following application and the second high tide at 1 DPT. Glyphosate concentrations in Spartina stems from treated plots declined 91 to 99% between 1 and 28 DPT; whereas, AMPA declined (86 and >96%) during this period. Comparison of maximum concentrations for glyphosate in seawater from this study with acute toxicity values in the literature indicates that under worst-case conditions direct effects to aquatic organisms would not be likely. C1 WASHINGTON UNIV,SCH FISHERIES WH10,WASHINGTON COOPERAT FISH & WILDLIFE RES UNIT,NATL BIOL SERV,SEATTLE,WA 98195. WASHINGTON UNIV,SCH FISHERIES WH10,FISHERIES RES INST,SEATTLE,WA 98195. WASHINGTON STATE DEPT FISH & WILDLIFE,ECOSYST SERV,OLYMPIA,WA 98504. RP Paveglio, FL (reprint author), US FISH & WILDLIFE SERV,REFUGES & WILDLIFE,9317 NE HIGHWAY 99,SUITE D,VANCOUVER,WA 98665, USA. NR 63 TC 20 Z9 24 U1 2 U2 11 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD JUN PY 1996 VL 15 IS 6 BP 961 EP 968 DI 10.1897/1551-5028(1996)015<0961:UORAXS>2.3.CO;2 PG 8 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UP251 UT WOS:A1996UP25100019 ER PT J AU Hagstrum, JT Murchey, BL AF Hagstrum, JT Murchey, BL TI Paleomagnetism of Jurassic radiolarian chert above the Coast Range ophiolite at Stanley Mountain, California, and implications for its paleogeographic origins SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID BAJA-CALIFORNIA; OREGON; REMAGNETIZATION; MEXICO; ACCRETION; PENINSULA; ISLANDS; ALASKA; ROCKS AB Upper Jurassic red tuffaceous chert above the Coast Range ophiolite at Stanley Mountain, California (lat 35 degrees N, long 240 degrees E), contains three components of remanent magnetization. The first component (A; removed by approximate to 100-approximate to 200 degrees C) has a direction near the present-day field for southern California and is probably a recently acquired thermoviscous magnetization. A second component (B; removed between approximate to 100 and approximate to 600 degrees C) is identical to that observed by previous workers in samples of underlying pillow basalt and overlying terrigenous sedimentary rocks. This component has constant normal polarity and direction throughout the entire section, although these rocks were deposited during a mixed polarity interval of the geomagnetic field. The B magnetization, therefore, is inferred to be a secondary magnetization acquired during accretion, uplift, or Miocene volcanism prior to regional clock wise rotation. The highest temperature component (C; removed between approximate to 480 and 680 degrees C) is of dual polarity and is tentatively interpreted as a primary magnetization, although it fails a reversal test possibly due to contamination by B. Separation of the B and C components is best shown by samples with negative-inclination C directions, and a corrected mean direction using only these samples indicates an initial paleolatitude of 32 degrees N +/- 8 degrees. Paleobiogeographic models relating radiolarian faunal distribution patterns to paleolatitude have apparently been incorrectly calibrated using the overprint B component. Few other paleomagnetic data have been incorporated in these models, and faunal distribution patterns are poorly known and mostly unquantified. The available data, therefore, do not support formation of the Coast Range ophiolite at Stanley Mountain near the paleoequator or accretion at approximate to 10 degrees N paleolatitude, as has been previously suggested based on paleomagnetic data, but indicate deposition near expected paleolatitudes for North America (35 degrees N +/- 4 degrees) during Late Jurassic time. RP Hagstrum, JT (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 46 TC 31 Z9 31 U1 0 U2 2 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JUN PY 1996 VL 108 IS 6 BP 643 EP 652 DI 10.1130/0016-7606(1996)108<0643:POJRCA>2.3.CO;2 PG 10 WC Geosciences, Multidisciplinary SC Geology GA UQ175 UT WOS:A1996UQ17500002 ER PT J AU Harlan, SS Geissman, JW Snee, LW Reynolds, RL AF Harlan, SS Geissman, JW Snee, LW Reynolds, RL TI Late Cretaceous remagnetization of Proterozoic mafic dikes, southern Highland Mountains, southwestern Montana: A paleomagnetic and Ar-40/Ar-39 study SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID CANADIAN SUPERIOR PROVINCE; NORTH-AMERICA; DIABASE DIKES; TECTONICS; ONTARIO; FIELD; AGE; GEOCHRONOLOGY; GEOCHEMISTRY; CALIBRATION AB Paleomagnetic results from Early Proterozoic metabasite sills and Middle Proterozoic diabase dikes from the southern Highland Mountains of southwestern Montana give well-defined, dual-polarity magnetizations that are statistically identical to those from a small Late Cretaceous pluton that cuts the dikes. The concordance of paleomagnetic directions from rocks of three widely separated ages indicates that the Proterozoic rocks were remagnetized, probably during Late Cretaceous time. Paleomagnetic, rock magnetic, and petrographic observations from the metabasite and diabase samples indicate that remanence is carried primarily by low-Ti magnetite. Combining virtual geomagnetic poles from metabasite sills, diabase dikes, and the Late Cretaceous pluton, we obtain a paleomagnetic pole at 85.5 degrees N, 310.7 degrees E (K = 19.9, A(95) = 9.1 degrees, N = 14 sites) that is similar to a reference pole from the 74 Ma Adel Mountain Volcanics of western Montana. Biotite and hornblende Ar-40/Ar-39 isotopic dates from host basement gneiss and a hornblende from a remagnetized metabasite sill yield ages of ca. 1800 Ma; these dates probably record cooling of the southern Highland Mountains following high-grade metamorphism at 1.9-1.8 Ga. The gneiss and metabasite age spectra show virtually no evidence of disturbance, indicating that the basement rocks were never heated to temperatures sufficient to cause even partial resetting of their argon systems. Thus, the overprint magnetization of the Highland Mountains rocks is not a thermoremanent magnetization acquired during conductive cooling of nearby Late Cretaceous plutons. Remagnetization of the metabasite sills and diabase dikes was probably caused by localized thermochemical and thermoviscous effects during circulation of Late Cretaceous hydrothermal fluids related to epithermal mineralization. The absence of significant disturbance to the Ar-40/Ar-39 age spectrum from the remagnetized metabasite hornblende indicates that some secondary magnetizations may go unrecognized and undated, even if Ar-40/Ar-39 dating is applied. C1 UNIV NEW MEXICO, DEPT EARTH & PLANETARY SCI, ALBUQUERQUE, NM 87131 USA. RP US GEOL SURVEY, POB 25046, MS 963, FED CTR, DENVER, CO 80225 USA. NR 73 TC 17 Z9 17 U1 0 U2 2 PU GEOLOGICAL SOC AMER, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0016-7606 EI 1943-2674 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JUN PY 1996 VL 108 IS 6 BP 653 EP 668 DI 10.1130/0016-7606(1996)108<0653:LCROPM>2.3.CO;2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA UQ175 UT WOS:A1996UQ17500003 ER PT J AU Jacobson, CE Oyarzabal, FR Haxel, GB AF Jacobson, CE Oyarzabal, FR Haxel, GB TI Subduction and exhumation of the Pelona-Orocopia-Rand schists, southern California SO GEOLOGY LA English DT Article ID SOUTHEASTERN CALIFORNIA; NORTHEASTWARD MOVEMENT; SOUTHWESTERN ARIZONA; MOUNTAINS; THRUST; EVOLUTION; ROCKS AB The Pelona, Orocopia, and Rand schists of southern California and southwestern Arizona are thought to have formed in either the same east-dipping subduction zone as the Franciscan complex or in a southwest-dipping subduction zone related to collision of an outboard continental fragment with North America. The principal justification for the collision model has been the observation that continental rocks overlying the schists locally show transport to the northeast. Field and petrographic studies now confirm that the northeast movement occurred during exhumation of the schist, not during subduction. Combined with regional geologic relations, this evidence makes the collision model unlikely. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. RP Jacobson, CE (reprint author), IOWA STATE UNIV SCI & TECHNOL,DEPT GEOL & ATMOSPHER SCI,AMES,IA 50011, USA. NR 43 TC 43 Z9 44 U1 2 U2 8 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JUN PY 1996 VL 24 IS 6 BP 547 EP 550 DI 10.1130/0091-7613(1996)024<0547:SAEOTP>2.3.CO;2 PG 4 WC Geology SC Geology GA UQ197 UT WOS:A1996UQ19700017 ER PT J AU Murphy, F Herkelrath, WN AF Murphy, F Herkelrath, WN TI A sample-freezing drive shoe for a wire line piston core sampler SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID OIL SPILL SITE; GRAVEL; SAND AB Loss of fluids and samples during retrieval of cores of saturated, noncohesive sediments results in incorrect measures of fluid distributions and an inaccurate measure of the stratigraphic position of the sample. To reduce these errors, we developed a hollow drive shoe that freezes in place the lowest 3 inches (75 mm) of a 1.88-inch-diameter (48 mm), 5-foot-long (1.5 m) sediment sample taken using a commercial wire line piston core sampler. The end of the core is frozen by piping liquid carbon dioxide at ambient temperature through a steel tube from a bottle at the land surface to the drive shoe where it evaporates and expands, cooling the interior surface of the shoe to about -109 degrees F (-78 degrees C). Freezing a core end takes about 10 minutes. The device was used to collect samples for a study of oil-water-air distributions, and for studies of water chemistry and microbial activity in unconsolidated sediments at the site of an oil spill near Bemidji, Minnesota. Before freezing was employed, samples of sandy sediments from near the water table sometimes flowed out of the core allowed for the retention of all material that entered the core barrel and lessened the redistribution of fluids within the core. The device is useful in the unsaturated and shallow saturated zones, but does not freeze cores well at depths greater than about 20 feet (6 m) below water, possibly because the feed tube plugs with dry ice with increased exhaust back-pressure, or because sediment enters the annulus between the core barrel and the core barrel liner and blocks the exhaust. RP Murphy, F (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MS 496,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 9 TC 31 Z9 31 U1 0 U2 2 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD SUM PY 1996 VL 16 IS 3 BP 86 EP 90 DI 10.1111/j.1745-6592.1996.tb00143.x PG 5 WC Water Resources SC Water Resources GA VD821 UT WOS:A1996VD82100007 ER PT J AU Vroblesky, DA Robertson, JF AF Vroblesky, DA Robertson, JF TI Temporal changes in VOC discharge to surface water from a fractured rock aquifer during well installation and operation, Greenville, South Carolina SO GROUND WATER MONITORING AND REMEDIATION LA English DT Article ID PRIORITY POLLUTANTS; VOLATILE AB Analysis of the vapor in passive vapor samplers retrieved from a streambed in fractured rock terrain implied that volatile organic carbon (VOC) discharge from ground water to surface water substantially increased following installation of a contaminant recovery well using air rotary drilling. The air rotary technique forced air into the aquifer near the stream. The injection produced an upward hydraulic gradient that appears to have transported water and contaminants from deeper parts of the aquifer through fractures into shallow parts of the aquifer. Once in the shallow flow regime, the contamination was transported to the stream, where it discharge during the next several weeks following well installation. After the recovery well was activated and began continuously pumping contaminated ground water to a treatment facility, the VOC concentrations in the stream bottom passive vapor samplers decreased to below detectable concentrations, suggesting that the withdrawal had captured the contaminated ground water that previously had discharged to the stream. RP Vroblesky, DA (reprint author), US GEOL SURVEY,STEPHENSON CTR,720 GRACERN RD,STE 129,COLUMBIA,SC 29210, USA. NR 9 TC 7 Z9 7 U1 1 U2 5 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 1069-3629 J9 GROUND WATER MONIT R JI Ground Water Monit. Remediat. PD SUM PY 1996 VL 16 IS 3 BP 196 EP 201 DI 10.1111/j.1745-6592.1996.tb00150.x PG 6 WC Water Resources SC Water Resources GA VD821 UT WOS:A1996VD82100014 ER PT J AU Ford, PL Scott, NJ AF Ford, PL Scott, NJ TI Descriptions of Bufo tadpoles from the southwestern coast of Jalisco, Mexico SO JOURNAL OF HERPETOLOGY LA English DT Article C1 UNIV NEW MEXICO,DEPT BIOL,ALBUQUERQUE,NM 87131. UNIV NEW MEXICO,US FISH & WILDLIFE SERV,MUSEUM SW BIOL,NATL ECOL RES CTR,ALBUQUERQUE,NM 87131. NR 15 TC 5 Z9 5 U1 0 U2 0 PU SOC STUD AMPHIBIANS REPTILES PI OXFORD PA DEPT OF ZOOLOGY MIAMI UNIV, OXFORD, OH 45056 SN 0022-1511 J9 J HERPETOL JI J. Herpetol. PD JUN PY 1996 VL 30 IS 2 BP 253 EP 257 DI 10.2307/1565517 PG 5 WC Zoology SC Zoology GA UQ487 UT WOS:A1996UQ48700015 ER PT J AU Andersen, DE AF Andersen, DE TI Intra-year reuse of great horned owl nest sites by barn owls in east-central Colorado SO JOURNAL OF RAPTOR RESEARCH LA English DT Article DE breeding; Bubo virginianus; Colorado; barn owl; great horned owl; nest site; Tyto alba ID HAWKS AB Barn owls (Tyto alba) sequentially reused nest sites of great horned owls (Bubo virginianus) within the same breeding season on two occasions in east-central Colorado during 1982 and 1983. Two of 22 cliff nest sites used by great horned owls during the 2-year period were subsequently reused by barn owls, while no red-tailed hawk (Buteo jamaicensis, N = 8) or common raven (Corvus corax, N = 20) cliff nests were sequentially used by barn owls. In temperate latitudes, only rarely are sympatric raptor species expected to exhibit breeding behavior that could accommodate intra-year sequential nesting at the same site. C1 UNIV WISCONSIN,DEPT WILDLIFE ECOL,MADISON,WI 53706. US FISH & WILDLIFE SERV,COLORADO FISH & WILDLIFE ASSISTANCE OFF,GOLDEN,CO 80401. NR 24 TC 2 Z9 2 U1 0 U2 3 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 12805 ST CROIX TRAIL, HASTINGS, MN 55033 SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD JUN PY 1996 VL 30 IS 2 BP 90 EP 92 PG 3 WC Ornithology SC Zoology GA UW194 UT WOS:A1996UW19400006 ER PT J AU Hogan, KM Hogan, ML Gable, J Bray, M AF Hogan, KM Hogan, ML Gable, J Bray, M TI Notes on the diet of short-eared owls (Asio flammeus) in Texas SO JOURNAL OF RAPTOR RESEARCH LA English DT Article DE Texas; short-eared owl; Asio flammeus; diet RP Hogan, KM (reprint author), US FISH & WILDLIFE SERV,LOWER RIO GRANDE NATL WILDLIFE REFUGE,RT 2,BOX 202A,ALAMO,TX 78516, USA. NR 17 TC 3 Z9 5 U1 0 U2 2 PU RAPTOR RESEARCH FOUNDATION INC PI HASTINGS PA 12805 ST CROIX TRAIL, HASTINGS, MN 55033 SN 0892-1016 J9 J RAPTOR RES JI J. Raptor Res. PD JUN PY 1996 VL 30 IS 2 BP 102 EP 104 PG 3 WC Ornithology SC Zoology GA UW194 UT WOS:A1996UW19400010 ER PT J AU Ishman, SE Foley, KM AF Ishman, SE Foley, KM TI Modern benthic foraminifer distribution in the Amerasian Basin, Arctic Ocean SO MICROPALEONTOLOGY LA English DT Article ID CIRCULATION; ICE AB A total of 38 box cores were collected from the Amerasian Basin, Arctic Ocean during the U.S. Geological Survey 1992 (PI92-AR) and 1993 (PI93-AR) Arctic Cruises aboard the U.S. Coast Guard Icebreaker Polar Star. In addition, the cruises collected geophysical data, piston cores and hydrographic data to address the geologic and oceanographic history of the western Arctic Ocean. This paper reports the results of the quantitative analyses of benthic foraminifer distribution data of the total (live + dead) assemblages derived from 22 box core-top samples. The results show that a distinct depth distribution of three dominant benthic foraminifer assemblages, the Textularia spp. - Spiroplectammina biformis, Cassidulina teretis and Oridorsalis tener - Eponides tumidulus Biofacies are strongly controlled by the dominant water masses within the Canada Basin: the Arctic Surface Water, Arctic Intermediate Water and Canada Basin Deep Water. The faunal distributions and their oceanographic associations in the Canada Basin are consistent with observations of benthic foraminifer distributions from other regions within the Arctic Ocean. RP Ishman, SE (reprint author), US GEOL SURVEY,NATL CTR 926A,RESTON,VA 22092, USA. NR 21 TC 20 Z9 21 U1 0 U2 1 PU MICROPALEONTOLOGY PRESS PI NEW YORK PA AMER MUSEUM NAT HISTORY 79TH ST AT CENTRAL PARK WEST, NEW YORK, NY 10024 SN 0026-2803 J9 MICROPALEONTOLOGY JI Micropaleontology PD SUM PY 1996 VL 42 IS 2 BP 206 EP 220 DI 10.2307/1485871 PG 15 WC Paleontology SC Paleontology GA UV731 UT WOS:A1996UV73100007 ER PT J AU Spirakis, CS AF Spirakis, CS TI The roles of organic matter in the formation of uranium deposits in sedimentary rocks SO ORE GEOLOGY REVIEWS LA English DT Article; Proceedings Paper CT Symposium on Organics and Ore Deposits/1993 Geological-Society-of-America Annual Meeting CY OCT 24, 1993 CL BOSTON, MA SP Geol Soc Amer ID HENRY BASIN; NEW-MEXICO; REDUCTION SPHEROIDS; NORTHERN-TERRITORY; VANADIUM DEPOSITS; COLORADO PLATEAU; ORE-DEPOSITS; GENESIS; GEOCHEMISTRY; UTAH AB Because reduced uranium species have a much smaller solubility than oxidized uranium species and because of the strong association of organic matter (a powerful reductant) with many uranium ores, reduction has long been considered to be the precipitation mechanism for many types of uranium deposits. Organic matter may also be involved in the alterations in and around tabular uranium deposits, including dolomite precipitation, formation of silicified layers, iron-titanium oxide destruction, dissolution of quartz grains, and precipitation of clay minerals, The diagenetic processes that produced these alterations also consumed organic matter. Consequently, those tabular deposits that underwent the more advanced stages of diagenesis, including methanogenesis and organic acid generation, display the greatest range of alterations and contain the smallest amount of organic matter. Because of certain similarities between tabular uranium deposits and Precambrian unconformity-related deposits, some of the same processes might have been involved in the genesis of Precambrian unconformity-related deposits. Hydrologic studies place important constraints on genetic models of various types of uranium deposits. In roll-front deposits, oxidized waters carried uranium to reductants (organic matter and pyrite derived from sulfate reduction by organic matter), After these reductants were oxidized at any point in the host sandstone, uranium minerals were reoxidized and transported further down the flow path to react with additional reductants. In this manner, the uranium ore migrated through the sandstone at a rate slower than the mineralizing ground water. In the case of tabular uranium deposits, the recharge of surface water into the ground water during flooding of lakes carried soluble humic material to the water table or to an interface where humate precipitated in tabular layers. These humate layers then established the chemical conditions for mineralization and related alterations. In the case of Precambrian unconformity-related deposits, free thermal convection in the thick sandstones overlying the basement rocks carried uranium to concentrations of organic matter in the basement rocks. RP Spirakis, CS (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 939,LAKEWOOD,CO 80225, USA. NR 73 TC 49 Z9 73 U1 4 U2 21 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-1368 J9 ORE GEOL REV JI Ore Geol. Rev. PD JUN PY 1996 VL 11 IS 1-3 BP 53 EP 69 DI 10.1016/0169-1368(95)00015-1 PG 17 WC Geology; Mineralogy; Mining & Mineral Processing SC Geology; Mineralogy; Mining & Mineral Processing GA UX606 UT WOS:A1996UX60600004 ER PT J AU Benson, L White, LD Rye, R AF Benson, L White, LD Rye, R TI Carbonate deposition, Pyramid Lake Subbasin, Nevada .4. Comparison of the stable isotope values of carbonate deposits (tufas) and the Lahontan lake-level record SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY LA English DT Article ID ICE-AGE CLIMATE; LATE-QUATERNARY; GREAT-BASIN; BOUNDARY-CONDITIONS; CIRCULATION MODEL; OXYGEN; PRECIPITATION; FRACTIONATION; SIMULATION; RATIOS AB In this paper, the fundamental importance of changes in hydrologic balance and hydrologic state on the delta(18)O and delta(13)C values of water and dissolved inorganic carbon (DIC) in lakes of the Lahontan basin is illustrated. Abrupt changes in delta(18)O and delta(13)C values of carbonate deposits (tufas) from the Pyramid Lake subbasin, Nevada, coincide with abrupt changes in lake-level and hydrologic state. Minima in lake-level at similar to 26,000, similar to 15,500 and similar to 12,000 yr B.P. are associated with relatively heavy delta(18)O and delta(13)C values; maxima in the lake-level record at similar to 14,000 and similar to 10,500 yr B.P. are associated with relatively light delta(18)O and delta(13)C values. We believe that the correlation between maxima and minima in the lake-level and delta(18)O records reflect the fundamental effect of lake-level dynamics on the delta(18)O value of lake water. Evaporation increases the delta(18)O value of lake water, whereas, streamflow discharge and on-lake precipitation decrease the delta(18)O value. Variation in the delta(18)O value of lake water, therefore, indicates change in the hydrologic balance; increases in delta(18)O accompany decreases in lake volume and decreases in delta(18)O accompany increases in lake volume. Covariance of delta(13)C and delta(18)O indicates that change in delta(13)C values of DIC also accompany change in lake volume. We offer the hypothesis (first put forward by J.A. McKenzie) that change in the productivity (photosynthesis) respiration balance is responsible for much of the observed variation in delta(13)C. Most Great Basin lakes, including Lake Lahontan, experienced changes in hydrologic state during the late Wisconsin. When a lake becomes hydrologically open, the residence time of water decreases. The greater the rate of spill, the greater the volume of evaporated (O-18-enriched) water removed from the spilling lake and the more negative the delta(18)O value of water remaining in the spilling lake. The concentration of DIC, as well as the concentrations of photosynthesis limiting nutrients (e.g., phosphorus, nitrogen, silica, molybdenum) decrease as spill increases. Increasing rates of spill, therefore, lead to overall decreases in photosynthetic rates relative to respiration rates and, as a consequence, the delta(13)C values of DIC become more negative. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Benson, L (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. NR 85 TC 61 Z9 64 U1 0 U2 12 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-0182 J9 PALAEOGEOGR PALAEOCL JI Paleogeogr. Paleoclimatol. Paleoecol. PD JUN PY 1996 VL 122 IS 1-4 BP 45 EP 76 DI 10.1016/0031-0182(95)00099-2 PG 32 WC Geography, Physical; Geosciences, Multidisciplinary; Paleontology SC Physical Geography; Geology; Paleontology GA UU138 UT WOS:A1996UU13800003 ER PT J AU Bice, KL Arthur, MA Marincovich, L AF Bice, KL Arthur, MA Marincovich, L TI Late Paleocene Arctic Ocean shallow-marine temperatures from mollusc stable isotopes SO PALEOCEANOGRAPHY LA English DT Article ID NORTHERN HEMISPHERE; TERTIARY CLIMATES; ELLESMERE ISLAND; HIGH-LATITUDES; SHELL; EVOLUTION; BIVALVES; RECORD; ALASKA AB Late Paleocene high-latitude (80 degrees N) Arctic Ocean shallow-marine temperatures are estimated from molluscan delta(18)O time series. Sampling of individual growth increments of two specimens of the bivalve Camptochlamys alaskensis provides a high-resolution record of shell stable isotope composition. The heavy carbon isotopic values of the specimens support a late Paleocene age for the youngest marine beds of the Prince Creek Formation exposed near Ocean Point, Alaska, The oxygen isotopic composition of regional freshwater runoff is estimated from the mean delta(18)O value of two freshwater bivalves collected from approximately coeval fluviatile beds. Over a 30-34 parts per thousand range of salinity, values assumed to represent the tolerance of C. alaskensis, the mean annual shallow-marine temperature recorded by these individuals is between 11 degrees and 22 degrees C. These values could represent maximum estimates of the mean annual temperature because of a possible warm-month bias imposed on the average delta(18)O value by slowing or cessation of growth in winter months. The amplitude of the molluscan delta(18)O time series probably records most of the seasonality in shallow-marine temperature. The annual temperature range indicated is approximately 6 degrees C, suggesting very moderate high-latitude marine temperature seasonality during the late Paleocene, On the basis of analogy with modern Chlamys species, C. alaskensis probably inhabited water depths of 30-50 m. The seasonal temperature range derived from delta(18)O is therefore likely to be damped relative to the full range of annual sea surface temperatures. High-resolution sampling of molluscan shell material across inferred growth bands represents an important proxy record of seasonality of marine and freshwater conditions applicable at any latitude, If applied to other regions and time periods, the approach used here would contribute substantially to the paleoclimate record of seasonality. C1 US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,MENLO PK,CA 94025. PENN STATE UNIV,DEPT GEOSCI,UNIVERSITY PK,PA 16802. RP Bice, KL (reprint author), PENN STATE UNIV,CTR EARTH SYST SCI,UNIVERSITY PK,PA 16802, USA. RI Arthur, Michael/E-2872-2014 OI Arthur, Michael/0000-0002-3028-6279 NR 54 TC 39 Z9 39 U1 3 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD JUN PY 1996 VL 11 IS 3 BP 241 EP 249 DI 10.1029/96PA00813 PG 9 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA VM328 UT WOS:A1996VM32800001 ER PT J AU Ryden, DW Ahlm, LA AF Ryden, DW Ahlm, LA TI Observations on the distribution and movements of Colorado squawfish, Ptychocheilus lucius, in the San Juan River, New Mexico, Colorado, and Utah SO SOUTHWESTERN NATURALIST LA English DT Article ID GREEN AB Seventeen adult Colorado squawfish (Ptychocheilus lucius) were captured between June 1991 and October 1994 during sampling conducted on the San Juan River in New Mexico, Colorado, and Utah. Thirteen individuals were surgically implanted with internal radio transmitters. Telemetry, capture, and recapture data indicated that most adult Colorado squawfish were sedentary and had a strong affinity for a 39.0 km reach of the river (river km 228.2 to 180.2) upstream of the Colorado-Utah border. Seven fish aggregated prior to spawning in and around the Mancos River confluence (km 197.3). Eleven fish, including six of the seven that aggregated in the vicinity of the Mancos River, moved a short distance upstream to a 5.8 km reach of the river (km 214.6 to 208.8) during the probable spawning seasons (late June to mid-August). Only one radiotelemetered Colorado squawfish during our study displayed migratory behavior and then only in association with spawning. Life stages of Colorado squawfish were spatially separated, with adults generally occurring upstream of captured larvae and juvenile fish. The recent formation of a waterfall at the confluence of the San Juan River and Lake Powell, and its subsequent inundation, poses a management conundrum for all life stages of this endangered species in the San Juan River. The waterfall appears to be a physical barrier to the upstream movement of adult Colorado squawfish from Lake Powell. However, it also seems to inhibit the invasion of the lower San Juan River by lentic predators, thereby protecting early life stages of Colorado squawfish that are found almost exclusively in this section of the river. RP Ryden, DW (reprint author), US FISH & WILDLIFE SERV, COLORADO RIVER FISHERY PROJECT, 764 HORIZON DR, S ANNEX A, GRAND JCT, CO 81505 USA. NR 21 TC 8 Z9 9 U1 0 U2 2 PU SOUTHWESTERN ASSOC NATURALISTS PI SAN MARCOS PA SOUTHWEST TEXAS STATE UNIV, DEPT BIOLOGY, 601 UNIVERSITY DR, SAN MARCOS, TX 78666 USA SN 0038-4909 EI 1943-6262 J9 SOUTHWEST NAT JI Southw. Natural. PD JUN PY 1996 VL 41 IS 2 BP 161 EP 168 PG 8 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA WH687 UT WOS:A1996WH68700011 ER PT J AU Rowlands, PG Brian, NJ AF Rowlands, PG Brian, NJ TI A perimeter tracing method for estimating basal cover: Monitoring the endangered sentry milk-vetch at Grand Canyon National Park, Arizona SO SOUTHWESTERN NATURALIST LA English DT Article AB We propose a perimeter tracing method for long-term monitoring of basal cover changes of the endangered sentry milk-vetch (Astragalus cremnophylax var. cremnophylax), a small, mat-forming herb growing on the south rim of Grand Canyon National Park. Basal cover was estimated using major and minor diameter measurements of the plant mat to either the nearest mm or half-cm. Basal area was calculated using the formula for an ellipse. Area derived from this ellipse-diameter method was overestimated by a factor of 1.24. Plant area was obtained more accurately by tracing the perimeter of the plant mat on transparent drafting film or mylar;area was derived either by weighing the mylar and converting weight to area or by digitizing the perimeter tracing. Perimeter tracings yield accurate basal cover; provide a permanent, archival product for year-to-year comparisons; and allow study of adjacent or overlying cover by other plant species. RP Rowlands, PG (reprint author), US GEOL SURVEY,BIOL RESOURCES DIV,SW FOREST SCI COMPLEX,2500 S PINE KNOLL DR,FLAGSTAFF,AZ 86001, USA. NR 18 TC 2 Z9 2 U1 1 U2 3 PU SOUTHWESTERN ASSN NATURALISTS PI SAN MARCOS PA SOUTHWEST TEXAS STATE UNIV, DEPT BIOLOGY, 601 UNIVERSITY DR, SAN MARCOS, TX 78666 SN 0038-4909 J9 SOUTHWEST NAT JI Southw. Natural. PD JUN PY 1996 VL 41 IS 2 BP 169 EP 178 PG 10 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA WH687 UT WOS:A1996WH68700012 ER PT J AU Celebi, M AF Celebi, M TI Successful performance of a base-isolated hospital building during the 17 January 1994 Northridge earthquake SO STRUCTURAL DESIGN OF TALL BUILDINGS LA English DT Article AB The purpose of this paper is to examine the response records and thereby the performance of the base-isolated University of Southern California (USC) hospital building during the M(s) = 6 . 8 Northridge (California) earthquake of 17 January 1994. The data retrieved from the building is the first set of data from any base-isolated building that (a) was tested to acceleration levels at the free-field similar to the zero period acceleration (ZPA) level postulated in the seismic design criteria of the building and (b) exhibits levels of relative displacement excursions which puts the isolators into the nonlinear range. The variation of the fundamental frequency as a function of changing instantaneous stiffness of the isolators is identifiable. During the shaking, the isolators (a) performed well and, having attained up to 10% hysteretic damping, effectively dissipated the incoming energy of motions and (b) reduced the drift ratios of the superstructure of the building to a maximum of 10% of the allowable, which should explain the fact that there was no damage to the structure or its contents. The primary conclusion of this study is that this base-isolated building performed well during the Northridge earthquake of 17 January 1994 when only approximately 10% of the displacement capability of the isolators were utilized. Therefore, there is every reason to believe that the building will perform well during future earthquakes in the region. RP Celebi, M (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 17 TC 11 Z9 12 U1 0 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 1062-8002 J9 STRUCT DES TALL BUIL JI Struct. Des. Tall Build. PD JUN PY 1996 VL 5 IS 2 BP 95 EP 109 PG 15 WC Construction & Building Technology; Engineering, Civil SC Construction & Building Technology; Engineering GA UN310 UT WOS:A1996UN31000002 ER PT J AU Behrendt, JC Saltus, R Damaske, D McCafferty, A Finn, CA Blankenship, D Bell, RE AF Behrendt, JC Saltus, R Damaske, D McCafferty, A Finn, CA Blankenship, D Bell, RE TI Patterns of late Cenozoic volcanic and tectonic activity in the West Antarctic rift system revealed by aeromagnetic surveys SO TECTONICS LA English DT Article ID TRANSANTARCTIC MOUNTAINS; ICE-SHEET; UPLIFT; BOUNDARY; EAST AB Aeromagnetic surveys, spaced less than or equal to 5 km, over widely separated areas of the largely ice- and sea-covered West Antarctic rift system, reveal similar patterns of 100- to 1700-nT, shallow-source magnetic anomalies interpreted as evidence of extensive late Cenozoic volcanism. We use the aeromagnetic data to extend the volcanic rift interpretation over West Antarctica starting with anomalies over (1) exposures of highly magnetic, late Cenozoic volcanic rocks several kilometers thick in the McMurdo-Ross Island area and elsewhere; continuing through (2) volcanoes and subvolcanic intrusions directly beneath the Ross Sea continental shelf defined by marine magnetic and seismic reflection data and aeromagnetic data and (3) volcanic structures interpreted beneath the Ross Ice Shelf partly controlled by seismic reflection determinations of seafloor depth to (4) an area of similar magnetic pattern over the West Antarctic Ice Sheet (400 lan from the nearest exposed volcanic rock), where interpretations of late Cenozoic volcanic rocks at the base of the ice are controlled in part by radar ice sounding, North trending magnetic rift fabric in the Ross Sea-Ross Ice Shelf and Corridor Aerogeophysics of the Southeast Ross Transect Zone (CASERTZ) areas, revealed by the aeromagnetic surveys, is probably a reactivation of older rift trends Gate Mesozoic?) and is superimposed on still older crosscutting structural trends revealed by magnetic terrace maps calculated from horizontal gradient of pseudogravity. Long wavelength (similar to 100-km wide) magnetic terraces from sources within the subvolcanic basement cross the detailed survey areas. One of these extends across the Ross Sea survey from the front of the Transantarctic Mountains with an east-southeast trend crossing the north trending rift fabric. The Ross Sea-Ross Ice Shelf sun ey area is characterized by highly magnetic northern and southern zones which are separated by magnetically defined faults from a more moderately magnetic central zone. Aeromagnetic data in the south delineate the Ross fault of unknown age. The extension of the southern Central Basin south of the Ross fault is associated with an 825-nT magnetic anomaly over the Ross Ice Shelf requiring inferred late Cenozoic volcanic rock essentially at the seafloor at its south end, as shown by magnetic models. Models show that the thickness of magnetic volcanic rocks beneath Hut Point Peninsula at McMurdo Station is probably <2 km. The detailed surveys, combined with data from >100,000 km of widely spaced aeromagnetic profiles, led to the interpretation of the mostly subglacial West Antarctic flood basalts(?) or their subglacially erupted and intruded equivalent. The volume of the exposed volcanos is small in contrast to the much greater volume (>10(6) km(3)) of late Cenozoic magnetic rock remaining at volcanic centers beneath the continental shelf, Ross Ice Shelf and West Antarctic Ice Sheet. We suggest as an alternative or supplemental explanation to the previously proposed mantle plume hypothesis for the late Cenozoic volcanism significantly greater lower lithosphere (mantle) stretching resulting in greater decompression melting than the limited Cenozoic crustal extension allows. However, this implies a space problem that is not obviously resolved, because the Antarctic Plate is essentially surrounded by spreading centers. C1 GERMAN FED INST GEOSCI & NAT RESOURCES,HANNOVER,GERMANY. UNIV TEXAS,INST GEOPHYS,AUSTIN,TX. COLUMBIA UNIV,LAMONT DOHERTY EARTH OBSERV,PALISADES,NY 10964. RP Behrendt, JC (reprint author), US GEOL SURVEY,MS 964,DENVER,CO 80225, USA. RI Blankenship, Donald/G-5935-2010 NR 62 TC 58 Z9 57 U1 1 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD JUN PY 1996 VL 15 IS 3 BP 660 EP 676 DI 10.1029/95TC03500 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UU428 UT WOS:A1996UU42800008 ER PT J AU OBrien, AK Eshleman, KN AF OBrien, AK Eshleman, KN TI Episodic acidification of a coastal plain stream in Virginia SO WATER AIR AND SOIL POLLUTION LA English DT Article DE episodic acidification ID CONTROLLING SUBSURFACE TRANSPORT; ACID-NEUTRALIZING CAPACITY; UPPER SUBCATCHMENT; ORGANIC-ACIDS; UNITED-STATES; STORM EVENTS; BASE STATUS; NEW-YORK; ALKALINITY; SNOWMELT AB This study investigates the episodic acidification of Reedy Creek, a wetland-influenced coastal plain stream near Richmond, Virginia. Primary objectives of the study were to quantify the episodic variability of acid-base chemistry in Reedy Creek, to examine the seasonal variability in episodic response and to explain the hydrological and geochemical factors that contribute to episodic acidification. Chemical response was similar in each of the seven storms examined, however, the ranges in concentrations observed were commonly greater in summer/fall storms than in winter/spring storms. An increase in SO42- concentration with discharge was observed during all storms and peak concentration occurred at or near peak flow. Small increases in Mg2+, Ca2+, K+ concentrations and dissolved organic carbon (DOG) were observed during most storms. At the same time, ANC, Na+ and Cl- concentrations usually decreased with increasing discharge. In summer/fall storms, the absolute increase in SO42- concentration was one-third to 15 times the increase observed in winter/spring storms; the decrease in ANC during summer/fall storms was usually within the range of the decrease observed in winter/spring storms. In contrast, the decrease in Na+ and Cl- concentrations during winter/spring storms was much greater than that observed during summer/fall storms. Data show that while base flow anion deficit was higher in summer/fall than in winter/spring, anion deficit decreased during most summer/fall storms. In contrast, base flow anion deficit was lower in spring and winter, but increased during winter/spring storms. Increased SO42- concentration was the main cause of episodic acidification during storms at Reedy Creek, but increased anion deficit indicates organic acids may contribute to episodic acidification during winter/spring storms. Changes in SO42- concentration coincident with the hydrograph rise indicate quick routing of water through the watershed. Saturation overland flow appears to be the likely mechanism by which solutes are transported to the stream during storm flow. C1 UNIV VIRGINIA,DEPT ENVIRONM SCI,CHARLOTTESVILLE,VA 22903. RP OBrien, AK (reprint author), US GEOL SURVEY,12201 SUNRISE VALLEY DR,MS-432,RESTON,VA 22092, USA. RI Eshleman, Keith/J-6531-2015 NR 48 TC 3 Z9 3 U1 0 U2 2 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0049-6979 J9 WATER AIR SOIL POLL JI Water Air Soil Pollut. PD JUN PY 1996 VL 89 IS 3-4 BP 291 EP 316 DI 10.1007/BF00171638 PG 26 WC Environmental Sciences; Meteorology & Atmospheric Sciences; Water Resources SC Environmental Sciences & Ecology; Meteorology & Atmospheric Sciences; Water Resources GA UT881 UT WOS:A1996UT88100006 ER PT J AU Watt, BE Malcolm, RL Hayes, MHB Clark, NWE Chipman, JK AF Watt, BE Malcolm, RL Hayes, MHB Clark, NWE Chipman, JK TI Chemistry and potential mutagenicity of humic substances in waters from different watersheds in Britain and Ireland SO WATER RESEARCH LA English DT Article DE humic; fulvic; chlorination; mutagenicity; CPMAS C-13 NMR; amino acids; neutral sugars ID DRINKING-WATER; BY-PRODUCTS; CHLORINATION; ACID; MORTALITY; CANCER; RESINS; ASSAY AB Humic substances are amorphous organic macromolecules responsible for the hue of natural waters. They are also known to be precursors of mutagens formed on chlorination prior to distribution of drinking water. In this study humic substances from the waters of primary streams, from major rivers, and from reservoirs were isolated and fractionated into humic acids (HA), fulvic acids (FA) and XAD-4 acids using columns of XAD-8 and of XAD-4 resins in tandem, and the fractions from the different sources were chlorinated and assayed for mutagenicity. CPMAS C-13 NMR spectroscopy showed marked differences in compositions not only between HA, FA, and XAD-4 acids from the same water samples, but also between the same fractions from water samples from different watersheds. There were found to be strong similarities between the fractions from watersheds which had closely related soil types. Aromaticity was greatest in HAs, and lowest in XAD-4 acids, and carboxyl contents and aliphatic character were greatest in the XAD-4 acids. Carbon content decreased in the order HA > FA > XAD-4 acids, and amino acids and neutral sugars contents decreased in the order HA > XAD-4 > FA. Titration data complemented aspects of the NMR data, demonstrating that carboxyl content decreased in the order XAD-I acids > FA > HA, and indicated that phenolic character was highest in HAs and lowest in the XAD-4 acids. All samples tested gave rise to bacterial mutagens on chlorination. Although the mutagenicities were of the same order of magnitude for the chlorinated humic samples from the different sources, the samples which showed the greatest number of revertant bacterial colonies were from the Thames and Trent, large rivers with humic materials from diverse environments, and relatively high in amino acid contents. Copyright (C) 1996 Elsevier Science Ltd C1 UNIV BIRMINGHAM,SCH BIOCHEM,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. US GEOL SURVEY,DIV WATER RESOURCES,DENVER,CO 80225. RP Watt, BE (reprint author), UNIV BIRMINGHAM,SCH CHEM,POB 363,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RI Hayes, Michael/C-3463-2011 NR 38 TC 38 Z9 40 U1 0 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0043-1354 J9 WATER RES JI Water Res. PD JUN PY 1996 VL 30 IS 6 BP 1502 EP 1516 DI 10.1016/0043-1354(95)00319-3 PG 15 WC Engineering, Environmental; Environmental Sciences; Water Resources SC Engineering; Environmental Sciences & Ecology; Water Resources GA UP853 UT WOS:A1996UP85300026 ER PT J AU Kimball, BA Christensen, PK AF Kimball, BA Christensen, PK TI Residence time of water discharging from the hanging gardens of Zion Park SO WATER RESOURCES BULLETIN LA English DT Article DE geochemistry; carbon dating; stable isotopes; mass transfer; recharge ID SYSTEMS AB The Hanging Gardens are a unique feature of Zion National Park. Knowledge of the source and residence time of water discharging from the Hanging Gardens is necessary to help preserve these features. Ground-water chemical and isotopic data distinguish the discharge from seeps and springs into two groups, one of low and one of high conductivity. Water with low conductivity likely originates as recharge near the seeps and springs, and it only interacts with the Navajo Sandstone. High conductivity water, on the other hand, originates as recharge on the tops of plateaus to the east, where it interacts with marine rocks of the Carmel Formation. Carbon dating of these ground waters indicates that the low conductivity water is essentially modern recharge, while the-high conductivity water was recharged 1,000 to 4,000 years ago. C1 NATL PK SERV,FT COLLINS,CO 80525. RP Kimball, BA (reprint author), US GEOL SURVEY,1745 W 1700 S,ROOM 1016,SALT LAKE CITY,UT 84104, USA. NR 17 TC 1 Z9 1 U1 0 U2 4 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD JUN PY 1996 VL 32 IS 3 BP 531 EP 540 PG 10 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA UV270 UT WOS:A1996UV27000011 ER PT J AU Clark, GM Ott, DS AF Clark, GM Ott, DS TI Springflow effects on chemical loads in the Snake River, south-central Idaho SO WATER RESOURCES BULLETIN LA English DT Article DE water quality; springs; ground-water/surface-water relations; nonpoint-source effects; nutrient loading; Snake River; south-central Idaho ID COASTAL AB The 150-kilometer middle reach of the Snake River (middle Snake) in south-central Idaho receives large quantities of water from springs discharging along the north side of the river from the regional Snake River Plain aquifer. Water-quality samples collected from nine north-side springs in April 1994 indicated that springs in the upstream part of the reach had larger concentrations of dissolved solids, dissolved nitrate, total nitrogen, tritium, and heavy isotopes of hydrogen and oxygen than to springs in the downstream part of the reach. Because the spring chemistry varies in the reach, discharge from the springs resulted in a degradation in water quality in some parts of the middle Snake and improvements in water quality in other parts. Depending on the annual discharge in the Snake River, the contribution from the north-side springs represented 33 to 66 percent of the discharge, 32 to 57 percent of the dissolved solids, 26 to 50 percent of the total nitrogen, and 7 to 14 percent of the total, phosphorus transported annually from the middle Snake. Synoptic sampling showed that the north-side springs contributed 84 percent of the discharge and 35, 40, and 10 percent of the dissolved solids, total nitrogen, and total phosphorus load, respectively, to the Snake River during the peak of the irrigation season in 1994. RP Clark, GM (reprint author), US GEOL SURVEY,230 COLLINS RD,BOISE,ID 83702, USA. NR 32 TC 3 Z9 3 U1 1 U2 1 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD JUN PY 1996 VL 32 IS 3 BP 553 EP 563 PG 11 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA UV270 UT WOS:A1996UV27000013 ER PT J AU Cook, PG Solomon, DK Sanford, WE Busenberg, E Plummer, LN Poreda, RJ AF Cook, PG Solomon, DK Sanford, WE Busenberg, E Plummer, LN Poreda, RJ TI Inferring shallow groundwater flow in saprolite and fractured rock using environmental tracers SO WATER RESOURCES RESEARCH LA English DT Article ID CONTAMINANT TRANSPORT; CHLOROFLUOROCARBON-11; CCL2F2; SYSTEM; SOLUTE; CCL3F; MEDIA; WATER; TILL AB The Ridge and Valley Province of eastern Tennessee is characterized by (1) substantial topographic relief, (2) folded and highly fractured rocks of various lithologies that have low primary permeability and porosity, and (3) a shallow residuum of medium permeability and high total porosity. Conceptual models of shallow groundwater flow and solute transport in this system have been developed but are difficult to evaluate using physical characterization or short-term tracer methods due to extreme spatial variability in hydraulic properties. In this paper we describe how chlorofluorocarbon 12, H-3, and He-3 were used to infer groundwater flow and solute transport in saprolite and fractured rock near Oak Ridge, Tennessee. In the shallow residuum, fracture spacings are <0.05 m, suggesting that concentrations of these tracers in fractures and in the matrix have time to diffusionally equilibrate. The relatively smooth nature of tracer concentrations with depth in the residuum is consistent with this model and quantitatively suggests recharge fluxes of 0.2 to 0.4 m yr(-1). In contrast, groundwater flow within the unweathered rock appears to be controlled by fractures with spacings of the order of 2 to 5 m, and diffusional equilibration of fractures and matrix has not occurred. For this reason, vertical fluid fluxes in the unweathered rock cannot be estimated from the tracer data. C1 US GEOL SURVEY,RESTON,VA 22092. UNIV ROCHESTER,DEPT GEOL SCI,ROCHESTER,NY 14627. OAK RIDGE NATL LAB,DIV ENVIRONM SCI,OAK RIDGE,TN 37831. RI Cook, Peter/H-3606-2011; Sanford, William/F-7380-2016; Solomon, Douglas/C-7951-2016; OI Sanford, William/0000-0001-9085-1367; Solomon, Douglas/0000-0001-6370-7124; Plummer, L. Niel/0000-0002-4020-1013 NR 43 TC 55 Z9 55 U1 4 U2 22 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD JUN PY 1996 VL 32 IS 6 BP 1501 EP 1509 DI 10.1029/96WR00354 PG 9 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UN704 UT WOS:A1996UN70400002 ER PT J AU Haukos, DA Smith, LM AF Haukos, DA Smith, LM TI Effects of moist-soil management on playa wetland soils SO WETLANDS LA English DT Article DE playa; soil characteristics; Southern High Plains; nitrogen; phosphorus; wetland ID DRAWDOWN; MARSH; LAKES AB We evaluated effects of moist-soil management on soils of eight playa wetlands for 2 years. Moist-soil management involves timed drawdown and irrigation of wetlands to promote germination, growth, and seed production of mudflat annuals for use by wintering waterfowl. Moist-soil management reduced soil resistance for germination (P = 0.02), raised pH closer to neutrality (P = 0.002), but had no effect on soil moisture in the top 4 cm of soil (P = 0.16; influence on soil moisture in the root zone is unknown) or on salinity measured as conductivity (P = 0.51). Moist-soil management did not affect nitrogen and phosphorus levels in playa soils over 2 seasons (P = 0.61). As a percentage of available nutrients, more soil nitrogen was lost during the wetter year compared to the dryer year (P = 0.02) - a trend that was reversed for soil phosphorus (P = 0.004). More nitrogen was lost in the wetter year (P = 0.02); whereas, more phosphorus was lost in the dryer year (P = 0.004). This indicates potential changes in limiting nutrients depending upon local precipitation events. Apparently, nutrient cycling is rapid in playas, producing large amounts of biomass despite having lower soil nutrient pools compared to other inland freshwater wetlands. Moist-soil management is a sustainable and compatible practice for playa wetlands because it enhances naturally occurring events. RP Haukos, DA (reprint author), TEXAS TECH UNIV,US FISH & WILDLIFE SERV,DEPT RANGE WILDLIFE & FISHERIES MANAGEMENT,LUBBOCK,TX 79409, USA. NR 35 TC 7 Z9 7 U1 2 U2 5 PU SOC WETLAND SCIENTISTS PI LAWRENCE PA 810 E TENTH ST, P O BOX 1897, LAWRENCE, KS 66044 SN 0277-5212 J9 WETLANDS JI Wetlands PD JUN PY 1996 VL 16 IS 2 BP 143 EP 149 PG 7 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UU259 UT WOS:A1996UU25900005 ER PT J AU Chilelli, ME Griffith, B Harrison, DJ AF Chilelli, ME Griffith, B Harrison, DJ TI Interstate comparisons of river otter harvest data SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE beaver; Castor canadensis; CITES; furbearer; harvest; Lutra canadensis; management; reproduction; river otter ID MAINE AB River otter (Lutra canadensis) harvest and biological data from 1970 to 1989 for 10 northeastern stales were examined to determine temporal and spatial characteristics, assess utility for ascertaining population trends, and provide guidelines for subsequent data collection and analyses. Analysis of river otter harvest data from several states in the northeastern United States allowed us to examine relationships that may otherwise be constrained by limited data within any single state or year. There was no directional bias among states in assigning otters to 3 age classes (juvenile, subadult, and adult) based on cementum annuli and radiographs. Use of radiographs improved the consistency of age classifications as juvenile or nonjuvenile compared to cementum annuli alone. Otter harvests were positively correlated with beaver (Castor canadensis) harvest and with average beaver pelt price from the previous year throughout most northeastern states. Thus, otter and beaver management practices are not independent. Females and juveniles composed a greater proportion of the harvest early in the season. Because the proportion of juveniles in the harvest of river otters was related to age estimation technique, aging procedures should be standardized throughout a region. Counts of corpora lutea and embryos provided consistent estimates of litter size in reproductively active females. However, embryo counts provided better estimates of pregnancy rate than corpora lutea counts. Subadults may contribute more to recruitment than previously believed. Catch/unit effort indices should be developed to assess otter population status in northeastern states. Combined with juvenile to nonjuvenile ratios, catch/unit effort may provide managers with the minimum information necessary for evaluating river otter population trends in their jurisdictions. C1 UNIV MAINE,US FISH & WILDLIFE SERV,MAINE COOPERAT FISH & WILDLIFE RES UNIT,ORONO,ME 04469. UNIV MAINE,DEPT WILDLIFE,ORONO,ME 04469. NR 45 TC 13 Z9 13 U1 2 U2 14 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD SUM PY 1996 VL 24 IS 2 BP 238 EP 246 PG 9 WC Biodiversity Conservation SC Biodiversity & Conservation GA VA175 UT WOS:A1996VA17500012 ER PT J AU Andrews, BJ Sullivan, M AF Andrews, BJ Sullivan, M TI Vermilion flycatcher and black Phoebe feeding on fish. SO WILSON BULLETIN LA English DT Article C1 BUR LAND MANAGEMENT,PHOENIX,AZ 85027. RP Andrews, BJ (reprint author), US FISH & WILDLIFE SERV,2321 W ROYAL PALM RD,SUITE 103,PHOENIX,AZ 85021, USA. NR 6 TC 2 Z9 3 U1 0 U2 0 PU WILSON ORNITHOLOGICAL SOC PI ANN ARBOR PA MUSEUM OF ZOOLOGY UNIV MICHIGAN, ANN ARBOR, MI 48109 SN 0043-5643 J9 WILSON BULL JI Wilson Bull. PD JUN PY 1996 VL 108 IS 2 BP 377 EP 378 PG 2 WC Ornithology SC Zoology GA UQ215 UT WOS:A1996UQ21500015 ER PT J AU Tseng, HY Onstott, TC Burruss, RC Miller, DS AF Tseng, HY Onstott, TC Burruss, RC Miller, DS TI Constraints on the thermal history of Taylorsville basin, Virginia, USA, from fluid-inclusion and fission-track analyses: Implications for subsurface geomicrobiology experiments SO CHEMICAL GEOLOGY LA English DT Article ID LASER RAMAN MICROPROBE AB Microbial populations have been found at the depth of 2621-2804 m in a borehole near the center of Triassic Taylorsville Basin, Virginia. To constrain possible scenarios for long-term survival in or introduction of these microbial populations to the deep subsurface, we attempted to refine models of thermal and burial history of the basin by analyzing aqueous and gaseous fluid inclusions in calcite/quartz veins or cements in cuttings from the same borehole, These results are complemented by fission-track data from the adjacent boreholes. Homogenization temperatures of secondary aqueous fluid inclusions range from 120 degrees to 210 degrees C between 2027- and 3069-m depth, with highest temperatures in the deepest samples. The salinities of these aqueous inclusions range from 0 to similar to 4.3 eq wt% NaCl. Four samples from the depth between 2413 and 2931 m contain both two-phase aqueous and one-phase methane-rich inclusions in healed microcracks. The relative CH4 and CO2 contents of these gaseous inclusions was estimated by microthermometry and laser Raman spectroscopy. If both types of inclusions in sample 2931 m were trapped simultaneously, the density of the methane-rich inclusions calculated from the Peng-Robinson equation of state implies an entrapment pressure of 360 +/- 20 bar at the homogenization temperature (162.5 +/- 12.5 degrees C) of the aqueous inclusions. This pressure falls between the hydrostatic and lithostatic pressures at the present depth 2931 m of burial. If we assume that the pressure regime was hydrostatic at the time of trapping, then the inclusions were trapped at 3.6 km in a thermal gradient of similar to 40 degrees C/km. The high temperatures recorded by the secondary aqueous inclusions are consistent with the pervasive resetting of zircon and apatite fission-track dates. In order to fit the fission-track length distributions of the apatite data, however, a cooling rate of 1-2 degrees C/Ma following the thermal maximum is required. To match the integrated dates, the thermal maximum would have occurred at similar to 200 Ma. The timing of the maximum temperature is consistent with rapid burial of the Taylorsville Basin to twice its present-day depth and thermal re-equilibration with a 40 degrees C/km geothermal gradient, followed by slow exhumation. The results may imply that the microorganisms did not survive in situ, but were transported from the cooler portions of the basin sometime after maximum burial and heating. C1 US GEOL SURVEY,DENVER,CO 80225. RENSSELAER POLYTECH INST,DEPT GEOL,TROY,NY 12180. RP Tseng, HY (reprint author), PRINCETON UNIV,DEPT GEOL & GEOPHYS SCI,PRINCETON,NJ 08544, USA. NR 34 TC 9 Z9 9 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0009-2541 J9 CHEM GEOL JI Chem. Geol. PD MAY 31 PY 1996 VL 127 IS 4 BP 297 EP 311 DI 10.1016/0009-2541(95)00130-1 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UT472 UT WOS:A1996UT47200003 ER PT J AU Abercrombie, RE Mori, J AF Abercrombie, RE Mori, J TI Occurrence patterns of foreshocks to large earthquakes in the western United States SO NATURE LA English DT Article ID MOMENT-TENSOR SOLUTIONS; LOMA-PRIETA EARTHQUAKE; CRITICAL SLIP DISTANCE; 24 NOVEMBER 1987; SOUTHERN-CALIFORNIA; SUPERSTITION HILLS; FOCAL MECHANISM; GREAT-BASIN; JULY 1986; SEQUENCE AB OBSERVATIONS of foreshocks preceding large earthquakes provide one of the few well documented cases of premonitory events that are clearly related to a subsequent earthquake. Unfortunately, the apparent randomness of foreshock occurrence-they precede some events and not others-has severely hampered their use in reliable earthquake prediction. Understanding the factors that control foreshock occurrence is critical for determining how large earthquakes initiate and whether reliable short-term prediction will ever be possible(1). Here,ve report the results of a comprehensive study of the occurrence patterns of foreshocks to large earthquakes in the western United States. The incidence of foreshocks decreases with increasing depth of the mainshock, and also depends on the mainshock slip orientation. This pattern of occurrence may be explained by a decrease in small-scale crustal heterogeneity with increasing depth, and suggests that increasing normal stress (both regional tectonic stress and lithostatic load) inhibits the occurrence of foreshocks. No relationship is observed between any aspect of foreshock occurrence and the magnitude of the subsequent mainshock, suggesting that the eventual size of the mainshock may be independent of the earthquake nucleation process, or that foreshocks are not part of this process. C1 UNIV SO CALIF,DEPT EARTH SCI,LOS ANGELES,CA 90089. US GEOL SURVEY,PASADENA,CA 91106. OI Abercrombie, Rachel/0000-0003-4515-5420 NR 56 TC 58 Z9 65 U1 0 U2 3 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAY 23 PY 1996 VL 381 IS 6580 BP 303 EP 307 DI 10.1038/381303a0 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UM403 UT WOS:A1996UM40300051 ER PT J AU Schoellhamer, DH AF Schoellhamer, DH TI Factors affecting suspended-solids concentrations in South San Francisco Bay, California SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID PHYTOPLANKTON BIOMASS; PRODUCTIVITY AB Measurements of suspended-solids concentration (SSC) were made at two depths at three sites in South San Francisco Bay (South Bay) to determine the factors that affect SSC. Twenty-eight segments of reliable and continuous SSC time series data longer than 14 days were collected from late 1991 or 1992 through September 1993. Spectral analysis and singular spectrum analysis were used to relate these data segments to time series of several potential forcing factors, including diurnal and semidiurnal tides, the spring-neap tidal cycle, wind shear, freshwater runoff, and longitudinal density differences. SSC is greatest during summer when a landward wind shear is applied to South Bay by the afternoon sea breeze. About one half the variance of SSC is caused by the spring-neap cycle, and SSC lags the spring-neap cycle by about 2 days. Relatively short duration of slack water limits the duration of deposition of suspended solids and consolidation of newly deposited bed sediment during the tidal cycle, so suspended solids accumulate in the water column as a spring tide is approached and slowly deposit as a neap tide is approached. Perturbations in SSC caused by wind and local runoff from winter storms during the study period were usually much smaller than SSC variations caused by the spring-neap cycle. Variations of SSC at the study sites at tidal timescales are tidally forced, and nonlinear physical processes are significant. Advective transport dominates during spring tides when water with higher SSC due to wind wave resuspension is advected to the main channel from shallow water, but during neap tides, advective transport is less significant. The findings of this and other studies indicate that the tidally averaged transport of suspended solids responds to seasonal variations of wind shear in South Bay. RP Schoellhamer, DH (reprint author), US GEOL SURVEY,2800 COTTAGE WAY,ROOM W-2233,SACRAMENTO,CA 95825, USA. NR 36 TC 58 Z9 58 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAY 15 PY 1996 VL 101 IS C5 BP 12087 EP 12095 DI 10.1029/96JC00747 PG 9 WC Oceanography SC Oceanography GA UL258 UT WOS:A1996UL25800017 ER PT J AU Dieterich, JH Kilgore, BD AF Dieterich, JH Kilgore, BD TI Imaging surface contacts: Power law contact distributions and contact stresses in quartz, calcite, glass and acrylic plastic SO TECTONOPHYSICS LA English DT Article ID FRACTAL GEOMETRY; ROCK; INDENTATION; FRACTURES; PRESSURE; CLOSURE; SYSTEM; AREA AB A procedure has been developed to obtain microscope images of regions of contact between roughened surfaces of transparent materials, while the surfaces are subjected to static loads or undergoing frictional slip. Static loading experiments with quartz, calcite, soda-lime glass and acrylic plastic at normal stresses to 30 MPa yield power law distributions of contact areas from the smallest contacts that can be resolved (3.5 mu m(2)) up to a limiting size that correlates with the grain size of the abrasive grit used to roughen the surfaces. In each material, increasing normal stress results in a roughly linear increase of the real area of contact. Mechanisms of contact area increase are by growth of existing contacts, coalescence of contacts and appearance of new contacts. Mean contacts stresses are consistent with the indentation strength of each material. Contact size distributions are insensitive to normal stress indicating that the increase of contact area is approximately self-similar. The contact images and contact distributions are modeled using simulations of surfaces with random fractal topographies. The contact process for model fractal surfaces is represented by the simple expedient of removing material at regions where surface irregularities overlap. Synthetic contact images created by this approach reproduce observed characteristics of the contacts and demonstrate that the exponent in the power law distributions depends on the scaling exponent used to generate the surface topography. RP Dieterich, JH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Kilgore, Brian/K-3433-2012 OI Kilgore, Brian/0000-0003-0530-7979 NR 27 TC 139 Z9 140 U1 3 U2 27 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0040-1951 J9 TECTONOPHYSICS JI Tectonophysics PD MAY 15 PY 1996 VL 256 IS 1-4 BP 219 EP 239 DI 10.1016/0040-1951(95)00165-4 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UV584 UT WOS:A1996UV58400012 ER PT J AU Parsons, T McCarthy, J Kohler, WM Ammon, CJ Benz, HM Hole, JA Criley, EE AF Parsons, T McCarthy, J Kohler, WM Ammon, CJ Benz, HM Hole, JA Criley, EE TI Crustal structure of the Colorado Plateau, Arizona: Application of new long-offset seismic data analysis techniques SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID FINITE-DIFFERENCE CALCULATION; METAMORPHIC CORE COMPLEX; WESTERN UNITED-STATES; SOUTHEASTERN CALIFORNIA; TRANSITION ZONE; BENEATH; REFLECTIONS; TOMOGRAPHY; MOUNTAINS; UPLIFT AB The Colorado Plateau is a large crustal block in the southwestern United States that has been raised intact nearly 2 km above sea level since Cretaceous marine sediments were deposited on its surface. Controversy exists concerning the thickness of the plateau crust and the source of its buoyancy. Interpretations of seismic data collected on the plateau vary as to whether the crust is closer to 40 or 50 km thick. A thick crust could support the observed topography of the Colorado Plateau isostatically, while a thinner crust would indicate the presence of an underlying low-density mantle, This paper reports results on long-offset seismic data collected during the 1989 segment of the U.S. Geological Survey Pacific to Arizona Crustal Experiment that extended from the Transition Zone into the Colorado Plateau in northwest Arizona, We apply two new methods to analyze long-offset data that employ finite difference travel time calculations: (1) a first-arrival time inverter to find upper crustal velocity structure and (2) a forward-modeling technique that allows the direct use of the inverted upper crustal solution in modeling secondary reflected arrivals. We find that the crustal thickness increases from 30 km beneath the metamorphic core complexes in the southern Basin and Range province to about 42 km beneath the northern Transition Zone and southern Colorado Plateau margin, We observe some crustal thinning (to similar to 37 km thick) and slightly higher lower crustal velocities farther inboard; beneath the Kaibab uplift on the north rim of the Grand Canyon the crust thickens to a maximum of 48 km. We observe a nonuniform crustal thickness beneath the Colorado Plateau that varies by similar to 15% and corresponds approximately to variations in topography with the thickest crust underlying the highest elevations, Crustal compositions (as inferred from seismic velocities) appear to be the same beneath the Colorado Plateau as those in the Basin and Range province to the southwest, implying that the plateau crust represents an unextended version of the Basin and Range. Some of the variability in crustal structure appears to correspond to preserved lithospheric discontinuities that date back to the Proterozoic Era. C1 ST LOUIS UNIV, DEPT EARTH & ATMOSPHER SCI, ST LOUIS, MO 63103 USA. US GEOL SURVEY, DENVER, CO 80225 USA. STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. RP Parsons, T (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 999, MENLO PK, CA 94025 USA. RI Parsons, Tom/A-3424-2008; OI Parsons, Tom/0000-0002-0582-4338 NR 53 TC 43 Z9 43 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11173 EP 11194 DI 10.1029/95JB03742 PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000002 ER PT J AU Peck, JA King, JW Colman, SM Kravchinsky, VA AF Peck, JA King, JW Colman, SM Kravchinsky, VA TI An 84-kyr paleomagnetic record from the sediments of Lake Baikal, Siberia SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SECULAR VARIATION; RELATIVE PALEOINTENSITY; GEOMAGNETIC-FIELD; MAGNETIC-FIELD; GRAIN-SIZE; EXCURSIONS; BRUNHES; JAPAN AB We have conducted a paleomagnetic study of sediment cores obtained from the Selenga prodelta region of Lake Baikal, Russia. This record, which spans approximately the last 84 kyr, contributes to a better understanding of the nature of geomagnetic field behavior in Siberia and is a useful correlation and dating tool. We demonstrate that the Lake Baikal sediments are recording variations in the geomagnetic field. The directional record displays secular variation behavior with a geomagnetic excursion at 20 ka and additional excursions appearing as large-amplitude secular variation at 41, 61, and 67 ka. Smoothing of the geomagnetic excursion behavior occurs in Lake Baikal sediments owing to the intermediate sedimentation rate (13 cm kyr(-1)). The Lake Baikal relative paleointensity record correlates to absolute paleointensity data for the last 10 kyr and to relative paleointensity records from the Mediterranean Sea and Indian Ocean for the last 84 kyr. This correlation suggests a strong global (i.e., dipole) component to these records and further supports the reliability of sediments as recorders of relative geomagnetic paleointensity. We show that a relative geomagnetic intensity stratigraphy has a potential resolution of 7 kyr by correlating continental and marine records. The geomagnetic intensity stratigraphy helps constrain the age of the difficult to date Lake Baikal sediments. C1 US GEOL SURVEY, WOODS HOLE, MA 02543 USA. E SIBERIAN RES INST GEOL GEOPHYS & MINERAL RESOUR, IRKUTSK, RUSSIA. RP Peck, JA (reprint author), UNIV RHODE ISL, GRAD SCH OCEANOG, NARRAGANSETT, RI 02882 USA. NR 48 TC 77 Z9 79 U1 1 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11365 EP 11385 DI 10.1029/96JB00328 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000017 ER PT J AU Moore, JG Ingram, BL Ludwig, KR Clague, DA AF Moore, JG Ingram, BL Ludwig, KR Clague, DA TI Coral ages and island subsidence, Hilo drill hole SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID MARINE SAMPLES; HAWAII; CALIBRATION; GROWTH; REEFS AB A 25.8-m-thick sedimentary section containing coral fragments occurs directly below a surface lava flow (the similar to 1340 pear old Panaewa lava flow) at the Hilo drill hole. Ten coral samples from this section dated by accelerator mass spectrometry (AMS) radiocarbon and five by thermal infrared multispectral scanner (TIMS) Th-230/U methods show good agreement. The calcareous unit is 9790 years old at the bottom and 1690 years old at the top and was deposited in a shallow lagoon behind an actively growing reef. This sedimentary unit is underlain by a 34-m-thick lava flow which in turn overlies a thin volcaniclastic silt with coral fragments that yield a single C-14 date of 10,340 years. The age-depth relations of the dated samples can be compared with proposed eustatic sea level curves after allowance for island subsidence is taken. Island subsidence averages 2.2 mm/yr for the last 47 years based on measurements from a tide gage near the drill hole or 2.5-2.6 mm/yr for the last 500,000 years based on the ages and depths of a series of drowned coral reefs offshore from west Hawaii. The age-depth measurements of coral fragments are more consistent with eustatic sea levels as determined by coral dating at Barbados and Albrolhos Islands than those based on oxygen isotopic data from deep sea cores. The Panaewa lava flow entered a lagoon underlain by coral debris and covered the drill site with 30.9 m of lava of which 11 m was above sea level, This surface has: now subsided to 4.2 m above sea level, but it demonstrates how a modern lava flow entering Hilo Bay would not only change the coastline but could extensively modify the offshore shelf. C1 UNIV CALIF BERKELEY, DEPT GEOL & GEOPHYS, BERKELEY, CA 94720 USA. US GEOL SURVEY, DENVER, CO 80225 USA. RP Moore, JG (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 910, MENLO PK, CA 94025 USA. NR 17 TC 29 Z9 29 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11599 EP 11605 DI 10.1029/95JB03215 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000037 ER PT J AU Sharp, WD Turrin, BD Renne, PR Lanphere, MA AF Sharp, WD Turrin, BD Renne, PR Lanphere, MA TI The Ar-40/Ar-39 and K/Ar dating of lavas from the Hilo 1-km core hole, Hawaii scientific drilling project SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GLASS; AGE; ANTARCTICA; EVOLUTION; HYDRATION AB Mauna Kea lava flows cored in the Hilo hole range in age from <200 ka to about 400 ka based on Ar-40/Ar-39 incremental heating and K-Ar analyses of 16 groundmass samples and one coexisting plagioclase. The lavas, all subaerially deposited, include a lower section consisting only of tholeiitic basalts and an upper section of interbedded alkalic, transitional tholeiitic, and tholeiitic basalts. The lower section has yielded predominantly complex, discordant Ar-40/Ar-39 age spectra that result from mobility of Ar-40 and perhaps K, the presence of excess Ar-40, and redistribution of Ar-39 by recoil. Comparison of K-Ar ages with Ar-40/Ar-39 integrated ages indicates that some of these samples have also lost Ar-39. Nevertheless, two plateau ages of 391 +/- 30 and 400 +/- 26 ka from deep in the hole, combined with data from the upper section, show that the tholeiitic section accumulated at an average rate of about 7 to 8 m/kyr and has an mean recurrence interval of 0.5 kyr/flow unit. Samples from the upper section yield relatively precise Ar-40/Ar-39 plateau and isotope correlation ages of 326 +/- 23, 241 +/- 5, 232 +/- 4, and 199 +/- 9 ka for depths of -415.7 m to -299.2 m. Within their uncertainty, these ages define a linear relationship with depth, with an average accumulation rate of 0.9 m/kyr and an average recurrence interval of 4.8 kyr/flow unit. The top of the Mauna Kea sequence at -280 m must be older than the plateau age of 132 +/- 32 ka, obtained for the basal Mauna Loa flow in the corehole. The upward decrease in lava accumulation rate is a consequence of the decreasing magma supply available to Mauna Kea as it rode the Pacific plate away from its magma source, the Hawaiian mantle plume. The age-depth relation in the core hole may be used to test and refine models that relate the growth of Mauna Kea to the thermal and compositional structure of the mantle plume. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP Sharp, WD (reprint author), BERKELEY GEOCHRONOL CTR, 2455 RIDGE RD, BERKELEY, CA 94720 USA. NR 32 TC 62 Z9 63 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11607 EP 11616 DI 10.1029/95JB03702 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000038 ER PT J AU Beeson, MH Clague, DA Lockwood, JP AF Beeson, MH Clague, DA Lockwood, JP TI Origin and depositional environment of clastic deposits in the Hilo drill hole, Hawaii SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID VOLCANO AB Volcaniclastic units cored at depths of about 87, 164, 178, 226, and 246 m below sea level and carbonate units located between depths of 27 and 53 m below sea level in the Hilo drill core were found to be deposited at or near sea level. Four of these units are hydroclastic deposits, formed when subaerially erupted Mauna Loa lava flows entered the ocean and fragmented to produce quenched, glassy fragments during hydrovolcanic explosions. Ash units 23 and 26, at 178 m depth, accumulated at sea level in a freshwater bog. They contain pyroxenes crystallized from tholeiitic magma that we infer erupted explosively at the summit of Kilauca volcano. Two carbon-rich layers from these ashes have a weighted average radiocarbon age of 35.6 +/- 0.9 ka; the ashes probably correlate with the oldest and thickest part of the Pahala ash. Ash unit 44, at the transition from Mauna Kea to Mauna Loa lava flows, was probably nearly 3.2 m thick and is inferred to be equivalent to the lower thick part of the composite Homelani ash mapped in Hilo and on the Ranks of Mauna Kea. The age of this part of Homelani ash is between 128 +/- 33 and 200 +/- 10 ka; it may have erupted subglacially during the Pohakuloa glacial maxima on Mauna Kea. Beach sand units 12 and 22 were derived from nearby Mauna Loa and Mauna Kea lava flows. The middle of beach sand unit 38 was derived mainly from lava erupted near the distal end of the subaerial east rift zone of Kilauea volcano; these sands were transported about 33 km northwest to Hilo Bay by prevailing longshore currents. Combined age, depth, and sea level markers in the core allow us to determine that lava flow recurrence intervals averaged one flow every 4 kyr during the past 86 kyr and one flow every 16 kpr between 86 and 200 ka at the drill site and that major explosive eruptions that deposit thick ash in Hilo have occurred only twice in the last 400 kyr. These recurrence intervals support the moderate lava Row hazard zonation (zone 3) for coastal Hilo previously determined from surficial mapping. RP Beeson, MH (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 29 TC 14 Z9 14 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11617 EP 11629 DI 10.1029/95JB03703 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000039 ER PT J AU Lipman, PW Moore, JG AF Lipman, PW Moore, JG TI Mauna Loa lava accumulation rates at the Hilo drill site: Formation of lava deltas during a period of declining overall volcanic growth SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SOUTHWEST RIFT-ZONE; SEA-LEVEL; STRUCTURAL EVOLUTION; HAWAII; CALIBRATION; BC AB Accumulation rates for lava flows erupted from Mauna Loa, as sampled in the uppermost 280 m of the Hilo drill hole, vary widely for short time intervals (several thousand years), but overall are broadly similar to those documented elsewhere on this volcano since 100 ka. Thickness variations and accumulation rates for Mauna Loa lavas at the Hilo drill site have been strongly affected by local paleotopography, including funneling and pending between Mauna Kea and Kilauea. In addition, gentle submerged slopes of Mauna Kea in Hilo Bay have permitted large shoreline displacements by Mauna Loa flows. Ages of eruptive intervals have been determined from published isotopic data and from eustatic sea level curves modified to include the isostatic subsidence of the island of Hawaii at 2.2-2.6 mm/yr. Prior to 10 ka, rates of Mauna Loa lava accumulation at the drill site varied from 0.6 to 4.3 mm/yr for dateable intervals, with an overall rate of 1.8 mm/yr. Major eruptive pulses at about 1.3 and 10 ka, each probably representing a single long-lived eruption based on lack of weathering between flow units, increase the overall accumulation rate to 2.4 mm/yr. The higher rate since 10 ka reflects construction of thick near-shoreline lava deltas as postglacial sea levels rose rapidly. Large lava deltas form only along coastal segments where initially subaerial slopes have been submerged by the combined effects of eustatic sea level rise, isostatic subsidence, or spreading of volcano flanks. Overall accumulation of 239 m of lava at the drill site since 100-120 ka closely balances submergence of the Hilo area, suggesting that processes of coastal lava deposition have been modulated by rise in sea level. The Hilo accumulation rate is slightly higher than average rates of 1-2 mm/yr determined elsewhere along the Mauna Loa coast, based on rates of shoreline coverage and dated sea cliff and fault scarp exposures. Low rates of coastal lava accumulation since 100 ka, near or below the rate of island-wide isostatic subsidence, indicate that Mauna Loa is no longer growing vigorously or even maintaining its size above sea level. RP Lipman, PW (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 910, MENLO PK, CA 94025 USA. NR 30 TC 23 Z9 23 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11631 EP 11641 DI 10.1029/95JB03214 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000040 ER PT J AU Paillet, FL Thomas, DM AF Paillet, FL Thomas, DM TI Hydrogeology of the Hawaii scientific drilling project borehole KP-1 .1. Hydraulic conditions adjacent to the well bore SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article AB Temperature and formation resistivity logs obtained in borehole KP-1 of the Hawaii Scientific Drilling Project indicate that the adjacent formation is characterized by several zones of distinctly different average temperature and water salinity. A series of hydraulic analyses and water sampling programs were conducted to rule out the possibility of local hydraulic effects associated with the presence of the borehole in the generation of these apparent groundwater zones. Hydraulic tests and sampling with the borehole cased to a depth of 710 m and open below that depth indicate that the deep aquifer contains seawater at a temperature nearly identical to that of the open ocean at the same depth. Various analyses give estimates of aquifer transmissivity of about 10(-3) m(2)/s in the vicinity of the borehole, Isolation of this deeper aquifer from the overlying groundwater zones was investigated by perforating the casing at six locations and then measuring the changes in water level in the bort hole, in the salinity of the fluid column, in the temperature profile of the fluid column, and in the rate of how in the fluid column induced by the perforations. These results positively confirm that the zones of distinctly different formation properties indicated on the temperature and resistivity logs are not caused by Bow in or around casing. Flow and fluid column salinity induced by the perforations also confirm significant differences between the hydraulic heads and geochemistry of the different groundwater zones inferred from the well logs. C1 UNIV HAWAII MANOA, HAWAII INST GEOPHYS, HONOLULU, HI 96822 USA. RP Paillet, FL (reprint author), US GEOL SURVEY, MS 403, BOX 25046 FED CTR, DENVER, CO 80225 USA. NR 9 TC 4 Z9 4 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11675 EP 11682 DI 10.1029/95JB03445 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000044 ER PT J AU Thomas, DM Paillet, FL Conrad, ME AF Thomas, DM Paillet, FL Conrad, ME TI Hydrogeology of the Hawaii scientific drilling project borehole KP-1 .2. Groundwater geochemistry and regional flow patterns SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID RADIOCARBON TIME SCALE; NORTH PACIFIC-OCEAN; C-14 DATA; CALIBRATION; BC; CARBON AB A series of downhole and surface water samples were taken from the I-km-deep KP-1 borehole located on the eastern flank of the island of Hawaii. Early samples from depths of more than 700 m showed salinities nearly equivalent to seawater but having anomalous cation concentrations that are attributed to ion exchange between formation fluids and residual drilling mud clays. Later deep samples found only minor variations from seawater cation chemistry that are consistent with low-temperature weathering of basalts; delta(18)O values are equivalent to seawater values and are consistent with this interpretation. Carbon 14 activities of dissolved inorganic carbonate indicate a water age ranging from 5890 to 7170 years B.P. and fluid transport rates of 1.8 to 2.2 m/yr. Fluid samples from perforations at 310 m in the borehole demonstrate that a freshwater aquifer is present at the Mauna Kea/Mauna Loa interface; borehole resistivity logs indicate that it is similar to 200 m thick. Although it has not yet been possible to obtain samples of the freshwater zone without contamination from the deep saline fluids, the chloride concentrations of the low-salinity zone are estimated using a mixing enthalpy calculation to be less than 100 mg/L. Light stable isotope data indicate that the fresh water at 320 m is derived from recharge entering the island at an average elevation of 2000 m. Inferred C-14 activities of the dissolved bicarbonate in the freshwater zone indicate an average calibrated age of 2200 years B.P. and an average fluid velocity of at least 14 m/yr. A regional water flow model is proposed that suggests that the fresh water found at the 320-m depth is derived from rainfall recharge from the middle elevations of Mauna Kea volcano. This rainfall is channeled beneath the Mauna Loa lavas by the thick soil layer separating the two volcanoes. A second shallow fresh-to-brackish water zone, derived from Mauna Loa recharge, is also inferred to exist below the carbonate formation that underlies the shallow basal lens. The results of our preliminary study of the groundwater system below the KP-1 drill site demonstrate that intervolcano and interflow aquicludes can have a substantial impact on water circulation and discharge from young island volcanoes. C1 UNIV CALIF BERKELEY, LAWRENCE BERKELEY LAB, BERKELEY, CA 94720 USA. US GEOL SURVEY, DENVER, CO 80225 USA. RP Thomas, DM (reprint author), UNIV HAWAII MANOA, HAWAII INST GEOPHYS & PLANETOL, SOEST, 2525 CORREA RD, HONOLULU, HI 96822 USA. RI Conrad, Mark/G-2767-2010 NR 35 TC 14 Z9 14 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11683 EP 11694 DI 10.1029/95JB03845 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000045 ER PT J AU Morin, RH Paillet, FL AF Morin, RH Paillet, FL TI Analysis of fractures intersecting Kahi Puka Well 1 and its relation to the growth of the island of Hawaii SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EVOLUTION; VOLCANO AB As part of the Hawaii Scientific Drilling Project, Kahi Puka Well 1 penetrated about 275 m of Mauna Loa basalts overlying a sequence of Mauna Kea flow units as it was drilled and cored to a total depth of 10-53 m below land surface. A borehole televiewer (BHTV) was run in most of the well in successive stages prior to casing in order to obtain magnetically oriented acoustic images of the borehole wall, A total of 283 individual fractures were identified from this log and characterized in terms of strike and dip. These data are divided into three vertical sections based upon age and volcanic source, and lower hemisphere stereographic plots identify two predominant, subparallel fracture subsets common to each section, Assuming that most of the steeply dipping fractures observed in the BHTV log are tensile features generated within basalt flows during deposition and cooling, this fracture information can be combined with models of the evolution of the island of Hawaii to investigate the depositional history of these Mauna Loa and Mauna Kea basalts over the past 400 kyr. The directions of high-angle fractures appear to be generally parallel to topography or to the coastline at the time of deposition, as is supported by surface mapping of modern flows. Consequently, an overall counterclockwise rotation of about 75 degrees in the strike of these fractures from the bottom to the top of the well represents a systematic change in depositional slope direction over time. We attribute the observed rotation in the orientations of the two predominant fracture subsets over the past 400 kyr to changes in the configurations of volcanic sources during shield building and to the structural interference of adjacent volcanoes that produces shifts in topographic patterns. RP Morin, RH (reprint author), US GEOL SURVEY, DENVER FED CTR, POB 25046, DENVER, CO 80225 USA. NR 16 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11695 EP 11699 DI 10.1029/95JB03848 PG 5 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000046 ER PT J AU Lassiter, JC DePaolo, DJ Tatsumoto, M AF Lassiter, JC DePaolo, DJ Tatsumoto, M TI Isotopic evolution of Mauna Kea volcano: Results from the initial phase of the Hawaii Scientific Drilling Project SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID HALEAKALA VOLCANO; MANTLE EVOLUTION; OCEANIC BASALTS; LOIHI SEAMOUNT; ORIGIN; LAVAS; PLUMES; ND; SR; GEOCHEMISTRY AB We have examined the Sr, Nd, and Pb isotopic compositions of Mauna Kea lavas recovered by the first drilling phase of the Hawaii Scientific Drilling Project. These lavas, which range in age from similar to 200 to 400 ka, provide a detailed record of chemical and isotopic changes in basalt composition during the shield/postshield transition and extend our record of Mauna Kea volcanism to a late-shield period roughly equivalent to the last similar to 100 ka of Mauna Loa activity. Stratigraphic variations in isotopic composition reveal a gradual shift over time toward a more depleted source composition (e.g., higher Nd-143/Nd-144, lower Sr-87/Sr-86, and lower He-3/He-4). This gradual evolution is in sharp contrast with the abrupt appearance of alkalic lavas at similar to 240 ka recorded by the upper 50 m of Mauna Kea lavas from the core. Intercalated tholeiitic and alkalic lavas from the uppermost Mauna Kea section are isotopically indistinguishable. Combined with major element evidence (e.g., decreasing SiO2 and increasing FeO) that the depth of melt segregation increased during the transition from tholeiitic to alkalic volcanism, the isotopic similarity of tholeiitic and alkalic lavas argues against significant lithosphere involvement during melt generation. Instead, the depleted isotopic signatures found in late shield-stage lavas are best explained by increasing the proportion of melt generated from a depleted upper mantle component entrained and heated by the rising central plume. Direct comparison of Mauna Kea and Mauna Loa lavas erupted at equivalent stages in these volcanoes' life cycles reveals persistent chemical and isotopic differences independent of the temporal evolution of each volcano. The oldest lavas recovered from the drillcore are similar to modern Kilauea lavas, but are distinct from Mauna Loa lavas. Mauna Kea lavas have higher Nd-143/Nd-144 and Pb-206/Pb-204 and lower Sr-87/Sr-86. Higher concentrations of incompatible tract elements in primary magmas, lower SiO2, and higher FeO also indicate that Mauna Kea lavas formed through smaller degrees of partial melting at greater depth than Mauna Loa lavas. These chemical and isotopic differences are consistently found between volcanoes along the western ''Loa'' and eastern ''Kea'' trends and reflect large-scale variations in source composition and melting environment. We propose a simple model of a radially zoned plume centered beneath the Loa trend. Loa trend lavas generated from the hot plume axis reflect high degrees of partial melting from a source containing a mixture of enriched plume-source material and entrained lower mantle. Kea trend lavas, in contrast, are generated from the cooler, peripheral portions of the plume, record lower degrees of partial melting, and tap a source containing a greater proportion of depleted upper mantle. C1 UNIV CALIF BERKELEY, DEPT GEOL & GEOPHYS, BERKELEY CTR ISOTOPE GEOCHEM, BERKELEY, CA 94720 USA. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. RI Lassiter, John/P-1892-2015 OI Lassiter, John/0000-0001-5249-168X NR 51 TC 102 Z9 103 U1 0 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAY 10 PY 1996 VL 101 IS B5 BP 11769 EP 11780 DI 10.1029/96JB00181 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL090 UT WOS:A1996UL09000051 ER PT J AU Lovley, DR Chapelle, FH AF Lovley, DR Chapelle, FH TI Hydrogen-based microbial ecosystems in the Earth SO SCIENCE LA English DT Article C1 US GEOL SURVEY,COLUMBIA,SC 29210. RP Lovley, DR (reprint author), UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003, USA. NR 4 TC 3 Z9 3 U1 3 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAY 10 PY 1996 VL 272 IS 5263 BP 896 EP 896 PG 1 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UK757 UT WOS:A1996UK75700066 ER PT J AU Evans, WC AF Evans, WC TI Geochemistry - A gold mine of methane SO NATURE LA English DT Editorial Material ID RIDGE RP Evans, WC (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. RI Evans, William/J-4283-2012 NR 10 TC 11 Z9 12 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAY 9 PY 1996 VL 381 IS 6578 BP 114 EP 115 DI 10.1038/381114a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UK139 UT WOS:A1996UK13900022 ER PT J AU Nielson, JE Wilshire, HG AF Nielson, JE Wilshire, HG TI Magma transport and metasomatism in the mantle: A critical review of current geochemical models - Reply SO AMERICAN MINERALOGIST LA English DT Article ID LAYERED PYROXENITES; XENOLITHS; PETROLOGY; EVOLUTION; MIGRATION; ARIEGE; LHERZ; ROCK AB Navon et al. (1996) demonstrated that the Navon and Stolper (1987) model can be formulated to reproduce a pattern of light-ion lithophile trace element (LIL) enrichments produced by a single, small-scale metasomatic process recorded in a composite xenolith from Dish Hill, California (Nielson et al. 1993). The Navon and Stolper model has failed repeatedly to reproduce the shape and lateral positions of LIL enrichment patterns for samples from peridotite massifs, which are of appropriate scale to test the assumption that LIL fractionation takes place in percolating melts over distances >100 m. The model results also produce unreasonably long times for solidification of thin dikes, which imply untenable thermal conditions for lithospheric mantle. Using parameters drawn from sample compositions, Nielson et al. (1993) demonstrated, and the calculations of Navon et al. (1996) have shown again, that fractionated trace element patterns of a melt are imprinted upon relatively refractory peridotite matrix in zones closest to a melt source. The observed process sequentially extracts LIL into matrix, analogous to the ion-exchange chromatography of water-purification columns. We have never contended that this process is mathematically distinct from the percolation model of Navon and Stolper (1987), which assumes concentration of LIL elements in melt. The choice of parameters defines the result, and one would notice a major difference in the taste of water from an ion-exchange column that traps target ions in matrix compared with one that concentrates those ions in the liquid. The difference between the models is in the selection of parameters and values: The model of Navon and Stolper (1987) assumes the reaction mechanism, uses theoretical melt compositions, and contains as many as nine unmeasurable parameters. We used the simplified model calculation to avoid reliance on theoretical parameters and to test our assumptions about the process. When the compositions of actual samples are taken as end-members of mantle reactions. the successful results imply that a fractionation-by-percolation process is not applicable to lithospheric mantle. Repetition of the observed small-scale reaction in refractory peridotite must extend the zone of reactions and relative enrichment, centimeter by centimeter, as long as melt aliquots percolate beyond peridotite matrix that had previously reacted to equilibrium with the melt composition. This process satisfactorily explains the wide variations of LIL fractionation patterns over short distances that characterize mantle rocks in xenoliths and massifs, all of which contain complex systems of mafic intrusions with varied LIL fractionation patterns. RP Nielson, JE (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 975,MENLO PK,CA 94025, USA. NR 30 TC 3 Z9 3 U1 0 U2 1 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD MAY-JUN PY 1996 VL 81 IS 5-6 BP 760 EP 765 PG 6 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA UP411 UT WOS:A1996UP41100023 ER PT J AU Coates, JD Phillips, EJP Lonergan, DJ Jenter, H Lovley, DR AF Coates, JD Phillips, EJP Lonergan, DJ Jenter, H Lovley, DR TI Isolation of Geobacter species from diverse sedimentary environments SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID ORGANIC-CARBON OXIDATION; MICROBIAL IRON REDUCTION; DISSIMILATORY FE(III); FE(III)-REDUCING BACTERIA; ANAEROBIC SEDIMENTS; FERRIC IRON; MICROORGANISM; MANGANESE; HYDROGEN; CONTAMINANTS AB In an attempt to better understand the microorganisms responsible for Fe(III) reduction in sedimentary environments, Fe(III)-reducing microorganisms were enriched for and isolated from freshwater aquatic sediments, a pristine deep aquifer, and a petroleum-contaminated shallow aquifer. Enrichments were initiated with acetate or toluene as the electron donor and Fe(III) as the electron acceptor. Isolations were made with acetate or benzoate. Five new strains which could obtain energy for growth by dissimilatory Fe(III) reduction were isolated. All five isolates are gram-negative strict anaerobes which grow with acetate as the electron donor and Fe(III) as the electron acceptor, Analysis of the 16S rRNA sequence of the isolated organisms demonstrated that they all belonged to the genus Geobacter in the delta subdivision of the Proteobacteria. Unlike the type strain, Geobacter metallireducens, three of the five isolates could use H-2 as an electron donor for Fe(III) reduction, The deep subsurface isolate is the first Fe(III) reducer shown to completely oxidize lactate to carbon dioxide, while one of the freshwater sediment isolates is only the second Fe(III) reducer known that can oxidize toluene. The isolation of these organisms demonstrates that Geobacter species are widely distributed in a diversity of sedimentary environments in which Fe(III) reduction is an important process. C1 UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003. US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092. UNIV MARYLAND,DEPT MARINE & ESTUARINE ENVIRONM SCI,COLLEGE PK,MD 20742. NR 44 TC 172 Z9 184 U1 2 U2 20 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAY PY 1996 VL 62 IS 5 BP 1531 EP 1536 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA UJ228 UT WOS:A1996UJ22800007 PM 8633852 ER PT J AU Dowdle, PR Laverman, AM Oremland, RS AF Dowdle, PR Laverman, AM Oremland, RS TI Bacterial dissimilatory reduction of arsenic(V) to arsenic(III) in anoxic sediments SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID ANAEROBIC-BACTERIA; NATURAL-WATERS; SPECIATION; ADSORPTION; SELENIUM; ARSENATE; LAKE; PH AB Incubation of anoxic salt marsh sediment slurries with 10 mM As(V) resulted in the disappearance over time of the As(V) in conjunction with its recovery as As(III). No As(V) reduction to As(III) occurred in heat-sterilized or formalin-killed controls or in live sediments incubated in air, The rate of As(V) reduction in slurries was enhanced by addition of the electron donor lactate, H-2, or glucose, whereas the respiratory inhibitor/uncoupler dinitrophenol, rotenone, or 2-heptyl-4-hydroxyquinoline N-oxide blocked As(V) reduction, As(V) reduction was also inhibited by tungstate but not by molybdate, sulfate, or phosphate, Nitrate inhibited As(V) reduction by its action as a preferred respiratory electron acceptor rather than as a structural analog of As(V), Nitrate-respiring sediments could reduce As(V) to As(III) once all the nitrate was removed, Chloramphenicol blocked the reduction of As(V) to As(III) in nitrate-respiring sediments, suggesting that nitrate and arsenate were reduced by separate enzyme systems, Oxidation of [2-C-14]acetate to (CO2)-C-14 by salt marsh and freshwater sediments was coupled to As(V). Collectively, these results show that reduction of As(V) in sediments proceeds by a dissimilatory process, Bacterial sulfate reduction was completely inhibited by As(V) as well as by As(III). C1 US GEOL SURVEY,MENLO PK,CA 94025. FREE UNIV AMSTERDAM,DEPT BIOL,1081 HV AMSTERDAM,NETHERLANDS. NR 32 TC 116 Z9 120 U1 3 U2 30 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAY PY 1996 VL 62 IS 5 BP 1664 EP 1669 PG 6 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA UJ228 UT WOS:A1996UJ22800028 PM 16535314 ER PT J AU Oremland, RS Lonergan, DJ Culbertson, CW Lovley, DR AF Oremland, RS Lonergan, DJ Culbertson, CW Lovley, DR TI Microbial degradation of hydrochlorofluorocarbons (CHCl2F and CHCl2CF3) in soils and sediments SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID CHLOROFLUOROMETHANES; CHLOROFLUOROCARBONS; CONSUMPTION; OXIDATION; CHLORINE; CFC-11; OZONE; SINK AB The ability of microorganisms to degrade trace levels of the hydrochlorofluorocarbons HCFC-21 and HCFC-123 was investigated, Methanotroph-linked oxidation of HCFC-21 was observed in aerobic soils, and anaerobic degradation of HCFC-21 occurred in freshwater and salt marsh sediments, Microbial degradation of HCFC-123 was observed in anoxic fresh water and salt marsh sediments, and the recovery of 1,1,1-trifluoro-2-chloroethane indicated the involvement of reductive dechlorination, No degradation of HCFC-123 was observed in aerobic soils. In some experiments, HCFCs were degraded at low (path per billion) concentrations, raising the possibility that bacteria in nature remove HCFCs from the atmosphere. C1 UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003. RP Oremland, RS (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS465,MENLO PK,CA 94025, USA. NR 28 TC 17 Z9 17 U1 0 U2 6 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAY PY 1996 VL 62 IS 5 BP 1818 EP 1821 PG 4 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA UJ228 UT WOS:A1996UJ22800056 PM 8633881 ER PT J AU Carrara, PE Kiver, EP Stradling, DF AF Carrara, PE Kiver, EP Stradling, DF TI The southern limit of Cordilleran ice in the Colville and Pend Oreille valleys of northeastern Washington during the late Wisconsin glaciation SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Article ID GLACIER PEAK TEPHRA; LAKE MISSOULA; JOKULHLAUPS; MONTANA; SHEET; AGE AB The southern limit of the lobes of the Cordilleran ice sheet in the Colville and Pend Oreille valleys of northeastern Washington during the Late Wisconsin (Fraser) glaciation has been placed at widely different positions by various investigators. The confusion that resulted in these different positions is due to the fact that both lobes, at times, terminated in glacial lakes and much of the terminal area of the Pend Oreille River lobe was swept by floods from glacial Lake Missoula. Evidence, presented in this paper, of the southern limit of these two lobes during the Late Wisconsin glaciation consists of (i) the southern limit of Late Wisconsinan till, (ii) the southern limit of lateral meltwater channels, (iii) meltwater channels whose headward areas coincide with the southern limit of Late Wisconsinan till, and (iv) reconstructed ice-surface profiles. This evidence suggests that the southern limit of the Colville lobe is represented by a moraine near the town of Springdale, whereas that of the Pend Oreille River lobe is near the town of Newport. The timing and extent of Late Wisconsinan deglaciation in the Colville Valley are provided by radiocarbon ages and Late Pleistocene tephras at sites upglacier from the terminal position. These data demonstrate that the Colville lobe had retreated at least 50 km by about 12 450 BP. In the Pend Oreille Valley, the presence of a Glacier Peak tephra layer near the town of Ione indicates that the Pend Oreille River lobe had retreated at least 70 km prior to deposition of the tephra. C1 EASTERN WASHINGTON UNIV, DEPT GEOL, CHENEY, WA 99004 USA. EASTERN WASHINGTON UNIV, DEPT GEOG & ANTHROPOL, CHENEY, WA 99004 USA. RP Carrara, PE (reprint author), US GEOL SURVEY, DENVER FED CTR, MAIL STOP 913, DENVER, CO 80225 USA. NR 43 TC 7 Z9 7 U1 2 U2 6 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 1200 MONTREAL ROAD, BUILDING M-55, OTTAWA, ON K1A 0R6, CANADA SN 0008-4077 EI 1480-3313 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD MAY PY 1996 VL 33 IS 5 BP 769 EP 778 DI 10.1139/e96-059 PG 10 WC Geosciences, Multidisciplinary SC Geology GA UW235 UT WOS:A1996UW23500012 ER PT J AU Groves, DJ Contant, B King, RJ Hodges, JI King, JG AF Groves, DJ Contant, B King, RJ Hodges, JI King, JG TI Status and trends of loon populations summering in Alaska, 1971-1993 SO CONDOR LA English DT Article DE aerial surveys; Alaska; breeding; distribution; Gavia; Gaviidae; loons; population trends; populations AB Loons (Gavia spp.) were counted during the Alaska-Yukon Waterfowl Breeding Population Survey from 1971 to 1993 and the Arctic Coastal Plain Waterbird Breeding Population Survey from 1986 to 1993. Population indices for Alaska (not corrected for visibility bias) are presented by species for boreal forest, tundra, and both habitats combined. Minimum mean population estimates (1977-1993) with 95% confidence intervals were 15,360 (+/-2,235) Red-throated Loons (G. stellata), 69,498 (+/-5,596) Pacific Loons (G. pacifica), 8,886 (+/-843) Common Loons (G. immer) and 2,636 (+/-614) Yellow-billed Loons (G. adamsii). Populations of Pacific, Common and Yellow-billed Loons did not change significantly between 1977 and 1993, whereas Red-throated Loons declined by 53% to a 1993 level of 9,843 (+/-2,447) (r(2) = 0.65, P < 0.001). Factors affecting results from aerial surveys are discussed. RP Groves, DJ (reprint author), US FISH & WILDLIFE SERV,3000 VINTAGE BLVD,SUITE 240,JUNEAU,AK 99801, USA. NR 16 TC 15 Z9 17 U1 0 U2 7 PU COOPER ORNITHOLOGICAL SOC PI LAWRENCE PA ORNITHOLOGICAL SOC NORTH AMER PO BOX 1897, LAWRENCE, KS 66044-8897 SN 0010-5422 J9 CONDOR JI Condor PD MAY PY 1996 VL 98 IS 2 BP 189 EP 195 DI 10.2307/1369136 PG 7 WC Ornithology SC Zoology GA UR913 UT WOS:A1996UR91300002 ER PT J AU Wilshire, HG McGuire, AV AF Wilshire, HG McGuire, AV TI Magmatic infiltration and melting in the lower crust and upper mantle beneath the Cima volcanic field, California SO CONTRIBUTIONS TO MINERALOGY AND PETROLOGY LA English DT Article ID SPINEL LHERZOLITE XENOLITHS; CARBONATITE METASOMATISM; PERIDOTITE XENOLITHS; CANARY-ISLANDS; PETROLOGY; GLASS; INCLUSIONS; GEOCHEMISTRY; AUSTRALIA; VICTORIA AB Xenoliths of lower crustal and upper mantle rocks from the Cima volcanic field (CVF) commonly contain glass pockets, veins, and planar trains of glass and/or fluid inclusions in primary minerals. Glass pockets occupy spaces formerly occupied by primary minerals of the host rocks, but there is a general lack of correspondence between the composition of the glass and that of the replaced primary minerals. The melting is considered to have been induced by infiltration of basaltic magma and differentiates of basaltic magma from complex conduits formed by hydraulic fracturing of the mantle and crustal rocks, and to have occurred during the episode of CVF magmatism between similar to 7.5 Ma and present. Variable compositions of quenched melts resulted from mixing of introduced melts and products of melting of primary minerals, reaction with primary minerals, partial crystallization, and fractionation resulting from melt and volatile expulsion upon entrainment of the xenoliths. High silica melts (> similar to 60% SiO2) may result by mixing introduced melts with siliceous melts produced by reaction of orthopyroxene. Other quenched melt compositions range from those comparable to the host basalts to those with intermediate Si compositions and elevated Al, alkalis, Ti, P, and S; groundmass compositions of CVF basalts are consistent with infiltration of fractionates of those basalts, but near-solidus melting may also contribute to formation of glass with intermediate silica contents with infiltration only of volatile constituents. C1 UNIV HOUSTON,DEPT GEOSCI,HOUSTON,TX 77204. RP Wilshire, HG (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 48 TC 7 Z9 7 U1 0 U2 3 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-7999 J9 CONTRIB MINERAL PETR JI Contrib. Mineral. Petrol. PD MAY PY 1996 VL 123 IS 4 BP 358 EP 374 DI 10.1007/s004100050162 PG 17 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA UP656 UT WOS:A1996UP65600003 ER PT J AU Wigington, PJ Baker, JP DeWalle, DR Kretser, WA Murdoch, PS Simonin, HA VanSickle, J McDowell, MK Peck, DV Barchet, WR AF Wigington, PJ Baker, JP DeWalle, DR Kretser, WA Murdoch, PS Simonin, HA VanSickle, J McDowell, MK Peck, DV Barchet, WR TI Episodic acidification of small streams in the northeastern United States: Episodic Response Project SO ECOLOGICAL APPLICATIONS LA English DT Article DE Adirondack Mountains; aluminum; brook trout; Catskill Mountains; episodic acidification; fish populations; northeastern US; Northern Appalachian Plateau; streams; streamwater chemistry dynamics ID EQUILIBRIUM CALCULATIONS; ALUMINUM CHEMISTRY; AQUEOUS ALUMINUM; UNCERTAINTY; WATERS; MODELS AB The Episodic Response Project (ERP) was an interdisciplinary study designed to address uncertainties about the occurrence, nature, and biological effects of episodic acidification of streams in the northeastern United States. The ERP research consisted of intensive studies of the chemistry and biological effects of episodes in 13 streams draining forested watersheds in the three study regions: the Northern Appalachian region of Pennsylvania and the Catskill and Adirondack Mountains of New York. Wet deposition was measured in each of the three study regions. Using automated instruments and samplers, discharge and chemistry of each stream was monitored intensively from fall 1988 through spring 1990. Biological studies focused on brook trout and native forage fish. Experimental approaches included in situ bioassays, radio transmitter studies of fish movement, and fish population studies. This paper provides an overview of the ERP, describes the methodology used in hydrologic and water chemistry components of the study, and summarizes the characteristics of the study sites, including the climatic and deposition conditions during the ERP and the general chemical characteristics of the study streams. C1 PENN STATE UNIV, SCH FOREST RESOURCES, UNIVERSITY PK, PA 16802 USA. PENN STATE UNIV, ENVIRONM RESOURCES RES INST, UNIVERSITY PK, PA 16802 USA. NEW YORK STATE DEPT ENVIRONM CONSERVAT, ADIRONDACK LAKES SURVEY CORP, RAY BROOK, NY 12977 USA. US GEOL SURVEY, ALBANY, NY 12201 USA. NEW YORK STATE DEPT ENVIRONM CONSERVAT, ROME, NY 13440 USA. MANTECH ENVIRONM TECHNOL INC, CORVALLIS, OR 97333 USA. LOCKHEED ENVIRONM SYST & TECHNOL CO, LAS VEGAS, NV 89119 USA. PACIFIC NW LAB, RICHLAND, WA 99352 USA. RP Wigington, PJ (reprint author), US EPA, CORVALLIS, OR 97333 USA. NR 33 TC 56 Z9 56 U1 0 U2 9 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 EI 1939-5582 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1996 VL 6 IS 2 BP 374 EP 388 DI 10.2307/2269377 PG 15 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UH485 UT WOS:A1996UH48500010 ER PT J AU Wigington, PJ DeWalle, DR Murdoch, PS Kretser, WA Simonin, HA VanSickle, J Baker, JP AF Wigington, PJ DeWalle, DR Murdoch, PS Kretser, WA Simonin, HA VanSickle, J Baker, JP TI Episodic acidification of small streams in the northeastern United States: Ionic controls of episodes SO ECOLOGICAL APPLICATIONS LA English DT Article DE Adirondack Mountains; base cations; Catskill Mountains; episodic acidification; hydrologic events; nitrogen; Northern Appalachian Plateau; organic acids; rainstorms; snow melt; streams; sulfate ID NEW-YORK; SURFACE WATERS; NITROGEN SATURATION; NEUTRALIZING CAPACITY; CATSKILL MOUNTAINS; FOREST ECOSYSTEMS; ADIRONDACK REGION; SULFUR RETENTION; ORGANIC-ACIDS; SNOWMELT AB As part of the Episodic Response Project (ERP), we intensively monitored discharge and stream chemistry of 13 streams located in the Northern Appalachian region of Pennsylvania and in the Catskill and Adirondack Mountains of New York from fall 1988 to spring 1990. The ERP clearly documented the occurrence of acidic episodes with minimum episodic pH less than or equal to 5 and inorganic monomeric Al (Al-im) concentrations > 150 mu g/L in at least two study streams in each region. Several streams consistently experienced episodes with maximum Al-im concentrations > 350 mu g/L. Acid neutralizing capacity (ANC) depressions resulted from complex interactions of multiple ions. Base cation decreases often made the most important contributions to ANC depressions during episodes. Organic acid pulses were also important contributors to ANC depressions in the Adirondack streams, and to a lesser extent, in the Catskill and Pennsylvania streams. Nitrate concentrations were low in the Pennsylvania streams, whereas the Catskill and Adirondack study streams had high NO3- concentrations and large episodic pulses (less than or equal to 54 mu eq/L). Most of the Pennsylvania study streams also frequently experienced episodic pulses of SO42- (less than or equal to 78 mu eq/L), whereas the Adirondack and Catskill streams did not. High baseline concentrations of SO42- (all three study areas) and NO3- (Adirondacks and Catskills) reduced episodic minimum ANC, even when these ions did not change during episodes. The ion changes that controlled the most severe episodes (lowest minimum episodic ANC) differed from the ion changes most important to smaller, more frequent episodes. Pulses of NO3- (Catskills and Adirondacks), SO42- (Pennsylvania), or organic acids became more important during major episodes. Overall, the behavior of streamwater SO42- and NO3- is an indicator that acidic deposition has contributed to the severity of episodes in the study streams. C1 PENN STATE UNIV, SCH FOREST RESOURCES, UNIVERSITY PK, PA 16802 USA. PENN STATE UNIV, ENVIRONM RESOURCES RES INST, UNIVERSITY PK, PA 16802 USA. US GEOL SURVEY, ALBANY, NY 12201 USA. NEW YORK STATE DEPT ENVIRONM CONSERVAT, ADIRONDACK LAKES SURVEY CORP, RAY BROOK, NY 12977 USA. NEW YORK STATE DEPT ENVIRONM CONSERVAT, ROME, NY 13440 USA. MANTECH ENVIRONM TECHNOL INC, ENVIRONM RES LAB, CORVALLIS, OR 97333 USA. RP Wigington, PJ (reprint author), US EPA, CORVALLIS, OR 97333 USA. NR 53 TC 90 Z9 90 U1 1 U2 5 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 1990 M STREET NW, STE 700, WASHINGTON, DC 20036 USA SN 1051-0761 EI 1939-5582 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1996 VL 6 IS 2 BP 389 EP 407 DI 10.2307/2269378 PG 19 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UH485 UT WOS:A1996UH48500011 ER PT J AU VanSickle, J Baker, JP Simonin, HA Baldigo, BP Kretser, WA Sharpe, WE AF VanSickle, J Baker, JP Simonin, HA Baldigo, BP Kretser, WA Sharpe, WE TI Episodic acidification of small streams in the northeastern United States: Fish mortality in field bioassays SO ECOLOGICAL APPLICATIONS LA English DT Article DE Adirondack Mountains; aluminum; bioassay; brook trout; Catskill Mountains; fish mortality; episodic acidification; logistic regression; Northern Appalachian Plateau; overdispersion; streams ID TROUT SALVELINUS-FONTINALIS; BROOK TROUT; LOW PH; LOW CALCIUM; ALUMINUM; ACID; SURVIVAL; TOXICITY; RESPONSES; EXPOSURE AB In situ bioassays were performed as part of the Episodic Response Project, to evaluate the effects of episodic stream acidification on mortality of brook trout (Salvelinus fontinalis) and forage fish species. We report the results of 122 bioassays in 13 streams of the three study regions: the Adirondack mountains of New York, the Catskill mountains of New York, and the Northern Appalachian Plateau of Pennsylvania. Bioassays during acidic episodes had significantly higher mortality than did bioassays conducted under nonacidic conditions, but there was little difference in mortality rates in bioassays experiencing acidic episodes and those experiencing acidic conditions throughout the test period. Multiple logistic regression models were used to relate bioassay mortality rates to summary statistics of time-varying stream chemistry (inorganic monomeric aluminum, calcium, pH, and dissolved organic carbon) estimated for the 20-d bioassay periods. The large suite of candidate regressors also included biological, regional, and seasonal factors, as well as several statistics summarizing various features of aluminum exposure duration and magnitude. Regressor variable selection and model assessment were complicated by multicollinearity and overdispersion. For the target fish species, brook trout, bioassay mortality was most closely related to time-weighted median inorganic aluminum. Median Ca and minimum pH offered additional explanatory power, as did stream-specific aluminum responses. Due to high multicollinearity, the relative importance of different aluminum exposure duration and magnitude variables was difficult to assess, but these variables taken together added no significant explanatory power to models already containing median aluminum. Between 59 and 79% of the variation in brook trout mortality was explained by models employing between one and five regressors. Simpler models were developed for smaller sets of bioassays that tested slimy and mottled sculpin (Cottus cognatus and C. bairdi) as well as blacknose dace (Rhinichthys atratulus). For these forage species a single inorganic aluminum exposure variable successfully accounted for 86-98% of the observed mortality. Even though field bioassays showed evidence of multiple toxicity factors, model results suggest that adequate mortality predictions can be obtained from a single index of inorganic Al concentrations during exposure periods. C1 US EPA,CORVALLIS,OR 97333. US GEOL SURVEY,ALBANY,NY 12201. NEW YORK STATE DEPT ENVIRONM CONSERVAT,ADIRONDACKS LAKE SURVEY CORP,RAY BROOK,NY 12977. PENN STATE UNIV,ENVIRONM RESOURCES RES INST,UNIVERSITY PK,PA 16802. RP VanSickle, J (reprint author), MANTECH ENVIRONM TECHNOL INC,200 SW 35TH ST,CORVALLIS,OR 97333, USA. NR 51 TC 56 Z9 56 U1 2 U2 15 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1996 VL 6 IS 2 BP 408 EP 421 PG 14 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UH485 UT WOS:A1996UH48500012 ER PT J AU Baker, JP VanSickle, J Gagen, CJ DeWalle, DR Sharpe, WE Carline, RF Baldigo, BP Murdoch, PS Bath, DW Kretser, WA Simonin, HA Wigington, PJ AF Baker, JP VanSickle, J Gagen, CJ DeWalle, DR Sharpe, WE Carline, RF Baldigo, BP Murdoch, PS Bath, DW Kretser, WA Simonin, HA Wigington, PJ TI Episodic acidification of small streams in the northeastern United States: Effects on fish populations SO ECOLOGICAL APPLICATIONS LA English DT Article DE Adirondack Mountains; aluminium; bioassays; Catskill Mountains; episodic acidification; fish behavior; fish mortality; fish populations; Northern Appalachian Plateau; pH; radiotelemetry; streams ID TROUT SALVELINUS-FONTINALIS; BROOK TROUT; LOW PH; MOTTLED SCULPINS; WATER CHEMISTRY; NORTH BRANCH; MOOSE RIVER; ALUMINUM; RESPONSES; SURVIVAL AB As part of the Episodic Response Project (ERP), we studied the effects of episodic acidification on fish in 13 small streams in the northeastern United States: four streams in the Adirondack region of New York, four streams in the Catskills, New York, and five streams in the northern Appalachian Plateau, Pennsylvania. In situ bioassays with brook trout (Salvelinus fontinalis) and a forage fish species (blacknose dace (Rhinichthys atratulus), mottled sculpin (Cottus bairdi), or slimy sculpin (Cottus cognatus), depending on the region) measured direct toxicity. Movements of individual brook trout, in relation to stream chemistry, were monitored using radiotelemetry. Electrofishing surveys assessed fish community status and the density and biomass of brook trout in each stream. During low flow, all streams except one had chemical conditions considered suitable for the survival and reproduction of most fish species (median pH 6.0-7.2 during low flow; inorganic Al < 60 mu g/L). ERP streams with suitable conditions during low flow, but moderate-to-severe episodic acidification during high flow, had higher fish mortality in bioassays, net downstream movement of brook trout during events, and lower brook trout density and biomass compared to nonacidic streams, and lacked acid-sensitive fish species (blacknose dace and sculpin). Movement of trout into refugia (areas with higher pH and lower Al) during episodes partially mitigated the adverse effects of episodes. Recolonization from alkaline tributaries or microhabitats can maintain low densities of fish in streams that experience severe acidic episodes, but it is not sufficient to sustain fish densities and community composition at levels expected in the absence of these episodes. Fish responses to acid-base chemistry were fairly consistent across regions. In general, trout abundance was reduced and acid-sensitive fish species were absent from ERP streams with median pH < 5.0-5.2 during high flow and inorganic Al > 100-200 mu g/L. We conclude that episodic acidification can have long-term effects on fish communities in small streams. C1 MANTECH ENVIRONM TECHNOL INC,CORVALLIS,OR 97333. PENN STATE UNIV,ENVIRONM RESOURCES RES INST,UNIVERSITY PK,PA 16802. PENN STATE UNIV,MERKLE LAB,NATL BIOL SURVEY,PENN COOPERAT FISH & WILDLIFE RES UNIT,UNIVERSITY PK,PA 16802. US GEOL SURVEY,ALBANY,NY 12201. NEW YORK STATE DEPT ENVIRONM CONSERVAT,ADIRONDACK LAKES SURVEY CORP,RAY BROOK,NY 12977. NEW YORK STATE DEPT ENVIRONM CONSERVAT,ROME,NY 13440. RP Baker, JP (reprint author), US EPA,CORVALLIS,OR 97333, USA. NR 68 TC 118 Z9 119 U1 4 U2 42 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD MAY PY 1996 VL 6 IS 2 BP 422 EP 437 DI 10.2307/2269380 PG 16 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UH485 UT WOS:A1996UH48500013 ER PT J AU Boyer, EW Hornberger, GM Bencala, KE McKnight, D AF Boyer, EW Hornberger, GM Bencala, KE McKnight, D TI Overview of a simple model describing variation of dissolved organic carbon in an upland catchment SO ECOLOGICAL MODELLING LA English DT Article; Proceedings Paper CT International Congress on Modelling and Simulation 1993 - Modelling Change in Environmental and Socioeconomic Systems CY DEC, 1993 CL PERTH, AUSTRALIA SP Modelling & Simulat Soc Austr, ISEM DE carbon; hydrology; river ecosystems; TOPMODEL AB Hydrological mechanisms controlling the variation of dissolved organic carbon (DOG) were investigated in the Deer Creek catchment located near Montezuma, CO. Patterns of DOC in streamflow suggested that increased flows through the upper soil horizon during snowmelt are responsible for flushing this DOG-enriched interstitial water to the streams. We examined possible hydrological mechanisms to explain the observed variability of DOC in Deer Creek by first simulating the hydrological response of the catchment using TOPMODEL and then routing the predicted flows through a simple model that accounted for temporal changes in DOG. Conceptually the DOC model can be taken to represent a terrestrial (soil) reservoir in which DOC builds up during low now periods and is flushed out when infiltrating meltwaters cause the water table to rise into this ''reservoir''. Concentrations of DOC measured in the upper soil and in streamflow were compared to model simulations. The simulated DOC response provides a reasonable reproduction of the observed dynamics of DOC in the stream at Deer Creek. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Boyer, EW (reprint author), UNIV VIRGINIA,DEPT ENVIRONM SCI,CLARK HALL,CHARLOTTESVILLE,VA 22903, USA. RI Bencala, Kenneth/A-6650-2010; Boyer, Elizabeth/D-6617-2013; OI MCKNIGHT, DIANE/0000-0002-4171-1533 NR 8 TC 72 Z9 74 U1 2 U2 26 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0304-3800 J9 ECOL MODEL JI Ecol. Model. PD MAY PY 1996 VL 86 IS 2-3 BP 183 EP 188 DI 10.1016/0304-3800(95)00049-6 PG 6 WC Ecology SC Environmental Sciences & Ecology GA UH257 UT WOS:A1996UH25700013 ER PT J AU Johnson, CA Cardellach, E Tritlla, J Hanan, BB AF Johnson, CA Cardellach, E Tritlla, J Hanan, BB TI Cierco Pb-Zn-Ag vein deposits: Isotopic and fluid inclusion evidence for formation during the mesozoic extension in the Pyrenees of Spain SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID BASE METAL DISTRICT; CATALONIAN COASTAL RANGES; SPANISH-CENTRAL-SYSTEM; STABLE-ISOTOPE; MINERALIZING PROCESSES; GEOCHEMISTRY; SULFUR; ORIGIN; SR; CONSTRAINTS AB The Cierco Pb-Zn-Ag vein deposits, located in the central Pyrenees of Spain, crosscut Paleozoic metasedimentary rocks and are in close proximity to Hercynian granodiorite dikes and plutons. Galena and sphalerite in the deposits have average delta(34)S values of -4.3 and -0.8 per mil (CDT), respectively. Coexisting mineral pairs give an isotopic equilibration temperature range of 89 degrees to 163 degrees C which overlaps with the 112 degrees to 198 degrees C range obtained from primary fluid inclusions. Coexisting quartz has a delta(18)O value of 19 +/- 1 per mil (VSMOW). The fluid which deposited these minerals is inferred to have had delta(18)O(H2O) and delta(34)S(H2S) values of 5 +/- 1 and -1 +/- 1 per mil, respectively. Chemical and microthermometric analyses of fluid inclusions in quartz and sphalerite indicate salinities of 3 to 29 wt percent NaCl equiv with Na+ and Ca2+ as the dominant cations in solution. The Br/Cl and I/Cl ratios differ from those characteristic of magmatic waters and pristine seawater, but show some similarity to those observed in deep ground waters in crystalline terranes, basinal brines, and evaporated seawater. Barite, which postdates the sulfides, spans isotopic ranges of 13 to 21 per mil, 10 to 15 per mil, and 0.7109 to 0.7123 for delta(34)S, delta(18)O, and Sr-87/Sr-86, respectively. The three parameters are correlated providing strong evidence that the barites are products of fluid mixing. We propose that the Cierco deposits formed along an extensional fault system at the margin of a marine basin during the breakup of Pangea at some time between the Early Triassic and Early Cretaceous. Sulfide deposition corresponded to an upwelling of hydrothermal fluid from the Paleozoic basement and was limited by the amount of metals carried by the fluid. Barite deposition corresponded to the waning of upward flow and the collapse of sulfate-rich surface waters onto the retreating hydrothermal plume. Calcite precipitated late ill the paragenesis as meteoric or marine waters descended into the fault system, possibly during a regression in the overlying basin. There are other deposits resembling Cierco elsewhere in the Iberian peninsula. Taken as a group, they are evidence that hydrothermal circulation systems were widespread during Mesozoic extension. Differences among the deposits can be related to the fact that H2S and other solutes had local and variable sources. C1 UNIV AUTONOMA BARCELONA,DEPT GEOL,BELLATERRA 08193,SPAIN. UNIV LEEDS,DEPT EARTH SCI,LEEDS LS2 9JT,W YORKSHIRE,ENGLAND. SAN DIEGO STATE UNIV,DEPT GEOL SCI,SAN DIEGO,CA 92182. RP Johnson, CA (reprint author), US GEOL SURVEY,BOX 25046,MAIL STOP 963,DENVER,CO 80225, USA. OI Hanan, Barry/0000-0002-8240-2200 NR 55 TC 25 Z9 27 U1 2 U2 7 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD MAY PY 1996 VL 91 IS 3 BP 497 EP 506 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VL034 UT WOS:A1996VL03400001 ER PT J AU Crowley, JK AF Crowley, JK TI Mg- and K-bearing borates and associated evaporites at Eagle Borax spring, Death Valley, California: A spectroscopic exploration SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID MINERALS AB Efflorescent crusts at the Eagle Borax spring in Death Valley, California, contain an array of rare Mg and K borate minerals, several of which are only known from one or two other localities. The Mg- and/or K-bearing borates include aristarainite, hydroboracite, kaliborite, mcallisterite, pinnoite, rivadavite, and santite. Ulexite and probertite also occur in the area, although their distribution is different, from that of the Mg and K borates. Other evaporite minerals in the spring vicinity include halite, thenardite, eugsterite, gypsum-anhydrite hexahydrite, and bloedite. Whereas the first five of these minerals are found throughout Death Valley, the last two Mg sulfates are more restricted in occurrence and are indicative of Mg-enriched ground water. Mineral associations observed at the Eagle Borax spring, and at many other borate deposits worldwide. can be explained by the chemical fractionation of borate-precipitating waters during the course of evaporative concentration The Mg sulfate and Mg borate minerals in the Eagle Borax efflorescent crusts point to the fractionation of Ca by the operation of a chemical divide involving Ca carbonate and Na-Ca borate precipitation in the subsurface sediments. At many other borate mining localities, the occurrence of ulexite in both Na borate (borax-kernite) and Ca borate (ulexite-colemanite) deposits similarly reflects ulexite's coprecipitation with Ca carbonate at an early concentration stage. Such ulexite may perhaps be converted to colemanite by later reaction with the coexisting Ca carbonate -the latter providing the additional Ca2+ ions needed for the conversion, Mg and Ca-Mg berates are the expected late-stage concentration products of waters forming ulexite-colemanite deposits and are therefore mist likely to occur in the marginal zones or nearby mud facies of ulexite-colemanite orebodies. Under some circumstances, Mg and Ca-Mg borates might provide a useful prospecting guide for ulexite-colemanite deposits, although the high solubility of Mg borate minerals may prevent their formation in lacustrine settings and certainly inhibits their geologic preservation. The occurrence a of Mg borates in borax-kernite deposits is also related to fractionation processes and points to the operation of an Mg borate chemical divide, characterized by Mg borate precipitation ahead of Mg carbonate. All of these considerations imply that Mg is a significant chemical component of many borate-depositing ground waters, even though Mg borate minerals may not be strongly evident in borate orebodies. The Eagle Borax spring borates and other evaporite minerals were studied using spectroscopic and X-ray powder diffraction methods, which were found to be highly complementary. Spectral reflectance measurements provide a sensitive means for detecting borates present in mixtures with other evaporites and can be used to screen samples rapidly for X-ray diffraction analysis. The apparently limited occurrence of Mg and K borate minerals compared to Ca and Na borates may stem partly from the inefficiency of X-ray diffraction methods for delineating the mineralogy of large and complex deposits. Spectral reflectance measurements can be made in the laboratory, in the field, on the mine face, and even remotely. Reflectance data should have an important role in studies of existing deposit mineralogy and related chemical fractionation processes,and perhaps in the discovery of new borate mineral resources. RP Crowley, JK (reprint author), US GEOL SURVEY,MAIL STOP 954,RESTON,VA 22092, USA. NR 39 TC 11 Z9 13 U1 0 U2 7 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD MAY PY 1996 VL 91 IS 3 BP 622 EP 635 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VL034 UT WOS:A1996VL03400009 ER PT J AU Field, JA Thurman, EM AF Field, JA Thurman, EM TI Glutathione conjugation and contaminant transformation SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Review ID S-TRANSFERASE; ESCHERICHIA-COLI; REDUCTASE ACTIVITY; MARINE-SEDIMENTS; HIGHER-PLANTS; METABOLISM; SOIL; HERBICIDE; SULFUR; ALACHLOR AB The recent identification of a novel sulfonated metabolite of alachlor in groundwater and metolachlor in soil is likely the result of glutathione conjugation. Glutathione conjugation is an important biochemical reaction that leads, in the case of alachlor, to the formation of a rather difficult to detect, water-soluble, and therefore highly mobile, sulfonated metabolite. Research from weed science, toxicology, and biochemistry is discussed to support the hypothesis that glutathione conjugation is a potentially important detoxification pathway carried our by aquatic and terrestrial plants and soil microorganisms. A brief review of the biochemical basis for glutathione conjugation is presented. We recommend that multidisciplinary research focus on the occurrence and expression of glutathione and its attendant enzymes in plants and microorganisms, relationships between electrophilic substrate structure and enzyme activity, and the potential exploitation of plants and microorganisms that are competent in glutathione conjugation for phytoremediation and bioremediation. C1 US GEOL SURVEY,LAWRENCE,KS 66049. RP Field, JA (reprint author), OREGON STATE UNIV,DEPT AGR CHEM,CORVALLIS,OR 97331, USA. RI Thurman, Earl/B-5131-2011 NR 107 TC 64 Z9 67 U1 0 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY PY 1996 VL 30 IS 5 BP 1413 EP 1418 DI 10.1021/es950287d PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UG954 UT WOS:A1996UG95400028 ER PT J AU Kolpin, DW Nations, BK Goolsby, DA Thurman, EM AF Kolpin, DW Nations, BK Goolsby, DA Thurman, EM TI Acetochlor in the hydrologic system in the midwestern United States, 1994 SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; HERBICIDES; WATER; ALACHLOR; IMMUNOASSAY; PESTICIDES; METABOLITE AB The herbicide acetochlor [2-chloro-N-(ethoxymethyl)-N-(2-ethyl-6-methylphenyl)acetamide] was given conditional registration in the United States by the U.S. Environmental Protection Agency in March 1994. This registration provided a rare opportunity to investigate the occurrence of a pesticide during its first season of extensive use in the midwestern United States. Water samples collected and analyzed by the U.S. Geological Survey during 1994 documented the distribution of acetochlor in the hydrologic system; it was detected in 29% of the rain samples from four sites in Iowa, 17% of the stream samples from 51 sites across nine states, and 0% of the groundwater samples from 38 wells across eight states. Acetochlor exhibited concentration increases in rain and streams following its application to corn in the midwestern United States, with 75% of the rainwater and 35% of the stream samples having acetochlor detected during this time period. Acetochlor concentrations in rain decreased as the growing season progressed. Based on the limited data collected for this study, it is anticipated that acetochlor concentrations will have a seasonal pattern in rain and streams similar to those of other acetanilide herbicides examined. Possible explanations for the absence of acetochlor in groundwater for this study include the rapid degradation of acetochlor in the soil zone, insufficient time for this first extensive use of acetochlor to have reached the aquifers sampled, and the possible lack of acetochlor use in the recharge areas for the wells examined. C1 US GEOL SURVEY,DENVER FED CTR,LAKEWOOD,CO 80225. US GEOL SURVEY,LAWRENCE,KS 66049. RP Kolpin, DW (reprint author), US GEOL SURVEY,400 S CLINTON ST,BOX 1230,IOWA CITY,IA 52244, USA. RI Thurman, Earl/B-5131-2011 NR 34 TC 54 Z9 58 U1 0 U2 7 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY PY 1996 VL 30 IS 5 BP 1459 EP 1464 DI 10.1021/es9503241 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UG954 UT WOS:A1996UG95400034 ER PT J AU Squillace, PJ Zogorski, JS Wilber, WG Price, CV AF Squillace, PJ Zogorski, JS Wilber, WG Price, CV TI Preliminary assessment of the occurrence and possible sources of MTBE in groundwater in the United States, 1993-1994 SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ORGANIC-COMPOUNDS; AIR-QUALITY; EMISSIONS; GASOLINE; EXPOSURE AB The 1990 Clean Air Act Amendments require fuel oxygenates to be added to gasoline used in some metropolitan areas to reduce atmospheric concentrations of carbon monoxide or ozone. Methyl tert-butyl ether (MTBE) is the most commonly used fuel oxygenate acid is a relatively new gasoline additive. Nevertheless, out of 60 volatile organic chemicals analyzed, MTBE was the second most frequently detected chemical in samples of shallow ambient groundwater from urban areas that were collected during 1993-1994 as part of the U.S. Geological Survey's National Water-Quality Assessment program. Samples were collected from five drinking water wells, 12 springs, and 193 monitoring wells in urban areas. No MTBE was detected in drinking water wells. At a reporting level of 0.2 mu g/L, MTBE was detected most frequently in shallow groundwater from urban areas (27% of 210 wells and springs sampled in eight areas) as compared to shallow groundwater from agricultural areas (1.3% of 549 wells sampled in 21 areas) or deeper groundwater from major aquifers (1.0% of 412 wells sampled in nine areas). Only 3% of the shallow wells sampled in urban areas had concentrations of MTBE that exceed 20 mu g/L, which is the estimated lower limit of the United States Environmental Protection Agency draft drinking water health advisory. Because MTBE is persistent and mobile in groundwater, it can move from shallow to deeper aquifers with time. In shallow urban groundwater, MTBE generally was not found with benzene, toluene, ethylbenzene, or xylene (BTEX) compounds, which commonly are associated with gasoline spills. This disassociation causes uncertainty as to the source of MTBE. Possible sources of MTBE in groundwater include point sources, such as leaking storage tanks, and non-point sources, such as recharge of precipitation and stormwater runoff. RP Squillace, PJ (reprint author), US GEOL SURVEY,1608 MT VIEW RD,RAPID CITY,SD 57702, USA. NR 56 TC 301 Z9 318 U1 11 U2 34 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAY PY 1996 VL 30 IS 5 BP 1721 EP 1730 DI 10.1021/es9507170 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UG954 UT WOS:A1996UG95400068 ER PT J AU Rattner, BA Melancon, MJ Custer, TW Hothem, RL AF Rattner, BA Melancon, MJ Custer, TW Hothem, RL TI Cytochrome P450 and contaminant concentrations in nestling black-crowned night-herons and their interrelation with sibling embryos SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE biomonitoring; cytochromes P450; green Bay; polychlorinated biphenyls; San Francisco Bay ID FUNCTION OXIDASE SYSTEM; HERRING GULL EMBRYOS; GREAT-LAKES; 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN EQUIVALENTS; POLYCHLORINATED-BIPHENYLS; INDUCTION; RESIDUES; CHICKS; EGGS AB Hepatic cytochrome P450-associated monooxygenase activities were measured in 11-d-old nestling black-crowned night-herons (Nycticorax nycticorax) collected from a reference site (next to Chincoteague National Wildlife Refuge, VA, USA) and three contaminated sites (Cat Island, Green Bay, WI, USA; Bah Island, San Francisco Bay, CA, USA; and West Marin Island, San Francisco Bay, CA, USA). Arylhydrocarbon hydroxylase and benzyloxyresorufin-O-dealkylase activities of nestlings from contaminated sites were only slightly elevated (less than threefold) compared with the reference site. Organochlorine pesticide and total polychlorinated biphenyl (PCB) concentrations in nestlings were greatest at contaminated sites, although much lower than found in concurrently collected eggs and pipping embryos. Pollutant concentrations of nestlings were rarely associated with monooxygenase activity. In contrast, concurrently collected pipping heron embryos (often siblings of the nestlings) exhibited pronounced monooxygenase induction (means at contaminated sites were elevated up to sevenfold and values of some embryos exceeded 25-fold induction). Furthermore, monooxygenase activity of pipping embryos was significantly correlated with total PCBs, arylhydrocarbon receptor-active PCB congeners, and toxic equivalents. The modest monooxygenase responses of heron nestlings suggest that this biomarker may have only limited value during this rapid-growth life stage. C1 UPPER MISSISSIPPI SCI CTR, NATL BIOL SERV, LA CROSSE, WI 54602 USA. CALIF PACIFIC SCI CTR, NATL BIOL SERV, DAVIS FIELD STN, DAVIS, CA 95616 USA. RP Rattner, BA (reprint author), US FISH & WILDLIFE SERV, PATUXENT WILDLIFE RES CTR, NATL BIOL SERV, LAUREL, MD 20708 USA. OI Custer, Thomas/0000-0003-3170-6519 NR 27 TC 26 Z9 26 U1 0 U2 2 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0730-7268 EI 1552-8618 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD MAY PY 1996 VL 15 IS 5 BP 715 EP 721 DI 10.1897/1551-5028(1996)015<0715:CPACCI>2.3.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UH986 UT WOS:A1996UH98600016 ER PT J AU Starnes, LB Gasper, DC AF Starnes, LB Gasper, DC TI Effects of surface mining on aquatic resources in North America SO FISHERIES LA English DT Editorial Material RP Starnes, LB (reprint author), US FISH & WILDLIFE SERV,POB 1306,ALBUQUERQUE,NM 87103, USA. NR 4 TC 2 Z9 2 U1 0 U2 2 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD MAY PY 1996 VL 21 IS 5 BP 24 EP 26 PG 3 WC Fisheries SC Fisheries GA UH015 UT WOS:A1996UH01500006 ER PT J AU Poppe, LJ Commeau, JA AF Poppe, LJ Commeau, JA TI Silt heavy-mineral distributions off the Southeastern United States SO GEO-MARINE LETTERS LA English DT Article ID SURFICIAL SEDIMENTS; CONTINENTAL-MARGIN; FRACTION; SHELF AB Until recently heavy-mineral studies of marine sediments were largely restricted to sand fractions. New techniques permitting analysis of decalcified silt fractions have been applied to sediments off the southeastern United States. Our data, which confirm predictions from the basic relationship among grain size, specific gravity, and equivalent hydraulic transport behavior, show that concentrations and average diameters of the silt heavy minerals progressively decrease seaward. Heavy minerals always constitute a substantially greater weight percent of the silt than of the sand fraction. Despite corroded surface textures suggestive of extensive weathering and dissolution, spatial trends in the detrital heavy-mineral populations are predominantly controlled by source and hydraulic factors. RP Poppe, LJ (reprint author), US GEOL SURVEY,WOODS HOLE,MA 02543, USA. NR 17 TC 2 Z9 2 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0276-0460 J9 GEO-MAR LETT JI Geo-Mar. Lett. PD MAY PY 1996 VL 16 IS 2 BP 115 EP 122 DI 10.1007/BF02202606 PG 8 WC Geosciences, Multidisciplinary; Oceanography SC Geology; Oceanography GA UQ916 UT WOS:A1996UQ91600010 ER PT J AU Berndt, ME Seal, RR Shanks, WC Seyfried, WE AF Berndt, ME Seal, RR Shanks, WC Seyfried, WE TI Hydrogen isotope systematics of phase separation in submarine hydrothermal systems: Experimental calibration and theoretical models SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID DE-FUCA RIDGE; MID-ATLANTIC RIDGE; HOT-SPRING FLUIDS; SUPERCRITICAL REGION; MIDOCEAN RIDGES; OCEAN RIDGES; CHEMISTRY; CONSTRAINTS; TEMPERATURES; 300-DEGREES-C AB Hydrogen isotope fractionation factors were measured for coexisting brines and vapors formed by phase separation of NaCl/H2O fluids at temperatures ranging from 399-450 degrees C and pressures from 277-397 bars. It was found that brines are depleted in D compared to coexisting vapors at all conditions studied. The magnitude of hydrogen isotope fractionation is dependent on the relative amounts of Cl in the two phases and can be empirically correlated to pressure using the following relationship: 1000 In alpha((vap-brine)) = 2.54(+/-0.83) + 2.87(+/-0.69) X log (Delta P), where alpha((vap-brine)) is the fractionation factor and Delta P is a pressure term representing distance from the critical curve in the NaCl/H2O system. The effect of phase separation on hydrogen isotope distribution in subseafloor hydrothermal systems depends on a number of factors, including whether phase separation is induced by heating at depth or by decompression of hydrothermal fluids ascending to the seafloor. Phase separation in most subseafloor systems appears to be a simple process driven by heating of seawater to conditions within the two-phase region, followed by segregation and entrainment of brine or vapor into a seawater dominated system. Resulting vent fluids exhibit large ranges in Cl concentration with no measurable effect on delta D. Possible exceptions to this include hydrothermal fluids venting at Axial and 9 degrees N on the East Pacific Rise. High delta D values of low Cl fluids venting at Axial are consistent with phase separation taking place at relatively shallow levels in the oceanic crust while negative delta D values in some low Cl fluids venting at 9 degrees N suggest involvement of a magmatic fluid component or phase separation of D-depleted brines derived during previous hydrothermal activity. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Berndt, ME (reprint author), UNIV MINNESOTA,DEPT GEOL,MINNEAPOLIS,MN 55455, USA. NR 36 TC 38 Z9 39 U1 4 U2 14 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 1996 VL 60 IS 9 BP 1595 EP 1604 DI 10.1016/0016-7037(96)00033-6 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UK230 UT WOS:A1996UK23000011 ER PT J AU Bau, M Koschinsky, A Dulski, P Hein, JR AF Bau, M Koschinsky, A Dulski, P Hein, JR TI Comparison of the partitioning behaviours of yttrium, rare earth elements, and titanium between hydrogenetic marine ferromanganese crusts and seawater SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID CENTRAL PACIFIC; SURFACE-CHARGE; TRACE-METALS; MASS-SPECTROMETRY; NORTH PACIFIC; DEEP-OCEAN; ICP-MS; GEOCHEMISTRY; PARTICLES; DEPOSITS AB In order to evaluate details of the partitioning behaviours of Y, rare earth elements (REEs), and Ti between inorganic metal oxide surfaces and seawater, we studied the distribution of these elements in hydrogenetic marine ferromanganese (Fe-Mn) crusts from the Central Pacific Ocean. Nonphosphatized Fe-Mn crusts display shale-normalized rare earths and yttrium (REY(SN)) patterns (Y inserted between Dy and Ho) that are depleted in light REEs (LREEs) and which show negative anomalies for Y-SN, and positive anomalies for La-SN, Eu-SN, Gd-SN, and in most cases, Ce-SN. They show considerably smaller Y/Ho ratios than seawater or common igneous and elastic rocks, indicating that Y and Ho are fractionated in the marine environment. Compared to P-poor crusts, REY(SN) patterns of phosphatized Fe-Mn crusts are similar, but yield pronounced positive Y-SN anomalies, stronger positive La-SN anomalies, and enrichment of the HREEs relative to the MREEs. The data suggest modification of REY during phosphatization and indicate that studies requiring primary REY distributions or isotopic ratios should be restricted to nonphosphatized (layers of) Fe-Mn crusts. Apparent bulk coefficients, K-D(M), describing trace metal partitioning between nonphosphatized hydrogenetic Fe-Mn crusts and seawater, are similar for Pr to Eu and decrease for Eu to Yb. Exceptionally high values of K-D(Ce), which are similar to those of Ti, result from oxidative scavenging of Ce and support previous suggestions that Ce(IV) is a hydroxide-dominated element in seawater. Yttrium and Gd show lower K-D values than their respective neighbours in the REY series. Results of modelling the exchange equilibrium between REY dissolved in seawater and REY sorbed on hydrous Fe-Mn oxides corroborate previous studies that suggested the surface complexation of REY can be approximated by their first hydroxide binding constant. Negative ''anomalies'' occur for stabilities of bulk surface complexes of Gd, La, and particularly Y. The differences in inorganic surface complex stability between Y and Ho and between Gd and its REE neighbours are similar to those shown by the stabilities of complexes with aminocarboxylic acids and are significantly larger than those shown by stabilities of complexes with carboxylic acids. Hence, sorption of Y and REEs onto hydrous Fe-Mn oxides may contribute significantly to the positive Y-SN and Gd-SN anomalies in seawater. C1 US GEOL SURVEY, MS 999, MENLO PK, CA 94025 USA. FREE UNIV BERLIN, FR ROHSTOFF & UMWELTGEOL, D-12249 BERLIN, GERMANY. RP Bau, M (reprint author), GEOFORSCHUNGSZENTRUM POTSDAM, PB 4 3 LAGERSTATTENBILDUNG, D-14473 POTSDAM, GERMANY. RI Bau, Michael/D-4457-2016; Koschinsky, Andrea /R-2927-2016 OI Koschinsky, Andrea /0000-0002-9224-0663 NR 71 TC 207 Z9 237 U1 6 U2 60 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 1996 VL 60 IS 10 BP 1709 EP 1725 DI 10.1016/0016-7037(96)00063-4 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL656 UT WOS:A1996UL65600005 ER PT J AU Waychunas, GA Fuller, CC Rea, BA Davis, JA AF Waychunas, GA Fuller, CC Rea, BA Davis, JA TI Wide angle X-ray scattering (WAXS) study of ''two-line'' ferrihydrite structure: Effect of arsenate sorption and counterion variation and comparison with EXAFS results SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID ABSORPTION-SPECTROSCOPY; SURFACE-CHEMISTRY; MODEL; LIMITATIONS; HYDROLYSIS; NITRATE; GELS AB Wide angle X-ray scattering (WAXS) measurements have been made on a suite of ''two-line'' ferrihydrite (FHY2) samples containing varying amounts of coprecipitated arsenate. Samples Prepared at pH 8 with counter ions chloride, nitrate, and a mixture of both also were examined. The raw WAXS scattering functions show that ''two-line'' ferrihydrite actually has a large number of non-Bragg (i.e., diffuse scattering) maxima up to our observation limit of 16 Angstrom(-1). The type of counter ion used during synthesis produces no significant change in this function. In unarsenated samples, Radial Distribution Functions (RDFs) produced from the scattering functions show a well-defined Fe-O peak at 2.02 Angstrom in excellent agreement with the mean distance of 2.01 Angstrom from extended X-ray absorption fine structure (EXAFS) analysis. The area under the Fe-O peak is consistent with only octahedral oxygen coordination about iron, and an iron coordination about oxygen of 2.2, in agreement with the EXAFS results, the sample composition, and XANES measurements. The second peak observed in the RDFs is clearly divided into two populations of correlations, at 3.07 and 3.52 Angstrom, respectively. These distances are close to the EXAFS-derived Fe-Fe subshell distances of 3.02-3.05 and 3.43-3.46 Angstrom, respectively, though this is misleading as the RDF peaks also include contributions from O-Fe and O-O correlations. Simulated RDFs of the FeOOH polymorphs indicate how the observed RDF structure relates to the EXAFS pair-correlation function, and allow comparisons with an ordered ferrihydrite structure. The effect of increasing arsenate content is dramatic, as the RDF peaks are progressively smeared out, indicating a wider range of interatomic distances even at moderate surface coverages, and a loss of longer range correlations. At an As/Fe ratio of 0.68, the surface saturation level of arsenate, the RDF shows little order beyond what would be expected from small pieces of dioctahedral Fe oxyhydroxyl chains or small ''sheet'' units. Analysis of the first RDF peak yields components due to As-O and Fe-O correlations. As the As-O component at 1.67 Angstrom increases in size, the Fe-O component decreases, reflecting a decrease in Fe coordination about the average oxygen. This reduction is consistent with a decrease in mean crystallite size as suggested by EXAFS studies. Analysis of the second RDF peak components shows the progressive decrease in Fe-Fe correlations, and the enhancement of As-Fe correlations, as arsenate level increases. Comparison of the experimental RDF from coprecipitated arsenate-saturated FHY2 with simulated RDFs of model iron oxyhydroxyl structures further constrains possible sizes and geometry for the precipitates, and is consistent with sorbed complexes of the bidentate binuclear (apical oxygen sharing) type. C1 US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. RP Waychunas, GA (reprint author), STANFORD UNIV,CTR MAT RES,STANFORD,CA 94305, USA. OI Fuller, Christopher/0000-0002-2354-8074 NR 38 TC 139 Z9 142 U1 4 U2 43 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 1996 VL 60 IS 10 BP 1765 EP 1781 DI 10.1016/0016-7037(96)89830-9 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL656 UT WOS:A1996UL65600009 ER PT J AU Bullen, TD Krabbenhoft, DP Kendall, C AF Bullen, TD Krabbenhoft, DP Kendall, C TI Kinetic and mineralogic controls on the evolution of groundwater chemistry and Sr-87/Sr-86 in a sandy silicate aquifer, northern Wisconsin, USA SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID FORESTED WATERSHEDS; WEATHERING RATES; CHEMICAL EVOLUTION; ISOTOPES; STRONTIUM; BALANCE; DISSOLUTION; RATIOS; LAKE AB Substantial flowpath-related variability of Sr-87/Sr-86 is observed in groundwaters collected from the Trout Lake watershed of northern Wisconsin. In the extensive shallow aquifer composed of sandy glacial outwash, groundwater is recharged either by seepage from lakes or by precipitation that infiltrates the inter-lake uplands. Sr-87/Sr-86 Of groundwater derived mainly as seepage from a precipitation-dominated lake near the head of the watershed decreases with progressive water chemical evolution along its flowpath due primarily to enhanced dissolution of relatively unradiogenic plagioclase. In contrast, Sr-87/Sr-86 Of groundwater derived mainly from precipitation that infiltrates upland areas is substantially greater than that of precipitation collected from the watershed, due to suppression of plagioclase dissolution together with preferential leaching of Sr from radiogenic phases such as K-feldspar and biotite. The results of a column experiment that simulated the effects of changing residence time of water in the aquifer sand indicate that mobile waters obtain relatively unradiogenic Sr, whereas stagnant waters obtain relatively radiogenic Sr. Nearly the entire range of strontium-isotope composition observed in groundwaters from the watershed was measured in the experimental product waters. The constant mobility of water along groundwater recharge flowpaths emanating from the lakes promotes the dissolution of relatively unradiogenic plagioclase, perhaps due to effective dispersal of clay mineral nuclei resulting from dissolution reactions. In contrast, episodic stagnation in the unsaturated zone along the upland recharge flowpaths suppresses plagioclase dissolution, perhaps due to accumulation of clay mineral nuclei on its reactive surfaces. Differences in redox conditions along these contrasting flowpaths probably enhance the observed differences in strontium isotope behavior. This study demonstrates that factors other than the calculated state of mineral saturation must be considered when attempting to simulate chemical evolution along flowpaths, and that reaction models must be able to incorporate changing contributions from reacting minerals in the calculations. C1 US GEOL SURVEY,DIV WATER RESOURCES,MADISON,WI 53719. RP Bullen, TD (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025, USA. NR 38 TC 121 Z9 125 U1 5 U2 26 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 1996 VL 60 IS 10 BP 1807 EP 1821 DI 10.1016/0016-7037(96)00052-X PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL656 UT WOS:A1996UL65600012 ER PT J AU Kvenvolden, KA AF Kvenvolden, KA TI Acceptance speech for the 1995 Alfred E. Treibs award SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Editorial Material ID MURCHISON METEORITE; AMINO-ACIDS; HYDROCARBONS; OIL RP Kvenvolden, KA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 22 TC 0 Z9 0 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD MAY PY 1996 VL 60 IS 10 BP 1839 EP 1842 DI 10.1016/0016-7037(96)89832-2 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UL656 UT WOS:A1996UL65600015 ER PT J AU Tilling, RI Jones, BF AF Tilling, RI Jones, BF TI Waters associated with an active basaltic volcano, Kilauea, Hawaii: Variation in solute sources, 1973-1991 SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID HYDROTHERMAL SYSTEM; PHLEGREAN FIELDS; ROCK COATINGS; CRATER LAKE; CHEMISTRY; ICELAND; ISLAND; GEOCHEMISTRY; EQUILIBRIA; ERUPTIONS AB Chemical and isotopic analyses of samples collected from a 1262-m-deep research borehole at the summit of Kilauea Volcano provide unique time-series data for composition of waters in the uppermost part of its hydrothermal system. These waters have a distinctive geochemical signature: a very low proportion of chloride relative to other anions compared with other Hawaiian waters-thermal (greater than or equal to 30 degrees C) or nonthermal (<30 degrees C)-and with most thermal waters of the world, Isotope data demonstrate that the borehole waters are of essentially meteoric origin, with minimal magmatic input. The water chemistry exhibits marked temporal variations, including pronounced short-term (days to weeks) effects of rainfall dilution and longer term (months to years) decline of total solutes, The 1973-1974 samples are Na-sulfate-dominant, but samples collected after July 1975 are (Mg + Ca)-bicarbonate-dominant. This compositional shift, probably abrupt, was associated with an increase in the partial pressure of CO2 (P-CO2) related to volcanic degassing of CO2 accompanying a large eruption (December 31, 1974) and associated intense seismicity. Following the initial sharp increase, the P-CO2 then decreased, approaching preeruption values in April 1976. Beginning in mid-1975, solute concentrations of the borehole waters decreased substantially, from approximate to 45 meq/L to <25 meq/L in only eight months; by 1991, total solute concentrations were <17 meq/L. This decline in solutes cannot be attributed to rainfall dilution and is inferred to reflect the decreasing availability with time of the easily leachable salts of alkali metals and sulfate, which originated in sublimates and fumarolic encrustations in fractures and cavities of rocks along the hydrologic how paths. The overall chemistry of the summit-borehole waters is largely determined by hydrolysis reactions associated with normal weathering of host tholeiitic basalts on a geologic time scale, despite short-term perturbations in composition caused by rainfall dilution or volcanic activity. C1 US GEOL SURVEY,MS 432,RESTON,VA 22092. RP Tilling, RI (reprint author), US GEOL SURVEY,MS 910,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 85 TC 10 Z9 10 U1 0 U2 2 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD MAY PY 1996 VL 108 IS 5 BP 562 EP 577 DI 10.1130/0016-7606(1996)108<0562:WAWAAB>2.3.CO;2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA UK855 UT WOS:A1996UK85500004 ER PT J AU Johnson, CA AF Johnson, CA TI Proterozoic low-Ti iron-oxide deposits in New York and New Jersey: Relation to Fe-oxide (Cu-U-Au-rare earth element) deposits and tectonic implications: Comment SO GEOLOGY LA English DT Article ID PETROLOGY; ZINC RP Johnson, CA (reprint author), US GEOL SURVEY,BOX 25046,MS 963,DENVER,CO 80225, USA. NR 13 TC 2 Z9 2 U1 1 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD MAY PY 1996 VL 24 IS 5 BP 475 EP 476 DI 10.1130/0091-7613(1996)024<0475:PLTIOD>2.3.CO;2 PG 2 WC Geology SC Geology GA UK827 UT WOS:A1996UK82700026 ER PT J AU McLelland, JM Foose, MP AF McLelland, JM Foose, MP TI Proterozoic low-Ti iron-oxide deposits in New York and New Jersey: Relation to Fe-oxide (Cu-U-Au-rare earth element) deposits and tectonic implications: Reply SO GEOLOGY LA English DT Article ID ADIRONDACK MTS; METAMORPHISM C1 US GEOL SURVEY,RESTON,VA 22092. RP McLelland, JM (reprint author), COLGATE UNIV,DEPT GEOL,HAMILTON,NY 13347, USA. NR 10 TC 2 Z9 2 U1 1 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD MAY PY 1996 VL 24 IS 5 BP 476 EP 477 PG 2 WC Geology SC Geology GA UK827 UT WOS:A1996UK82700027 ER PT J AU Stark, MA Davis, SD AF Stark, MA Davis, SD TI Remotely triggered microearthquakes at The Geysers geothermal field, California SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID INDUCED SEISMICITY; EARTHQUAKE; MECHANISM; RUPTURE AB Microearthquake (MEQ) activity recorded on a local network at The Geysers geothermal field has been observed to increase dramatically within seconds to minutes after the arrival of surface waves from large regional earthquakes. This behavior was observed not only following the 1992 Landers earthquake, for which remotely triggered seismicity (at The Geysers and elsewhere) has been documented, but also for the following events: Gulf of Alaska (M(S) 7.6, March 6, 1988); Loma Prieta (M(S) 7.1, October 17, 1989): two events within the Gorda Plate (M(S) 6.4 on July 13, 1991 and M(S) 7.1 on August 17, 1991); Petrolia (M(S) 7.0, April 25, 1992); and Northridge (M(S) 6.6, January 17, 1994). The exact onset times of most swarms are difficult to pinpoint but all start within minutes of the passage of seismic waves and in at least one case (Gulf of Alaska) the onset appears to coincide with the expected arrival of the surface waves. These swarms generally last for a few hours at most, and decay with time in a manner similar to aftershock sequences. We propose that the dynamic stresses associated with seismic waves emanating from these earthquakes may trigger the onset of these swarms. The Landers event may have been particularly efficient at generating remotely triggered swarms throughout the western U.S. because of its size and shallow focal depth, which would promote large surface waves. Our data demonstrate, however, that the phenomenon is not unique to the Landers event. C1 US GEOL SURVEY,MEMPHIS,TN. MEMPHIS STATE UNIV,CTR EARTHQUAKE RES & INFORMAT,MEMPHIS,TN 38152. RP Stark, MA (reprint author), PHILIPPINE GEOTHERMAL INC,UNOCAL GEOTHERMAL DIV,MANILA,PHILIPPINES. NR 29 TC 28 Z9 29 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAY 1 PY 1996 VL 23 IS 9 BP 945 EP 948 DI 10.1029/96GL00011 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UK814 UT WOS:A1996UK81400011 ER PT J AU Watson, K Rowan, LC Bowers, TL AntonPacheco, C Gumiel, P Miller, SH AF Watson, K Rowan, LC Bowers, TL AntonPacheco, C Gumiel, P Miller, SH TI Lithologic analysis from multispectral thermal infrared data of the alkalic rock complex at Iron Hill, Colorado SO GEOPHYSICS LA English DT Article ID MEASURING EMISSIVITY; IMAGES; INFORMATION; SCANNER AB Airborne thermal-infrared multispectral scanner (TIMS) data of the Iron Hill carbonatite-alkalic igneous rock complex in south-central Colorado are analyzed using a new spectral emissivity ratio algorithm and confirmed by field examination using existing 1:24 000-scale geologic maps an petrographic studies. Color composite images show that the alkalic rocks could be clearly identified and that differences existed among alkalic rocks in several parts of the complex. An unsupervised classification algorithm defines four alkalic rock classes within the complex: biotitic pyroxenite, uncompahgrite, augitic pyroxenite, and fenite + nepheline syenite. Felsic rock classes defined in the surrounding country rock are an extensive class consisting of tuff, granite, and felsite, a less extensive class of granite and felsite, and quartzite. The general composition of the classes can be determined from comparisons of the TIMS spectra with laboratory spectra. Carbonatite rocks are not classified, and we attribute that to the fact that dolomite, the predominant carbonate mineral in the complex, has a spectral feature that falls between TIMS channels 5 and 6. Mineralogical variability in the fenitized granite contributed to the nonuniform pattern of the fenite-nepheline syenite class. The biotitic pyroxenite, which resulted from alteration of the pyroxenite, is spatially associated and appears to be related to narrow carbonatite dikes and sills. Results from a linear unmixing algorithm suggest that the detected spatial extent of the two mixed felsic rock classes was sensitive to the amount of vegetation cover. These results illustrate that spectral thermal infrared data can be processed to yield compositional information that can be a cost-effective tool to target mineral exploration, particularly in igneous terranes. C1 US GEOL SURVEY,RESTON,VA 22092. INST TECNOL GEOMINERO ESPANA,E-28003 MADRID,SPAIN. RP Watson, K (reprint author), US GEOL SURVEY,MS 964,DENVER,CO 80228, USA. NR 30 TC 6 Z9 6 U1 1 U2 5 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD MAY-JUN PY 1996 VL 61 IS 3 BP 706 EP 721 DI 10.1190/1.1443998 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UN408 UT WOS:A1996UN40800009 ER PT J AU Houseknecht, D AF Houseknecht, D TI Communicating science in a politically charged environment SO GEOTIMES LA English DT Article RP Houseknecht, D (reprint author), US GEOL SURVEY,ENERGY RESOURCES SURVEYS PROGRAM,959 NATL CTR,RESTON,VA 22092, USA. NR 2 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD MAY PY 1996 VL 41 IS 5 BP 16 EP 19 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UW476 UT WOS:A1996UW47600008 ER PT J AU Banks, WSL Paylor, RL Hughes, WB AF Banks, WSL Paylor, RL Hughes, WB TI Using thermal-infrared imagery to delineate ground-water discharge SO GROUND WATER LA English DT Article AB On March 8 and 9, 1992, a thermal-infrared-multispectral scanner (TIMS) was flown over two military ordnance disposal facilities at the Edgewood Area of Aberdeen Proving Ground, Maryland, The data, collected by the National Aeronautics and Space Administration, in cooperation with the U.S. Army and the U.S. Geological Survey, were used to locate ground-water discharge zones in surface water, The images from the flight show areas where ground-water discharge is concentrated, as well as areas of diffuse discharge, Concentrated discharge is predominant in isolated or nearly isolated ponds and creeks in the study area, Diffuse discharge is found near parts of the shoreline where the study area meets the surrounding estuaries of the Chesapeake Bay and the Gunpowder River, The average temperature for surface water, measured directly in the field, and the average temperature, calculated from atmospherically corrected TIMS images, was 10.6 degrees C (Celsius) at the first of two sites. Potentiometric surface maps of both field sites show discharge toward the nontidal marshes, the estuaries which surround the field sites, and creeks which drain into the estuaries, The average measured temperature of ground water at both sites was 10.7 degrees C. The calculated temperature from the TIMS imagery at both sites where ground-water discharge is concentrated within a surface-water body is 10.4 degrees C, In the estuaries which surround the field sites, field measurements of temperature were made resulting in an average temperature of 9.0 degrees C, The average calculated TIMS temperature from the estuaries was 9.3 degrees C. Along the shoreline at the first site and within 40 to 80 meters of the western and southern shores of the second site, water was 1 degrees to 2 degrees C warmer than water more than 80 meters away, This pattern of warmer water grading to cooler water in an offshore direction could result from diffuse ground-water discharge, Tonal differences in the TIMS imagery could indicate changes in surface-water temperatures, These tonal differences can be interpreted to delineate the location and extent of ground-water discharge to bodies of surface water. C1 US GEOL SURVEY,STEPHENSON CTR,COLUMBIA,SC 29210. RP Banks, WSL (reprint author), US GEOL SURVEY,8600 LASALLE RD,TOWSON,MD 21286, USA. NR 10 TC 32 Z9 33 U1 4 U2 12 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAY-JUN PY 1996 VL 34 IS 3 BP 434 EP 443 DI 10.1111/j.1745-6584.1996.tb02024.x PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA UJ269 UT WOS:A1996UJ26900008 ER PT J AU Ge, SM Lu, N AF Ge, SM Lu, N TI A semianalytical solution of one-dimensional advective-dispersive solute transport under an arbitrary concentration boundary condition SO GROUND WATER LA English DT Article AB By employing the principle of superposition, we offer a semianalytical solution for a one-dimensional advective-dispersive solute transport equation under an arbitrary concentration boundary condition. The technique is applicable to many other existing analytical solutions of solute transport problems. C1 US GEOL SURVEY,FOOTHIL ENGN CONSULTANTS,LAKEWOOD,CO 80225. RP Ge, SM (reprint author), UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309, USA. NR 4 TC 2 Z9 2 U1 0 U2 5 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAY-JUN PY 1996 VL 34 IS 3 BP 501 EP 503 DI 10.1111/j.1745-6584.1996.tb02031.x PG 3 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA UJ269 UT WOS:A1996UJ26900015 ER PT J AU Clow, DW Mast, MA Campbell, DH AF Clow, DW Mast, MA Campbell, DH TI Controls on surface water chemistry in the upper Merced River basin, Yosemite National Park, California SO HYDROLOGICAL PROCESSES LA English DT Article DE surface water chemistry; granitic bedrock; Yosemite ID CENTRAL ADIRONDACK MOUNTAINS; MAJOR ION CHEMISTRY; SIERRA-NEVADA; NEW-YORK; PANOLA-MOUNTAIN; WILDERNESS AREA; ACIDIFICATION; COLORADO; SOILS; LAKES AB Surface water draining granitic bedrock in Yosemite National Park exhibits considerable variability in chemical composition, despite the relative homogeneity of bedrock chemistry. Other geological factors, including the jointing and distribution of glacial till, appear to exert strong controls on water composition. Chemical data from three surface water surveys in the upper Merced River basin conducted in August 1981, June 1988 and August 1991 were analysed and compared with mapped geological, hydrological and topographic features to identify the solute sources and processes that control water chemistry within the basin during baseflow. Water at most of the sampling sites was dilute, with alkalinities ranging from 26 to 77 mu equiv. l(-1). Alkalinity was much higher in two subcatchments, however, ranging from 51 to 302 mu equiv. l(-1). Base cations and silica were also significantly higher in these two catchments than in the rest of the watershed. Concentrations of weathering products in surface water were correlated to the fraction of each subcatchment underlain by surficial material, which is mostly glacial till. Silicate mineral weathering is the dominant control on concentrations of alkalinity, silica and base cations, and ratios of these constituents in surface water reflect the composition of local bedrock. Chloride concentrations in surface water samples varied widely, ranging from < 1 to 96 mu equiv. l(-1). The annual volume-weighted mean chloride concentration in the Merced River at the Happy Isles gauge from 1968 to 1990 was 26 mu equiv. l(-1), which was five times higher than in atmospheric deposition (4-5 mu equiv, l(-1)), suggesting that a source of chloride exists within the watershed. Saline groundwater springs, whose locations are probably controlled by vertical jointing in the bedrock, are the most likely source of the chloride. Sulphate concentrations varied much less than most other solutes, ranging from 3 to 14 mu equiv. l(-1). Concentrations of sulphate in quarterly samples collected at the watershed outlet also showed relatively little variation, suggesting that sulphate may be regulated to some extent by a within-watershed process, such as sulphate adsorption. RP Clow, DW (reprint author), US GEOL SURVEY, DENVER FED CTR, MS 415, DENVER, CO 80225 USA. OI Clow, David/0000-0001-6183-4824 NR 65 TC 29 Z9 29 U1 1 U2 7 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD MAY PY 1996 VL 10 IS 5 BP 727 EP 746 DI 10.1002/(SICI)1099-1085(199605)10:5<727::AID-HYP316>3.3.CO;2-4 PG 20 WC Water Resources SC Water Resources GA UP510 UT WOS:A1996UP51000006 ER PT J AU Bowers, JE AF Bowers, JE TI Seedling emergence on Sonoran Desert dunes SO JOURNAL OF ARID ENVIRONMENTS LA English DT Article DE dunes; seed size; seedling emergence; Sonoran Desert ID ESTABLISHMENT; ECOLOGY; SAND AB Seedling emergence of psammophiles (plants restricted to active dunes) was examined with germination experiments and with field observations at the Algodones Dunes, California, U.S.A., and the Sierra del Rosario Dunes, Sonora, Mexico. In the field, perennial psammophiles germinated in response to smaller rainfall triggers (greater than or equal to 10mm) than other woody desert plants (greater than or equal to 16mm). In germination experiments, seedlings of three perennial psammophiles, Astragalus magdalenae var. peirsonii, Helianthus niveus subsp. tephrodes, and Palafoxia arida var. gigantea emerged in larger numbers from greater soil depths than those of three nonpsammophiles, Cercidium microphyllum, Fouquieria splendens, and Palafoxia arida var. arida. Seed size for these six species did not correlate in any consistent fashion with emergence depth, suggesting that food reserves are nor the only variable that ensures emergence of deeply buried psammophile seeds. (C) 1996 Academic Press Limited RP Bowers, JE (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 31 TC 28 Z9 36 U1 1 U2 16 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0140-1963 J9 J ARID ENVIRON JI J. Arid. Environ. PD MAY PY 1996 VL 33 IS 1 BP 63 EP 72 DI 10.1006/jare.1996.0046 PG 10 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA UW528 UT WOS:A1996UW52800006 ER PT J AU Cayan, DR AF Cayan, DR TI Interannual climate variability and snowpack in the western United States SO JOURNAL OF CLIMATE LA English DT Article ID NORTHERN HEMISPHERE WINTER; HEIGHT FIELD; CIRCULATION PATTERNS; PRECIPITATION; TEMPERATURE; STREAMFLOW; COVER; TELECONNECTIONS; FLUCTUATIONS; CALIFORNIA AB An important part of the water supply in the western United States is derived from runoff fed by mountain snowmelt. Snow accumulation responds to both precipitation and temperature variations, and forms an interesting climatic index, since it integrates these influences over the entire late fall-spring period. Here, effects of cool season climate variability upon snow water equivalent (SWE) over the western part of the conterminous United States are examined. The focus is on measurements on/around 1 April, when snow accumulation is typically greatest. The primary data, from a network of mountainous snow courses, provides a good description of interannual fluctuations in snow accumulations, since many snow courses have records of five decades or more. For any given year, the spring SWE anomaly at a particular snow course is likely to be 25%-60% of its long-term average. Five separate regions of anomalous SWE variability are distinguished, using a rotated principal components analysis. Although effects vary with region and with elevation, in general, the anomalous winter precipitation has the strongest influence on spring SWE fluctuations. Anomalous temperature has a weaker effect overall, but it has great influence in lower elevations such as in the coastal Northwest, and during spring in higher elevations. The regional snow anomaly patterns are associated with precipitation and temperature anomalies in winter and early spring. Patterns of the precipitation, temperature, and snow anomalies extend over broad regional areas, much larger than individual watersheds. These surface anomalies are organized by the atmospheric circulation, with primary anomaly centers over the North Pacific Ocean as well as over western North America. For most of the regions, anomalously low SWE is associated with a winter circulation resembling the PNA pattern. With a strong low in the central North Pacific and high pressure over the Pacific Northwest, this pattern diverts North Pacific storms northward, away from the region. Both warm and cool phases of El Nino-Southern Oscillation tend to produce regional pattens with out-of-phase SWE anomalies in the Northwest and the Southwest. C1 US GEOL SURVEY,LA JOLLA,CA. RP Cayan, DR (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,DIV CLIMATE RES,LA JOLLA,CA 92093, USA. NR 44 TC 246 Z9 248 U1 4 U2 35 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0894-8755 J9 J CLIMATE JI J. Clim. PD MAY PY 1996 VL 9 IS 5 BP 928 EP 948 DI 10.1175/1520-0442(1996)009<0928:ICVASI>2.0.CO;2 PG 21 WC Meteorology & Atmospheric Sciences SC Meteorology & Atmospheric Sciences GA UN856 UT WOS:A1996UN85600003 ER PT J AU Gallagher, SP AF Gallagher, SP TI Seasonal occurrence and habitat characteristics of some vernal pool branchiopoda in northern California, USA SO JOURNAL OF CRUSTACEAN BIOLOGY LA English DT Article ID ANOSTRACA; SHRIMP AB New information on the life history and habitats of branchiopods in California vernal pools is presented. Pools were sampled biweekly during the 1992-1993 season. Branchinecta lynchi had 3 distinct hatches in 1 season which were dependent on pools drying and refilling with cold temperature water. Linderiella occidentalis and Lepidurus packardi were not observed after pools first dried and then filled a second time in 1 season. Physical habitat factors, including pool depth, surface area, and volume, were examined in relation to species presence. Pool area and volume are not as important as depth for pools in which these species occurred. Habitat duration for B. lynchi was between 3 and 14 weeks. Most pools containing B. lynchi had a duration of 7 weeks and females with shelled cysts in their brood pouches were observed after 6 weeks early in the season and after 2 weeks later in the season when temperatures were higher. Linderiella occidentalis and Lepidurus packardi require deeper pools with durations greater than 7 weeks. RP Gallagher, SP (reprint author), US FISH & WILDLIFE SERV,3310 EL CAMINO AVE,SUITE 130,SACRAMENTO,CA 95821, USA. NR 17 TC 9 Z9 9 U1 1 U2 15 PU CRUSTACEAN SOC PI SAN ANTONIO PA 840 EAST MULBERRY, SAN ANTONIO, TX 78212 SN 0278-0372 J9 J CRUSTACEAN BIOL JI J. Crustac. Biol. PD MAY PY 1996 VL 16 IS 2 BP 323 EP 329 DI 10.2307/1548890 PG 7 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA UM913 UT WOS:A1996UM91300013 ER PT J AU Chen, CL Ling, CH AF Chen, CL Ling, CH TI Granular-flow rheology: Role of shear-rate number in transition regime SO JOURNAL OF ENGINEERING MECHANICS-ASCE LA English DT Article ID STRESSES; SUSPENSIONS AB This paper examines the rationale behind the semiempirical formulation of a generalized viscoplastic fluid (GVF) model in the light of the Reiner-Rivlin constitutive theory and the viscoplastic theory, thereby identifying the parameters that control the rheology of granular flow. The shear-rate number (N) proves to be among the most significant parameters identified from the GVF model. As N --> 0 and N --> infinity, the GVF model can reduce asymptotically to the theoretical stress versus shear-rate relations in the macroviscous and grain-inertia regimes, respectively, where the grain concentration (C) also plays a major role in the rheology of granular flow. Using available data obtained from the rotating-cylinder experiments of neutrally buoyant solid spheres dispersing in an interstitial fluid, the shear stress for granular flow in transition between the two regimes proves dependent on N and C in addition to some material constants, such as the coefficient of restitution. The insufficiency of data on rotating-cylinder experiments cannot presently allow the GVF model to predict how a granular flow may behave in the entire range of N; however, the analyzed data provide an insight on the interrelation among the relevant dimensionless parameters. RP Chen, CL (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,345 MIDDLEFIELD RD,MS-496,MENLO PK,CA 94025, USA. NR 42 TC 43 Z9 44 U1 0 U2 6 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9399 J9 J ENG MECH-ASCE JI J. Eng. Mech.-ASCE PD MAY PY 1996 VL 122 IS 5 BP 469 EP 480 DI 10.1061/(ASCE)0733-9399(1996)122:5(469) PG 12 WC Engineering, Mechanical SC Engineering GA UH331 UT WOS:A1996UH33100009 ER PT J AU Loague, K Bernknopf, RL Green, RE Giambelluca, TW AF Loague, K Bernknopf, RL Green, RE Giambelluca, TW TI Uncertainty of groundwater vulnerability assessments for agricultural regions in Hawaii: Review SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article ID PESTICIDE CONTAMINATION; SOIL; IMPACT; WATER; RAINFALL; MODELS; CLASSIFICATION; VARIABILITY; SIMULATIONS; INDEXES AB There are important challenges associated with assessing potential groundwater vulnerability hazards that may result from regional scale applications of agrochemicals. The increasing availability of Geographic Information System (GIS) software to those involved in assisting with landuse decisions has resulted in the widespread production of multicolored risk management maps for many environmentally sensitive issues. Soil-based GIS's have recently been coupled to various solute-leaching models to make near-surface groundwater vulnerability assessments for guidance in pesticide regulation in several states. In general, these assessments rest on soil, climatic, and chemical data that are extremely sparse and contain considerable uncertainty. It is also important to acknowledge the uncertainty associated with the transport/fate processes that are not accounted for by the modeling approach used to make the assessment. In this paper, we review the results from a series of papers that have focused on characterization of uncertainty in pesticide mobility estimates, using the attenuation and retardation indices (AF and RF), for the Pearl Harbor Basin on the Hawaiian island of Oahu. Relative to data error uncertainties, we discuss the impacts of: (i) soil, climatic, and chemical data base uncertainties, (ii) reductions in data base uncertainties, (iii) extrapolation of soil data base information based on soil taxonomy and soil survey, and (iv) importing information from outside the region of interest. Relative to model error uncertainties, we compare pesticide leaching estimates from the simple AF and RF mobility indices with simulations from the EPA's Pesticide Root Zone Model (PRZM) and field observations. Finally, we outline a Regional Integrated Risk Assessment approach for characterizing regional scale groundwater vulnerability for near-surface nonpoint sources. C1 US GEOL SURVEY,OFF CHIEF GEOLOGIST,MENLO PK,CA 94025. UNIV HAWAII,DEPT AGRON & SOIL SCI,HONOLULU,HI 96822. UNIV HAWAII,DEPT GEOG,HONOLULU,HI 96822. RP Loague, K (reprint author), STANFORD UNIV,DEPT GEOG & ENVIRONM SCI,STANFORD,CA 94305, USA. OI Giambelluca, Thomas/0000-0002-6798-3780 NR 86 TC 55 Z9 56 U1 0 U2 16 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAY-JUN PY 1996 VL 25 IS 3 BP 475 EP 490 PG 16 WC Environmental Sciences SC Environmental Sciences & Ecology GA UM247 UT WOS:A1996UM24700021 ER PT J AU Blevins, DW Wilkison, DH Kelly, BP Silva, SR AF Blevins, DW Wilkison, DH Kelly, BP Silva, SR TI Movement of nitrate fertilizer to glacial till and runoff from a claypan soil SO JOURNAL OF ENVIRONMENTAL QUALITY LA English DT Article AB Although water from 20 to 25% of shallow farmstead wells in northern Missouri has concentrations of nitrate (NO3-) exceeding 10 mg L(-1) as nitrogen (N), many potential sources for this NO3- are usually present. A field experiment was designed to trace and isolate the amount of a single application of N fertilizer lost to a glacial-till aquifer and runoff from a 400 m(2) corn (Zea mays L.) plot with bromide (Br-) and isotopically labeled (N-15) fertilizer. Soil at the plot is a Albaquic Hapludalf of the Adco Series containing a 61 cm claypan beneath 41 to 43 cm of topsoil. Groundwater levels ranged from 0.38 to 2.40 m below the land surface. Transport of water and NO3- to the saturated zone was not substantially retarded by the claypan. Labeled-N fertilizer accounted for as much as 8.6 mg L(-1) of the NO3- (as N) in groundwater, but only in the top 1 to 2 m of the saturated zone. After two growing seasons (16 mo), <2% of the labeled-N fertilizer was lost to runoff, about 30% was in the saturated zone, 27.3% was removed with the grain, and about 5% remained in the unsaturated zone. A large part of the remaining labeled N may have been lost in gaseous N forms. The presence of labeled NO3- only in the top 2 m of the aquifer, slow horizontal transport, and winter recharge indicate grass crops such as wheat (Triticum aestivum L.) or rye (Secale cereals L.) might be used to extract near-surface N during the winter recharge period. Also, fall fertilizations can be expected to readily leach. Because groundwater concentrations of labeled NO3- were still increasing after two growing seasons, rotation of crops requiring small N inputs could be expected to limit the cumulative effect of large annual fertilizer applications on groundwater. C1 US GEOL SURVEY,WESTERN REG BRANCH REG RES,MENLO PK,CA 94025. RP Blevins, DW (reprint author), US GEOL SURVEY,301 W LEXINGTON,ROOM 227,FED BLDG,INDEPENDENCE,MO 64050, USA. NR 25 TC 49 Z9 50 U1 0 U2 3 PU AMER SOC AGRONOMY PI MADISON PA 677 S SEGOE RD, MADISON, WI 53711 SN 0047-2425 J9 J ENVIRON QUAL JI J. Environ. Qual. PD MAY-JUN PY 1996 VL 25 IS 3 BP 584 EP 593 PG 10 WC Environmental Sciences SC Environmental Sciences & Ecology GA UM247 UT WOS:A1996UM24700034 ER PT J AU Cronin, MA Bodkin, J Ballachey, B Estes, J Patton, JC AF Cronin, MA Bodkin, J Ballachey, B Estes, J Patton, JC TI Mitochondrial-DNA variation among subspecies and populations of sea otters (Enhydra lutris) SO JOURNAL OF MAMMALOGY LA English DT Article DE Enhydra lutris; sea otter; mitochondrial DNA; subspecies; genetic variation ID NATURAL-POPULATIONS; ELECTROPHORETIC VARIATION; SPATIAL HETEROGENEITY; GENETIC-VARIATION; LARGE MAMMALS; SEQUENCE; GENOME; HETEROZYGOSITY; ORGANIZATION; SYSTEMATICS AB We used restriction-enzyme analysis of polymerase-chain reaction-amplified, mitochondrial DNA (mtDNA) to assess genetic differentiation of subspecies and populations of sea otters, Enhydra lutris, throughout the range of the species. There were several haplotypes of mtDNA in each subspecies and geographically separate populations. MtDNA sequence divergence of haplotypes of sea otters was 0.0004-0.0041 base substitutions per nucleotide. E. I. nereis appears to have monophyletic mitochondrial DNA, while E. I. lutris and E. I. kenyoni do not. Different frequencies of haplotypes of mtDNA among populations reflect current restriction of gene flow and the unique histories of different populations. There are two or three haplotypes of mtDNA and diversity of haplotypes is 0.1376-0.5854 in each population of otters. This is consistent with theoretical work, which suggests that population bottlenecks of sea otters probably did not result in major losses of genetic variation for individual populations, or the species as a whole. C1 US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. UNIV CALIF SANTA CRUZ,NATL BIOL SERV,SANTA CRUZ,CA 95064. LGL ECOL GENET INC,BRYAN,TX 77801. NR 56 TC 23 Z9 26 U1 4 U2 12 PU AMER SOC MAMMALOGISTS PI PROVO PA BRIGHAM YOUNG UNIV, DEPT OF ZOOLOGY, PROVO, UT 84602 SN 0022-2372 J9 J MAMMAL JI J. Mammal. PD MAY PY 1996 VL 77 IS 2 BP 546 EP 557 DI 10.2307/1382828 PG 12 WC Zoology SC Zoology GA UM562 UT WOS:A1996UM56200027 ER PT J AU Elder, WP Saul, LR AF Elder, WP Saul, LR TI Taxonomy and biostratigraphy of Coniacian through Maastrichtian Anchura (Gastropoda: Aporrhaiidae) of the North American Pacific Slope SO JOURNAL OF PALEONTOLOGY LA English DT Article ID SOUTHERN-CALIFORNIA; SACRAMENTO-VALLEY; BRITISH-COLUMBIA; WASHINGTON STATE; NANAIMO GROUP; STRATIGRAPHY AB North American Pacific Slope deposits of Coniacian to Maastrichtian age have yielded eight biostratigraphically useful species of Anchura: A. (Helicaulax?) popenoei new species, Coniacian; A. halberdopsis new species, early Campanian; A. callosa Whiteaves, 1903, early Campanian; A. falciformis (Gabb, 1864), late early to middle Campanian; A. phaba new species, middle to late Campanian; A. ainikta new species, middle to late Campanian; A. gibbera Webster, 1983, late Campanian to early Maastrichtian; A. baptos new species, late Maastrichtian to early Danian. In addition, two other possible species are A. nanaimoensis (Whiteaves, 1879), middle to late Campanian, and Anchura?new species, late Maastrichtian. These species together with two additional Turonian species, A. (Helicaulax) tricosa Saul and Popenoe, 1993, and A. (H.) condoniana Anderson, 1902, allow the definition at least eight Late Cretaceous Anchura zones for the Pacific Slope. These zones have durations of 1.5 m.y. to 4 m.y. Anchura (H.?) popenoei from northern California appears most closely related to A. (Helicaulax) tricosa Saul and Popenoe, 1993, of Turonian age from southern California. Anchura callosa, A. falciformis, A. nanaimoensis, and A. phaba appear to be closely related based on sculptural elements, as does A. gibbera despite having an anterior spur on the wing. However, these species appear to belong to two latitudinally differentiated faunal provinces. Species having a northern range include A. callosa, A. falciformis, and A. nanaimoensis, whereas A. phaba and A. gibbera are from more southern deposits, as are also A. halberdopsis, A. ainikta, and A. baptos. C1 MUSEUM NAT HIST,LOS ANGELES,CA 90007. RP Elder, WP (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 58 TC 19 Z9 19 U1 0 U2 1 PU PALEONTOLOGICAL SOC INC PI ITHACA PA 1259 TRUMANSBURG ROAD, ITHACA, NY 14850 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD MAY PY 1996 VL 70 IS 3 BP 381 EP 399 PG 19 WC Paleontology SC Paleontology GA UN134 UT WOS:A1996UN13400005 ER PT J AU Getahun, A Reed, MH Symonds, R AF Getahun, A Reed, MH Symonds, R TI Mount St Augustine volcano fumarole wall rock alteration: Mineralogy, zoning, composition and numerical models of its formation process SO JOURNAL OF VOLCANOLOGY AND GEOTHERMAL RESEARCH LA English DT Article ID MULTICOMPONENT CHEMICAL-EQUILIBRIA; ERUPTIVE DEPOSITS; GAS-ANALYSES; ALASKA; EMISSIONS; HELENS; ATMOSPHERE; ELEMENTS; SYSTEMS; PLUMES AB Intensely altered wall rock was collected from high-temperature (640 degrees C) and low-temperature (375 degrees C) vents at Augustine volcano in July 1989, The high-temperature altered rock exhibits distinct mineral zoning differentiated by color bands. In order of decreasing temperature, the color bands and their mineral assemblages are: (a) white to grey (tridymite-anhydrite); (b) pink to red (tridymite-hematite-Fe hydroxide-molysite (FeCl3) with minor amounts of anhydrite and halite); and (c) dark green to green (anhydrite-halite-sylvite-tridymite with minor amounts of molysite, soda and potash alum, and other sodium and potassium sulfates). The alteration products around the low-temperature vents are dominantly cristobalite and amorphous silica with minor potash and soda alum, aphthitalite, alunogen and anhydrite. Compared to fresh 1986 Augustine lava, the altered rocks exhibit enrichments in silica, base metals, halogens and sulfur and show very strong depletions in Al in all alteration zones and in iron, alkali and alkaline earth elements in some of the alteration zones. To help understand the origins of the mineral assemblages in altered Augustine rocks, we applied the thermochemical modeling program, GASWORKS, in calculations of: (a) reaction of the 1987 and 1989 gases with wall rock at 640 and 375 degrees C; (b) cooling of the 1987 gas from 870 to 100 degrees C with and without mineral fractionation; (c) cooling of the 1989 gas from 757 to 100 degrees C with and without mineral fractionation; and (d) mixing of the 1987 and 1989 gases with air. The 640 degrees C gas-rock reaction produces an assemblage consisting of silicates (tridymite, albite, diopside, sanidine and andalusite), oxides (magnetite and hercynite) and sulfides (bornite, chalcocite, molybdenite and sphalerite). The 375 degrees C gas-rock reaction produces dominantly silicates (quartz, albite, andalusite, microcline, cordierite, anorthite and tremolite) and subordinate amounts of sulfides (pyrite, chalcocite and wurtzite), oxides (magnetite), sulfates (anhydrite) and halides (halite). The cooling calculations produce: (a) anhydrite, halite, sylvite; (b) Cu, Mo, Fe and Zn sulfides; (c) Mg fluoride at high temperature (> 370 degrees C); (d) chlorides, fluorides and sulfates of Mn, Fe, Zn, Cu and Al at intermediate temperature (170-370 degrees C); and (e) hydrated sulfates, liquid sulfur, crystalline sulfur, hydrated sulfuric acid and water at low temperature (< 170 degrees C). The volcanic gas-air mixing calculation produces major amounts of Na and K sulfates, minor amounts of hematite and trace amounts (< 1%) of anhydrite at log gas/air (lg/a) ratios > 0.41 (> 628 degrees C). This is followed by precipitation of sulfates of Fe, Cu, Pb, Zn and Al at lg/a ratios between 0.41 and -0.4 (628-178 degrees C). At a lg/r ratio of less than or equal to -0.4 (178 degrees C), anhydrous sulfates are replaced by their hydrated forms and hygroscopic sulfuric acid forms. At these low g/a ratios, hydrated sulfuric acid becomes the dominant phase in the system. Comparison of the thermochemical modeling results with the natural samples suggests that the alteration assemblages include: (1) minerals that precipitate from direct cooling of the volcanic gas; (2) phases that form by volcanic gases mixing with air; and (3) phases that form by volcanic gas-air-rock reaction. A complex interplay of the three processes produces the observed mineral zoning. Another implication of the numerical simulation results is that most of the observed incrustation and sublimate minerals apparently formed below 700 degrees C. C1 UNIV OREGON,DEPT GEOL SCI,EUGENE,OR 97403. US GEOL SURVEY,CASCADES VOLCANO OBSERV,VANCOUVER,WA 98661. NR 46 TC 37 Z9 39 U1 1 U2 11 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-0273 J9 J VOLCANOL GEOTH RES JI J. Volcanol. Geotherm. Res. PD MAY PY 1996 VL 71 IS 2-4 BP 73 EP 107 DI 10.1016/0377-0273(95)00071-2 PG 35 WC Geosciences, Multidisciplinary SC Geology GA UT297 UT WOS:A1996UT29700001 ER PT J AU Decho, AW Luoma, SN AF Decho, AW Luoma, SN TI Flexible digestion strategies and trace metal assimilation in marine bivalves SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID MUSSEL MYTILUS-EDULIS; POTAMOCORBULA-AMURENSIS; MACOMA-BALTHICA; ABSORPTION; COPEPODS; SESTON; FOOD AB Pulse-chase experiments show that two marine bivalves take optimal advantage of different types of particulate food by varying food retention time in a flexible two-phase digestive system. For example, carbon is efficiently assimilated from bacteria by subjecting nearly all the ingested bacteria to prolonged digestion. Prolonging digestion also enhances assimilation of metals, many of which are toxic in minute quantities if they are biologically available. Detritus-feeding aquatic organisms have always lived in environments naturally rich in particle-reactive metals. We suggest that avoiding excess assimilation of metals could be a factor in the evolution of digestion strategies. We tested that suggestion by studying digestion of particles containing different Cr concentrations. We show that bivalves are capable of modifying the digestive processing of food to reduce exposure to high, biologically available, Cr concentrations. The evolution of a mechanism in some species to avoid high concentrations of metals in food could influence how effects of modern metal pollution are manifested in marine ecosystems. C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 17 TC 77 Z9 79 U1 2 U2 5 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD MAY PY 1996 VL 41 IS 3 BP 568 EP 572 PG 5 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UW657 UT WOS:A1996UW65700021 ER PT J AU Marlow, MS Hart, PE Carlson, PR Childs, JR Mann, DM Anima, RJ Kayen, RE AF Marlow, MS Hart, PE Carlson, PR Childs, JR Mann, DM Anima, RJ Kayen, RE TI Misinterpretation of lateral acoustic variations on high-resolution seismic reflection profiles as fault offsets of Holocene bay mud beneath the southern part of San Francisco Bay, California SO MARINE AND PETROLEUM GEOLOGY LA English DT Article DE high-resolution seismic reflection profiles; faults; San Francisco Bay; California ID VELOCITY AB We collected high-resolution seismic reflection profiles in the southern part of San Francisco Bay in 1992 and 1993 to investigate possible Holocene faulting along postulated transbay bedrock fault zones. The initial analog records show apparent offsets of reflection packages along sharp vertical boundaries. These records were originally interpreted as showing a complex series of faults along closely spaced, sharp vertical boundaries in the upper 10 m (0.013 s two-way travel time) of Holocene bay mud. A subsequent survey in 1994 was run with a different seismic reflection system, which utilized a higher power source. This second system generated records with deeper penetration (max. 20 m, 0.026 s two-way travel time) and demonstrated that the reflections originally interpreted as fault offsets by faulting 19 were actually laterally continuous reflection horizons. The pitfall in the original interpretations was caused by lateral variations in the amplitude brightness of reflection events, coupled with a long (greater than 15 ms) source signature of the low-power system. These effects combined to show apparent offsets of reflection packages along sharp vertical boundaries. These boundaries, as shown by the second system, in fact occur where the reflection amplitude diminishes abruptly on laterally continuous reflection events. This striking lateral variation in reflection amplitude is attributable to the localized presence of biogenic(?) gas. RP Marlow, MS (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 10 TC 5 Z9 5 U1 0 U2 2 PU BUTTERWORTH-HEINEMANN LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0264-8172 J9 MAR PETROL GEOL JI Mar. Pet. Geol. PD MAY PY 1996 VL 13 IS 3 BP 341 EP 348 DI 10.1016/0264-8172(95)00069-0 PG 8 WC Geosciences, Multidisciplinary SC Geology GA UB085 UT WOS:A1996UB08500004 ER PT J AU McGann, M Sloan, D AF McGann, M Sloan, D TI Recent introduction of the foraminifer Trochammina hadai Uchio into San Francisco Bay, California, USA SO MARINE MICROPALEONTOLOGY LA English DT Article ID CLAM POTAMOCORBULA-AMURENSIS; REMARKABLE INVASION; MARINE ORGANISMS; DISPERSAL C1 UNIV CALIF BERKELEY,MUSEUM PALEONTOL,BERKELEY,CA 94720. RP McGann, M (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 16 TC 12 Z9 12 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD MAY PY 1996 VL 28 IS 1 BP 1 EP 3 DI 10.1016/0377-8398(95)00077-1 PG 3 WC Paleontology SC Paleontology GA UP557 UT WOS:A1996UP55700001 ER PT J AU Hartzell, S Liu, PC AF Hartzell, S Liu, PC TI Calculation of earthquake rupture histories using a hybrid global search algorithm: Application to the 1992 Landers, California, earthquake SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article ID WAVE-FORM INVERSION; COMPLEX BODY WAVES; 1979 IMPERIAL-VALLEY; GENETIC ALGORITHMS; NONLINEAR INVERSION; GROUND-MOTION; FINITE FAULT; SLIP; SEQUENCE; LOCATION AB A method is presented for the simultaneous calculation of slip amplitudes and rupture times for a finite fault using a hybrid global search algorithm. The method we use combines simulated annealing with the downhill simplex method to produce a more efficient search algorithm then either of the two constituent parts. This formulation has advantages over traditional iterative or linearized approaches to the problem because it is able to escape local minima in its search through model space for the global optimum. We apply this global search method to the calculation of the rupture history for the Landers, California, earthquake. The rupture is modeled using three separate finite-fault planes to represent the three main fault segments that failed during this earthquake. Both the slip amplitude and the time of slip are calculated for a grid work of subfaults. The data used consist of digital, teleseismic P and SH body waves. Long-period, broadband, and short-period records are utilized to obtain a wideband characterization of the source, The results of the global search inversion are compared with a more traditional linear-least-squares inversion for only slip amplitudes. We use a multi-time-window linear analysis to relax the constraints on rupture time and rise time in the least-squares inversion. Both inversions produce similar slip distributions, although the linear-least-squares solution has a 10% larger moment (7.3 X 10(26) dyne-cm compared with 6.6 x 10(26) dyne-cm). Both inversions fit the data equally well and point out the importance of (1) using a parameterization with sufficient spatial and temporal flexibility to encompass likely complexities in the rupture process, (2) including suitable physically based constraints on the inversion to reduce instabilities in the solution, and (3) focusing on those robust rupture characteristics that rise above the details of the parameterization and data set. C1 CHINESE ACAD SCI,INST GEOPHYS,BEIJING 100101,PEOPLES R CHINA. RP Hartzell, S (reprint author), US GEOL SURVEY,BRANCH EARTHQUAKE & LANDSLIDE HAZARDS,BOX 25046,MS 966,LAKEWOOD,CO 80225, USA. NR 49 TC 21 Z9 26 U1 1 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD MAY PY 1996 VL 95 IS 1-2 BP 79 EP 99 DI 10.1016/0031-9201(95)03108-1 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ030 UT WOS:A1996UQ03000005 ER PT J AU Mueller, PA Wooden, JL Mogk, DW Nutman, AP Williams, IS AF Mueller, PA Wooden, JL Mogk, DW Nutman, AP Williams, IS TI Extended history of a 3.5 Ga trondhjemitic Gneiss, Wyoming province, USA: Evidence from U-Pb systematics in zircon SO PRECAMBRIAN RESEARCH LA English DT Article ID CRUST-MANTLE EVOLUTION; BEARTOOTH MOUNTAINS; SUPERIOR PROVINCE; MONTANA; GEOCHRONOLOGY; COMPLEX; RANGE; ROCKS AB The Beartooth-Bighorn magmatic zone (BBMZ) and the Montana metasedimentary province (MMP) are two major subprovinces of the Archean Wyoming province. In the northwestern Beartooth Mountains, these subprovinces are separated by a structurally, lithologically and metamorphically complex assemblage of lithotectonic units that include: (1) a strongly deformed complex of trondhjemitic gneiss and interlayered amphibolites; and (2) an amphibolite facies mafic unit that occurs in a nappe that structurally overlies the gneiss complex. Zircons from a trondhjemitic blastomylonite in the gneiss complex yield concordant U-Pb ages of 3.5 Ga, establishing it as the oldest rock yet documented in the Wyoming province. Two younger events are also recorded by zircons in this rock: (1) an apparently protracted period of high-grade metamorphism and/or intrusion of additional magmas at similar to 3.25 Ga; and (2) growth of hydrothermal zircon at similar to 2.55 Ga, apparently associated with ductile deformation that immediately preceded structural emplacement of the gneiss. Although this latter event appears confined to areas along the BBMZ-MMP boundary, evidence of similar to 3.25 Ga igneous activity is found in the overlying amphibolite (3.24 Ga) and throughout the MMP. These data suggest that this boundary first developed as a major intracratonic zone of displacement at or before 3.25 Ga. The limited occurrences of 2.8 Ga magmatic activity in the MMP suggest that it had a controlling influence on late Archean magmatism as well. C1 US GEOL SURVEY,MENLO PK,CA 94025. MONTANA STATE UNIV,DEPT EARTH SCI,BOZEMAN,MT 59717. AUSTRALIAN NATL UNIV,RES SCH EARTH SCI,CANBERRA,ACT 2601,AUSTRALIA. RP Mueller, PA (reprint author), UNIV FLORIDA,DEPT GEOL,GAINESVILLE,FL 32611, USA. RI Williams, Ian/F-4302-2012; OI Williams, Ian/0000-0003-4465-6493; Mueller, Paul/0000-0003-2608-193X NR 31 TC 34 Z9 34 U1 0 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0301-9268 J9 PRECAMBRIAN RES JI Precambrian Res. PD MAY PY 1996 VL 78 IS 1-3 BP 41 EP 52 DI 10.1016/0301-9268(95)00067-4 PG 12 WC Geosciences, Multidisciplinary SC Geology GA UP261 UT WOS:A1996UP26100003 ER PT J AU Szabo, BJ Bush, CA Benson, LV AF Szabo, BJ Bush, CA Benson, LV TI Uranium-series dating of carbonate (tufa) deposits associated with Quaternary fluctuations of Pyramid Lake, Nevada SO QUATERNARY RESEARCH LA English DT Article ID TOTAL-SAMPLE DISSOLUTION; BASIN; STROMATOLITES; PLEISTOCENE; CHRONOLOGY; CORALS; C-14; AGES; TH/U AB Uranium-series dating of dense tufa deposited in a small cave, at former lake margins, and in large tufa mounds clarifies the timing of lake-level variation during the past 400,000 yr in the Pyramid Lake basin. A moderate-sized lake occasionally overflowed the Emerson Pass sill at elevation of similar to 1207 m between ca. 400,000 and 170,000 and from ca, 60,000 to 20,000 yr B.P., as shown by Th-230/U-234 ages of the cave samples, Th-230-excess ages of tubular tufas, and average isochron-plot ages of shoreline-deposited tufas. (By comparison, modern Pyramid Lake is similar to 50 m below this sill). There is a lack of tufa record during the intervening period from ca, 170,000 to 60,000 yr B.P. After ca. 20,000 yr, Pyramid Lake underwent abrupt changes in level and, based on previous C-14 ages, reached its highest elevation (ca 1335 m) at ca. 14,000 yr B.P. The youngest uranium-series ages are comparable with previously reported C-14 ages. (C) 1996 University of Washington. C1 US GEOL SURVEY,BOULDER,CO 80303. RP Szabo, BJ (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 15 TC 17 Z9 20 U1 1 U2 5 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD MAY PY 1996 VL 45 IS 3 BP 271 EP 281 DI 10.1006/qres.1996.0028 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UR753 UT WOS:A1996UR75300004 ER PT J AU SarnaWojcicki, AM Meyer, CE Hillhouse, JW Hall, NT Curtis, GH AF SarnaWojcicki, AM Meyer, CE Hillhouse, JW Hall, NT Curtis, GH TI Age of the Thornton Beach, California, mammoth fossil updated SO QUATERNARY RESEARCH LA English DT Letter ID FISSION-TRACK AGE; POLARITY TRANSITION; NORTHERN CALIFORNIA; ROCKLAND TEPHRA; UNITED-STATES; SEDIMENTS C1 GEOMATRIX CONSULTANTS,SAN FRANCISCO,CA 94111. BERKELEY GEOCHRONOL CTR,BERKELEY,CA 94709. RP SarnaWojcicki, AM (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 37 TC 1 Z9 1 U1 1 U2 1 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD MAY PY 1996 VL 45 IS 3 BP 327 EP 331 DI 10.1006/qres.1996.0034 PG 5 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UR753 UT WOS:A1996UR75300010 ER PT J AU Cloern, JE AF Cloern, JE TI Phytoplankton bloom dynamics in coastal ecosystems: A review with some general lessons from sustained investigation of San Francisco Bay, California SO REVIEWS OF GEOPHYSICS LA English DT Review ID PARTICULATE ORGANIC-MATTER; PLANKTON COMMUNITY RESPIRATION; PARTIALLY STRATIFIED ESTUARY; NORTHERN ADRIATIC SEA; NEUSE RIVER ESTUARY; SPRING-BLOOM; MARINE-PHYTOPLANKTON; FATTY-ACIDS; RED TIDE; BIOCHEMICAL-COMPOSITION AB Phytoplankton blooms are prominent features of biological variability in shallow coastal ecosystems such as estuaries, lagoons, bays, and tidal rivers. Long-term observation and research in San Francisco Bay illustrates some patterns of phytoplankton spatial and temporal variability and the underlying mechanisms of this variability. Blooms are events of rapid production and accumulation of phytoplankton biomass that are usually responses to changing physical forcings originating in the coastal ocean (e.g., tides), the atmosphere (wind), or on the land surface (precipitation and river runoff). These physical forcings have different timescales of variability, so algal blooms can be short-term episodic events, recurrent seasonal phenomena, or rare events associated with exceptional climatic or hydrologic conditions. The biogeochemical role of phytoplankton primary production is to transform and incorporate reactive inorganic elements into organic forms, and these transformations are rapid and lead to measurable geochemical change during blooms. Examples include the depletion of inorganic nutrients (N, P, Si), supersaturation of oxygen and removal of carbon dioxide, shifts in the isotopic composition of reactive elements (C, N), production of climatically active trace gases (methyl bromide, dimethylsulfide), changes in the chemical form and toxicity of trace metals (As, Cd, Ni, Zn), changes in the biochemical composition and reactivity of the suspended particulate matter, and synthesis of organic matter required for the reproduction and growth of heterotrophs, including bacteria, zooplankton, and benthic consumer animals. Some classes of phytoplankton play special roles in the cycling of elements or synthesis of specific organic molecules, but we have only rudimentary understanding of the forces that select for and promote blooms of these species. Mounting evidence suggests that the natural cycles of bloom variability are being altered on a global scale by human activities including the input of toxic contaminants and nutrients, manipulation of river flows, and translocation of species. This hypothesis will be a key component of our effort to understand global change at the land-sea interface. Pursuit of this hypothesis will require creative approaches for distinguishing natural and anthropogenic sources of phytoplankton population variability, as well as recognition that the modes of human disturbance of coastal bloom cycles operate interactively and cannot be studied as isolated processes. RP Cloern, JE (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 496, MENLO PK, CA 94025 USA. RI Cloern, James/C-1499-2011; OI Cloern, James/0000-0002-5880-6862 NR 360 TC 416 Z9 423 U1 23 U2 176 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD MAY PY 1996 VL 34 IS 2 BP 127 EP 168 DI 10.1029/96RG00986 PG 42 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UR752 UT WOS:A1996UR75200001 ER PT J AU Kirby, SH Stein, S Okal, EA Rubie, DC AF Kirby, SH Stein, S Okal, EA Rubie, DC TI Metastable mantle phase transformations and deep earthquakes in subducting oceanic lithosphere SO REVIEWS OF GEOPHYSICS LA English DT Review ID OLIVINE-SPINEL TRANSFORMATION; FOCUS EARTHQUAKES; DESCENDING LITHOSPHERE; MOMENT TENSOR; ISLAND ARCS; NORTHWEST PACIFIC; SLAB PENETRATION; HIGH-PRESSURE; SYSTEM MG2SIO4-FE2SIO4; HISTORICAL EARTHQUAKES AB Earth's deepest earthquakes occur as a population in subducting or previously subducted lithosphere at depths ranging from about 325 to 690 km. This depth interval closely brackets the mantle transition zone, characterized by rapid seismic velocity increases resulting from the transformation of upper mantle minerals to higher-pressure phases. Deep earthquakes thus provide the primary direct evidence for subduction of the lithosphere to these depths and allow us to investigate the deep thermal, thermodynamic, and mechanical ferment inside slabs. Numerical simulations of reaction rates show that the olivine --> spinel transformation should be kinetically hindered in old, cold slabs descending into the transition zone. Thus wedge-shaped zones of metastable peridotite probably persist to depths of more than 600 km. Laboratory deformation experiments on some metastable minerals display a shear instability called transformational faulting. This instability involves sudden failure by localized superplasticity in thin shear zones where the metastable host mineral transforms to a denser, finer-grained phase. Hence in cold slabs, such faulting is expected for the polymorphic reactions in which olivine transforms to the spinel structure and clinoenstatite transforms to ilmenite. It is thus natural to hypothesize that deep earthquakes result from transformational faulting in metastable peridotite wedges within cold slabs. This consideration of the mineralogical states of slabs augments the traditional largely thermal view of slab processes and explains some previously enigmatic slab features. It explains why deep seismicity occurs only in the approximate depth range of the mantle transition zone, where minerals in downgoing slabs should transform to spinel and ilmenite structures. The onset of deep shocks at about 325 km is consistent with the onset of metastability near the equilibrium phase boundary in the slab. Even if a slab penetrates into the lower mantle, earthquakes should cease at depths near 700 km, because the seismogenic phase transformations in the slab are completed or can no longer occur. Substantial metastability is expected only in old, cold slabs, consistent with the observed restriction of deep earthquakes to those settings. Earthquakes should be restricted to the cold cores of slabs, as in any model in which the seismicity is temperature controlled, via the distribution of metastability. However, the geometries of recent large deep earthquakes pose a challenge for any such models. Transformational faulting may give insight into why deep shocks lack appreciable aftershocks and why their source characteristics, including focal mechanisms indicating localized shear failure rather than implosive deformation, are so similar to those of shallow earthquakes. Finally, metastable phase changes in slabs would produce an internal source of stress in addition to those due to the weight of the sinking slab. Such internal stresses may explain the occurrence of earthquakes in portions of lithosphere which have foundered to the bottom of the transition zone and/or are detached from subducting slabs. Metastability in downgoing slabs could have considerable geodynamic significance. Metastable wedges would reduce the negative buoyancy of slabs, decrease the driving force for subduction, and influence the state of stress in slabs. Heat released by metastable phase changes would raise temperatures within slabs and facilitate the transformation of spinel to the lower mantle mineral assemblage, causing slabs to equilibrate more rapidly with the ambient mantle and thus contribute to the cessation of deep seismicity. Because wedge formation should occur only for fast subducting slabs, it may act as a ''parachute'' and contribute to regulating plate speeds. Wedge formation would also have consequences for mantle evolution because the density of a slab stagnated near the bottom of the transition zone would increase as it heats up and the wedge transforms to denser spinel, favoring the subsequent sinking of the slab into the lower mantle. C1 NORTHWESTERN UNIV,DEPT GEOL SCI,EVANSTON,IL 60208. UNIV BAYREUTH,BAYER GEOINST,D-95440 BAYREUTH,GERMANY. RP Kirby, SH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MAIL STOP 977,MENLO PK,CA 94025, USA. NR 233 TC 299 Z9 316 U1 4 U2 41 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD MAY PY 1996 VL 34 IS 2 BP 261 EP 306 DI 10.1029/96RG01050 PG 46 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UR752 UT WOS:A1996UR75200004 ER PT J AU Lawrence, GB David, MB AF Lawrence, GB David, MB TI Chemical evaluation of soil-solution in acid forest soils SO SOIL SCIENCE LA English DT Article ID DISPLACEMENT; CENTRIFUGATION; DEPOSITION; CHEMISTRY; ALUMINUM; SPODOSOL AB Soil-solution chemistry is commonly studied in forests through the use of soil lysimeters. This approach is impractical for regional survey studies, however, because lysimeter installation and operation is expensive and time consuming. To address these problems, a new technique was developed to compare soil-solution chemistry among red spruce stands in New York, Vermont, New Hampshire, and Maine. Soil solutions were expelled by positive air pressure from soil that had been placed in a sealed cylinder. Before the air pressure was applied, a solution chemically similar to throughfall was added to the soil to bring it to approximate field capacity. After the solution sample was expelled, the soil was removed from the cylinder and chemically analyzed. The method was tested with homogenized Oa and Bs horizon soils collected from a red spruce stand in the Adirondack Mountains of New York, a red spruce stand in east-central Vermont, and a mixed hardwood stand in the Catskill Mountains of NewYork. Reproducibility, effects of varying the reaction time between adding throughfall and expelling soil solution (5-65 minutes) and effects of varying the chemical composition of added throughfall, were evaluated. In general, results showed that (i) the method was reproducible (coefficients of variation were generally < 15%), (ii) variations in the length of reaction-time did not affect expelled solution concentrations, and (iii) adding and expelling solution did not cause detectable changes in soil exchange chemistry. Concentrations of expelled solutions varied with the concentrations of added throughfall; the lower the CEC, the more sensitive expelled solution concentrations were to the chemical concentrations of added throughfall. Addition of a tracer (NaBr) showed that the expelled solution was a mixture of added solution and solution that preexisted in the soil. Comparisons of expelled solution concentrations with concentrations of soil solutions collected by zero-tension and tension lysimetry indicated that expelled solution concentrations were higher than those obtained with either type of lysimeter, although there was less difference with tension lysimeters than zero-tension lysimeters. The method used for collection of soil solution should be taken into consideration whenever soil solution data are being interpreted. C1 UNIV ILLINOIS,DEPT NAT RESOURCES & ENVIRONM SCI,URBANA,IL 61801. RP Lawrence, GB (reprint author), US GEOL SURVEY,425 JORDAN RD,TROY,NY 12180, USA. NR 26 TC 24 Z9 27 U1 1 U2 4 PU WILLIAMS & WILKINS PI BALTIMORE PA 351 WEST CAMDEN ST, BALTIMORE, MD 21201-2436 SN 0038-075X J9 SOIL SCI JI Soil Sci. PD MAY PY 1996 VL 161 IS 5 BP 298 EP 313 DI 10.1097/00010694-199605000-00005 PG 16 WC Soil Science SC Agriculture GA UM382 UT WOS:A1996UM38200005 ER PT J AU David, MB Lawrence, GB AF David, MB Lawrence, GB TI Soil and soil solution chemistry under red spruce stands across the northeastern United States SO SOIL SCIENCE LA English DT Article ID FOREST SOILS; ATMOSPHERIC DEPOSITION; STREAMWATER CHEMISTRY; WHITEFACE MOUNTAIN; ACIDIC DEPOSITION; ORGANIC-CARBON; ALUMINUM; SPODOSOL; MODEL; WATER AB Red spruce ecosystems in the northeastern United States are of interest because this species is undergoing regional decline,Their underlying soils have been examined closely at only a few sites, and information available on red spruce soils throughout this region is limited. This study was conducted to examine soil and soil solution chemistry at red spruce sites in the northeastern US that encompass the range of soil conditions in which red spruce grow. Soils and soil solutions from Oa and B horizons were obtained over a 2-year period from 12 undisturbed red spruce forests (elevations of 80-975 m) in Neu York, Vermont, New Hampshire, and Maine. All sites had extremely acid Spodosols (Oa soil pH range 2.56 to 3.11 in 0.01 M CaCl2), with generally low concentrations of base cations and high concentrations of Al on soil exchange sites. There was considerable range in exchange chemistry across the sites, however, with exchangeable Ca in Oa horizons ranging from 2.1 to 21.6 cmol(c) kg(-1) and exchangeable Al from 3.6 to 18.3 cmol(c) kg(-1). Solution chemistry had high concentrations of DOC in the Oa horizons (1160 - 15200 mu mol L(-1)), with higher concentrations in the fall than in the spring, which was probably a reflection of fresh litter inputs. Despite high concentrations of DOC in all solutions, inorganic At was found in some Oa solutions at concentrations as high as 26 mu mol L(-1). Ratios of Ca2+ to inorganic Al concentrations were less than 1.0 in the Oa horizon of one site, and were well below 1.0 in B horizons of all sites. That soil chemistry was related to soil solution chemistry was demonstrated by solution Al concentrations in the forest floor having significant relationships with pyrophosphate extractable Al, although it was not related in the B horizon, Soil exchangeable Ca/Al ratios in the Oa horizon explained 75% of the variation in solution Ca2+/inorganic Al ratios when mean values were used for each site. Our studies have expanded the range of soil chemical conditions measured for red spruce soils. By characterizing the regional variability, these results will enable site intensive process studies to be better applied to regional problems such as spruce decline. C1 US GEOL SURVEY, DIV WATER RESOURCES, TROY, NY 12180 USA. RP David, MB (reprint author), UNIV ILLINOIS, DEPT NAT RESOURCES & ENVIRONM SCI, W-503 TURNER HALL, 1102 S GOODWIN AVE, URBANA, IL 61801 USA. NR 41 TC 37 Z9 38 U1 1 U2 4 PU LIPPINCOTT WILLIAMS & WILKINS PI PHILADELPHIA PA 530 WALNUT ST, PHILADELPHIA, PA 19106-3621 USA SN 0038-075X J9 SOIL SCI JI Soil Sci. PD MAY PY 1996 VL 161 IS 5 BP 314 EP 328 DI 10.1097/00010694-199605000-00006 PG 15 WC Soil Science SC Agriculture GA UM382 UT WOS:A1996UM38200006 ER PT J AU Healy, RW Striegl, RG Russell, TF Hutchinson, GL Livingston, GP AF Healy, RW Striegl, RG Russell, TF Hutchinson, GL Livingston, GP TI Numerical evaluation of static-chamber measurements of soil-atmosphere gas exchange: Identification of physical processes SO SOIL SCIENCE SOCIETY OF AMERICA JOURNAL LA English DT Article ID NITROUS-OXIDE; FIELD MEASUREMENT; FLUX; TRANSPORT; N2O AB The exchange of gases between soil and atmosphere is an important process that affects atmospheric chemistry and therefore climate. The static-chamber method is the most commonly used technique for estimating the rate of that exchange. We examined the method under hypothetical field conditions where diffusion was the only mechanism for gas transport and the atmosphere outside the chamber was maintained at a fixed concentration. Analytical and numerical solutions to the soil gas diffusion equation in one and three dimensions demonstrated that gas flux density to a static chamber deployed on the soil surface was less in magnitude than the ambient exchange rate in the absence of the chamber. This discrepancy, which increased with chamber deployment time and air-filled porosity of soil, is attributed to two physical factors: distortion of the soil gas concentration gradient (the magnitude was decreased in the vertical component and increased in the radial component) and the slow transport rate of diffusion relative to mixing within the chamber. Instantaneous flux density to a chamber decreased continuously with time; steepest decreases occurred so quickly following deployment and in response to such slight changes in mean chamber headspace concentration that they would likely go undetected by most field procedures. Adverse influences of these factors were reduced by mixing the chamber headspace, minimizing deployment time, maximizing the height and radius of the chamber, and pushing the rim of the chamber into the soil. Nonlinear models were superior to a linear regression model for estimating flux densities from mean headspace concentrations, suggesting that linearity of headspace concentration with time was not necessarily a good indicator of measurement accuracy. C1 UNIV COLORADO, DEPT MATH, DENVER, CO 80217 USA. USDA ARS, NPA, NAT RESOURCES RES CTR, SOIL PLANT NUTR RES UNIT, FT COLLINS, CO 80522 USA. NASA, AMES RES CTR, DIV EARTH SCI, JOHNSON CONTROLS WORLD SERV, MOFFETT FIELD, CA 94035 USA. RP Healy, RW (reprint author), US GEOL SURVEY, DENVER FED CTR, DIV WATER RESOURCES, MS 413, BOX 25046, LAKEWOOD, CO 80215 USA. NR 29 TC 166 Z9 173 U1 9 U2 66 PU SOIL SCI SOC AMER PI MADISON PA 677 SOUTH SEGOE ROAD, MADISON, WI 53711 USA SN 0361-5995 EI 1435-0661 J9 SOIL SCI SOC AM J JI Soil Sci. Soc. Am. J. PD MAY-JUN PY 1996 VL 60 IS 3 BP 740 EP 747 PG 8 WC Soil Science SC Agriculture GA UK989 UT WOS:A1996UK98900007 ER PT J AU Knights, BC Lasee, BA AF Knights, BC Lasee, BA TI Effects of implanted transmitters on adult bluegills at two temperatures SO TRANSACTIONS OF THE AMERICAN FISHERIES SOCIETY LA English DT Article ID DUMMY TRANSMITTERS; CHANNEL CATFISH; EXPULSION; TISSUE AB Laterally compressed panfishes are small and have limited intraperitoneal space; thus, they may suffer adversely from surgically implanted transmitters even if the transmitter meets the generally recommended ratio of transmitter weight to fish weight of 2%. We studied the effects of intraperitoneal transmitters (2.81 g) on survival, growth, healing, and health of bluegills Lepomis macrochirus (mean weight 133 g) held for g weeks at 6 degrees C and 20 degrees C. Radio-tagged bluegills at 20 degrees C had a mortality rate of 10% and tag loss rate of 15%. At 6 degrees C, bluegills had no mortality or tag loss. Radio-tagged and reference fish fed in both 20 degrees C raceways; however, a few reference fish appeared dominant at feeding time. This dominance by a few reference fish was also indicated by a large weight gain for three reference fish in each 20 degrees C raceway. At 6 degrees C, neither reference fish nor radio-tagged fish fed activity. Radio-tagged fish held at 20 degrees C exhibited pelvic fin erosion, erythema and necrosis at the antenna exit and at suture insertions, and lost or loose sutures, effects not observed in other test fishes. Examination of fish held at 20 degrees C also showed enclosure of the transmitters in a fibrous capsule and adhesion of visceral organs. Epithelialization over the incision occurred in radio-tagged bluegills at both temperatures, but there was little further healing at 6 degrees C. At 20 degrees C, tissue responses included chronic inflammation and dermal granulation. Radio-tagged fish did not appear to be more susceptible than reference fish to bacterial infection. Mortality, adverse morphological effects, altered behavior, and limited healing in bluegills suggest that implanted transmitters impaired their health. Thus, movement and habitat use data collected by telemetry for this species and perhaps for other panfishes should be interpreted with caution. C1 US FISH & WILDLIFE SERV,LA CROSSE FISH HLTH CTR,ONLASKA,WI 54650. RP Knights, BC (reprint author), NATL BIOL SERV,UPPER MISSISSIPPI SCI CTR,POB 818,LA CROSSE,WI 54602, USA. NR 15 TC 83 Z9 89 U1 0 U2 10 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0002-8487 J9 T AM FISH SOC JI Trans. Am. Fish. Soc. PD MAY PY 1996 VL 125 IS 3 BP 440 EP 449 DI 10.1577/1548-8659(1996)125<0440:EOITOA>2.3.CO;2 PG 10 WC Fisheries SC Fisheries GA UK980 UT WOS:A1996UK98000009 ER PT J AU Wiele, SM Smith, JD AF Wiele, SM Smith, JD TI A reach-averaged model of diurnal discharge wave propagation down the Colorado River through the Grand Canyon SO WATER RESOURCES RESEARCH LA English DT Article AB As part of the Glen Canyon Environmental Studies, we have developed a discharge model that routes daily discharge waves released from Glen Canyon Dam to Diamond Creek, 386 km downstream. Owing to the length of the diurnal discharge wave and the sparseness of the available topographic data, the latter were averaged over the entire length of the system. Terms too small to be significant in the momentum equation were identified by scaling arguments based on data from past dam releases and on channel hydraulic geometry. Channel friction results primarily from form drag on large topographic elements and from variations in cross-sectional area and flow depth, rather than bed roughness, producing a stage-dependent friction that is not well represented by a constant value of standard channel roughness parameters, such as Manning's n. Channel friction as a function of stage was determined from field data available at high discharge (792 m(3)/s) and intermediate discharge (425 m(3)/s) and by using simple kinematic wave theory together with wave speed measurements to determine channel friction at low discharge (about 142 m(3)/s). Model predictions of wave speed and shape agree well with data from five streamflow gaging stations and 42 stage gaging stations located along this segment of the Colorado River. RP Wiele, SM (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. NR 31 TC 23 Z9 23 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAY PY 1996 VL 32 IS 5 BP 1375 EP 1386 DI 10.1029/96WR00199 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UH882 UT WOS:A1996UH88200021 ER PT J AU Lu, N Ge, SM AF Lu, N Ge, SM TI Effect of horizontal heat and fluid flow on the vertical temperature distribution in a semiconfining layer SO WATER RESOURCES RESEARCH LA English DT Article AB By including the constant flow of heat and fluid in the horizontal direction, we develop an analytical solution for the vertical temperature distribution within the semiconfining layer of a typical aquifer system. The solution is an extension of the previous one-dimensional theory by Bredehoeft and Papadopulos [1965]. It provides a quantitative tool for analyzing the uncertainty of the horizontal heat and fluid flow. The analytical results demonstrate that horizontal flow of heat and fluid, if at values much smaller than those of the vertical, has a negligible effect on the vertical temperature distribution but becomes significant when it is comparable to the vertical. C1 US GEOL SURVEY,FOOTHILL ENGN CONSULTANTS,LAKEWOOD,CO 80225. UNIV COLORADO,DEPT GEOL SCI,BOULDER,CO 80309. NR 7 TC 65 Z9 68 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAY PY 1996 VL 32 IS 5 BP 1449 EP 1453 DI 10.1029/95WR03095 PG 5 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UH882 UT WOS:A1996UH88200029 ER PT J AU Jones, LM AF Jones, LM TI Earthquake prediction: The interaction of public policy and science SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT Colloquium on Earthquake Prediction - The Scientific Challenge CY FEB 10-11, 1995 CL NATL ACAD SCI, IRVINE, CA SP Natl Sci Fdn, So Calif Earthquake Ctr HO NATL ACAD SCI ID SAN-ANDREAS FAULT; CALIFORNIA; PROBABILITIES; RUPTURE; HAZARD; MODELS; SLIP AB Earthquake prediction research has searched for both informational phenomena, those that provide information about earthquake hazards useful to the public, and causal phenomena, causally related to the physical processes governing failure on a fault, to improve our understanding of those processes. Neither informational nor causal phenomena are a subset of the other. I propose a classification of potential earthquake predictors of informational, causal, and predictive phenomena, where predictors are causal phenomena that provide more accurate assessments of the earthquake hazard than can be gotten from assuming a random distribution. Achieving higher, more accurate probabilities than a random distribution requires much more information about the precursor than just that it is causally related to the earthquake. RP Jones, LM (reprint author), US GEOL SURVEY,PASADENA,CA 91106, USA. NR 33 TC 4 Z9 4 U1 0 U2 2 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 30 PY 1996 VL 93 IS 9 BP 3721 EP 3725 DI 10.1073/pnas.93.9.3721 PG 5 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UK557 UT WOS:A1996UK55700002 PM 11607656 ER PT J AU Dieterich, JH Kilgore, B AF Dieterich, JH Kilgore, B TI Implications of fault constitutive properties for earthquake prediction SO PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA LA English DT Article; Proceedings Paper CT Colloquium on Earthquake Prediction - The Scientific Challenge CY FEB 10-11, 1995 CL NATL ACAD SCI, IRVINE, CA SP Natl Sci Fdn, So Calif Earthquake Ctr HO NATL ACAD SCI ID SOUTHERN-CALIFORNIA; ROCK FRICTION; NUCLEATION; STABILITY; VELOCITY; GRANITE; INSTABILITY; EQUATIONS; BEHAVIOR; DEPTH AB The rate- and state-dependent constitutive formulation for fault slip characterizes an exceptional variety of materials over a wide range of sliding conditions. This formulation provides a unified representation of diverse sliding phenomena including slip weakening over a characteristic sliding distance D-c, apparent fracture energy at a rupture front, time-dependent healing after rapid slip, and various other transient and slip rate effects. Laboratory observations and theoretical models both indicate that earthquake nucleation is accompanied by long intervals of accelerating slip. Strains from the nucleation process on buried faults generally could not be detected if laboratory values of D-c apply to faults in nature. However, scaling of D-c is presently an open question and the possibility exists that measurable premonitory creep may precede some earthquakes. Earthquake activity is modeled as a sequence of earthquake nucleation events. In this model, earthquake clustering arises from sensitivity of nucleation times to the stress changes induced by prior earthquakes. The model gives the characteristic Omori aftershock decay law and assigns physical interpretation to aftershock parameters. The seismicity formulation predicts large changes of earthquake probabilities result from stress changes. Two mechanisms for foreshocks are proposed that describe observed frequency of occurrence of foreshock-mainshock pairs by time and magnitude. With the first mechanism, foreshocks represent a manifestation of earthquake clustering in which the stress change at the time of the foreshock increases the probability of earthquakes at all magnitudes including the eventual mainshock. With the second model, accelerating fault slip on the mainshock nucleation zone triggers foreshocks. RP Dieterich, JH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Kilgore, Brian/K-3433-2012 OI Kilgore, Brian/0000-0003-0530-7979 NR 29 TC 119 Z9 126 U1 4 U2 15 PU NATL ACAD SCIENCES PI WASHINGTON PA 2101 CONSTITUTION AVE NW, WASHINGTON, DC 20418 SN 0027-8424 J9 P NATL ACAD SCI USA JI Proc. Natl. Acad. Sci. U. S. A. PD APR 30 PY 1996 VL 93 IS 9 BP 3787 EP 3794 DI 10.1073/pnas.93.9.3787 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UK557 UT WOS:A1996UK55700012 PM 11607666 ER PT J AU Bell, JF Calvin, WM OckertBell, ME Crisp, D Pollack, JB Spencer, J AF Bell, JF Calvin, WM OckertBell, ME Crisp, D Pollack, JB Spencer, J TI Detection and monitoring of H2O and CO2 ice clouds on Mars SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID INFRARED SPECTROSCOPY; REFLECTANCE SPECTRA; GENERAL-CIRCULATION; MARTIAN ATMOSPHERE; CARBONATES; MARINER-9; CLIMATE; REGIONS AB We have developed an observational scheme for the detection and discrimination of Mars atmospheric H-2 and CO2 clouds using ground-based instruments in the near infrared. We report the results of our cloud detection and characterization study using Mars near IR images obtained during the 1990 and 1993 oppositions, We focused on specific wavelengths that have the potential, based on previous laboratory studies of H2O and CO2 ices, of yielding the greatest degree of cloud detectability and compositional discriminability. We have detected and mapped absorption features at some of these wavelengths in both the northern and southern polar regions of Mars, Compositional information on the nature of these absorption features was derived from comparisons with laboratory ice spectra and with a simplified radiative transfer model of a CO2 ice cloud overlying a bright surface. Our results indicate that both H2O and CO2 ices can be detected and distinguished in the polar hood clouds. The region near 3.00 mu m is mast useful for the detection of water ice clouds because there is a strong H2O ice absorption at this wavelength but only a weak CO2 ice band, The region near 3.33 mu m is most useful for the detection of CO2 ice clouds because there is a strong, relatively narrow CO2 ice band at this wavelength but only broad ''continuum'' H2O ice absorption. Weaker features near 2.30 mu m could arise from CO2 ice at coarse grain sizes, or surface/dust minerals. Narrow features near 2.00 mu m, which could potentially be very diagnostic of CO2 ice clouds, suffer from contamination by Mars atmospheric CO2 absorptions and are difficult to interpret because of the rather poor knowledge of surface elevation at high latitudes. These results indicate that future ground-based, Earth-orbital, and spacecraft studies over a more extended span of the seasonal cycle should yield substantial information on the style and timing of volatile transport on Mars, as well as a more detailed understanding of the role of CO2 condensation in the polar heat budget. C1 US GEOL SURVEY,BRANCH ASTROGEOL,FLAGSTAFF,AZ 86001. CALTECH,JET PROP LAB,PASADENA,CA 91109. NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. LOWELL OBSERV,FLAGSTAFF,AZ 86001. RP Bell, JF (reprint author), CORNELL UNIV,DEPT ASTRON,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853, USA. NR 60 TC 28 Z9 28 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD APR 25 PY 1996 VL 101 IS E4 BP 9227 EP 9237 DI 10.1029/96JE00689 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UG926 UT WOS:A1996UG92600002 ER PT J AU Smith, MP Sansom, IJ Repetski, JE AF Smith, MP Sansom, IJ Repetski, JE TI Histology of the first fish SO NATURE LA English DT Article ID HARD TISSUES; VERTEBRATES; ORIGIN AB THE first description of Anatolepis Bockelie & Fortey was from early Ordovician sediments of Ny Friesland, Spitsbergen(1,2), but the genus is now known from many localities in North America and Greenland, ranging in age hom the Late Cambrian period to the Early Ordovician(3-6). Although initially interpreted as an agnathan fish(2,3) that predated other representatives(7), this has been widely disputed because the available histological data were unconvincing(6,8-10) and the scales fell outside the known morphological range of other accepted early vertebrates(9-11). Further doubt was cast upon the vertebrate affinity of Anatolepis when specimens from East Greenland were interpreted as the cuticular fragments of aglaspid arthropods(6), although this interpretation has also been refuted(12). Here we report on the morphology and histology of large collections of Anatolepis, and demonstrate the presence of dentine, a tissue unique to vertebrates, confirming that the taxon is both a vertebrate and the oldest known fish. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP Smith, MP (reprint author), UNIV BIRMINGHAM,SCH EARTH SCI,BIRMINGHAM B15 2TT,W MIDLANDS,ENGLAND. RI Sansom, Ivan/B-4078-2009 NR 27 TC 39 Z9 39 U1 0 U2 5 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD APR 25 PY 1996 VL 380 IS 6576 BP 702 EP 704 DI 10.1038/380702a0 PG 3 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UG827 UT WOS:A1996UG82700047 ER PT J AU Johnson, CA AF Johnson, CA TI Determination of N-15/N-14 and C-13/C-12 in solid and aqueous cyanides SO ANALYTICAL CHEMISTRY LA English DT Article AB The stable isotopic compositions of nitrogen and carbon in cyanide compounds can be determined by combusting aliquots in sealed tubes to form Nz gas and CO2 gas and analyzing the gases by mass spectrometry. Free cyanide (CNaq- + HCNaq) in simple solutions can also be analyzed by first precipitating the cyanide as copper(II) ferrocyanide and then combusting the precipitate, Reproducibility is +/-0.5 parts per thousand or better for both delta(15)N and delta(13)C. If empirical corrections are made on the basis of carbon yields, the reproducibility of delta(13)C can be improved to +/-0.2 parts per thousand. The analytical methods described herein are sufficiently accurate and precise to apply stable isotope techniques to problems of cyanide degradation in natural waters and industrial process solutions. RP Johnson, CA (reprint author), US GEOL SURVEY, BOX 25046, MS 963, DENVER, CO 80225 USA. NR 8 TC 9 Z9 10 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0003-2700 J9 ANAL CHEM JI Anal. Chem. PD APR 15 PY 1996 VL 68 IS 8 BP 1429 EP 1431 DI 10.1021/ac950843m PG 3 WC Chemistry, Analytical SC Chemistry GA UE566 UT WOS:A1996UE56600022 ER PT J AU Dziak, RP Fox, CG Embley, RW Lupton, JE Johnson, GC Chadwick, WW Koski, RA AF Dziak, RP Fox, CG Embley, RW Lupton, JE Johnson, GC Chadwick, WW Koski, RA TI Detection of and response to a probable volcanogenic T-wave event swarm on the western Blanco Transform Fault Zone SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PACIFIC AB The East Blanco Depression (EBD), a pull-apart basin within the western Blanco Transform Fault Zone (BTFZ), was the site of an intense earthquake T-wave swarm that began at 1317Z on January 9, 1994. Although tectonically generated earthquakes occur frequently along the BTFZ, this swarm was unusual in that it was preceded and accompanied by periodic, low-frequency, long-duration acoustic signals, that originated from near the swarm epicenters. These tremor-like signals were very similar in character to acoustic energy produced by a shallow-submarine eruption near Socorro Island, a seamount several hundred km west of Baja, California. The similar to 69 earthquakes and similar to 400 tremor-like events at the EBD occurred sporadically, with two periods of peak activity occurring between January 5-16 and 27-31. The swarm-like character of the earthquakes and the similarity of the tremor activity to the Socorro eruption indicated that the EBD was undergoing an intrusion or eruption episode. On January 27, six CTD/rosette casts were conducted at the site. Water samples from two of the stations yielded anomalous He-3 concentrations, with maxima at similar to 2800 m depth over the main basin. In June 1994 two camera tows within the basin yielded evidence of pillow-lava volcanism and hydrothermal deposits, but no conclusive evidence of a recent seafloor eruption. In September 1994, deployments of the U.S. Navy's Advanced Tethered Vehicle resulted in the discovery of an active hydrothermal mound on the flanks of a pillow-lava volcano. The hydrothermal mound consists of Fe-rich hydrothermal precipitate and bacterial mats. Temperatures to 60 degrees C were measured 30 cm below the surface. This is the first discovery of active hydrothermal vents along an oceanic fracture zone. Although no conclusive evidence of volcanic activity associated with the T-wave event swarm was found during these response efforts, the EBD has been the site of recent seafloor eruptions. C1 NOAA,PACIFIC MARINE ENVIRONM LAB,SEATTLE,WA 98115. US GEOL SURVEY,MENLO PK,CA 94025. HATFIELD MARINE SCI CTR,PACIFIC MARINE ENVIRONM LAB,NOAA,NEWPORT,OR 97365. RP Dziak, RP (reprint author), OREGON STATE UNIV,HATFIELD MARINE SCI CTR,COOPERAT INST MARINE RESOURCES STUDIES,DEPT GEOSCI,NEWPORT,OR 97365, USA. RI Johnson, Gregory/I-6559-2012 OI Johnson, Gregory/0000-0002-8023-4020 NR 16 TC 18 Z9 18 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 1996 VL 23 IS 8 BP 873 EP 876 DI 10.1029/96GL00240 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UF439 UT WOS:A1996UF43900021 ER PT J AU Ross, A Foulger, GR Julian, BR AF Ross, A Foulger, GR Julian, BR TI Non-double-couple earthquake mechanisms at The Geysers geothermal area, California. SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Inverting P- and S-wave polarities and P:SH amplitude ratios using linear programming methods suggests that about 20% of earthquakes at The Geysers geothermal area have significantly non-double-couple focal mechanisms, with explosive volumetric components as large as 33% of the seismic moment. This conclusion contrasts with those of earlier studies, which interpreted data in terms of double couples. The non-double-couple mechanisms are consistent with combined shear and tensile faulting, possibly caused by industrial water injection. Implosive mechanisms, which might be expected because of rapid steam withdrawal, have not been found. Significant compensated-linear-vector-dipole (CLVD) components in some mechanisms may indicate rapid fluid flow accompanying crack opening. C1 US GEOL SURVEY,BRANCH SEISMOL,MENLO PK,CA 94025. RP Ross, A (reprint author), UNIV DURHAM,DEPT GEOL SCI,S RD,DURHAM DH1 3LE,ENGLAND. NR 15 TC 41 Z9 41 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 15 PY 1996 VL 23 IS 8 BP 877 EP 880 DI 10.1029/96GL00590 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UF439 UT WOS:A1996UF43900022 ER PT J AU Hauhs, M Neal, C Hooper, R Christophersen, N AF Hauhs, M Neal, C Hooper, R Christophersen, N TI Summary of a workshop on ecosystem modeling: The end of an era? SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Editorial Material C1 UNIV BAYREUTH,BITOK,D-95440 BAYREUTH,GERMANY. INST HYDROL,WALLINGFORD OX11 8BB,OXON,ENGLAND. US GEOL SURVEY,ATLANTA,GA 30360. UNIV OSLO,DEPT INFORMAT,N-0316 OSLO,NORWAY. NR 4 TC 14 Z9 15 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD APR 12 PY 1996 VL 183 IS 1-2 BP 1 EP 5 DI 10.1016/0048-9697(95)04968-1 PG 5 WC Environmental Sciences SC Environmental Sciences & Ecology GA UH963 UT WOS:A1996UH96300001 ER PT J AU Kirchner, JW Hooper, RP Kendall, C Neal, C Leavesley, G AF Kirchner, JW Hooper, RP Kendall, C Neal, C Leavesley, G TI Testing and validating environmental models SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE ecosystem models; model evaluation ID ACIDIFICATION MODEL; CATCHMENTS; CHEMISTRY; BIRKENES; NORWAY AB Generally accepted standards for testing and validating ecosystem models would benefit both modellers and model users, Universally applicable test procedures are difficult to prescribe, given the diversity of modelling approaches and the many uses for models, However, the generally accepted scientific principles of documentation and disclosure provide a useful framework for devising general standards for model evaluation, Adequately documenting model tests requires explicit performance criteria, and explicit benchmarks against which model performance is compared. A model's validity, reliability, and accuracy can be most meaningfully judged by explicit comparison against the available alternatives, In contrast, current practice is often characterized by vague, subjective claims that model predictions show 'acceptable' agreement with data; such claims provide little basis for choosing among alternative models, Strict model tests (those that invalid models are unlikely to pass) are the only ones capable of convincing rational skeptics that a model is probably valid, However, 'false positive' rates as low as 10% can substantially erode the power of validation tests, making them insufficiently strict to convince rational skeptics, Validation tests are often undermined by excessive parameter calibration and overuse of ad hoc model features, Tests are often also divorced from the conditions under which a model will be used, particularly when it is designed to forecast beyond the range of historical experience, In such situations, data from laboratory and field manipulation experiments can provide particularly effective tests, because one can create experimental conditions quite different from historical data, and because experimental data can provide a more precisely defined 'target' for the model to hit, We present a simple demonstration showing that the two most common methods for comparing model predictions to environmental time series (plotting model time series against data time series, and plotting predicted versus observed values) have little diagnostic power. We propose that it may be more useful to statistically extract the relationships of primary interest from the time series, and test the model directly against them. C1 US GEOL SURVEY,ATLANTA,GA 30360. US GEOL SURVEY,MENLO PK,CA 94025. INST HYDROL,WALLINGFORD OX10 8BB,OXON,ENGLAND. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Kirchner, JW (reprint author), UNIV CALIF BERKELEY,DEPT GEOL & GEOPHYS,BERKELEY,CA 94720, USA. RI Kirchner, James/B-6126-2009 OI Kirchner, James/0000-0001-6577-3619 NR 13 TC 52 Z9 53 U1 2 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD APR 12 PY 1996 VL 183 IS 1-2 BP 33 EP 47 DI 10.1016/0048-9697(95)04971-1 PG 15 WC Environmental Sciences SC Environmental Sciences & Ecology GA UH963 UT WOS:A1996UH96300005 ER PT J AU Lipman, PW AF Lipman, PW TI Natural hazards - Chapman,D SO NATURE LA English DT Book Review RP Lipman, PW (reprint author), US GEOL SURVEY,VOLCANO HAZARDS PROGRAM,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD APR 11 PY 1996 VL 380 IS 6574 BP 492 EP 493 DI 10.1038/380492b0 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UE663 UT WOS:A1996UE66300037 ER PT J AU Benz, HM Chouet, BA Dawson, PB Lahr, JC Page, RA Hole, JA AF Benz, HM Chouet, BA Dawson, PB Lahr, JC Page, RA Hole, JA TI Three-dimensional P and S wave velocity structure of Redoubt Volcano, Alaska SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID LOCAL EARTHQUAKE DATA; TOMOGRAPHIC INVERSION; HYPOCENTERS; COMPLEX; HELENS AB The three-dimensional P and S wave structure of Redoubt Volcano, Alaska, and the underlying crust to depths of 7-8 km is determined from 6219 P wave and 4008 S wave first-arrival times recorded,by a 30-station seismograph network deployed bn and around the volcano. First-ai rival times are calculated using a finite-difference. technique, which allows for flexible parameterization of the slowness model and easy inclusion of topography and source-receiver geometry. The three-dimensional P wave velocity structure and hypocenters are determined simultaneously, while the three-dimensional S wave velocity model is determined using the relocated seismicity and an initial S wave velocity model derived from the P wave velocity model assuming an average Vp/Vs ratio of 1.78. Convergence is steady with approximately 73% and 52% reduction in P and S wave arrival time RMS, respectively, after 10 iterations. The most prominent feature observed in the three-dimensional velocity models derived for both P and S waves is a relative low-velocity, near-vertical, pipelike structure approximately 1 km in diameter that extends from 1 to 6 km beneath sea level. This' feature aligns axially with the bulk of seismicity and is interpreted as a highly fractured and altered zone encompassing a magma conduit. The velocity structure beneath the north flank Of the volcano between depths of 1 and 6 lan is characterized by large lateral velocity variations High velocities within this region are interpreted as remnant dikes and bills and low velocities as regions along which magma migrates. No large low-velocity body suggestive of a magma chamber is resolved in the upper 7-8 lan of th crust. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. STANFORD UNIV, DEPT GEOPHYS, STANFORD, CA 94305 USA. US GEOL SURVEY, FAIRBANKS, AK 99775 USA. RP Benz, HM (reprint author), US GEOL SURVEY, BOX 25046, MS966, DENVER, CO 80225 USA. NR 25 TC 160 Z9 161 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1996 VL 101 IS B4 BP 8111 EP 8128 DI 10.1029/95JB03046 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF005 UT WOS:A1996UF00500009 ER PT J AU Fleck, RJ Turrin, BD Sawyer, DA Warren, RG Champion, DE Hudson, MR Minor, SA AF Fleck, RJ Turrin, BD Sawyer, DA Warren, RG Champion, DE Hudson, MR Minor, SA TI Age and character of basaltic rocks of the Yucca Mountain region, southern Nevada SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WELLS-VOLCANIC-CENTER; WESTERN UNITED-STATES; LATHROP-WELLS; ISOTOPIC EVIDENCE; CENOZOIC BASALTS; WASTE REPOSITORY; GREAT-BASIN; GEOCHRONOLOGY; SITE; GEOCHEMISTRY AB Volcanism in the Yucca Mountain region of southern Nevada in the last 5 m.y. is restricted to moderate-to-small volumes of subalkaline basaltic magmas, produced during at least 6 intervals, and spanning an age range from 4.6 Ma to about 125 ka. Where paleomagnetic evidence is available, the period of volcanism at individual eruptive centers apparently was geologically short-lived, even where multiple eruptions involved different magma types. K-Ar studies are consistent with most other geochronologic information, such as the minimum ages of exposure-dating techniques, and show no evidence of renewed volcanism after a significant quiescence at any of the centers in the Yucca Mountain region. A volcanic recurrence interval of 860 +/- 350 kyr is computed from a large K-Ar data set and an evaluation of their uncertainties. Monte Carlo error propagations demonstrate the validity of uncertainties obtained for weighted-mean ages when modified using the goodness of fit parameter, MSWD. Elevated Sr-87/Sr-86 initial ratios (Sr-i) in the basalts, nearly constant at 0.707, combined with low SiO2 and Rb/Sr ratios indicate a subcontinental, lithospheric mantle source, previously enriched in radiogenic Sr and depleted in Rb. Beginning with eruptions of the most voluminous eruptive center, the newly dated Pliocene Thirsty Mountain volcano, basaltic magmas have decreased in eruptive volume, plagioclase-phenocryst content, various trace element ratios, and TiO2, while increasing in light rare earth elements, U, Th, P2O5, and Light REE/heavy REE ratios. These time-correlated changes are consistent with either increasing depths of melting or a decreasing thermal gradient in the Yucca Mountain region during the last 5 ray. C1 US GEOL SURVEY, DENVER, CO 80225 USA. LOS ALAMOS NATL LAB, LOS ALAMOS, NM 87545 USA. RP Fleck, RJ (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 937, MENLO PK, CA 94025 USA. NR 84 TC 27 Z9 27 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1996 VL 101 IS B4 BP 8205 EP 8227 DI 10.1029/95JB03123 PG 23 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF005 UT WOS:A1996UF00500014 ER PT J AU Taylor, MAJ Zheng, G Rice, JR Stuart, WD Dmowska, R AF Taylor, MAJ Zheng, G Rice, JR Stuart, WD Dmowska, R TI Cyclic stressing and seismicity at strongly coupled subduction zones SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID INTERMEDIATE-DEPTH EARTHQUAKES; OUTER-RISE EARTHQUAKES; STRAIN ACCUMULATION; TEMPORAL VARIATION; GREAT EARTHQUAKES; PHYSICAL MODEL; NANKAI TROUGH; DEFORMATION AB We use the finite element method to analyze stress variations in and near a strongly coupled subduction zone during an earthquake cycle. Deformation is assumed to be uniform along strike (plane strain on a cross section normal to the trench axis), and periodic earthquake slip is imposed consistent with the long-term rate of plate convergence and degree of coupling. Simulations of stress and displacement rate fields represent periodic fluctuations in time superimposed on an average field. The oceanic plate, descending slab, and continental lithosphere are assumed here to respond elastically to these fluctuations, and the remaining mantle under and between plates is assumed to respond as Maxwell viscoelastic. In the first part of the analysis we find that computed stress fluctuations in space and time are generally consistent with observed earthquake mechanism variations with time since a great thrust event. In particular, trench-normal extensional earthquakes tend to occur early in the earthquake cycle toward the outer rise but occur more abundantly late in the cycle in the subducting slab downdip of the main thrust zone. Compressional earthquakes, when they occur at all, have the opposite pattern. Our results suggest also that the actual timing of extensional outer rise events is controlled by the rheology of the shallow aseismic portion of the thrust interface. The second part of the analysis shows the effects of mantle relaxation on the rate of ground surface deformation during the earthquake cycle. Models without relaxation predict a strong overall compressional strain rate in the continental plate above the main thrust zone, with the strain rate constant between mainshocks. However with significant relaxation present, a localized region of unusually low compressional, or even slightly extensional, strain rate develops along the surface of the continental plate above and somewhat inland from the downdip edge of the locked main thrust zone. The low strain rate starts in the middle or late part of the cycle, depending on position. This result suggests that the negligible or small contraction measured on the Shumagin Islands, Alaska, during 1980 to 1991, may not invalidate an interpretation of that region as being a moderately coupled subduction zone. Zn contrast, mantle relaxation causes only modest temporal nonuniformity of uplift rates in the overriding plate and of extensional stress rates in: the subducting plate, even when the Maxwell time is an order of magnitude less than the recurrence interval. C1 HARVARD UNIV, DEPT EARTH & PLANETARY SCI, CAMBRIDGE, MA 02138 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. RP Taylor, MAJ (reprint author), HARVARD UNIV, DIV APPL SCI, PIERCE 327, 29 OXFORD ST, CAMBRIDGE, MA 02138 USA. OI Rice, James/0000-0001-6151-4310 NR 29 TC 44 Z9 45 U1 1 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD APR 10 PY 1996 VL 101 IS B4 BP 8363 EP 8381 DI 10.1029/95JB03561 PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF005 UT WOS:A1996UF00500023 ER PT J AU Kaeding, LR AF Kaeding, LR TI Summer use of coolwater tributaries of a geothermally heated stream by rainbow and brown trout, Oncorhynchus mykiss and Salmo trutta SO AMERICAN MIDLAND NATURALIST LA English DT Article ID FINAL PREFERENDUM; TEMPERATURE; FISH AB The Firehole River, Yellowstone National Park, Wyoming, receives substantial amounts of geothermally heated, mineralized water from hot springs and geysers and is a sport fishery for rainbow trout, Oncorhynchus mykiss and brown trout, Salmo trutta. During summer, both species use cool-water tributaries and mainstem areas upstream from the major sources of geothermal effluents as refuges from elevated river temperatures. Visual counts and electrofishing techniques were used to estimate populations and distributions of these two species of trout near the confluences of the Firehole River and two coolwater tributaries from June through September. Numbers of fish in tributaries increased exponentially in relation to nearby Firehole River temperatures that ultimately exceeded incipient upper lethal levels for rainbow and brown trout. Despite temperatures nearer the final temperature preferenda for both species, however, the coolwater tributaries were not inhabited exclusively during the time when Firehole River temperatures and tributary use by trout were high; periodic forays from tributaries were made, perhaps in response to food availability. Rainbow and brown trout in the middle and lower Firehole River in summer live near their upper lethal temperatures, an existence that will be made more tenuous by climate warming. RP Kaeding, LR (reprint author), US FISH & WILDLIFE SERV,POB 184,YELLOWSTONE NATL PK,WY 82190, USA. NR 26 TC 11 Z9 11 U1 0 U2 10 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD APR PY 1996 VL 135 IS 2 BP 283 EP 292 DI 10.2307/2426711 PG 10 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UG152 UT WOS:A1996UG15200011 ER PT J AU Hartfield, P Hartfield, E AF Hartfield, P Hartfield, E TI Observations on the conglutinates of Ptychobranchus greeni (Conrad, 1834) (Mollusca: Bivalvia: Unionoidea) SO AMERICAN MIDLAND NATURALIST LA English DT Article AB The conglutinates of Ptychobranchus greeni, a freshwater mussel, mimic aquatic dipteran larvae in shape, size, and coloration. They possess a terminal adhesive filament that may function as a holdfast to attach the conglutinate to rock or gravel substrata and maintain them in the riffle and shoal habitats of potential fish hosts. The decline and subsequent disappearance of P. greeni from much of its historic range may be partially explained by sedimentation and eutrophication within these habitats that limit the ability of the conglutinates to attach to the substratum. C1 MISSISSIPPI MUSEUM NAT SCI,JACKSON,MS 39213. RP Hartfield, P (reprint author), US FISH & WILDLIFE SERV,JACKSON,MS 39213, USA. NR 8 TC 19 Z9 19 U1 0 U2 5 PU AMER MIDLAND NATURALIST PI NOTRE DAME PA UNIV NOTRE DAME, NOTRE DAME, IN 46556 SN 0003-0031 J9 AM MIDL NAT JI Am. Midl. Nat. PD APR PY 1996 VL 135 IS 2 BP 370 EP 375 DI 10.2307/2426721 PG 6 WC Biodiversity Conservation; Ecology SC Biodiversity & Conservation; Environmental Sciences & Ecology GA UG152 UT WOS:A1996UG15200021 ER PT J AU Li, YG Vidale, JE AF Li, YG Vidale, JE TI Low-velocity fault-zone guided waves: Numerical investigations of trapping efficiency SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; FINITE-DIFFERENCE; EARTHQUAKE; CALIFORNIA; PARKFIELD; AFTERSHOCKS; SEISMOGRAMS; INVERSION; BARRIERS AB Recent observations have shown that shear waves trapped within low-velocity fault zones may be the most sensitive measure of fault-zone structure (Li et al., 1994a, 1994b). Finite-difference simulations demonstrate the effects of several types of complexity on observations of fault-zone trapped waves. Overlying sediments with a thickness more than one or two fault-zone widths and fault-zone step-overs more than one or two fault widths disrupt the wave guide. Fault kinks and changes in fault-zone width with depth leave readily observable trapped waves. We also demonstrate the effects of decreased trapped wave excitation with increasing hypocentral offset from the fault and the effects of varying the contrast between the velocity in the fault zone and surrounding hard rock. Careful field studies may provide dramatic improvements in our knowledge of fault-zone structure. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Li, YG (reprint author), UNIV SO CALIF,DEPT EARTH SCI,LOS ANGELES,CA 90089, USA. RI Vidale, John/H-4965-2011 OI Vidale, John/0000-0002-3658-818X NR 39 TC 69 Z9 71 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD APR PY 1996 VL 86 IS 2 BP 371 EP 378 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UJ351 UT WOS:A1996UJ35100009 ER PT J AU Liu, HP Maier, RL Warrick, RE AF Liu, HP Maier, RL Warrick, RE TI An improved air-powered impulsive shear-wave source SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article AB We have previously constructed an air-powered, impulsive, SH-wave source for shear-wave velocity measurements using a downhole configuration. One shortcoming of that source is the existence of a forerunning signal generated by the reaction to the rapid acceleration of an inertial mass when a poppet valve is opened. By changing the poppet valve to a ball valve, a cleaner signal is generated. The improvement comes about because when a ball valve is opened, its flow capacity increases gradually, resulting in a smooth and gradual acceleration of the inertial mass. Tests involving ground coupling and driving air pressure were conducted to investigate physical parameters of shear-wave generation. We illustrate as an application the measurement of shear-wave velocity in a loess layer. RP Liu, HP (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 9 TC 7 Z9 7 U1 2 U2 3 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD APR PY 1996 VL 86 IS 2 BP 530 EP 537 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UJ351 UT WOS:A1996UJ35100025 ER PT J AU Diaz, JI Palanques, A Nelson, CH Guillen, J AF Diaz, JI Palanques, A Nelson, CH Guillen, J TI Morpho-structure and sedimentology of the Holocene Ebro prodelta mud belt (northwestern Mediterranean Sea) SO CONTINENTAL SHELF RESEARCH LA English DT Article ID EAST CHINA SEA; CONTINENTAL-SHELF; DELTA; MARGIN; RIVER; SPAIN AB The Ebro ''mud belt'' is a Holocene prodeltaic deposit which has developed around, and southwestward from, the present Ebro Delta plain, covering most of the inner and middle Ebro continental shelf. Seismic-reflection profiles of this mud belt exhibit a complex sigmoid-oblique configuration. Top-set strata dip gently seaward to the 20 m isobath, and overly the fore-set beds which are exposed in up to 40-60 m water depth. Top-set and fore-set beds have mostly parallel and high continuity reflectors. Thin, acoustically transparent bottom-set beds are present at the base of the fore-set beds and extend to the distal edge of the prodelta (60-80 m water depth), where they overly relict transgressive sand deposits. There is no evidence of mass movement. The suspended load discharged by the river is mainly transported alongshelf by advective processes. This dynamics produces thin clinoform deposits that extend alongshelf for tens of kilometres. Mud belt deposition began about 10,000-11,000 years BP. Accumulation rate ranges from less than 0.5 mm y(-1) on the seaward and southern edges of the deposit to about 2.5 mm y(-1) near the present river mouth. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Diaz, JI (reprint author), CSIC,INST CIENCIAS MAR,PASEO JUAN BORBON S-N,E-08039 BARCELONA,SPAIN. RI Guillen, Jorge/E-6564-2010; Palanques, Albert/C-2661-2013 OI Guillen, Jorge/0000-0001-7162-8135; NR 40 TC 36 Z9 39 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD APR PY 1996 VL 16 IS 4 BP 435 EP & DI 10.1016/0278-4343(95)00019-4 PG 21 WC Oceanography SC Oceanography GA TL511 UT WOS:A1996TL51100003 ER PT J AU Sternberg, RW Cacchione, DA Paulson, B Kineke, GC Drake, DE AF Sternberg, RW Cacchione, DA Paulson, B Kineke, GC Drake, DE TI Observations of sediment transport on the Amazon subaqueous delta SO CONTINENTAL SHELF RESEARCH LA English DT Article ID HUANGHE YELLOW-RIVER; CONTINENTAL-SHELF; COMBINED WAVE; BOTTOM; MOUTH AB A 19-day time series of fluid, flow, and suspended-sediment characteristics in the benthic boundary layer is analyzed to identify major sedimentary processes active over the prodelta region of the Amazon subaqueous delta. Measurements were made by the benthic tripod GEOPROBE placed on the seabed in 65 m depth near the base of the deltaic foreset beds from 11 February to 3 March 1990, during the time of rising water and maximum sediment discharge of the Amazon River; and the observations included: hourly measurements of velocity and suspended-sediment concentration at four levels above the seabed; waves and tides; and seabed elevation. Results of the first 14-day period of the time series record indicate that sediment resuspension occurred as a result of tidal currents (91% of the time) and surface gravity waves (46% of the time). Observations of suspended sediment indicated that particle flux in this region is 0.4-2% of the flux measured on the adjacent topset deposits and is directed to the north and landward relative to the Brazilian coast (268 degrees T). Fortnightly variability is strong, with particle fluxes during spring tides five times greater than during neap tides. On the 15th day of the data record, a rapid sedimentation event was documented in which 44 cm of sediment was deposited at the study site over a 14-h period. Evaluation of various mechanisms of mass sediment movement suggests that this event represents downslope migration of fluid muds from the upper foreset beds that were set in motion by boundary shear stresses generated by waves and currents. This transport mechanism appears to occur episodically and may represent a major source of sediment to the lower foreset-bottomset region of the subaqueous delta. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. CH2M HILL INC, BELLEVUE, WA 98009 USA. RP Sternberg, RW (reprint author), UNIV WASHINGTON, SCH OCEANOG, SEATTLE, WA 98195 USA. NR 31 TC 53 Z9 55 U1 0 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0278-4343 J9 CONT SHELF RES JI Cont. Shelf Res. PD APR-MAY PY 1996 VL 16 IS 5-6 BP 697 EP 715 DI 10.1016/0278-4343(95)00045-3 PG 19 WC Oceanography SC Oceanography GA UA184 UT WOS:A1996UA18400007 ER PT J AU Sinigoi, S Quick, JE Mayer, A Budahn, J AF Sinigoi, S Quick, JE Mayer, A Budahn, J TI Influence of stretching and density contrasts on the chemical evolution of continental magmas: An example from the Ivrea-Verbano zone SO CONTRIBUTIONS TO MINERALOGY AND PETROLOGY LA English DT Article ID IGNEOUS COMPLEX; CRUST; DEFORMATION; MANTLE; GABBRO AB The southern Ivrea-Verbano Zone of the Italian Western Alps contains a huge mafic complex that intruded high-grade metamorphic rocks while they were resident in the lower crust. Geologic mapping and chemical variations of the igneous body were used to study the evolution of underplated crust. Slivers of crustal rocks (septa) interlayered with igneous mafic rocks are concentrated in a narrow zone deep in the complex (Paragneiss-bearing Belt) and show evidence of advanced degrees of partial melting, Variations of rare-earth-element patterns and Sr isotope composition of the igneous rocks across the sequence are consistent with increasing crustal contamination approaching the septa. Therefore, the Paragneiss-bearing Belt is considered representative of an ''assimilation region'' where in-situ interaction between mantle- and crust-derived magmas resulted in production of hybrid melts. Buoyancy caused upwards migration of the hybrid melts that incorporated the last septa and were stored at higher levels, feeding the Upper Mafic Complex. Synmagmatic stretching of the assimilation region facilitated mixing and homogenization of melts. Chemical variations of granitoids extracted from the septa show that deep septa are more depleted than shallow ones. This suggests that the first incorporated septa were denser than the later ones, as required by the high density of the first-injected mafic magmas, It is inferred that density contrasts between mafic melts and crustal rocks play a crucial role for the processes of contamination of continental magmas. In thick underplated crust, the extraction of early felsic/hybrid melts from the lower crust may be required to increase the density of the lower crust and to allow the later mafic magmas to penetrate higher crustal levels. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Sinigoi, S (reprint author), UNIV TRIESTE,IST MINERAL & PETROG,PIAZZALE EUROPA 1,I-34100 TRIESTE,ITALY. OI SINIGOI, Silvano/0000-0001-6812-4083 NR 33 TC 31 Z9 31 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-7999 J9 CONTRIB MINERAL PETR JI Contrib. Mineral. Petrol. PD APR PY 1996 VL 123 IS 3 BP 238 EP 250 DI 10.1007/s004100050153 PG 13 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA UG529 UT WOS:A1996UG52900002 ER PT J AU Brown, KM Bangs, NL Froelich, PN Kvenvolden, KA AF Brown, KM Bangs, NL Froelich, PN Kvenvolden, KA TI The nature, distribution, and origin of gas hydrate in the Chile Triple Junction region SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Chile Margin Triple Junction; Leg 141; gas hydrates; resistivity; seismic logging ID BOTTOM-SIMULATING-REFLECTORS; BASE; SEDIMENTS; MARINE; RIDGE; ZONE AB A bottom simulating reflector (BSR) is regionally distributed throughout much of the Chile Triple Junction (CTJ) region. Downhole temperature and logging data collected during Ocean Drilling Program (ODP) Leg 141 suggest that the seismic BSR is generated by low seismic velocities associated with the presence of a few percent free gas in a similar to 10 m thick zone just beneath the hydrate-bearing zone. The data also indicate that the temperature and pressure at the BSR best corresponds to the seawater/methane hydrate stability field. The origin of the large amounts of methane required to generate the hydrates is, however, problematic. Low total organic carbon contents and low alkalinities argue against significant in situ biogenic methanogenesis, but additional input from thermogenic sources also appears to be precluded, Increasing thermal gradients, associated with the approach of the spreading ridge system, may have caused the base of the hydrate stability field to migrate 300 m upwards in the sediments. We propose that the upward migration of the base of the stability field has concentrated originally widely dispersed hydrate patches into the more continuous hydrate body we see today. The methane can be concentrated if the gas hydrates can form from dissolved methane, transported into the hydrate zone via diffusion or fluid advection. A strong gradient may exist in dissolved methane concentration across the BSR leading to the steady reabsorbtion of the free gas zone during the upward migration of the BSR even in the absence of fluid advection. C1 UNIV TEXAS,INST GEOPHYS,AUSTIN,TX 78759. GEORGIA INST TECHNOL,ATLANTA,GA 30332. US GEOL SURVEY,MENLO PK,CA 94025. RP Brown, KM (reprint author), UNIV CALIF SAN DIEGO,SCRIPPS INST OCEANOG,LA JOLLA,CA 92093, USA. RI Bangs, Nathan/A-1584-2009 OI Bangs, Nathan/0000-0002-4377-3463 NR 40 TC 54 Z9 63 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD APR PY 1996 VL 139 IS 3-4 BP 471 EP 483 DI 10.1016/0012-821X(95)00243-6 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UM492 UT WOS:A1996UM49200012 ER PT J AU Lidz, BH AF Lidz, BH TI Cesare Emiliani (1922-1995) - Memorial SO EARTH-SCIENCE REVIEWS LA English DT Item About an Individual RP Lidz, BH (reprint author), US GEOL SURVEY,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-8252 J9 EARTH-SCI REV JI Earth-Sci. Rev. PD APR PY 1996 VL 40 IS 1-2 BP 1 EP 2 DI 10.1016/S0012-8252(96)90060-4 PG 2 WC Geosciences, Multidisciplinary SC Geology GA UM098 UT WOS:A1996UM09800001 ER PT J AU Ha, PY Kinzie, RA AF Ha, PY Kinzie, RA TI Reproductive biology of Awaous guamensis, an amphidromous Hawaiian goby SO ENVIRONMENTAL BIOLOGY OF FISHES LA English DT Article DE fecundity; fish reproduction; gobiidae; iteroparity; oocyte maturation; spawning season; stream; fish; Awaous stamineus; Lentipes concolor; Kuhlia sandvicensis; Sicyopteris stimpsoni ID FRESH-WATER GOBIES; PADOGOBIUS-MARTENSI; LENTIPES-CONCOLOR; OOCYTE GROWTH; FISHES AB Spawning season, size at first reproduction, oocyte maturation, and fecundity of Awaous guamensis, an amphidromous Hawaiian goby, were studied from June 1989 through May 1991 in the Wainiha River, Kaua'i, Hawai'i. Female fish larger than 73 mm standard length (SL) had mature gonads from August through December in 1989 and 1990. Gonadosomatic index (GSI) values for mature females ranged from 0.2 to 14.5 during the spawning season. Male fish larger than 64 mm SL had elevated GSI values from June 1989 through December 1989 and from August 1990 through December 1990. Mature sperm were found in two male fish collected in January and February. GSI values for mature males ranged from less than 0.01 to 4.0 in the spawning season. Size-frequency distributions of measurements of vitellogenic oocyte diameters and microscopic observations of oocytes indicated this species has group-synchronous oocyte development. Ovarian maturation stages examined over a 29-month period suggest that members of the stock spawned at different times within the spawning season, although mass spawning events have been documented for this species. Estimates of clutch sizes from nests measured in situ were comparable to estimates of potential fecundity from in vitro examination of ovaries, and indicated that female fish deposited an entire clutch during a spawning event. No evidence for multiple spawning by an individual fish in a single season was found. However, microscopic observations of brown bodies in some ovaries suggested that individual fish probably spawn more than once in a lifetime. C1 UNIV HAWAII,DEPT ZOOL,HONOLULU,HI 96822. RP Ha, PY (reprint author), US FISH & WILDLIFE SERV,POB 50167,HONOLULU,HI 96850, USA. NR 37 TC 27 Z9 27 U1 3 U2 6 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0378-1909 J9 ENVIRON BIOL FISH JI Environ. Biol. Fishes PD APR PY 1996 VL 45 IS 4 BP 383 EP 396 DI 10.1007/BF00002531 PG 14 WC Ecology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA UA942 UT WOS:A1996UA94200008 ER PT J AU Landmeyer, JE Vroblesky, DA Chapelle, FH AF Landmeyer, JE Vroblesky, DA Chapelle, FH TI Stable carbon isotope evidence of biodegradation zonation in a shallow jet-fuel contaminated aquifer SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID GROUNDWATER; CO2; GEOCHEMISTRY; REDUCTION; SEDIMENTS; CULTURES; TOLUENE; SULFATE AB delta(13)C values in dissolved inorganic carbon (DIC) ranged from -28 to +11.9 parts per thousand in a sandy, noncarbonate shallow aquifer contaminated with jet-fuel petroleum hydrocarbons. This range was observed over a 4-year study in shallow and deep monitoring wells and comprised delta(13)C values representative of the aerobic and anaerobic microbial biodegradation of C-13-depleted jet fuel (delta(13)C similar to -27 parts per thousand). The delta(13)C DIC values were found to be influenced by the extent of rainwater infiltration of dissolved oxygen or sulfate or, conversely, by the absence of recharge, lack of dissolved oxygen or sulfate input to the aquifer, and the ensuing methanogenic conditions. After some recharge events delivered dissolved oxygen or sulfate to the shallow part of the aquifer, low to medium DIC delta(13)C values were measured, and reflected biodegradation of delta(13)C-depleted jet fuel under aerobic (delta(13)C DIC similar to -26 parts per thousand) or sulfate-reducing (delta(13)C DIC similar to -18 parts per thousand) conditions; the deeper part of the aquifer isolated from recharge was methanogenic and had higher delta(13)C DIC values. Conversely, when rainfall was absent and dissolved oxygen and sulfate concentrations were low in the aquifer, higher DIC delta(13)C values were measured in both shallow and deep contaminated groundwater (delta(13)C DIC up to +11.9 parts per thousand) where H-2 concentrations indicated that the predominant terminal electron-accepting process was methanogenesis. The highest delta(13)C values (+2.6 to +11.9 parts per thousand) were from contaminated groundwater that contained no dissolved oxygen and little sulfate, CH4 concentrations up to 1985 mu mol/L, and acetate concentrations exceeding 12 000 mu mol/L. These results suggest that stable carbon isotopes in DIC can be used to indicate the zonation of C-13-depleted hydrocarbon biodegradation processes under the influence of hydrologically controlled electron-acceptor availability. RP Landmeyer, JE (reprint author), US GEOL SURVEY,STEPHENSON CTR,DIV WATER RESOURCES,SUITE 129,720 GRACERN RD,COLUMBIA,SC 29210, USA. NR 29 TC 54 Z9 54 U1 2 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR PY 1996 VL 30 IS 4 BP 1120 EP 1128 DI 10.1021/es950325t PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UC413 UT WOS:A1996UC41300030 ER PT J AU Desimone, LA Howes, BL AF Desimone, LA Howes, BL TI Denitrification and nitrogen transport in a coastal aquifer receiving wastewater discharge SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID ISOTOPE FRACTIONATION; OXIDE REDUCTION; NATURAL DENITRIFICATION; DENITRIFYING BACTERIA; ACETYLENE INHIBITION; GROUNDWATER NITRATE; SEPTIC SYSTEMS; GRAVEL AQUIFER; SANDY AQUIFER; WATER-TABLE AB Denitrification and nitrogen transport were quantified in a sandy glacial aquifer receiving wastewater from a septage-treatment facility on Cape God, MA. The resulting groundwater plume contained high concentrations of NO3- (32 ms of N L(-1)), total dissolved nitrogen (40.5 mg of N L(-1)), and dissolved organic carbon (1.9 mg of C L(-1)) and developed a central anoxic zone after 17 months of effluent discharge. Denitrifying activity was measured using four approaches throughout the major biogeochemical zones of the plume. Three approaches that maintained the structure of aquifer materials yielded comparable rates: acetylene block in intact sediment cores, 9.6 ng of N cm(-3) d(-1) (n = 61); in situ N-2 production, 3.0 ng of N cm(-3) d(-1) (n = 11), and in situ NO3- depletion, 7.1 ng of N cm(-3) d(-1) (n = 3). In contrast, the mixing of aquifer materials using a standard slurry method yielded rates that were more than 15-fold higher (150 ng of N cm(-3) d(-1) n = 16) than other methods. Concentrations and delta(15)N of groundwater and effluent N-2, NO3-, and NH4+ were consistent with the lower rates of denitrification determined by the intact-core or in situ methods. These methods and a plumewide survey of excess N-2 indicate that 2-9% of the total mass of fired nitrogen recharged to the anoxic zone of the plume was denitrified during the 34-month study period. Denitrification was limited by organic carbon (not NO3-) concentrations, as evidenced by a nitrate and carbon addition experiment, the correlation of denitrifying activity with in situ concentrations of dissolved organic carbon, and the assessments of available organic carbon in plume sediments. Carbon limitation is consistent with the observed conservative transport of 85-96% of the nitrate in the anoxic zone. Although denitrifying activity removed a significant amount (46-250 kg) of fixed nitrogen during transport, the effects of aquifer denitrification on the nitrogen load to receiving ecosystems are likely to be small (<10%). C1 WOODS HOLE OCEANOG INST,DEPT BIOL,WOODS HOLE,MA 02543. RP Desimone, LA (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,28 LORD RD,SUITE 280,MARLBOROUGH,MA 01752, USA. NR 54 TC 47 Z9 52 U1 1 U2 15 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR PY 1996 VL 30 IS 4 BP 1152 EP 1162 DI 10.1021/es950366p PG 11 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UC413 UT WOS:A1996UC41300035 ER PT J AU Vroblesky, DA Bradley, PM Chapelle, FH AF Vroblesky, DA Bradley, PM Chapelle, FH TI Influence of electron donor on the minimum sulfate concentration required for sulfate reduction in a petroleum hydrocarbon-contaminated aquifer SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID METHANE PRODUCTION; TOLUENE; IRON; BENZENE; TRANSFORMATION; DEGRADATION; SEDIMENTS; WATER AB Fluctuations in the availability of electron donor (petroleum hydrocarbons) affected the competition between sulfate-reducing bacteria (SRB) and methanogenic bacteria (MB) for control of electron flow in a petroleum hydrocarbon-contaminated aquifer. The data suggest that abundant electron donor availability allowed MB to sequester a portion of the electron flow even when sulfate was present in sufficient concentrations to support sulfate reduction. For example, in an area of abundant electron-donor availability, SRB appeared to be unable to sequester the electron flow from MB in the presence of 1.4 mg/L sulfate. The data also suggest that when electron-donor availability was limited, SRB outcompeted MB for available substrate at a lower concentration of sulfate than when electron donor was plentiful. For example, in an area of limited electron-donor availability, SRB appeared to maintain dominance of electron flow at sulfate concentrations less than 1 mg/L. The presence of abundant electron donor and a limited amount of sulfate reduced competition for available substrate, allowing both SRB and MB to metabolize available substrates concurrently. RP Vroblesky, DA (reprint author), US GEOL SURVEY, STEPHENSON CTR, 720 GRACERN RD, SUITE 129, COLUMBIA, SC 29210 USA. NR 31 TC 29 Z9 29 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X EI 1520-5851 J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD APR PY 1996 VL 30 IS 4 BP 1377 EP 1381 DI 10.1021/es950684o PG 5 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA UC413 UT WOS:A1996UC41300065 ER PT J AU Larson, JM Karasov, WH Sileo, L Stromborg, KL Hanbidge, BA Giesy, JP Jones, PD Tillitt, DE Verbrugge, DA AF Larson, JM Karasov, WH Sileo, L Stromborg, KL Hanbidge, BA Giesy, JP Jones, PD Tillitt, DE Verbrugge, DA TI Reproductive success, developmental anomalies, and environmental contaminants in double-crested cormorants (Phalacrocorax auritus) SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE polychlorinated biphenyls; ethoxyresorufin-O-deethylase; double-crested cormorant; neonatal deformity; TCDD equivalents ID POLYCHLORINATED-BIPHENYLS PCBS; HEPATOMA-CELL BIOASSAY; CROWNED NIGHT-HERONS; GREAT-LAKES; GREEN-BAY; ORGANOCHLORINE CONTAMINANTS; AROMATIC-HYDROCARBONS; LONG-ISLAND; RESIDUES; EGGS AB To test an association between environmental contaminants and the prevalence of congenital anomalies in colonial waterbirds, we collected representative eggs for chemical analysis from double-crested cormorant nests at colonies in Lake Michigan, Wisconsin, USA, and Lake Winnipegosis, Manitoba, Canada, and periodically revisited the nests to determine the hatching success, survivorship of hatchlings, and number of deformed hatchlings in the remainder of each clutch. Total concentrations of polychlorinated biphenyls (PCBs) in eggs were determined by capillary gas chromatography. The combined activity of planar chlorinated hydrocarbons (PCHs) in the eggs was measured in an in vitro bioassay based on the induction of ethoxyresorufin-O-deethylase (EROD) activity in rat hepatoma cells. The combined EROD induction activity was expressed as 2,3,7,8-tetrachlorodibenzo-p-dioxin equivalents (TCDD-EQ). Total concentrations of PCBs and TCDD-EQ were seven to eight times greater in eggs from Lake Michigan (7.8 mu g/g and 138 pg/g, respectively) than in those from Lake Winnipegosis (1.0 mu g/g and 19 pg/g, respectively). The proportion of eggs hatching at the Lake Michigan colony (59%) was less (p < 0.05) than at Lake Winnipegosis (70%), and the prevalence of hatchlings with deformed bills was greater (p < 0.001) at. Lake Michigan (0.79 vs. 0.06%). However, within the Lake Michigan colony, concentrations of PCBs and TCDD-EQ were not correlated with either hatching success or the occurrence of deformities in nestlings. C1 US FISH & WILDLIFE SERV,GREEN BAY,WI 54311. UNIV WISCONSIN,CTR ENVIRONM TOXICOL,MADISON,WI 53706. UNIV WISCONSIN,DEPT WILDLIFE ECOL,MADISON,WI 53706. NATL WILDLIFE HLTH CTR,MADISON,WI 53711. MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,DEPT FISHERIES & WILDLIFE,E LANSING,MI 48824. RI Jones, Paul/O-2046-2015 OI Jones, Paul/0000-0002-7483-5380 NR 52 TC 44 Z9 46 U1 1 U2 8 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD APR PY 1996 VL 15 IS 4 BP 553 EP 559 DI 10.1897/1551-5028(1996)015<0553:RSDAAE>2.3.CO;2 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA UD132 UT WOS:A1996UD13200021 ER PT J AU Reheis, MC Dixon, TH AF Reheis, MC Dixon, TH TI Kinematics of the Eastern California shear zone: Evidence for slip transfer from Owens and Saline Valley fault zones to Fish Lake Valley fault zone SO GEOLOGY LA English DT Article AB Late Quaternary slip rates and satellite-based geodetic data for the western Great Basin constrain regional fault-slip distribution and evolution. The geologic slip rate on the Fish Lake Valley fault zone (the northwest extension of the Furnace Creek fault zone) increases northward from about 3 to 5 mm/yr, in agreement with modeled geodetic data. The increase coincides with the intersections of the Deep Springs fault, connected to the Owens Valley fault zone, and of other faults connected to the Saline Valley fault, The combined geologic and geodetic data suggest that (1) the northwest-striking faults of the Eastern California shear zone north of the Garlock fault are connected by north- to northeast-striking normal faults that transfer slip in a series of right steps, and (2) the amount and distribution of slip among the many faults of this broad, complex plate boundary have changed through time. C1 UNIV MIAMI,ROSENSTIEL SCH MARINE & ATMOSPHER SCI,MIAMI,FL 33149. RP Reheis, MC (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS-913,DENVER,CO 80225, USA. NR 19 TC 53 Z9 53 U1 0 U2 6 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD APR PY 1996 VL 24 IS 4 BP 339 EP 342 DI 10.1130/0091-7613(1996)024<0339:KOTECS>2.3.CO;2 PG 4 WC Geology SC Geology GA UE646 UT WOS:A1996UE64600013 ER PT J AU McLelland, JM Foose, MP AF McLelland, JM Foose, MP TI Proterozoic low-Ti iron-oxide deposits in New York and New Jersey: Relation to Fe-oxide (Cu-U-Au-rare earth element) deposits and tectonic implications: Reply SO GEOLOGY LA English DT Article C1 US GEOL SURVEY,RESTON,VA 22092. RP McLelland, JM (reprint author), COLGATE UNIV,DEPT GEOL,HAMILTON,NY 13347, USA. NR 4 TC 0 Z9 0 U1 1 U2 1 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD APR PY 1996 VL 24 IS 4 BP 383 EP 384 PG 2 WC Geology SC Geology GA UE646 UT WOS:A1996UE64600027 ER PT J AU Mueller, S Choy, GL Spence, W AF Mueller, S Choy, GL Spence, W TI Inelastic models of lithospheric stress .1. Theory and application to outer-rise plate deformation SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Review DE lithospheric deformation; oceanic lithosphere; plate convergence; residual stress ID SAN-ANDREAS FAULT; COUPLED SUBDUCTION ZONES; OCEANIC INTRAPLATE SEISMICITY; SCIENTIFIC-RESEARCH BOREHOLE; 3.5 KM DEPTH; HEAT-FLOW; CAJON PASS; CONVERGENT MARGINS; CONTINENTAL-CRUST; FLUID PRESSURE AB Outer-rise stress distributions determined in the manner that mechanical engineers evaluate inelastic stress distributions within conventional materials are contrasted with those predicted using simple elastic-plate models that are frequently encountered in studies of outer-rise seismicity. This comparison indicates that the latter are inherently inappropriate for studies of intraplate earthquakes, which are a direct manifestation of lithospheric inelasticity. We demonstrate that the common practice of truncating elastically superimposed stress profiles so that they are not permitted to exceed laboratory-based estimates of lithospheric yield strength will result in an accurate characterization of lithospheric stress only under relatively restrictive circumstances. In contrast to elastic-plate models, which predict that lithospheric stress distributions depend exclusively upon the current load, inelastic plate models predict that stress distributions are also significantly influenced by the plate-loading history, and, in many cases, this influence is the dominant factor in determining the style of potential seismicity (e.g. thrust versus normal faulting), Numerous 'intuitive' interpretations of outer-rise earthquakes have been founded upon the implicit assumption that a unique relationship exists between a specified combination of plate curvature and in-plane force, and the resulting lithospheric stress distribution. We demonstrate that the profound influence of deformation history often invalidates such interpretations. Finally, we examine the reliability of 'yield envelope' representations of lithospheric strength that are constructed on the basis of empirically determined frictional sliding relationships and silicate plastic-flow laws. Although representations of this nature underestimate the strength of some major interplate faults, such as the San Andreas, they appear to represent a reliable characterization of the strength of intraplate oceanic lithosphere. C1 UNIV TOKYO,EARTHQUAKE RES INST,BUNKYO KU,TOKYO 113,JAPAN. RP Mueller, S (reprint author), US GEOL SURVEY,NATL EARTHQUAKE INFORMAT CTR,DENVER FED CTR,BOX 25046,MS 967,DENVER,CO 80225, USA. NR 121 TC 15 Z9 15 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD APR PY 1996 VL 125 IS 1 BP 39 EP 53 DI 10.1111/j.1365-246X.1996.tb06533.x PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UD902 UT WOS:A1996UD90200005 ER PT J AU Mueller, S Spence, W Choy, GL AF Mueller, S Spence, W Choy, GL TI Inelastic models of lithospheric stress .2. Implications for outer-rise seismicity and dynamics SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Review DE lithospheric deformation; plate convergence; seismicity; subduction ID COUPLED SUBDUCTION ZONES; OCEANIC INTRAPLATE SEISMICITY; INDO-AUSTRALIAN PLATE; SAN-ANDREAS FAULT; RUPTURE PROCESS; EXPERIMENTAL DEFORMATION; ISLANDS EARTHQUAKE; CHILEAN EARTHQUAKE; HEAT-FLOW; ASPERITY INTERACTION AB Outer-rise seismicity and dynamics are examined using inelastic models of lithospheric deformation, which allow a more realistic characterization of stress distributions and failure behaviour. We conclude that thrust- and normal-faulting outer-rise earthquakes represent substantially different states of stress within the oceanic Lithosphere. Specifically, the normal-faulting events occur in response to downward plate bending, which establishes the 'standard', bending-dominated state of outer-rise stress, and the thrust-faulting events occur in response to an elevated level of in-plane compression, which develops only in response to exceptional circumstances. This interpretation accounts for the observation that normal-faulting outer-rise earthquakes occur more frequently and are more widely distributed than their thrust-faulting counterparts, an observation for which the simple bending model offers no explanation. In addition, attributing both thrust- and normal-faulting outer-rise earthquakes to plate bending implies that both classes of events should occur within relatively close lateral proximity to one another because both are allegedly a manifestation of the same bending-dominated stress distribution, whereas, in reality, this is not observed. We propose that the tendency for thrust-faulting outer-rise earthquakes to exhibit greater source depths than their normal-faulting counterparts (an observation that is frequently cited in support of the bending interpretation of the former) is merely a consequence of the fact that bending-induced tension is confined to the upper lithosphere. Our model predicts that outer-rise in-plane-force variations may promote thrust-faulting outer-rise activity prior to an underthrusting interplate subduction earthquake and normal-faulting outer-rise activity following such an earthquake, but that both forms of outer-rise activity are unlikely to be associated with the same subduction earthquake. A corollary implication of our model is that subduction earthquakes are Likely to be either preceded by or followed by an absence of large outer-rise earthquakes. Levels of in-plane compression necessary to generate thrust-faulting outer-rise earthquakes are attributed to stress concentrations within the subducting plate that are induced by relatively localized resistance to regionally distributed plate-driving forces. Resistance of this nature may result from either the attempted subduction of relatively buoyant (i.e. isostatically compensated) bathymetric features or the existence of strong interplate asperities. C1 UNIV TOKYO,EARTHQUAKE RES INST,TOKYO 113,JAPAN. RP Mueller, S (reprint author), US GEOL SURVEY,DENVER FED CTR,NATL EARTHQUAKE INFORMAT CTR,BOX 25046,MS 967,DENVER,CO 80225, USA. NR 119 TC 12 Z9 12 U1 0 U2 2 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0956-540X J9 GEOPHYS J INT JI Geophys. J. Int. PD APR PY 1996 VL 125 IS 1 BP 54 EP 72 DI 10.1111/j.1365-246X.1996.tb06534.x PG 19 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UD902 UT WOS:A1996UD90200006 ER PT J AU Lockner, DA Byerlee, JD Savage, JC AF Lockner, DA Byerlee, JD Savage, JC TI Fault zone strength and failure criteria - Comment SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article RP Lockner, DA (reprint author), US GEOL SURVEY,MS 977,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 5 TC 0 Z9 0 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD APR 1 PY 1996 VL 23 IS 7 BP 789 EP 790 DI 10.1029/96GL00853 PG 2 WC Geosciences, Multidisciplinary SC Geology GA UD380 UT WOS:A1996UD38000024 ER PT J AU Shinn, EA AF Shinn, EA TI No rocks, no water, no ecosystem SO GEOTIMES LA English DT Article RP Shinn, EA (reprint author), US GEOL SURVEY,CTR COASTAL GEOL,600 4TH ST S,ST PETERSBURG,FL 33701, USA. NR 0 TC 0 Z9 1 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD APR PY 1996 VL 41 IS 4 BP 16 EP 19 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UW475 UT WOS:A1996UW47500006 ER PT J AU Fountain, AG AF Fountain, AG TI Effect of snow and firn hydrology on the physical and chemical characteristics of glacial runoff SO HYDROLOGICAL PROCESSES LA English DT Article DE glacial runoff; ice; snow; firn; streamflow; stream chemistry ID BULK MELT WATERS; SOLUTE ACQUISITION; SYSTEM CHARACTERISTICS; PREFERENTIAL ELUTION; PRECIPITATION; POLLUTANTS; MELTWATER; AEROSOLS; ALASKA; COVER AB Near-surface processes on glaciers, including water flow over bare ice and through seasonal snow and firn, have a significant effect on the speed, volume and chemistry of water flow through the glacier. The transient nature of the seasonal snow profoundly affects the water discharge and chemistry. Water flow through snow is fairly slow compared with flow over bare ice and a thinning snowpack on a glacier decreases the delay between peak meltwater input and peak stream discharge. Furthermore, early spring melt flushes the snowpack of solutes and by mid-summer the melt water flowing into the glacier is fairly clean by comparison. The firn, a relatively constant feature of glaciers, attenuates variations in water drainage into the glacier by temporarily storing water in saturated layer. Bare ice exerts opposite influences by accentuating variations in runoff by water flowing over the ice surface. The melt of firn and ice contributes relatively clean (solute-free) water to the glacier water system. RP Fountain, AG (reprint author), US GEOL SURVEY,POB 25046,MS-412,DENVER,CO 80225, USA. NR 70 TC 47 Z9 49 U1 0 U2 15 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD APR PY 1996 VL 10 IS 4 BP 509 EP 521 DI 10.1002/(SICI)1099-1085(199604)10:4<509::AID-HYP389>3.0.CO;2-3 PG 13 WC Water Resources SC Water Resources GA UK106 UT WOS:A1996UK10600003 ER PT J AU Ono, A Sakuma, F Arai, K Yamaguchi, Y Fujisada, H Slater, PN Thome, KJ Palluconi, FD Kieffer, HH AF Ono, A Sakuma, F Arai, K Yamaguchi, Y Fujisada, H Slater, PN Thome, KJ Palluconi, FD Kieffer, HH TI Preflight and in-flight calibration plan for ASTER SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID ABSOLUTE CALIBRATION AB Preflight and in-flight radiometric calibration plans are described for the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) that is a multispectral optical imager of high spatial resolution. It is designed for the remote sensing from orbit of land surfaces and clouds, and is expected to be launched in 1998 on NASA's EOS AM-1 spacecraft. ASTER acquires images in three separate spectral regions, the visible and near-infrared (VNIR), the shortwave infrared (SWIR), and the thermal infrared (TIR) with three imaging radiometer subsystems. The absolute radiometric accuracy is required to be better than 4% for VNIR and SWIR radiance measurements and 1 to 3 K, depending on the temperature regions from 200 to 370 K, for TIR temperature measurements. A reference beam is introduced at the entrance pupil of each imaging radiometer to provide the in-fight calibration. Thus, the ASTER instrument includes internal onboard calibration units that comprise incandescent lamps for the VNIR and SWIR and a blackbody radiator for the TIR as reference sources. The calibration reliability of the VNIR and SWIR is enhanced by a dual system of onboard calibration units as well as by high-stability halogen lamps. A ground calibration system of spectral radiances traceable to fixed-point blackbodies is used for the preflight VNIR and SWIR calibration. Because of the possibility of nonuniform contamination effects on the partial-aperture onboard calibration, it is desirable to check their results with respect to other methods. Reflectance- and radiance-based vicarious methods have been developed for this purpose. These, and methods involving in-flight cross-calibration with other sensors are also described. C1 NATL RES LAB METROL,THERMOPHYS METROL DEPT,TSUKUBA,IBARAKI 305,JAPAN. SAGA UNIV,SAGA 840,JAPAN. GEOL SURVEY JAPAN,TSUKUBA,IBARAKI 305,JAPAN. ELECTROTECH LAB,TSUKUBA,IBARAKI 305,JAPAN. CALTECH,JET PROP LAB,PASADENA,CA. US GEOL SURVEY,FLAGSTAFF,AZ 86001. RI Thome, Kurtis/D-7251-2012 NR 32 TC 33 Z9 33 U1 0 U2 5 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1996 VL 13 IS 2 BP 321 EP 335 DI 10.1175/1520-0426(1996)013<0321:PAIFCP>2.0.CO;2 PG 15 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UG675 UT WOS:A1996UG67500006 ER PT J AU Kieffer, HH Wildey, RL AF Kieffer, HH Wildey, RL TI Establishing the moon as a spectral radiance standard SO JOURNAL OF ATMOSPHERIC AND OCEANIC TECHNOLOGY LA English DT Article ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY; ATMOSPHERIC EXTINCTION; ABSOLUTE CALIBRATION; ENERGY DISTRIBUTION; ALPHA-LYRAE; STARS; PHOTOMETRY; TRANSFORMATION; EPHEMERIDES; LIBRARY AB A new automated observatory dedicated to the radiometry of the moon has been constructed to provide new radiance information for calibration of earth-orbiting imaging instruments, particularly Earth Observing System instruments. Instrumentation includes an imaging photometer with 4.5-in. resolution on a fully digital mount and a full-aperture radiance calibration source. Interference filters within 0.35-0.95 mu m correspond to standard stellar magnitude systems, accommodate wavelengths of lunar spectral contrast, and approximate some bandpasses of planned earth-orbiting instruments (ASTER, Landsat-7 ETM, MISR, MODIS, and SeaWIFS). The same equipment is used for lunar and stellar observations, with the use of an aperture stop in lunar imaging to comply with Nyquist's theorem and lengthen exposure times to avoid scintillation effects. A typical robotic night run involves observation of about 60 photometric standard stars and the moon; about 10 of the standard stars are observed repeatedly to determine atmospheric extinction, and the moon is observed several times. Observations are to be made on every photometric night during the bright half of the month for at least 4.5 years to adequately cover phase and libration variation. Each lunar image is reduced to absolute exoatmospheric radiance and reprojected to a fixed selenographic grid system. The collection of these images at various librations and phase angles will be reduced to photometric models for each of the approximately 120 000 points in the lunar grid for each filter. Radiance models of the moon can then be produced for the precise geometry of an orbiting instrument observation. Expected errors are under 1% relative and 2.5% absolute. A second telescope operating from 1.0 to 2.5 mu m is planned. C1 NO ARIZONA UNIV,DEPT PHYS & ASTRON,FLAGSTAFF,AZ 86011. RP Kieffer, HH (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 88 TC 95 Z9 95 U1 0 U2 7 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108-3693 SN 0739-0572 J9 J ATMOS OCEAN TECH JI J. Atmos. Ocean. Technol. PD APR PY 1996 VL 13 IS 2 BP 360 EP 375 DI 10.1175/1520-0426(1996)013<0360:ETMAAS>2.0.CO;2 PG 16 WC Engineering, Ocean; Meteorology & Atmospheric Sciences SC Engineering; Meteorology & Atmospheric Sciences GA UG675 UT WOS:A1996UG67500009 ER PT J AU Lonergan, DJ Jenter, HL Coates, JD Phillips, EJP Schmidt, TM Lovley, DR AF Lonergan, DJ Jenter, HL Coates, JD Phillips, EJP Schmidt, TM Lovley, DR TI Phylogenetic analysis of dissimilatory Fe(III)-reducing bacteria SO JOURNAL OF BACTERIOLOGY LA English DT Article ID SULFATE-REDUCING BACTERIA; 16S RIBOSOMAL-RNA; GRADIENT GEL-ELECTROPHORESIS; DESULFUROMONAS-ACETOXIDANS; MICROBIAL-POPULATIONS; SP-NOV; PELOBACTER-CARBINOLICUS; HYBRIDIZATION PROBES; COMPLETE OXIDATION; ACETATE OXIDATION AB Evolutionary relationships among strictly anaerobic dissimilatory Fe(III)-reducing bacteria obtained from a diversity of sedimentary environments were examined by phylogenetic analysis of 16S rRNA gene sequences. Members of the genera Geobacter, Desulfuromonas, Pelobacter, and Desulfuromusa formed a monophyletic group within the delta subdivision of the class Proteobacteria, On the basis of their common ancestry and the shared ability to reduce Fe(III) and/or S-0, we propose that this group be considered a single family, Geobacteraceae. Bootstrap analysis, characteristic nucleotides, and higher-order secondary structures support the division of Geobacteraceae into two subgroups, designated the Geobacter and Desulfuromonas clusters. The genus Desulfuromusa and Pelobacter acidigallici make up a distinct branch within the Desulfuromonas cluster, Several members of the family Geobacteraceae, none of which reduce sulfate, were found to contain the target sequences of probes that have been previously used to define the distribution of sulfate-reducing bacteria and sulfate-reducing bacterium-like microorganisms. The recent isolations of Fe(III)-reducing microorganisms distributed throughout the domain Bacteria suggest that development of 16S rRNA probes that would specifically target all Fe(III) reducers may not be feasible, However, all of the evidence suggests that if a 16S rRNA sequence falls within the family Geobacteraceae, then the organism has the capacity for Fe(III) reduction. The suggestion, based on geological evidence, that Fe(III) reduction was the first globally significant process for oxidizing organic matter back to carbon dioxide is consistent with the finding that acetate-oxidizing Fe(III) reducers are phylogenetically diverse. C1 UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003. UNIV MARYLAND,DEPT MARINE & ESTUARINE ENVIRONM SCI,COLLEGE PK,MD 20742. US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092. MICHIGAN STATE UNIV,DEPT MICROBIOL,E LANSING,MI 48824. OI Schmidt, Thomas/0000-0002-8209-6055 NR 71 TC 234 Z9 244 U1 4 U2 29 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0021-9193 J9 J BACTERIOL JI J. Bacteriol. PD APR PY 1996 VL 178 IS 8 BP 2402 EP 2408 PG 7 WC Microbiology SC Microbiology GA UF036 UT WOS:A1996UF03600032 PM 8636045 ER PT J AU Seal, RR Robie, RA Hemingway, BS Evans, HT AF Seal, RR Robie, RA Hemingway, BS Evans, HT TI Heat capacity and entropy at the temperatures 5 K to 720 K and thermal expansion from the temperatures 298 K to 573 K of synthetic enargite (Cu3AsS4) SO JOURNAL OF CHEMICAL THERMODYNAMICS LA English DT Article ID PHASE-EQUILIBRIA; CALORIMETRY; COPPER AB The heat capacity of synthetic Cu3AsS4 (enargite) was measured by quasi-adiabatic calorimetry from the temperatures 5 K to 355 K and by differential scanning calorimetry from T = 339 K to T = 720 K. Heat-capacity anomalies were observed at T = (58.5 +/- 0.5) K (Delta(trs)H(m) degrees = 1.4 . R . K; Delta(trs)S(m) degrees = 0.02 . R) and at T = (66.5 +/- 0.5) K (Delta(trs)H(m) degrees = 4.6 . R . K; Delta(trs)S(m) degrees = 0.08 . R), where R = 8.31451 J . K-1. mol(-1). The causes of the anomalies are unknown. At T = 298.15 K, C(p,m)degrees and S-m degrees(T) are (190.4 +/- 0.2) J . K-1. mol(-1) and (257.6 +/- 0.6) J . K-1. mol(-1), respectively. The superambient heat capacities are described from T = 298.15 K to T = 944 K by the least-squares regression equation: C(p,m)degrees/(J . K-1. mol(-1)) = (196.7 +/- 1.2) + (0.0499 +/- 0.0016).(T/K) - (1918 000 +/- 84 000).(T/K)(-2). The thermal expansion of synthetic enargite was measured from T = 298.15 K to T = 573 K by powder X-ray diffraction. The thermal expansion of the unit-cell volume (Z = 2) is described from T = 298.15 K to T = 573 K by the least-squares equation: V/pm(3) = 10(6) .(288.2 +/- 0.2) + 10(4) .(1.49 +/- 0.04).(T/K). (C) 1996 Academic Press Limited C1 US GEOL SURVEY,RESTON,VA 22092. NR 9 TC 12 Z9 12 U1 0 U2 4 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0021-9614 J9 J CHEM THERMODYN JI J. Chem. Thermodyn. PD APR PY 1996 VL 28 IS 4 BP 405 EP 412 PG 8 WC Thermodynamics; Chemistry, Physical SC Thermodynamics; Chemistry GA UL369 UT WOS:A1996UL36900006 ER PT J AU Fuller, CC Davis, JA Coston, JA Dixon, E AF Fuller, CC Davis, JA Coston, JA Dixon, E TI Characterization of metal adsorption variability in a sand and gravel aquifer, Cape Cod, Massachusetts, USA SO JOURNAL OF CONTAMINANT HYDROLOGY LA English DT Article ID GRADIENT TRACER TEST; SORPTION; DISSOLUTION; SEDIMENTS; OXIDES; SOILS AB Several geochemical properties of an aquifer sediment that control metal-ion adsorption were investigated to determine their potential use as indicators of the spatial variability of metal adsorption. Over the length of a 4.5-m-long core from a sand and gravel aquifer, lead (Pb2+) and zinc (Zn2+) adsorption at constant chemical conditions (pH 5.3) varied by a factor of 2 and 4, respectively. Pb2+ and Zn2+ were adsorbed primarily by Fe- and Al-oxide coatings on quartz-grain surfaces. Per unit surface area, both Pb2+ and Zn2+ adsorption were significantly correlated with the amount of Fe and Al that dissolved from the aquifer material in a partial chemical extraction. The variability in conditional binding constants for Pb2+ and Zn2+ adsorption (log K-ADS) derived from a simple non-electrostatic surface complexation model were also predicted by extracted Fe and Al normalized to surface area. Because the abundance of Fe- and Al-oxide coatings that dominate adsorption does not vary inversely with grain size by a simple linear relationship, only a weak, negative correlation was found between the spatial variability of Pb2+ adsorption and grain size in this aquifer. The correlation between Zn2+ adsorption and grain size was not significant. Partial chemical extractions combined with surface-area measurements have potential use for estimating metal adsorption variability in other sand and gravel aquifers of negligible carbonate and organic carbon content. RP Fuller, CC (reprint author), US GEOL SURVEY, DIV WATER RESOURCES, 345 MIDDLEFIELD RD, MS 465, MENLO PK, CA 94025 USA. OI Fuller, Christopher/0000-0002-2354-8074 NR 34 TC 53 Z9 53 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-7722 J9 J CONTAM HYDROL JI J. Contam. Hydrol. PD APR PY 1996 VL 22 IS 3-4 BP 165 EP 187 DI 10.1016/0169-7722(95)00090-9 PG 23 WC Environmental Sciences; Geosciences, Multidisciplinary; Water Resources SC Environmental Sciences & Ecology; Geology; Water Resources GA UN092 UT WOS:A1996UN09200002 ER PT J AU Kennedy, ET Costa, R Smathers, WM AF Kennedy, ET Costa, R Smathers, WM TI Economic incentives - New directions for red-cockaded woodpecker habitat conservation SO JOURNAL OF FORESTRY LA English DT Article ID POLLUTION CONTROL; MARKETS; SYSTEM C1 US FISH & WILDLIFE SERV,RED COCKADED WOODPECKER FIELD OFF,CLEMSON,SC. CLEMSON UNIV,S CAROLINA AGR EXPT STN,DEPT AGR & APPL ECON,CLEMSON,SC. RP Kennedy, ET (reprint author), CLEMSON UNIV,ENVIRONM SCI & POLICY PROGRAM,STROM THURMOND INST GOVT & PUBL AFFAIRS,CLEMSON,SC 29634, USA. NR 19 TC 10 Z9 10 U1 2 U2 4 PU SOC AMER FORESTERS PI BETHESDA PA 5400 GROSVENOR LANE, BETHESDA, MD 20814 SN 0022-1201 J9 J FOREST JI J. For. PD APR PY 1996 VL 94 IS 4 BP 22 EP 26 PG 5 WC Forestry SC Forestry GA UE489 UT WOS:A1996UE48900008 ER PT J AU Darby, SE Thorne, CR Simon, A AF Darby, SE Thorne, CR Simon, A TI Numerical simulation of widening and bed deformation of straight sand-bed rivers .2. Model evaluation SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article ID ALLUVIAL CHANNELS AB In this paper the numerical model presented in the companion paper is tested and applied. Assessment of model accuracy was based on two approaches. First, predictions of evolution of a 13.5 km reach of the South Fork of the Forked Deer River, in west Tennessee, were compared to observations over a 24-yr period. Results suggest that although the model was able to qualitatively predict trends of widening and deepening, quantitative predictions were not reliable. Simulated widths and depths were within 15% of the corresponding observed values, but observed change in these parameters at the study sites were also close to these values. Simulated rates of depth adjustment were within 15% of observed rates, but observed rates of channel widening at the study sites were approximately three times those simulated by the model. In the second approach, the model was used to generate relationships between stable channel width and bank-full discharge. The model was able to successfully replicate the form of empirically derived regime-width equations. Simulations were used to demonstrate the model's ability to obtain more realistic predictions of bed evolution in widening channels. C1 UNIV NOTTINGHAM,DEPT GEOG,NOTTINGHAM NG7 2RD,ENGLAND. US GEOL SURVEY,RALEIGH,NC 27607. RI Darby, Stephen/J-5799-2012 NR 24 TC 22 Z9 27 U1 0 U2 6 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD APR PY 1996 VL 122 IS 4 BP 194 EP 202 DI 10.1061/(ASCE)0733-9429(1996)122:4(194) PG 9 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA UC583 UT WOS:A1996UC58300003 ER PT J AU Reiners, PW Nelson, BK Nelson, SW AF Reiners, PW Nelson, BK Nelson, SW TI Evidence for multiple mechanisms of crustal contamination of magma from compositionally zoned plutons and associated ultramafic intrusions of the Alaska range SO JOURNAL OF PETROLOGY LA English DT Article DE crustal contamination; Alaska Range; isotope geochemistry; Zoned plutons; assimilation ID SOUTH-CENTRAL ALASKA; DENALI FAULT SYSTEM; TRACE-ELEMENT; ISOTOPIC EVIDENCE; BASALTIC MAGMA; SM-ND; ASSIMILATION; COMPLEX; CALIFORNIA; SR AB Models of continental crustal magmagenesis commonly invoke the interaction of mafic mantle-derived magma and continental crust to explain geochemical and petrologic characteristics of crustal volcanic and plutonic rocks. This interaction and the specific mechanisms of crustal contamination associated with it are poorly understood An excellent opportunity to study the progressive effects of crustal contamination is offered by the composite plutons of the Alaska Range, a series of nine early Tertiary, multiply intruded, compositionally zoned (peridotite to granite) plutons. Large initial Sr and Nd isotopic contrasts between the crustal country rock and likely parental magmas allow evaluation of the mechanisms and extents of crustal contamination that accompanied the crystallization of these ultramafic through granitic rocks. Three contamination processes are distinguished in these plutons. The most obvious of these is assimilation of crustal country rock concurrent with magmatic fractional crystallization (AFC), as indicated by a general trend toward crustal-like isotopic signatures with increasing differentiation. Second, many ultramafic and mafic rocks have late-stage phenocryst reaction and orthocumulate textures that suggest interaction with felsic melt. These rocks also have variable and enriched isotopic compositions that suggest that this felsic melt was isotopically enriched and probably derived from crustal country rock. Partial melt from the flysch country rock may have reacted with and contaminated these partly crystalline magmas following the precipitation and accumulation of the cumulus phenocrysts but before complete solidification of the magma. This suggests that in magmatic mush (especially of ultramafic composition) crystallizing in continental crust, a second distinct process of crustal contamination may be super-imposed on AFC or magma mixing involving the main magma body. Finally, nearly all rocks, including mafic and ultramafic (Sr-87/Sr-86)(i) that are too high, and epsilon(T) N-d that are too low, to represent the expected isotopic composition of typical depleted mantle. However, gabbro xenoliths with typical depleted-mantle isotopic compositions are found in the plutons. This situation requires either an additional enriched mantle component to provide the parental magma for these plutons, or some mechanism of crustal contamination of the parent magma that did not cause significant crystallization and differentiation of the magma to more felsic compositions. Thermodynamic modeling indicates that assimilation of alkali- and water-rich partial melt of the metapelite country rock by fractionating, near-liquidus basaltic magma could cause significant contamination while suppressing significant crystallization and differentiation. C1 US GEOL SURVEY,ANCHORAGE,AK 99508. RP Reiners, PW (reprint author), UNIV WASHINGTON,BOX 351310,SEATTLE,WA 98195, USA. NR 50 TC 22 Z9 22 U1 1 U2 6 PU OXFORD UNIV PRESS UNITED KINGDOM PI OXFORD PA WALTON ST JOURNALS DEPT, OXFORD, ENGLAND OX2 6DP SN 0022-3530 J9 J PETROL JI J. Petrol. PD APR PY 1996 VL 37 IS 2 BP 261 EP 292 DI 10.1093/petrology/37.2.261 PG 32 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UJ933 UT WOS:A1996UJ93300003 ER PT J AU Work, TM Hale, J AF Work, TM Hale, J TI Causes of owl mortality in Hawaii, 1992 to 1994 SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE barn owl; Tyto alba; short eared owl; Asio flammeus; pueo; disease; toxicology; pathology; food habits ID BARN-OWLS; BIRDS AB Eighty-one barn owls (Tyto alba) and five Hawaiian owls or pueo (Asio flammeus sandwichensis) from Kauai, Oahu, Lanai, Molokai, Maul and Hawaii (USA) were evaluated for cause of death, November 1992 through August 1994. The most common cause of death in barn owls was trauma (50%) followed by infectious disease (28%) and emaciation (22%). Most traumas apparently resulted from vehicular collisions. Trichomoniasis was the predominant infectious disease and appeared to be a significant cause of death in barn owls in Hawaii. Pasteurellosis and aspergillosis were encountered less commonly. No predisposing cause of emaciation was detected. Stomach contents from 28 ham owls contained mainly insects (64%) of the family Tetigoniidae and Gryllidae, and rodents (18%); the remainder had mixtures of rodents and insects or grass, Three pueo died from trauma and one each died from emaciation and pasteurellosis. We found no evidence of organochlorine, organophosphorus, or carbamate pesticides as causes of death in pueo or barn owls. C1 US FISH & WILDLIFE SERV,ECOL SERV,ENVIRONM CONTAMINANTS BRANCH,HONOLULU,HI 96850. RP Work, TM (reprint author), NATL BIOL SERV,NATL WILDLIFE HLTH CTR,HONOLULU FIELD STN,POB 50167,HONOLULU,HI 96850, USA. RI Work, Thierry/F-1550-2015 OI Work, Thierry/0000-0002-4426-9090 NR 46 TC 19 Z9 19 U1 2 U2 14 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD APR PY 1996 VL 32 IS 2 BP 266 EP 273 PG 8 WC Veterinary Sciences SC Veterinary Sciences GA UF941 UT WOS:A1996UF94100012 PM 8722264 ER PT J AU Allen, GT Veatch, JK Stroud, RK Vendel, CG Poppenga, RH Thompson, L Shafer, JA Braselton, WE AF Allen, GT Veatch, JK Stroud, RK Vendel, CG Poppenga, RH Thompson, L Shafer, JA Braselton, WE TI Winter poisoning of coyotes and raptors with Furadan-laced carcass baits SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE Carbofuran; Furadan(R); Haliaeetus leucocephalus; Buteo jamaicensis; Canis latrans; winter ID INSECTICIDES; HISTORIES; TOXICITY; BIRDS AB Three bald eagles (Haliaeetus leucocephalus), a red-tailed hawk (Buteo jamaicensis), and two coyotes (Canis latrans) found in a field in north-central Kansas (USA) in December 1992 were poisoned by flowable carbofuran (Furadan(R) 4F) placed on sheep (Ovis aries) carcasses to kill coyotes. The carbofuran was placed on the carcasses in October 1992, but the coyotes and raptors apparently were killed in late December. Thus, flowable Furadan(R) can cause direct and secondary deaths of wildlife under some circumstances for at least 60 days following placement. C1 KANSAS STATE UNIV,COLL VET MED,DEPT VET DIAGNOSIS,MANHATTAN,KS 66506. US FISH & WILDLIFE SERV,FORENS LAB,ASHLAND,OR 97530. US FISH & WILDLIFE SERV,LENEXA,KS 66285. MICHIGAN STATE UNIV,ANIM HLTH DIAGNOST LAB,LANSING,MI 48909. KANSAS DEPT WILDLIFE & PK,SCANDIA,KS 66966. RP Allen, GT (reprint author), US FISH & WILDLIFE SERV,315 HOUSTON ST,SUITE E,MANHATTAN,KS 66502, USA. NR 14 TC 23 Z9 25 U1 1 U2 2 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD APR PY 1996 VL 32 IS 2 BP 385 EP 389 PG 5 WC Veterinary Sciences SC Veterinary Sciences GA UF941 UT WOS:A1996UF94100034 PM 8722286 ER PT J AU Williams, BK Johnson, FA Wilkins, K AF Williams, BK Johnson, FA Wilkins, K TI Uncertainty and the adaptive management of waterfowl harvests SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE adaptive management; compensatory management; harvest; hunting; modeling; population model; uncertainty; waterfowl AB Adaptive management of waterfowl harvests accounts for uncertainties about population responses to harvest, with a focus on the reduction of uncertainties pursuant to harvest objectives and other management goals. Important sources of uncertainty include limited knowledge about underlying biological relationships (structural uncertainty), sampling variation in population monitoring (partial observability), and uncontrolled variation in the setting of harvest rates (partial controllability). We used a model for adaptive harvest management to investigate the use of harvests in reducing structural uncertainties. The model allows for both compensatory and additive relationships between harvest and survival, and also includes predictors incorporating the compensatory and additive hypotheses, along with a procedure for updating predictor probabilities. The model was used to (i) characterize population changes through time, and predict population changes based on simulated data; (ii) compare predicted and observed population sizes in an effort to identify the appropriate predictor for the population; and (iii) examine the effect of harvest rate, monitoring variation, and partial controllability on the rate of reduction in structural uncertainty. Results indicate that harvest can be used to learn about additive and compensatory relationships, whichever is operative for a population. Within limits, learning can occur even with imprecise data about population status, and with substantial imprecision in the setting of harvest rates. However, learning rates are depressed by high levels of monitoring and/or harvest imprecision. C1 UNIV VERMONT,NATL BIOL SERV,VERMONT COOPERAT FISH & WILDLIFE RES UNIT,BURLINGTON,VT 05405. US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,LAUREL,MD. UNIV VERMONT,SCH NAT RESOURCES,BURLINGTON,VT 05405. NR 17 TC 70 Z9 70 U1 0 U2 13 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD APR PY 1996 VL 60 IS 2 BP 223 EP 232 DI 10.2307/3802220 PG 10 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA UF002 UT WOS:A1996UF00200002 ER PT J AU Drewien, RC Brown, WM Benning, DS AF Drewien, RC Brown, WM Benning, DS TI Distribution and abundance of sandhill cranes in Mexico SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE aerial surveys; band recoveries; brood size; Chihuahua; Durango; ground surveys; Crus canadensis; Mexico; recruitment; sandhill crane; wetlands; winter populations ID CONTINENTAL NORTH-AMERICA; WESTERN TEXAS; POPULATION AB We summarized sandhill crane (Grus canadensis [cranes]) counts from Mexico recorded during 23 January aerial waterfowl surveys by the U.S. Fish and Wildlife Service (FWS) between 1953 and 1994. Cranes were recorded at 39 areas in 14 states; 97.4% were in the Northern Highlands, 0.4% in the Central Highlands, 1.5% along the Gulf Coast, and 0.7% on the Pacific Coast. Most wintered in the states of Chihuahua (91.7%) and Durango (4.7%). Total counts of >30,000 cranes were recorded in 1979 and 1994; 70,000 were reported in Chihuahua in February 1947. Laguna de Babicora, Chihuahua, was the most important winter area. We also conducted ground and aerial surveys in Chihuahua during most winters 1970-92 and occasionally in Durango and Sonora. We found a mean of 21,649 cranes at 6 study areas in Chihuahua with highest mean counts at Laguna de Babicora (16,012), followed by Ascension (2,405) and Laguna de los Mexicanos (1,469). Our surveys indicated that >50,000 cranes winter in Mexico. At 6 study areas in Chihuahua, all 3 migratory subspecies were present with the lesser subspecies (G. c. canadensis [lessers]) composing 88.9%. The greater (G. c. tabida [greaters]) and Canadian subspecies (G. c. rowani [Canadians]) composed the remainder but could not be differentiated in field surveys; about 25% of cranes classified as greaters may have been Canadians. Annual recruitment and brood size averaged 10.1% and 1.18 in lessers and 6.5% and 1.14 in greaters. Lessers and Canadians wintering in the Interior Highlands belong to the Western Subpopulation of the Midcontinent Population (MCP), while greaters are from the Rocky Mountain Population (RMP). Based on sightings of marked cranes, band recoveries, and field observations, we estimated that about 10% of the RMP wintered in Mexico in Chihuahua and Durango. RMP cranes were more abundant in northern Chihuahua than at sites farther south (P < 0.001). Gulf Coast cranes are probably Canadians and lessers from the MCP, Gulf Coast Subpopulation. Population affiliations of Pacific Coast cranes are uncertain. Laguna de Babicora, the most important crane wintering area in Mexico, is threatened by proposed habitat alterations. Loss of this wetland would adversely affect cranes and other migratory birds, including several endangered species. Conservation plans and action are needed to protect this key winter site. C1 US FISH & WILDLIFE SERV,OFF MIGRATORY BIRD MANAGEMENT,GOLDEN,CO 80401. RP Drewien, RC (reprint author), UNIV IDAHO,HOMOCKER WILDLIFE RES INST,BOX 3246,MOSCOW,ID 83843, USA. NR 53 TC 14 Z9 15 U1 1 U2 7 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD APR PY 1996 VL 60 IS 2 BP 270 EP 285 DI 10.2307/3802225 PG 16 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA UF002 UT WOS:A1996UF00200007 ER PT J AU Hein, JR Gibbs, AE Clague, DA Torresan, M AF Hein, JR Gibbs, AE Clague, DA Torresan, M TI Hydrothermal mineralization along submarine rift zones, Hawaii SO MARINE GEORESOURCES & GEOTECHNOLOGY LA English DT Article DE Hawaii; hydrothermal; manganese oxides; mineralization; minor-metal enrichment; rift zones ID RARE-EARTH ELEMENTS; EAST-PACIFIC-RISE; BACK-ARC BASIN; HOT-SPOT AREAS; DE-FUCA RIDGE; SOUTHWEST PACIFIC; LOIHI-SEAMOUNT; GROWTH-RATES; VENT FIELD; SW PACIFIC AB This is the first article to describe mineralization of midplate submarine rift zones and hydrothermal manganese oxide mineralization of midplate volcanic edifices. Hydrothermal Mn oxides were recovered from submarine extensions of two Hawaiian rift zones, along Haleakala and Puna Ridges. These Mn oxides form two types of deposits, metallic stratiform layers in volcaniclastic rocks and cement for elastic rocks; both deposit types are composed of todorokite and birnessite. Thin Fe-Mn crusts that coat some rocks formed by a combination of hydrogenetic and hydrothermal processes and are composed of delta-MnO2. The stratiform layers have high Mn contents (mean 40%) and a large fractionation between Mn and Fe (Fe/Mn = 0.04). Unlike most other hydrothermal Mn oxide deposits, those from Hawaiian rift zones are enriched in the trace metals Zn, Co, Ba, Mo, Sr, V, and especially Ni (mean 0.16%). Metals are derived from three sources: mafic and ultramafic rocks leached by circulating hydrothermal fluids, clastic material (in Mn-cemented sandstone), and seawater that mixed with the hydrothermal fluids. Mineralization on Haleakala Ridge occurred sometime during the past 200 to 400 ka, when the summit was at a water depth of more than 1,000 m. Hydrothermal circulation was probably driven by heat produced by intrusion of dikes, magma reservoirs, and flow of magma through axial and lateral conduits. The supply of seawater to ridge interiors must be extensive because of their high porosity and permeability. Precipitation of Mn oxide below the seafloor is indicated by its occurrence as cement, growth textures that show mineralizing fluids were introduced from below, and pervasive replacement of original matrix of clastic rocks. C1 US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, HILO, HI USA. RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 999, MENLO PK, CA 94025 USA. NR 66 TC 28 Z9 30 U1 0 U2 4 PU TAYLOR & FRANCIS INC PI PHILADELPHIA PA 530 WALNUT STREET, STE 850, PHILADELPHIA, PA 19106 USA SN 1064-119X EI 1521-0618 J9 MAR GEORESOUR GEOTEC JI Mar. Geores. Geotechnol. PD APR-JUN PY 1996 VL 14 IS 2 BP 177 EP 203 PG 27 WC Engineering, Ocean; Engineering, Geological; Oceanography; Mining & Mineral Processing SC Engineering; Oceanography; Mining & Mineral Processing GA UT705 UT WOS:A1996UT70500006 ER PT J AU Poore, RZ Sloan, LC AF Poore, RZ Sloan, LC TI Introduction - Climates and climate variability of the pliocene SO MARINE MICROPALEONTOLOGY LA English DT Editorial Material ID ICE-CORE; RECORD C1 UNIV CALIF SANTA CRUZ,INST MARINE SCI,SANTA CRUZ,CA 95064. RP Poore, RZ (reprint author), US GEOL SURVEY,NATL CTR,MS 955,RESTON,VA 22092, USA. NR 7 TC 18 Z9 18 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 1 EP 2 DI 10.1016/0377-8398(96)80628-1 PG 2 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800001 ER PT J AU Dowsett, H Barron, J Poore, R AF Dowsett, H Barron, J Poore, R TI Middle Pliocene sea surface temperatures: A global reconstruction SO MARINE MICROPALEONTOLOGY LA English DT Article ID NORTH-ATLANTIC OCEAN; GRAPHIC CORRELATION; MEDITERRANEAN SEA; COASTAL-PLAIN; PALEOCEANOGRAPHY; RECORD; LEVEL; CHRONOLOGY; OSTRACODA; DEPOSITS AB Identification and analyses of Pliocene marine microfossils from 64 globally distributed stratigraphic sequences have been used to produce a middle Pliocene sea surface temperature reconstruction of the Earth. This reconstruction shows little or no change from current conditions in low latitude regions and significant warming of the ocean surface at mid and higher latitudes of both hemispheres, This pattern of warming is consistent with terrestrial records and suggests a combination of enhanced meridional ocean heat transport and enhanced greenhouse effect were responsible for the middle Pliocene warmth. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Dowsett, H (reprint author), US GEOL SURVEY,NATL CTR 955,RESTON,VA 22092, USA. OI Dowsett, Harry/0000-0003-1983-7524 NR 79 TC 177 Z9 185 U1 4 U2 15 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 13 EP 25 DI 10.1016/0377-8398(95)00050-X PG 13 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800003 ER PT J AU Thompson, RS Fleming, RF AF Thompson, RS Fleming, RF TI Middle Pliocene vegetation: Reconstructions, paleoclimatic inferences, and boundary conditions for climate modeling SO MARINE MICROPALEONTOLOGY LA English DT Review ID EARLY PLEISTOCENE CLIMATE; ATLANTIC COASTAL-PLAIN; WESTERN UNITED-STATES; NEW-ZEALAND; POLLEN ASSEMBLAGE; ISOTOPE RECORD; NORTH-AMERICA; BRESSE BASIN; LATE NEOGENE; LATE MIOCENE AB The general characteristics of global vegetation during the middle Pliocene warm period can be reconstructed from fossil pollen and plant megafossil data. The largest differences between Pliocene vegetation and that of today occurred at high latitudes in both hemispheres, where warming was pronounced relative to today. In the Northern Hemisphere coniferous forests lived in the modern tundra and polar desert regions, whereas in the Southern Hemisphere southern beech apparently grew in coastal areas of Antarctica. Pliocene middle latitude vegetation differed less, although moister-than-modem conditions supported forest and woodland growth in some regions now covered by steppe or grassland. Pliocene tropical vegetation reflects essentially modern conditions in some regions and slightly cooler-than-or warmer-than-modern climates in other areas. Changes in topography induced by tectonics may be responsible for many of the climatic changes since the Pliocene in both middle and lower latitudes. However, the overall latitudinal progression of climatic conditions on land parallels that seen in the reconstruction of middle Pliocene sea-surface temperatures. Pliocene paleovegetational data was employed to construct a 2 degrees x 2 degrees global grid of estimated mid-Pliocene vegetational cover for use as boundary conditions for numerical General Circulation Model simulations of middle Pliocene climates. Continental outlines and topography were first modified to represent the Pliocene landscape on the 2 degrees x 2 degrees grid. A modem 1 degrees x 1 degrees vegetation grid was simplified and mapped on this Pliocene grid, and then modified following general geographic trends evident in the Pliocene paleovegetation data set. RP Thompson, RS (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MAIL STOP 919,DENVER,CO 80225, USA. NR 151 TC 79 Z9 82 U1 3 U2 18 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 27 EP 49 DI 10.1016/0377-8398(95)00051-8 PG 23 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800004 ER PT J AU Thompson, RS AF Thompson, RS TI Pliocene and early Pleistocene environments and climates of the western Snake River Plain, Idaho SO MARINE MICROPALEONTOLOGY LA English DT Article ID UNITED-STATES; GREAT-BASIN; HISTORY; DEPOSITS; NEVADA AB Sedimentological, palynological, and magnetic susceptibility data provide paleoenvironmental and paleoclimatic information from a 989 ft (301 m) core of sediments from the upper Glenns Ferry and Bruneau Formations from near the town of Bruneau in Owyhee County, Idaho. Chronology is based on stratigraphic position, paleomagnetism, and biostratigraphic data, which collectively suggest a late Gauss Normal-Polarity Chron age for the Glenns Ferry sediments and a middle Matuyama Reversed-Polarity Chron age for the Bruneau sediments. A deep lake was present on the western Snake River Plain during the portions of the time represented by the Glenns Ferry Formation, and the mudstones of the lower half of the core were apparently deposited in this lake. The terminal regression of the Glenns Ferry lake may be represented in the Bruneau core by sandy mudstones and sands that overlie the deep-water mudstones. A cobble layer present in the core between the Glenns Ferry lake beds and those of the overlying Bruneau Formation may indicate through-flow by the ancestral Snake River. Palynological data from the Glenns Ferry sediments in the Bruneau core reveal a pollen flora similar to the modern regional pollen flora, with very rare occurrences of now-extirpated taxa common earlier in the Tertiary. Palynological data from the Pliocene portion of this core indicate conditions more moist than today, with cooler summers and perhaps warmer winters. Quasi-periodic fluctuations in coniferous pollen (primarily Pinus) versus arid steppe taxa (primarily Chenopodiaceae/Amaranrhus) indicate significant variations in moisture through the lower two-thirds of the Glenns Ferry portion of the core. Shorter wave-length fluctuations in magnetic susceptibility and (inversely) Artemisia may reflect variations in temperature or other unidentified climatic variables. The pollen spectra from the Bruneau Formation sediments in the Bruneau core are dominated by Artemisia and resemble those of the Wisconsinan glacial period on the Snake River Plain, and hence indicate cold and dry conditions during some portion of the early Pleistocene. The deep-water Glenns Ferry lacustrine episode appears to date between approximately 3.5 to 3.3 and 2.5 Ma, and thus occurred during the middle Pliocene period of warmer-than-modern global temperatures. Similar sustained wetter-than-present conditions occurred in the same age range at sites across the western U.S.A. from southern California and Arizona to northern California and Idaho. This moist period was apparently followed by an interval of regional arid conditions that persisted for several hundred thousand years. RP Thompson, RS (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 919,DENVER,CO 80225, USA. NR 51 TC 9 Z9 9 U1 1 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 141 EP 156 DI 10.1016/0377-8398(95)00056-9 PG 16 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800010 ER PT J AU Ishman, SE AF Ishman, SE TI A benthic foraminiferal record of middle to late Pliocene (3.15-2.85 Ma) deep water change in the North Atlantic SO MARINE MICROPALEONTOLOGY LA English DT Article ID OCEAN CIRCULATION; SOUTHERN-OCEAN; SEA; PHYTODETRITUS; DEGLACIATION; VARIABILITY; IMPACT AB Records of benthic foraminifera from North Atlantic DSDP Site 607 and Hole 610A indicate changes in deep water conditions through the middle to late Pliocene (3.15 to 2.85 Ma). Quantitative analyses of modern associations in the North Atlantic indicate that seven species, Fontbotia wuellerstorfi, Cibicidoides kullenbergi, Uvigerina peregrina, Nuttallides umboniferus, Melonis pompilioides, Globocassidulina subglobosa and Epistominella exigua are useful for paleoenvironmental interpretation. The western North Atlantic basin (Site 607) was occupied by North Atlantic Deep Water (NADW) until similar to 2.88 Ma. At that time, N. umboniferus increased, indicating an influx of Southern Ocean Water (SOW). The eastern North Atlantic basin (Hole 610A) was occupied by a relatively warm water mass, possibly Northeastern Atlantic Deep Water (NEADW),through similar to 2.94 Ma when SOW more strongly influenced the site. These interpretations are consistent with benthic delta(18)O and delta(13)C records from 607 and 610A (Raymo et al., 1992). The results presented in this paper suggest that the North Atlantic was strongly influenced by northern component deep water circulation until 2.90-2.95 Ma. After that there was a transition toward a glacially driven North Atlantic circulation more strongly influenced by SOW associated with the onset of Northern Hemisphere glaciation. The circulation change follows the last significant SST and atmospheric warming prior to similar to 2.6 Ma. RP Ishman, SE (reprint author), US GEOL SURVEY,NATL CTR 970,RESTON,VA 22092, USA. NR 49 TC 10 Z9 10 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 165 EP 180 DI 10.1016/0377-8398(95)00058-5 PG 16 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800012 ER PT J AU Dowsett, H Willard, D AF Dowsett, H Willard, D TI Southeast Atlantic marine and terrestrial response to middle Pliocene climate change SO MARINE MICROPALEONTOLOGY LA English DT Article ID SEA DRILLING PROJECT; COASTAL-PLAIN; SITE 532; LEG 75; LEVEL; PALEOCEANOGRAPHY; CHRONOLOGY; SEDIMENTS; BENGUELA; MARGIN AB Analysis of planktic foraminifers and pollen from Deep Sea Drilling Project Site 532 located on the continental margin of southwest Africa provides information on the link between Pliocene paleoceanographic conditions and paleoenvironments of southwest Africa. Increased upwelling at Site 532 correlates with southward migration of onshore vegetation regions. Both terrestrial and marine changes can be explained by changes in the southern hemisphere surface temperature gradient which affected the paleo-position of subtropical high pressure cells and productivity of water masses during the Pliocene. When the subtropical high pressure cells were further south, Southern Ocean waters were warmer, contained less sea ice, Southern Ocean diatom productivity was high, and nutrient depleted water upwelled off southwest Africa. When the subtropical high pressure cells were in a configuration similar to the present, Southern Ocean waters were cooler and contained more sea ice, the aerial extent of Southern Ocean diatom productivity was limited, and nutrient rich waters upwelled off southwest Africa as the Benguela upwelling system migrated closer to the position of Site 532. RP Dowsett, H (reprint author), US GEOL SURVEY,NATL CTR 955,RESTON,VA 22092, USA. OI Dowsett, Harry/0000-0003-1983-7524 NR 53 TC 20 Z9 20 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 181 EP 193 DI 10.1016/0377-8398(95)00059-3 PG 13 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800013 ER PT J AU Barron, JA AF Barron, JA TI Diatom constraints on the position of the Antarctic Polar Front in the middle part of the Pliocene SO MARINE MICROPALEONTOLOGY LA English DT Article ID SOUTHERN-OCEAN; SEDIMENTS AB The relative percentages of diatom taxa in 5 deep-sea cores (DSDP 266, ODP 699A, ODP 747A, ODP 751A, and Eltanin Core 50-28) from the Southern Ocean are determined for an interval centered on 3.1 to 2.9 Ma in the middle part of the Pliocene. This climatically warm interval, which is being studied by the PRISM Project of the U.S. Geological Survey, coincides. with a proposed interval of major deglaciation of East Antarctica. The maximum southerly position of the Antarctic Polar Front between 3.1 and 3.0 Ma is inferred from these diatom studies, the presence of calcareous nannofossils in the sediments, and sedimentologic and micropaleontologic information from the literature. It is suggested that the Antarctic Polar Front may have migrated by as much as 6 degrees of latitude further to the south in the southeastern Atlantic and Indian Oceans during this Pliocene warm interval but probably lay close to its present day position in the southwest Atlantic and Drake Passage. Summer sea surface temperatures are inferred to have been no more than 3 degrees-4 degrees C warmer than present at latitudes between 55 degrees and 60 degrees S. RP Barron, JA (reprint author), US GEOL SURVEY,MS 915,MENLO PK,CA 94025, USA. NR 48 TC 46 Z9 46 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 195 EP & DI 10.1016/0377-8398(95)00060-7 PG 17 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800014 ER PT J AU Fleming, RF Barron, JA AF Fleming, RF Barron, JA TI Evidence of Pliocene Nothofagus in Antarctica from Pliocene marine sedimentary deposits (DSDP Site 274) SO MARINE MICROPALEONTOLOGY LA English DT Article ID NORTH-ATLANTIC; OCEAN; SEA AB Microfossil assemblages in Pliocene sediments from DSDP Site 274 (68 degrees 59.81'S, 173 degrees 25.64'E) provide data on the age of the sediments and suggest the presence of Norhofagus (southern beech) in Antarctica during the Pliocene. A suite of 17 samples was collected in an interval from Samples 28-274-6R-1, 83-87 cm to 28-274-11R-4, 73-77 cm (48.33-100.29 mbsf). Biostratigraphic study of the abundant diatom assemblages combined with published radiolarian data indicates that the sample interval ranges in age from 5.0 to 2.2 Ma, with an apparent unconformity between about 3.8 and 3.2 Ma. Nothofagidites (the genus for fossil pollen referable to Nothofagus) occurs throughout the interval, as well as pollen and spores with known stratigraphic ranges that unequivocally indicate reworking from older rocks. Species of Nothofagidites recovered include N. asperus, N. brachyspinulosus, N. flemingii, N. senectus, and N. sp. cf. N. lachlamiae; the latter form is previously known from the Sirius Group in the Transantarctic Mountains. Abundant palynomorphs were recovered in only three of the samples from Site 274 (Samples 28-274-9R-2, 15-19 cm; 28-274-9R-2, 48-52 cm; and 28-274-9R-2, 65-69 cm). Based on the diatom and radiolarian biostratigraphic data, the ages of these samples range from 3.00 to 3.01 Ma. The relative abundance of N. sp. cf. N. lachlaniae in the three samples is an order of magnitude higher than relative abundances for the other species of Nothofagidites in the same samples. The significantly higher relative abundance of N. sp. cf. N. lachlaniae suggests that this pollen was derived from trees of Norhofagus that were living in Antarctica during the mid Pliocene. Diatom assemblages from these three samples indicate that sediments in this interval were rapidly deposited as biogenic oozes in an open-ocean setting relatively free of sea ice, thus decreasing the possibility of reworking from a single source bed rich in N. sp. cf. N. lachlaniae. Clearly, more detailed work in additional well-dated cores from around Antarctica is needed before a clear picture of the Neogene history of Antarctic terrestrial vegetation emerges. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Fleming, RF (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 919,DENVER,CO 80225, USA. NR 35 TC 25 Z9 29 U1 0 U2 2 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0377-8398 J9 MAR MICROPALEONTOL JI Mar. Micropaleontol. PD APR PY 1996 VL 27 IS 1-4 BP 227 EP 236 DI 10.1016/0377-8398(95)00062-3 PG 10 WC Paleontology SC Paleontology GA UP078 UT WOS:A1996UP07800016 ER PT J AU Foord, EE AF Foord, EE TI Clinobisvanite, eulytite, and namibite from the Pala pegmatite district, San Diego Co, California, USA SO MINERALOGICAL MAGAZINE LA English DT Article DE clinobisvanite; eulytite; namibite; Pala pegmatite district; California; bismuth minerals RP Foord, EE (reprint author), US GEOL SURVEY,MS 905,BOX 25046,DENVER,CO 80225, USA. NR 7 TC 0 Z9 0 U1 0 U2 0 PU MINERALOGICAL SOCIETY PI LONDON PA 41 QUEENS GATE, LONDON, ENGLAND SW7 5HR SN 0026-461X J9 MINERAL MAG JI Mineral. Mag. PD APR PY 1996 VL 60 IS 399 BP 387 EP 388 DI 10.1180/minmag.1996.060.399.14 PG 2 WC Mineralogy SC Mineralogy GA UL910 UT WOS:A1996UL91000014 ER PT J AU Piper, DZ Isaacs, CM AF Piper, DZ Isaacs, CM TI Instability of bottom-water redox conditions during accumulation of quaternary sediment in the Japan Sea SO PALEOCEANOGRAPHY LA English DT Review ID RARE-EARTH ELEMENTS; NORTH PACIFIC-OCEAN; BLACK-SEA; PARTICULATE MATTER; TRACE-ELEMENTS; ORGANIC-MATTER; CARIACO TRENCH; MINOR ELEMENTS; GEOCHEMISTRY; SEAWATER AB The concentrations of Cd, Cr, Cu, Mo, Ni, Sb, U, V, and Zn were measured in early Quaternary sediment (1.32 to 1.08 Ma) from the Oki Ridge in the Japan Sea. The elements were partitioned between a detrital fraction, composed of terrigenous and volcaniclastic aluminosilicate debris, and a marine fraction, composed of biogenic and hydrogenous debris derived from seawater. The most important factors controlling minor-element accumulation rates in the marine fraction were (1) primary productivity in the photic zone, which largely controlled the flux of particulate organic-matter-bound minor elements settling through the water column and onto the seafloor, and (2) bottom-water redox, which determined the suite of elements that accumulated directly from seawater. This marine fraction of minor elements on Oki Ridge recorded six periods of high minor-element abundance. Assuming a constant bulk sediment accumulation rate, each period lasted roughly 5,000 to 10,000 years with a 41,000-year cycle. Accumulation rates of individual elements such as Cd, Mo, and U suggest sulfate-reducing conditions were established in the bottom water during the 10,000-year periods; accumulation rates of Cr and V during the intervening periods are indicative of less reducing, denitrifying conditions. Interelement ratios, for example, Cu:Mo, V:Cr, and Sb:Mo, further reflect bottom-water instability, such that bottom-water redox actually varied from sulfate reducing to denitrifying during the periods of highest minor-element accumulation rates; it varied from denitrifying to oxidizing during the intervening periods. Sediment lithology supports these interpretations of the minor-element distributions; the sediment is finely laminated for several of the periods represented by Cd, Mo, and U maxima and weakly laminated to bioturbated for the intervening periods. The geochemistry of this sediment demonstrates the unambiguous signal of Mo, principally, but of several other minor elements as well in recording sulfate-reducing conditions in bottom water. The forcing function that altered their accumulation, that is, that altered primary productivity and bottom water redox conditions, is problematic. Currently held opinion suggests that O-2 depletion was most strongly developed during glacial advances. Low sea level during such times is interpreted to have enhanced primary productivity and restricted bottom-water advection. RP Piper, DZ (reprint author), US GEOL SURVEY, M-S 902, MENLO PK, CA 94025 USA. NR 103 TC 37 Z9 37 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 0883-8305 J9 PALEOCEANOGRAPHY JI Paleoceanography PD APR PY 1996 VL 11 IS 2 BP 171 EP 190 DI 10.1029/95PA03553 PG 20 WC Geosciences, Multidisciplinary; Oceanography; Paleontology SC Geology; Oceanography; Paleontology GA UZ847 UT WOS:A1996UZ84700004 ER PT J AU Mankinen, EA Irwin, WP Blome, CD AF Mankinen, EA Irwin, WP Blome, CD TI Far-travelled Permian chert of the North Fork Terrane, Klamath Mountains, California SO TECTONICS LA English DT Article ID PALEOMAGNETIC DATA; TECTONIC HISTORY; PROVINCE; MAGNETOSTRATIGRAPHY; PALEOLATITUDES; ACCRETION; ROTATION; COMPLEX; AMERICA; CHINA AB Permian chert in the North Fork terrane and correlative rocks of the Klamath Mountains province has a remanent magnetization that is prefolding and presumably primary. Paleomagnetic results indicate that the chert formed at a paleolatitude of 8.6 degrees +/- 2.5 degrees but in which hemisphere remains uncertain. This finding requires that these rocks have undergone at least 8.6 degrees +/- 4.4 degrees of northward transport relative to Permian North America since their deposition. Paleontological evidence suggests that the Permian limestone of the Eastern Klamath terrane originated thousands of kilometers distant from North America. The limestone of the North Fork terrane may have formed at a similar or even greater distance as suggested by its faunal affinity to the Eastern Klamath terrane and more westerly position. Available evidence indicates that convergence of the North Fork and composite Central Metamorphic-Eastern Klamath terranes occurred during Triassic or Early Jurassic time and that their joining together was a Middle Jurassic event. Primary and secondary magnetizations indicate that the new composite terrane containing these and other rocks of the Western Paleozoic and Triassic belt behaved as a single rigid block that has been latitudinally concordant with the North American craton since Middle Jurassic time. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. US GEOL SURVEY,MENLO PK,CA 94025. NR 63 TC 16 Z9 16 U1 1 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD APR PY 1996 VL 15 IS 2 BP 314 EP 328 DI 10.1029/95TC03054 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF110 UT WOS:A1996UF11000008 ER PT J AU Parsons, T McCarthy, J AF Parsons, T McCarthy, J TI Crustal and upper mantle velocity structure of the Salton Trough, southeast California SO TECTONICS LA English DT Article ID FINITE-DIFFERENCE CALCULATION; METAMORPHIC CORE COMPLEX; COLORADO PLATEAU; IMPERIAL-VALLEY; ARIZONA; CONSTRAINTS; PACIFIC; GULF; RIFT AB This paper presents data and modelling results from a crustal and upper mantle wide-angle seismic transect across the Salton Trough region in southeast California. The Salton Trough is a unique part of the Basin and Range province where mid-ocean ridge/transform spreading in the Gulf of California has evolved northward into the continent. In 1992, the U.S. Geological Survey (USGS) conducted the final leg of the Pacific to Arizona Crustal Experiment (PACE). Two perpendicular models of the crust and upper mantle were fit to wide-angle reflection and refraction travel times, seismic amplitudes, and Bouguer gravity anomalies. The first profile crossed the Salton Trough from the southwest to the northeast, and the second was a strike line that paralleled the Salton Sea along its western edge. We found thin crust (similar to 21-22 km thick) beneath the axis of the Salton Trough (Imperial Valley) and locally thicker crust (similar to 27 km) beneath the Chocolate Mountains to the northeast. We modelled a slight thinning of the crust further to the northeast beneath the Colorado River (similar to 24 km) and subsequent thickening beneath the metamorphic core complex belt northeast of the Colorado River. There is a deep, apparently young basin (similar to 5-6 km unmetamorphosed sediments) beneath the Imperial Valley and a shallower (similar to 2-3 km) basin beneath the Colorado River. A regional 6.9-km/s layer (between similar to 15-km depth and the Moho) underlies the Salton Trough as well as the Chocolate Mountains where it pinches out at the Moho. This lower crustal layer is spatially associated with a low-velocity (7.6-7.7 km/s) upper mantle. We found that our crustal model is locally compatible with the previously suggested notion that the crust of the Salton Trough has formed almost entirely from magmatism in the lower crust and sedimentation in the upper crust. However, we observe an apparently magmatically emplaced lower crust to the northeast, outside of the Salton Trough, and propose that this layer in part predates Salton Trough rifting. It may also in part result from migration of magmatic spreading centers associated with the southern San Andreas fault system. These spreading centers may have existed east of their current locations in the past and may have influenced the lower crust and upper mantle to the east of the current Salton Trough. RP Parsons, T (reprint author), US GEOL SURVEY,BRANCH PACIFIC MARINE GEOL,MAIL STOP 999,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Parsons, Tom/A-3424-2008; OI Parsons, Tom/0000-0002-0582-4338 NR 30 TC 29 Z9 30 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD APR PY 1996 VL 15 IS 2 BP 456 EP 471 DI 10.1029/95TC02616 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF110 UT WOS:A1996UF11000018 ER PT J AU Johnson, SY AF Johnson, SY TI Depositional history of the Eocene Chumstick Formation: Implications of tectonic partitioning for the history of the Leavenworth and Entiat-Eagle Creek fault systems, Washington - Comment SO TECTONICS LA English DT Article ID CENTRAL CASCADES; STRIKE-SLIP; EVOLUTION; NORTHWEST; STRATIGRAPHY; BASIN RP Johnson, SY (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 966,BOX 25046,DENVER,CO 80225, USA. NR 23 TC 2 Z9 2 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD APR PY 1996 VL 15 IS 2 BP 506 EP 509 DI 10.1029/95TC03694 PG 4 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UF110 UT WOS:A1996UF11000021 ER PT J AU Hay, LE Knapp, LK AF Hay, LE Knapp, LK TI Integrating a geographic information system, a scientific visualization system, and a precipitation model SO WATER RESOURCES BULLETIN LA English DT Article DE orographic precipitation; hydroclimatic modeling; Geographic Information System (GIS); Scientific Visualization System (SVS); software AB Investigating natural, potential, and human-induced impacts on hydrologic systems commonly requires complex modeling with overlapping data requirements, plus massive amounts of one- to four-dimensional data at multiple scales and formats. Given the complexity of most hydrologic studies, the requisite software infrastructure must incorporate many components including simulation modeling and spatial analysis with a flexible, intuitive display. Integrating geographic information systems (GIS) and scientific visualization systems (SVS) provides such an infrastructure. This paper describes an integrated system consisting of an orographic precipitation model, a GIS, and an SVS. The results of this study provide a basis for improving the understanding of hydro-climatic processes in mountainous regions. An additional benefit of the integrated system, the value of which is often underestimated, is the improved ability to communicate model results, leading to a broader understanding of the model assumptions, sensitivities, and conclusions at a management level. C1 INT BUSINESS MACHINE GOVT SYST,BOULDER,CO 80301. RP Hay, LE (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 412,BOX 25046,DENVER,CO 80225, USA. NR 14 TC 0 Z9 0 U1 0 U2 1 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD APR PY 1996 VL 32 IS 2 BP 357 EP 369 PG 13 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA UG715 UT WOS:A1996UG71500015 ER PT J AU Lee, TM AF Lee, TM TI Hydrogeologic controls on the groundwater interactions with an acidic lake in karst terrain, Lake Barco, Florida SO WATER RESOURCES RESEARCH LA English DT Article ID RECHARGE; SEEPAGE AB Transient groundwater interactions and lake stage were simulated for Lake Barco, an acidic seepage lake in the mantled karst of north central Florida. Karst subsidence features affected groundwater flow patterns in the basin and groundwater fluxes to and from the lake. Subsidence features peripheral to the lake intercepted potential groundwater inflow and increased leakage from the shallow perimeter of the lake bed. Simulated groundwater fluxes were checked against net groundwater flow derived from a detailed lake hydrologic budget with short-term lake evaporation computed by the energy budget method. Discrepancies between modeled and budget-derived net groundwater flows indicated that the model underestimated groundwater inflow, possibly contributed to by transient water table mounding near the lake. Recharge from rainfall reduced lake leakage by 10 to 15 times more than it increased groundwater inflow. As a result of the karst setting, the contributing groundwater basin to the lake was 2.4 ha for simulated average rainfall conditions, compared to the topographically derived drainage basin area of 81 ha. Short groundwater inflow path lines and rapid travel times limit the contribution of acid-neutralizing solutes from the basin, making Lake Barco susceptible to increased acidification by acid rain. RP Lee, TM (reprint author), US GEOL SURVEY,4710 EISENHOWER BLVD,SUITE B-5,TAMPA,FL 33634, USA. NR 54 TC 32 Z9 32 U1 3 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1996 VL 32 IS 4 BP 831 EP 844 DI 10.1029/96WR00162 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UC939 UT WOS:A1996UC93900007 ER PT J AU Szabo, Z Rice, DE Plummer, LN Busenberg, E Drenkard, S AF Szabo, Z Rice, DE Plummer, LN Busenberg, E Drenkard, S TI Age dating of shallow groundwater with chlorofluorocarbons, tritium helium 3, and flow path analysis, southern New Jersey coastal plain SO WATER RESOURCES RESEARCH LA English DT Article ID HYDROLOGIC TRACERS; CCL2F2; CCL3F; HE-3; FLUOROCARBONS; ATMOSPHERE; RECHARGE; RELEASE; TOOLS AB Groundwater age dating through the combination of transient tracer methods (chlorofluorocarbons (CFCs) and tritium/helium 3 (H-3/He-3)) and groundwater flow path analysis is useful for investigating groundwater travel times, flow patterns, and recharge rates, as demonstrated by this study of the homogeneous shallow, unconfined Kirkwood-Cohansey aquifer system in the southern New Jersey coastal plain. Water samples for age dating were collected from three sets of nested observation wells (10 wells) with 1.5-m-long screens located near groundwater divides. Three steady state finite difference groundwater flow models were calibrated by adjusting horizontal and vertical hydraulic conductivities to match measured heads and head differences (range, 0.002-0.23 m) among the nested wells, with a uniform recharge rate of 0.46 m per year and porosities of 0.35 (sand) and 0.45 (silt) that were assumed constant for all model simulations and travel time calculations. The simulated groundwater travel times increase with depth in the aquifer, ranging from about 1.5 to 6.5 years for the shallow wells (screen bottoms 3-4 m below the water table), from about 10 to 25 years for the medium-depth wells (screen bottoms 8-19 m below the water table), and from about 30 to more than 30 years for the deep wells (screen bottoms 24-26 m below the water table). Apparent groundwater ages based on CFC- and H-3/He-3-dating techniques and model-based travel times could not be statistically differentiated,, and all were strongly correlated with depth. Confinement of He-3 was high because of the rapid vertical flow velocity (of the order of 1 m/yr), resulting in clear delineation of groundwater travel times based on the H-3/He-3-dating technique. The correspondence between the H-3/He-3 and CFC ages indicates that dispersion has had a minimal effect on the tracer-based ages of water in this aquifer. Differences between the tracer-based apparent ages for seven of the 10 samples were smaller than the error values, A slight bias toward older apparent ages, found not to be statistically significant, was noted for the H-3/He-3-dating technique relative to the CFC-dating technique. This result may be caused by enrichment of local air in CFC-11 and CFC-12 from urban and industrial sources in the northeastern United States and minor contamination from sampling equipment. The demonstrated validity of the combined tracer-dating techniques to determine the age of water in the Kirkwood-Cohansey aquifer system indicates that groundwater flow models can be refined when apparent ages based on H-3/He-3- and CFC-dating are used as calibration targets. C1 US GEOL SURVEY,RESTON,VA 22092. LAMONT DOHERTY EARTH OBSERV,PALISADES,NY. COLUMBIA UNIV,DEPT GEOL SCI,NEW YORK,NY 10027. RP Szabo, Z (reprint author), US GEOL SURVEY,810 BEAR TAVERN RD,SUITE 206,W TRENTON,NJ 08628, USA. OI Plummer, L. Niel/0000-0002-4020-1013 NR 43 TC 99 Z9 106 U1 4 U2 26 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1996 VL 32 IS 4 BP 1023 EP 1038 DI 10.1029/96WR00068 PG 16 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UC939 UT WOS:A1996UC93900023 ER PT J AU Komor, SC Magner, JA AF Komor, SC Magner, JA TI Nitrate in groundwater and water sources used by riparian trees in an agricultural watershed: A chemical and isotopic investigation in southern Minnesota SO WATER RESOURCES RESEARCH LA English DT Article ID BUFFER STRIPS; STREAM; ZONE; SEDIMENT; DYNAMICS AB This study evaluates processes that affect nitrate concentrations in groundwater beneath riparian zones in an agricultural watershed. Nitrate pathways in the upper 2 m of groundwater were investigated beneath wooded and grass-shrub riparian zones next to cultivated fields, Because trees can be important components of the overall nitrate pathway in wooded riparian zones, water sources used by riparian trees and possible effects of trees on nitrate concentrations in groundwater were also investigated. Average nitrate concentrations in shallow groundwater beneath the cultivated fields were 5.5 mg/L upgradient of the wooded riparian zone and 3.5 mg/L upgradient of the grass-shrub zone. Shallow groundwater beneath the fields passed through the riparian zones and discharged into streams that had average nitrate concentrations of 8.5 mg/L (as N). Lateral variations of delta D values in groundwater showed that mixing among different water sources occurred beneath the riparian zones. In the wooded riparian zone, nitrate concentrations in shallow groundwater were diluted by upwelling, nitrate-poor, deep groundwater. Upwelling deep groundwater contained ammonium with a delta(15)N of 5 parts per thousand that upon nitrification and mixing with nitrate in shallow groundwater caused nitrate delta(15)N values in shallow groundwater to decrease by as much as 19.5 parts per thousand, Stream water penetrated laterally beneath the wooded riparian zone as far as 19 m from the stream's edge and beneath the grass-shrub zone as far as 27 m from the stream's edge. Nitrate concentrations in shallow groundwater immediately upgradient of where it mixed with stream water averaged 0.4 mg/L in the wooded riparian zone and 0.8 mg/L near the grass-shrub riparian zone. Nitrate concentrations increased toward the streams because of mixing with nitrate-rich stream water. Because nitrate concentrations were larger in stream water than shallow groundwater, concentrated nitrate in the streams cannot have come from shallow groundwater at these sites. Water sources of riparian trees were identified by comparing delta D values of sap water, soil water, groundwater, and stream water. Soil water was the main water source for trees in the outer 4 to 6 m of one part of the wooded riparian zone and outer 10 m of another part. Groundwater was a significant water source fur trees closer to the streams where the water table was less than about 2.1 to 2.7 m below the surface. No evidence was found in the nitrate concentration profiles that trees close to the streams that took up groundwater through their roots also took up nitrate from groundwater. The lack of such evidence is attributed to the nitrate concentration profiles being insufficiently sensitive indicators of nitrate removal by trees. C1 MINNESOTA POLLUT CONTROL AGCY,ST PAUL,MN 55155. US GEOL SURVEY,MOUNDS VIEW,MN 55112. NR 34 TC 24 Z9 24 U1 2 U2 11 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD APR PY 1996 VL 32 IS 4 BP 1039 EP 1050 DI 10.1029/95WR03815 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA UC939 UT WOS:A1996UC93900024 ER PT J AU Chouet, BA AF Chouet, BA TI Long-period volcano seismicity: Its source and use in eruption forecasting SO NATURE LA English DT Review ID MOUNT ST-HELENS; FLUID-DRIVEN CRACK; SOURCE MODEL; TREMOR; MECHANISM; JAPAN; EARTHQUAKES; EXCITATION; ANATOMY; KILAUEA AB At an active volcano, long-period seismicity (with typical periods in the range 0.2-2 s) reflects pressure fluctuations resulting from unsteady mass transport in the sub-surface plumbing system, and hence provides a glimpse of the internal dynamics of the volcanic edifice. When this activity occurs at shallow depths, it may signal the pressure-induced disruption of the steam-dominated region of the volcano, and can accordingly be a useful indicator of impending eruption. RP Chouet, BA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. RI Jiao, Liqing/A-8821-2011 NR 76 TC 480 Z9 487 U1 15 U2 82 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD MAR 28 PY 1996 VL 380 IS 6572 BP 309 EP 316 DI 10.1038/380309a0 PG 8 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA UC379 UT WOS:A1996UC37900049 ER PT J AU Moldowan, JM Ekuan, A Dahl, J Kvenvolden, KA Hostettler, FD AF Moldowan, JM Ekuan, A Dahl, J Kvenvolden, KA Hostettler, FD TI Bioremediation effects on steranes: Examples from the Exxon Valdez on spill. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 STANFORD UNIV,DEPT GEOL & ENVIRONM SCI,STANFORD,CA 94305. US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 2 EP GEOC PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202668 ER PT J AU Thurman, EM Aga, DS Zimmerman, LR Goolsby, DA AF Thurman, EM Aga, DS Zimmerman, LR Goolsby, DA TI Use of enzyme immunoassay for large water-quality surveys of major herbicides. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,LAWRENCE,KS 66049. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 4 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202365 ER PT J AU Aga, DS Zimmerman, LR Yockel, ME Thurman, EM AF Aga, DS Zimmerman, LR Yockel, ME Thurman, EM TI Integration immunoassay with conventional methods in the study of the fate and transport of herbicides in soil SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,LAWRENCE,KS 66049. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 13 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202374 ER PT J AU Yu, P Yang, IC Ryan, JN AF Yu, P Yang, IC Ryan, JN TI The use of tritium to determine the mean residence time of the unsaturated zone groundwater at Yucca mountain SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 UNIV COLORADO,DEPT CIVIL ENVIRONM & ARCHITECTURAL ENGN,BOULDER,CO 80309. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 20 EP GEOC PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202686 ER PT J AU Dombrowski, TR Thurman, EM AF Dombrowski, TR Thurman, EM TI Evaluation of immunoassay for determination of pesticide concentrations at a large-scale ground-water contamination site SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,LAWRENCE,KS 66049. ROCKY MT ARSENAL,COMMERCE CITY,CO 80022. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 39 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202400 ER PT J AU Eganhouse, RP AF Eganhouse, RP TI Depositional history of sediments near a major submarine municipal wastewater outfall SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,NATL CTR 432,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 45 EP ENVR PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202406 ER PT J AU Lerch, RN Thurman, EM AF Lerch, RN Thurman, EM TI Extraction of hydroxylated atrazine degradation products from soil by cation exchange. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 ARS,USDA,CROPPING SYST & WATER QUAL RES UNIT,COLUMBIA,MO. US GEOL SURVEY,DIV WATER RESOURCES,ORGAN GEOCHEM RES GRP,LAWRENCE,KS. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 68 EP AGRO PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200141 ER PT J AU McBeath, MK Davis, JA Coston, JA AF McBeath, MK Davis, JA Coston, JA TI Adsorption of uranium onto a noncrystalline aluminosilicate. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 1 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 68 EP GEOC PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202735 ER PT J AU Waychunas, GA Davis, JA Fuller, CC Kohler, M AF Waychunas, GA Davis, JA Fuller, CC Kohler, M TI EXAFS study of Fe3+ sorbed onto a silica surface: The effects of surface coverage, ageing and dehydration. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 STANFORD UNIV,CTR MAT RES,STANFORD,CA 94305. US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 73 EP COLL PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202031 ER PT J AU Battaglin, WA Hay, LE Goolsby, DA AF Battaglin, WA Hay, LE Goolsby, DA TI Effects of sampling strategies on estimates of annual mean herbicide concentrations in midwestern rivers SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 76 EP AGRO PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200149 ER PT J AU Thorn, KA AF Thorn, KA TI Examples of NMR in the analysis of environmental contaminants and contaminant interactions. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 USGS,ARVADA,CO 80002. NR 0 TC 0 Z9 0 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 100 EP ANYL PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200367 ER PT J AU Price, LC AF Price, LC TI Significance of oil-like hydrocarbons in metamorphic and ore-deposit rocks SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 108 EP GEOC PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202775 ER PT J AU Eganhouse, RP Dorsey, TF Phinney, CS AF Eganhouse, RP Dorsey, TF Phinney, CS TI Factors controlling the fate of petroleum hydrocarbons in a sand and gravel aquifer. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,RESTON,VA 22092. US GEOL SURVEY,NWQL,DENVER,CO 80225. NIST,GAITHERSBURG,MD 20899. SCCWRP,WESTMINSTER,CA 92683. NR 0 TC 0 Z9 0 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 109 EP ENVR PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202470 ER PT J AU Smith, KS Ranville, JF Plumlee, GS Macalady, DL AF Smith, KS Ranville, JF Plumlee, GS Macalady, DL TI Predictive double-layer modeling of metal sorption in mine-drainage systems. SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. COLORADO SCH MINES,DEPT CHEM & GEOCHEM,GOLDEN,CO 80401. RI Ranville, James/H-1428-2011 NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 127 EP GEOC PN 1 PG 2 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48202794 ER PT J AU Goolsby, DA Thurman, EM Kolpin, DW Battaglin, WA AF Goolsby, DA Thurman, EM Kolpin, DW Battaglin, WA TI Triazine herbicides in the hydrologic cycle in the Mississippi River basin SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 143 EP AGRO PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200215 ER PT J AU Thurman, EM Goolsby, DA AF Thurman, EM Goolsby, DA TI Occurrence of deethylatrazine and deisopropylatrazine in surface and ground water SO ABSTRACTS OF PAPERS OF THE AMERICAN CHEMICAL SOCIETY LA English DT Meeting Abstract C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. US GEOL SURVEY,LAWRENCE,KS 66049. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0065-7727 J9 ABSTR PAP AM CHEM S JI Abstr. Pap. Am. Chem. Soc. PD MAR 24 PY 1996 VL 211 BP 144 EP AGRO PN 1 PG 1 WC Chemistry, Multidisciplinary SC Chemistry GA UA482 UT WOS:A1996UA48200216 ER PT J AU Wershaw, R Llaguno, EC Leenheer, J Sperline, R Song, Y AF Wershaw, R Llaguno, EC Leenheer, J Sperline, R Song, Y TI Mechanism of formation of humus coatings on mineral surfaces .2. Attenuated total reflectance spectra of hydrophobic and hydrophilic fractions of organic acids from compost leachate on alumina SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE adsorption; alumina; humus coatings; infrared spectroscopy; organic acids ID INTERFACE AB Hydrophobic and hydrophilic fractions were isolated from a compost leachate. The adsorption isotherms of both fractions on alumina were measured by attenuated total reflectance infrared spectroscopy. The shapes of the adsorption isotherms of the two fractions were different. The isotherms for the hydrophilic fraction showed little change in surface excess with increasing solution concentration above 4 mg L(-1). The isotherms for the hydrophobic fraction, on the other hand, displayed a marked increase in surface excess with increasing solution concentration. This increase is evidence for the formation of aggregates (admicelles or hemimicelles) on the alumina surface. Linear dichroism calculations indicated that more of the carboxylate groups in the adsorbed hydrophobic molecules than in the absorbed hydrophilic fraction were free to rotate. The hindered rotation of the carboxylate groups in the adsorbed hydrophilic-fraction molecules probably indicates that these groups are bound to surface aluminum ions by a bidentate mechanism in which the two oxygen atoms of a single carboxylate group bind to separate aluminum ions. C1 UNIV PHILIPPINES,QUEZON 1101,PHILIPPINES. UNIV ARIZONA,DEPT CHEM,STRATEG MET RECOVERY RES FACIL,TUCSON,AZ 85721. RP Wershaw, R (reprint author), US GEOL SURVEY,MAIL STOP 408,FED CTR,DENVER,CO 80225, USA. NR 15 TC 29 Z9 30 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD MAR 20 PY 1996 VL 108 IS 2-3 BP 199 EP 211 DI 10.1016/0927-7757(95)03401-3 PG 13 WC Chemistry, Physical SC Chemistry GA UB008 UT WOS:A1996UB00800007 ER PT J AU Wershaw, RL Llaguno, EC Leenheer, JA AF Wershaw, RL Llaguno, EC Leenheer, JA TI Mechanism of formation of humus coatings on mineral surfaces .3. Composition of adsorbed organic acids from compost leachate on alumina by solid-state (13)CNMR SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article DE adsorption; alumina surfaces; compost leachate; DOC; humus coatings; solid-state C-13 NMR spectra ID SUSPENDED PARTICLES; C-13 NMR; ADSORPTION; MATTER; CHARGE; COMPLEXATION; LIGNIN; WATERS AB The adsorption of compost leachate DOC on alumina is used as a model for elucidation of the mechanism of formation of natural organic coatings on hydrous metal oxide surfaces in soils and sediments. Compost leachate DOC is composed mainly of organic acid molecules. The solid-state C-13 NMR spectra of these organic acids indicate that they are very similar in composition to aquatic humic substances. Changes in the solid-state C-13 NMR spectra of compost leachate DOC fractions adsorbed on alumina indicate that the DOC molecules are most likely adsorbed on metal oxide surfaces through a combination of polar and hydrophobic interaction mechanisms. This combination of polar and hydrophobic mechanism leads to the formation of bilayer coatings of the leachate molecules on the oxide surfaces. C1 UNIV PHILIPPINES, QUEZON 1101, PHILIPPINES. RP US GEOL SURVEY, MAIL STOP 408, FED CTR, DENVER, CO 80225 USA. NR 28 TC 38 Z9 39 U1 2 U2 14 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 EI 1873-4359 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD MAR 20 PY 1996 VL 108 IS 2-3 BP 213 EP 223 DI 10.1016/0927-7757(95)03402-1 PG 11 WC Chemistry, Physical SC Chemistry GA UB008 UT WOS:A1996UB00800008 ER PT J AU Calvin, WM Johnson, RE Spencer, JR AF Calvin, WM Johnson, RE Spencer, JR TI O-2 on ganymede: Spectral characteristics and plasma formation mechanisms SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID FAST IONS; SATELLITES; FROST; ICE AB Weak absorption features in the visible reflectance spectrum of Jupiter's satellite Ganymede have been correlated to those observed in the spectrum of molecular oxygen. We examine the spectral characteristics of these absorption features in all phases of O-2 and conclude that the molecular oxygen is most likely present at densities similar to the liquid or solid gamma-phase. The contribution of O-2 to spectral features observed on Ganymede in the near-infrared wavelength region affects the previous estimates of photon pathlength in ice. The concentration of the visible absorption features on the trailing hemisphere of Ganymede suggests an origin due to bombardment by magnetospheric ions. We derive an approximate O-2 formation rate from this mechanism and consider the state of O-2 within the surface. C1 UNIV VIRGINIA,DEPT ENGN PHYS,CHARLOTTESVILLE,VA 22903. LOWELL OBSERV,FLAGSTAFF,AZ 86001. RP Calvin, WM (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 30 TC 66 Z9 67 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 1996 VL 23 IS 6 BP 673 EP 676 DI 10.1029/96GL00450 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UD379 UT WOS:A1996UD37900018 ER PT J AU Julian, BR Ross, A Foulger, GR Evans, JR AF Julian, BR Ross, A Foulger, GR Evans, JR TI Three-dimensional seismic image of a geothermal reservoir: The Geysers, California SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Three-dimensional seismic travel-time tomography of The Geysers geothermal area, in the coast ranges of northern California, shows a strong (-9%) anomaly in V-p/V-s, the ratio of the compressional and shear wave V-p alone and corresponds speeds, that is not evident in V-p closely to the most intensively exploited part of the This anomaly probably indicates low pore pressure and relatively dry conditions, caused partly by boiling of pore water as steam is extracted. Steam pressure decreases over the last decade have probably caused seismologically measurable changes in wave speeds. Tomographic measurement of V-p/V-s is a promising technique both for identifying geothermal resources and for monitoring them during exploitation. C1 UNIV DURHAM,DEPT GEOL SCI,DURHAM DH1 3LE,ENGLAND. RP Julian, BR (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. NR 16 TC 38 Z9 38 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 15 PY 1996 VL 23 IS 6 BP 685 EP 688 DI 10.1029/95GL03321 PG 4 WC Geosciences, Multidisciplinary SC Geology GA UD379 UT WOS:A1996UD37900021 ER PT J AU Bogden, PS MalanotteRizzoli, P Signell, R AF Bogden, PS MalanotteRizzoli, P Signell, R TI Open-ocean boundary conditions from interior data: Local and remote forcing of Massachusetts Bay SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID INVERSE PROBLEM AB Massachusetts and Cape Cod Bays form a semienclosed coastal basin that opens onto the much larger Gulf of Maine, Subtidal circulation in the bay is driven by local winds and remotely driven flows from the gulf. The local-wind forced flow is estimated with a regional shallow water model driven by wind measurements, The model uses a gravity wave radiation condition along the open-ocean boundary. Results compare reasonably well with observed currents near the coast. In some offshore regions however, modeled flows are an order of magnitude less energetic than the data. Strong flows are observed even during periods of weak local wind forcing. Poor model-data comparisons are attributable, at least in part, to open-ocean boundary conditions that neglect the effects of remote forcing. Velocity measurements from within Massachusetts Bay are used to estimate the remotely forced component of the flow, The data are combined with shallow water dynamics in an inverse-model formulation that follows the theory of Bennett and McIntosh [1982], who considered tides. We extend their analysis to consider the subtidal response to transient forcing. The inverse model adjusts the a priori open-ocean boundary condition, thereby minimizing a combined measure of model-data misfit and boundary condition adjustment. A ''consistency criterion'' determines the optimal trade-off between the two. The criterion is based on a measure of plausibility for the inverse solution. The ''consistent'' inverse solution reproduces 56% of the average squared variation in the data, The local-wind-driven flow alone accounts for half of the model skill. The other half is attributable to remotely forced flows from the Gulf of Maine. The unexplained 44% comes from measurement errors and model errors that are not accounted for in the analysis. C1 MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA USA. US GEOL SURVEY, WOODS HOLE, MA 02543 USA. RP YALE UNIV, DEPT GEOL & GEOPHYS, POB 208109, NEW HAVEN, CT 06520 USA. OI Signell, Richard/0000-0003-0682-9613 NR 11 TC 34 Z9 34 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9275 EI 2169-9291 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1996 VL 101 IS C3 BP 6487 EP 6500 DI 10.1029/95JC03705 PG 14 WC Oceanography SC Oceanography GA UA574 UT WOS:A1996UA57400012 ER PT J AU Hodge, SM Doppelhammer, SK AF Hodge, SM Doppelhammer, SK TI Satellite imagery of the onset of streaming flow of ice streams C and D, West Antarctica SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID SHEET AB Five overlapping Landsat multispectral scanner satellite images of the interior of the West Antarctic ice sheet were enhanced with principal component analysis, high-pass filtering, and linear contrast stretching and merged into a mosaic by aligning surface features in the overlap areas. The mosaic was registered to geodetic coordinates, to an accuracy of about 1 km, using the five scene centers as control points. The onset of streaming flow of two tributaries of ice stream C and one tributary of ice stream D is visible in the mosaic. The onset appears to occur within a relatively short distance, less than the width of the ice stream, typically at a subglacial topographic feature such as a step or ridge. The ice streams extend farther up into the interior than previously mapped. Ice stream D starts about 150 km from the ice divide, at an altitude of about 1500 m, approximately halfway up the convex-upward dome shape of the interior ice sheet. Tee stream D is relatively much longer than ice stream C, possibly because ice stream D is currently active whereas ice stream C is currently inactive. The grounded portion of the West Antarctic ice sheet is perhaps best conceptualized as an ice sheet in which ice streams are embedded over most of its area, with slow moving ice converging into fast moving ice streams in a widely distributed pattern, much like that of streams and rivers in a hydrologic basin. A relic margin appears to parallel most of the south margin of the tributary of ice stream D, separated from the active shear margin by about 10 km or less for a distance of over 200 km. This means there is now evidence for recent changes having occurred in three of the five major ice streams which drain most of West Antarctica (B, C, and D), two of which (B and D) are currently active. RP Hodge, SM (reprint author), UNIV PUGET SOUND,US GEOL SURVEY,TACOMA,WA 98416, USA. NR 18 TC 24 Z9 24 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1996 VL 101 IS C3 BP 6669 EP 6677 DI 10.1029/95JC02961 PG 9 WC Oceanography SC Oceanography GA UA574 UT WOS:A1996UA57400026 ER PT J AU Josberger, EG Gloersen, P Chang, A Rango, A AF Josberger, EG Gloersen, P Chang, A Rango, A TI The effects of snowpack grain size on satellite passive microwave observations from the Upper Colorado River Basin SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WATER EQUIVALENT; NIMBUS-7 SMMR; PARAMETERS; RADIOMETRY; COVER AB Understanding the passive microwave emissions of a snowpack, as observed by satellite sensors, requires knowledge of the snowpack properties: water equivalent, grain size, density, and stratigraphy. For the snowpack in the Upper Colorado River Basin, measurements of snow depth and water equivalent are routinely available from the U.S. Department of Agriculture, but extremely limited information is available for the other properties. To provide this information, a field program from 1984 to 1995 obtained profiles of snowpack grain size, density, and temperature near the time of maximum snow accumulation, at sites distributed across the basin. A synoptic basin-wide sampling program in 1985 showed that the snowpack exhibits consistent properties across large regions. Typically, the snowpack in the Wyoming region contains large amounts of depth hear, with grain sizes up to 5 lmm, while the snowpack in Colorado and Utah is dominated by rounded snow grains less than 2 mm in diameter. In the Wyoming region, large depth hear crystals in shallow snowpacks yield the lowest emissivities or coldest brightness temperatures observed across the entire basin. Yearly differences in the average grain sizes result primarily from variations in the relative amount of depth hear within the snowpack. The average grain size for the Colorado and Utah regions shows much less variation than do the grain sizes from the Wyoming region. Furthermore, the greatest amounts of depth hear occur in the Wyoming region during 1987 and 1992, years with strong El Nino Southern Oscillation, but the Colorado and Utah regions do not show this behavior. C1 NASA,GODDARD SPACE FLIGHT CTR,GREENBELT,MD 20771. USDA ARS,HYDROL LAB,BELTSVILLE,MD 20705. RP Josberger, EG (reprint author), UNIV PUGET SOUND,US GEOL SURVEY,TACOMA,WA 98416, USA. NR 24 TC 16 Z9 17 U1 0 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1996 VL 101 IS C3 BP 6679 EP 6688 DI 10.1029/95JC02959 PG 10 WC Oceanography SC Oceanography GA UA574 UT WOS:A1996UA57400027 ER PT J AU Josberger, EG Mognard, NM AF Josberger, EG Mognard, NM TI Southern Ocean monthly wave fields for austral winters 1985-1988 by Geosat radar altimeter SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID WIND STRESS; VALIDATION AB Four years of monthly averaged wave height fields for the austral winters 1985-1988 derived from the Geosat altimeter data show a spatial variability of the scale of 500-1000 km that varies monthly and annually. This variability is superimposed on the zonal patterns surrounding the Antarctic continent and characteristic of the climatology derived from the U.S. Navy [1992] Marine Climatic Atlas of the World. The location and the intensity of these large-scale features, which are not found in the climatological fields, exhibit strong monthly and yearly variations. A global underestimation of the climatological mean wave heights by more than 1 m is also found over large regions of the Southern Ocean. The largest monthly averaged significant wave heights are above 5 m and are found during August of every year in the Indian Ocean, south of 40 degrees S. The monthly wave fields show more variability in the Atlantic and Pacific Oceans than in the Indian Ocean. The Seasat data from 1978 and the Geosat data from 1985 and 1988 show an eastward rotation of the largest wave heights. However, this rotation is absent in 1986 and 1987; the former was a year of unusually low sea states, and the latter was a year of unusually high sea states, which suggests a link to the Fl Nino-Southern Oscillation event of 1986. C1 CTR NATL ETUD SPATIALES,CTR ETUD SPATIALE BIOSPHERE,F-31055 TOULOUSE,FRANCE. RP Josberger, EG (reprint author), UNIV PUGET SOUND,US GEOL SURVEY,TACOMA,WA 98416, USA. NR 13 TC 4 Z9 8 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD MAR 15 PY 1996 VL 101 IS C3 BP 6689 EP 6696 DI 10.1029/95JC02963 PG 8 WC Oceanography SC Oceanography GA UA574 UT WOS:A1996UA57400028 ER PT J AU Verdin, JP AF Verdin, JP TI Remote sensing of ephemeral water bodies in western Niger SO INTERNATIONAL JOURNAL OF REMOTE SENSING LA English DT Article AB Research was undertaken to evaluate the feasibility of monitoring the small ephemeral water bodies of the Sahel with the 1.1 km resolution data of the National Oceanic and Atmospheric Administration (NOAA) Advanced Very High Resolution Radiometer (AVHRR). Twenty-one lakes of western Niger with good ground observation records were selected for examination. Thematic Mapper images from 1988 were first analysed to determine surface areas and temperature differences between water and adjacent land. Six AVHRR scenes from the 1988-89 dry season were then studied. It was found that a lake can be monitored until its surface area drops below 10 ha, in most cases. Furthermore, with prior knowledge of the location and shape of a water body, its surface area can be estimated from AVHRR band 5 data to within about 10 ha. These results are explained by the sharp temperature contrast between water and land, on the order of 13 degrees C. RP Verdin, JP (reprint author), US GEOL SURVEY,EROS DATA CTR,SIOUX FALLS,SD 57198, USA. NR 11 TC 35 Z9 35 U1 0 U2 1 PU TAYLOR & FRANCIS LTD PI LONDON PA ONE GUNDPOWDER SQUARE, LONDON, ENGLAND EC4A 3DE SN 0143-1161 J9 INT J REMOTE SENS JI Int. J. Remote Sens. PD MAR 10 PY 1996 VL 17 IS 4 BP 733 EP 748 PG 16 WC Remote Sensing; Imaging Science & Photographic Technology SC Remote Sensing; Imaging Science & Photographic Technology GA UC012 UT WOS:A1996UC01200007 ER PT J AU Zoback, ML Richardson, RM AF Zoback, ML Richardson, RM TI Stress perturbation associated with the Amazonas and other ancient continental rifts SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CONTERMINOUS UNITED-STATES; SOUTH-AMERICAN PLATE; MADRID SEISMIC ZONE; LITHOSPHERIC STRESS; CRUSTAL STRUCTURE; DRIVING FORCE; TECTONICS; FRICTION AB The state of stress in the vicinity of old continental rifts is examined to investigate the possibility that crustal structure associated with ancient rifts (specifically a dense rift pillow in the lower crust) may modify substantially the regional stress field. Both shallow (2.0-2.6 km depth) breakout data and deep (20-45 km depth) crustal earthquake focal mechanisms indicate a N to NNE maximum horizontal compression in the vicinity of the Paleozoic Amazonas rift in central Brazil. This compressive stress direction is nearly perpendicular to the rift structure and represents a similar to 75 degrees rotation relative to a regional E-W compressive stress direction in the South American plate. Elastic two-dimensional finite element models of the density structure associated with the Amazonas rift (as inferred from independent gravity modeling) indicate that elastic support of this dense feature would generate horizontal rift-normal compressional stresses between 60 and 120 MPa, with values of 80-100 MPa probably most representative of the overall structure. The observed similar to 75 degrees stress rotation constrains the ratio of the regional horizontal stress difference to the rift-normal compressive stress to be between 0.25 and 1.0, suggesting that this rift-normal stress may be from 1 to 4 times larger than the regional horizontal stress difference. A general expression for the modification of the normalized local horizontal shear stress (relative to the regional horizontal shear stress) shows that the same ratio of the rift-normal compression relative to the regional horizontal stress difference, which controls the amount of stress rotation, also determines whether the superposed stress increases or decreases the local maximum horizontal shear stress. The potential for fault reactivation of ancient continental rifts in general is analyzed considering both the local stress rotation and modification of horizontal shear stress for both thrust and strike-slip stress regimes. In the Amazonas rift case, because the observed stress rotation only weakly constrains the ratio of the regional horizontal stress difference to the rift-normal compression to be between 0.25 and 1.0, our analysis is inconclusive because the resultant normalized horizontal shear stress may be reduced (for ratios >0.5) or enhanced (for ratios <0.5). Additional information is needed on all three stress magnitudes to predict how a change in horizontal shear stress directly influences the likelihood of faulting in the thrust-faulting stress regime in the vicinity of the Amazonas rift. A rift-normal stress associated with the seismically active New Madrid ancient rift may be sufficient to rotate the horizontal stress field consistent with strike-slip faults parallel to the axis of the rift, although this results in a 20-40% reduction in the local horizontal shear stress within the seismic zone. Sparse stress data in the vicinity of the seismically quiescent Midcontinent rift of the central United States suggest a stress state similar to that of New Madrid, with the local horizontal shear stress potentially reduced by as much as 60%. Thus the markedly different levels of seismic activity associated with these two subparallel ancient rifts is probably due to other factors than stress perturbations due to dense rift pillows. The modeling and analysis here demonstrate that rift-normal compressive stresses are a significant source of stress acting on the lithosphere and that in some cases may be a contributing factor to the association of intraplate seismicity with old zones of continental extension. C1 UNIV ARIZONA, DEPT GEOSCI, SO ARIZONA SEISM OBSERV, TUCSON, AZ 85721 USA. RP US GEOL SURVEY, BRANCH SEISMOL, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 42 TC 60 Z9 60 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1996 VL 101 IS B3 BP 5459 EP 5475 DI 10.1029/95JB03256 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA372 UT WOS:A1996UA37200006 ER PT J AU Yeats, RS Prentice, CS AF Yeats, RS Prentice, CS TI Introduction to special section: Paleoseismology SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Editorial Material ID SAN-ANDREAS FAULT; HOLOCENE EARTHQUAKES; SOUTHERN-CALIFORNIA; SUBDUCTION ZONE; PALLETT CREEK; WASHINGTON; RECURRENCE; WASATCH; MARGIN C1 US GEOL SURVEY, MS 977, MENLO PK, CA 94025 USA. RP Yeats, RS (reprint author), OREGON STATE UNIV, DEPT GEOSCI, 104 WILKINSON HALL, CORVALLIS, OR 97331 USA. NR 47 TC 37 Z9 49 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1996 VL 101 IS B3 BP 5847 EP 5853 DI 10.1029/95JB03134 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA372 UT WOS:A1996UA37200035 ER PT J AU Lienkaemper, JJ Borchardt, G AF Lienkaemper, JJ Borchardt, G TI Holocene slip rate of the Hayward fault at Union City, California SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CREEP AB Measured offsets of well-dated alluvial fan deposits near the Masonic Home in Union City constrain Holocene slip rate of the Hayward fault between 7 and 9 mm/yr. Our best minimum geologic slip rate over the past 8.27 +/- 0.08 kyr (i.e., 8270 years) is 8.0 +/- 0.7 mm/yr. A steep stream (its channel cut into bedrock) flows southwest out of the East Bay Hills, crosses the fault, and deposits its load on an alluvial fan. We cut two 5-m-deep, fault-parallel trenches 20-30 m southwest of the main fault through the crest of the fan. Walls of the trenches reveal a series of nested distributary channel fills. These channels had cut into old surfaces that are indicated by paleosols developed on flood silts. We distinguished many channel fills by their shape, clast size, flow direction, elevation, and relation to paleosols, enabling us to correlate them between both trenches. Two distinct episodes of fan deposition occurred during the Holocene. Reconstructing the apex positions of these fan units indicates that about 42 +/- 6 m and 66 +/- 6 m of fault slip has occurred since their inceptions at about 4.58 +/- 0.05 ka, and 8.27 +/- 0.05 ka, respectively. We lowered the age and age uncertainty of the younger unit from earlier reports based on new multiple radiocarbon dates. The 4.58 ka slip rate of 9.2 +/- 1.3 mm/yr is not significantly different at 95% confidence from the 8.27 ka slip rate of 8.0 +/- 0.7 mm/yr. Because current regional strain rates are fully consistent with Neogene plate tectonic rates (Lisowski et al., 1991) and the historic surface rate of creep in Union City is only 4.7 +/- 0.1 mm/yr (Galehouse, 1994), the larger, greater than or equal to 8 mm/yr, Holocene slip rate implies that strain is now accumulating on a locked zone at depth. The 8 mm/yr rate is probably minimal because earlier trenching evidence nearby implies that some unknown additional amount of fault deformation occurs outside of the narrow fault zone assumed in measuring slip. Lienkaemper et al. (1991) suggest that the fast creep rate of 9 mm/yr, measured near the southern end of the Hayward fault, may underestimate the deep slip rate, because 1868 surface slip occurred there in addition to the continuing fast creep. If the historic deep slip rate equals the long-term rate, then the 9 mm/yr creep rate reflects the minimum seismic loading rate of the Hayward fault better than the greater than or equal to 8 mm/yr Holocene rates do. C1 SOIL TECTON, BERKELEY, CA 94705 USA. RP Lienkaemper, JJ (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 977, MENLO PK, CA 94025 USA. NR 19 TC 19 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1996 VL 101 IS B3 BP 6099 EP 6108 DI 10.1029/95JB01378 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA372 UT WOS:A1996UA37200050 ER PT J AU Nelson, AR Shennan, I Long, AJ AF Nelson, AR Shennan, I Long, AJ TI Identifying coseismic subsidence in tidal-wetland stratigraphic sequences at the Cascadia subduction zone of western North America SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Review ID SEA-LEVEL RISE; SALT MARSHES; TECTONIC SUBSIDENCE; SOUTHERN-CALIFORNIA; WASHINGTON-STATE; NANKAI TROUGH; UPLIFT RATES; PUGET-SOUND; NEW-ZEALAND; OREGON AB Tidal-wetland stratigraphy reveals that great plate boundary earthquakes have caused hundreds of kilometers of coast to subside at the Cascadia subduction zone. However, determining earthquake recurrence intervals and mapping the coastal extent of past great earthquake ruptures in this region are complicated by the effects of many sedimentologic, hydrographic, and oceanographic processes that occur on the coasts of tectonically passive as well as active continental margins. Tidal-wetland stratigraphy at many Cascadia estuaries differs little from that at similar sites on passive-margin coasts where stratigraphic sequences form through nonseismic processes unrelated to coseismic land level changes. Methods developed through study of similar stratigraphic sequences in Europe provide a framework for investigating the Cascadia estuarine record. Five kinds of criteria must be evaluated when inferring regional coastal subsidence due to great plate boundary earthquakes: the suddenness and amount of submergence, the lateral extent of submerged tidal-wetland soils, the coincidence of submergence with tsunami deposits, and the degree of synchroneity of submergence events at widely spaced sites. Evaluation of such criteria at the Cascadia subduction zone indicates regional coastal subsidence during at least two great earthquakes. Evidence for a coseismic origin remains equivocal, however, for the many peat-mud contacts in Cascadia stratigraphic sequences that lack (1) contrasts in lithology or fossils indicative of more than half a meter of submergence, (2) well-studied tsunami deposits, or (3) precise ages needed for regional correlation. Paleoecologic studies of fossil assemblages are particularly important in estimating the size of sudden sea level changes recorded by abrupt peat-mud contacts and in helping to distinguish erosional and gradually formed contacts from coseismic contacts. Reconstruction of a history of great earthquakes for the Cascadia subduction zone will require rigorous application of the above criteria and many detailed investigations. C1 UNIV DURHAM, DEPT GEOG, DURHAM DH1 3LE, ENGLAND. UNIV SOUTHAMPTON, DEPT GEOG, SOUTHAMPTON SO17 1BJ, HANTS, ENGLAND. RP Nelson, AR (reprint author), US GEOL SURVEY, BOX 25046, MS 966, DENVER, CO 80225 USA. OI Shennan, Ian/0000-0003-3598-0224 NR 185 TC 130 Z9 135 U1 3 U2 10 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1996 VL 101 IS B3 BP 6115 EP 6135 DI 10.1029/95JB01051 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA372 UT WOS:A1996UA37200052 ER PT J AU Tuttle, MP Schweig, ES AF Tuttle, MP Schweig, ES TI Recognizing and dating prehistoric liquefaction features: Lessons learned in the New Madrid seismic zone, central United States SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EARTHQUAKES AB The New Madrid seismic zone (NMSZ), which experienced severe liquefaction during the great New Madrid, Missouri, earthquakes of 1811 and 1812 as well as during several prehistoric earthquakes, is a superb laboratory for the study of world-class, earthquake-induced liquefaction features and their use in paleoseismology. In seismically active regions like the NMSZ, frequent large earthquakes can produce a complex record of liquefaction events that is difficult to interpret. Lessons learned studying liquefaction features in the NMSZ may help to unravel the paleoseismic record in other seismically active regions. Soil characteristics of liquefaction features, as well as their structural and stratigraphic relations to Native American occupation horizons and other cultural features, can help to distinguish prehistoric liquefaction features from historic features. In addition, analyses of artifact assemblages and botanical content of cultural horizons can help to narrow the age ranges of liquefaction features. Future research should focus on methods for defining source areas and estimating magnitudes of prehistoric earthquakes from liquefaction features. Also, new methods for dating liquefaction features are needed. C1 MEMPHIS STATE UNIV, CTR EARTHQUAKE RES & INFORMAT, MEMPHIS, TN 38152 USA. US GEOL SURVEY, MEMPHIS, TN USA. RP Tuttle, MP (reprint author), UNIV MARYLAND, DEPT GEOL, COLLEGE PK, MD 20742 USA. NR 27 TC 24 Z9 25 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1996 VL 101 IS B3 BP 6171 EP 6178 DI 10.1029/95JB02894 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA372 UT WOS:A1996UA37200055 ER PT J AU McCalpin, JP Nishenko, SP AF McCalpin, JP Nishenko, SP TI Holocene paleoseismicity, temporal clustering, and probabilities of future large (M>7) earthquakes on the Wasatch fault zone, Utah SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; SYNTHETIC SEISMICITY MODEL; MIDDLE AMERICA TRENCH; NORTH-CENTRAL UTAH; GREAT EARTHQUAKES; RECURRENCE; CALIFORNIA; PALEOEARTHQUAKES; SEGMENTATION; PROVINCE AB The chronology of M>7 paleoearthquakes on the central five segments of the Wasatch fault zone (WFZ) is one of the best dated in the world and contains 16 earthquakes in the past 5600 years with an average repeat time of 350 years. Repeat times for individual segments vary by a factor of 2, and range from about 1200 to 2600 years. Four of the central five segments ruptured between similar to 620+/-30 and 1230+/-60 calendar years B.P. The remaining segment (Brigham City segment) has not ruptured in the past 2120+/-100 years. Comparison of the WFZ space-time diagram of paleoearthquakes with synthetic paleoseismic histories indicates that the observed temporal clusters and gaps have about an equal probability (depending on model assumptions) of reflecting random coincidence as opposed to intersegment contagion. Regional seismicity suggests that for exposure times of 50 and 100 years, the probability for an earthquake of M>7 anywhere within the Wasatch Front region, based on a Poisson model, is 0.16 and 0.30, respectively. A fault-specific WFZ model predicts 50 and 100 year probabilities for a M>7 earthquake on the WFZ itself, based on a Poisson model, as 0.13 and 0.25, respectively. Ln contrast, segment-specific earthquake probabilities that assume quasi-periodic recurrence behavior on the Weber, Prove, and Nephi segments are less (0.01-0.07 in 100 years) than the regional or fault-specific estimates (0.25-0.30 in 100 years), due to the short elapsed times compared to average recurrence intervals on those segments. The Brigham City and Salt Lake City segments, however, have time-dependent probabilities that approach or exceed the regional and fault specific probabilities. For the Salt Lake City segment, these elevated probabilities are due to the elapsed time being approximately equal to the average late Holocene recurrence time. For the Brigham City segment, the elapsed time is significantly longer than the segment-specific late Holocene recurrence time. C1 US GEOL SURVEY, NATL EARTHQUAKE INFORMAT CTR, DENVER, CO 80225 USA. RP McCalpin, JP (reprint author), GEO HAZ CONSULTING INC, POB 1377, ESTES PK, CO 80517 USA. NR 84 TC 73 Z9 79 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD MAR 10 PY 1996 VL 101 IS B3 BP 6233 EP 6253 DI 10.1029/95JB02851 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA372 UT WOS:A1996UA37200059 ER PT J AU Cygan, GL Chou, IM Sherman, DM AF Cygan, GL Chou, IM Sherman, DM TI Reinvestigation of the annite equals sanidine plus magnetite plus H-2 reaction using f(H-2)-sensor technique SO AMERICAN MINERALOGIST LA English DT Article ID TEMPERATURES; CALIBRATION; PRESSURES; HYDROGEN; BUFFERS; SENSORS; STATE; MICAS; FH2 AB The decomposition of the iron mica, annite, to sanidine plus magnetite and vapor, KFe3AlSi3O10(OH)(2) = KAlSi3O8 + Fe3O4 + H-2, has been reexamined experimentally with the use of a variety of buffers coupled with f(H2) sensors at 2 kbar and between 400 and 840 degrees C. Various capsule configurations were used in this study to delineate the equilibrium constant for this reaction in conjunction with Fe-57 Mossbauer spectroscopy measurements to monitor the oxy-annite component in mica in selected experiments. Results at the most reducing and highest temperature conditions of this study extend the annite stability field to higher temperature and f(O2) values than those defined in previous work. Lower temperature results indicate that the annite-sanidine-magnetite stability boundary does not intersect the hematite + magnetite + H2O buffer at 400 degrees C as previously reported but rather is subparallel to the buffer curve at lower f(O2) values. The equilibrium f(H2) (in bars) for the assemblage annite + sanidine + magnetite + vapor at 2 kbar and between 400 and 840 degrees C can be described by the relation log f(H2) (+/-0.08) = 13.644 - (17368/T) + (5.168 x 10(6))/T-2, where T is temperature in kelvins. C1 UNIV BRISTOL,DEPT GEOL,BRISTOL BS8 1RJ,AVON,ENGLAND. RP Cygan, GL (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. RI Sherman, David/A-7538-2008 OI Sherman, David/0000-0003-1835-6470 NR 38 TC 10 Z9 11 U1 1 U2 1 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD MAR-APR PY 1996 VL 81 IS 3-4 BP 475 EP 484 PG 10 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA UG199 UT WOS:A1996UG19900021 ER PT J AU Coates, JD Anderson, RT Lovley, DR AF Coates, JD Anderson, RT Lovley, DR TI Oxidation of polycyclic aromatic hydrocarbons under sulfate-reducing conditions SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID SOIL-WATER SYSTEMS; MICROBIAL-DEGRADATION; REDOX CONDITIONS; FLOODED SOIL; FRESH-WATER; NAPHTHALENE; SEDIMENTS; BIODEGRADATION; REDUCTION; BACTERIUM AB [C-14] naphthalene and phenanthrene were oxidized to (CO2)-C-14 without a detectable lag under strict anaerobic conditions in sediments from San Diego Bay, San Diego, Calif., that were heavily contaminated with polycyclic aromatic hydrocarbons (PAHs) but not in less contaminated sediments. Sulfate reduction,vas necessary for PAH oxidation. These results suggest that the self-purification capacity of PAH-contaminated sulfate-reducing environments may be greater than previously recognized. C1 UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003. US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092. NR 28 TC 163 Z9 170 U1 4 U2 16 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD MAR PY 1996 VL 62 IS 3 BP 1099 EP 1101 PG 3 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA TY365 UT WOS:A1996TY36500059 PM 16535261 ER PT J AU Driscoll, CT Cirmo, CP Fahey, TJ Blette, VL Bukaveckas, PA Burns, DA Gubala, CP Leopold, DJ Newton, RM Raynal, DJ Schofield, CL Yavitt, JB Porcella, DB AF Driscoll, CT Cirmo, CP Fahey, TJ Blette, VL Bukaveckas, PA Burns, DA Gubala, CP Leopold, DJ Newton, RM Raynal, DJ Schofield, CL Yavitt, JB Porcella, DB TI The experimental watershed liming study: Comparison of lake and watershed neutralization strategies SO BIOGEOCHEMISTRY LA English DT Article DE acidification; acid neutralizing capacity; calcite; lake chemistry; liming ID CALCIUM-CARBONATE TREATMENT; NORTHERN HARDWOOD FOREST; SHORT-TERM CHANGES; ACIDIC LAKES; CHEMISTRY; ACIDIFICATION; ILWAS; REACIDIFICATION; DEPOSITION; ALUMINUM AB The Experimental Watershed Liming Study (EWLS) was initiated to evaluate the application of CaCO3 to a forested watershed in an effort to mitigate the acidification of surface water. The objective of the EWLS was to assess the response of the Woods Lake watershed to an experimental addition of CaCO3. During October 1989, 6.89 Mg CaCO3/ha was applied by helicopter to two subcatchments comprising about 50% (102.5 ha) of the watershed area. The EWLS involved individual investigations of the response of soil and soil water chemistry, forest and wetland vegetation, soil microbial processes, wetland, stream and lake chemistry, and phytoplankton and fish to the CaCO3 treatment. In addition, the Integrated Lake/Watershed Acidification (ILWAS) model was applied to the site to evaluate model performance and duration of the treatment. The results of these studies are detailed in this volume. The purposes of this introduction and synthesis paper are to: 1) present the overall design of the EWLS, 2) discuss the linkages between the individual studies that comprise the EWLS, and 3) summarize the response of the lakewater chemistry to watershed addition of CaCO3 and compare these results to previous studies of direct lake addition. An analysis of lake chemistry revealed the watershed treatment resulted in a gradual change in pH, acid neutralizing capacity (ANC) and Ca2+ in the water column. This pattern was in contrast to direct lake additions of CaCO3, which were characterized by abrupt changes following base addition and subsequent rapid reacidification. Over the three-year study period, the supply of ANC to drainage waters was largely derived from dissolution of CaCO3 in wetlands. Relatively little dissolution of CaCO3 occurred in freely draining upland soils. The watershed treatment had only minor effects on forest vegetation. The watershed treatment eliminated the episodic acidification of streamwater and the near-shore region of the lake during snowmelt, a phenomenon that occurred during direct lake treatments. Positive ANC water in the near-shore area may improve chemical conditions for fish reproduction, and allow for the development of a viable fish population. The watershed CaCO3 treatment also decreased the transport of Al from the watershed to the lake, and increased the concentrations of dissolved organic carbon (DOG) and dissolved silica (H4SiO4) in stream and lakewater. The watershed treatment appeared to enhance soil nitrification, increasing concentrations of NO3- in soilwater and surface waters. However, the acidity associated with this NO3- release was small compared to the increase in ANC due to CaCO3 addition and did not alter the acid-base status of Woods Lake. Acid neutralizing capacity (ANC) budgets for 12-month periods before and after the watershed treatment showed that the lake shifted from a large source of ANC to a minor source due to retention of SO42-, NO3-, Al and the elevated inputs of Ca2+ associated with the watershed CaCO3 application. In contrast to the direct lake treatments, Ca2+ inputs from the watershed application were largely transported from the lake. C1 CORNELL UNIV,DEPT NAT RESOURCES,ITHACA,NY 14853. SMITH COLL,DEPT GEOL,NORTHAMPTON,MA 01063. UNIV LOUISVILLE,DEPT BIOL,LOUISVILLE,KY 40292. USGS,TROY,NY 12180. SUNY SYRACUSE,COLL ENVIRONM SCI & FORESTRY,SYRACUSE,NY 13210. ELECT POWER RES INST,PALO ALTO,CA 94303. RP Driscoll, CT (reprint author), SYRACUSE UNIV,DEPT CIVIL & ENVIRONM ENGN,SYRACUSE,NY 13244, USA. RI Burns, Douglas/A-7507-2009; Driscoll, Charles/F-9832-2014; OI Bukaveckas, Paul/0000-0002-2636-7818; Driscoll, Charles/0000-0003-2692-2890 NR 73 TC 52 Z9 52 U1 2 U2 19 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD MAR PY 1996 VL 32 IS 3 BP 143 EP 174 DI 10.1007/BF02187137 PG 32 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA UT830 UT WOS:A1996UT83000001 ER PT J AU Newton, RM Burns, DA Blette, VL Driscoll, CT AF Newton, RM Burns, DA Blette, VL Driscoll, CT TI Effect of whole catchment liming on the episodic acidification of two Adirondack streams SO BIOGEOCHEMISTRY LA English DT Article DE acidic precipitation; Adirondack mountains; liming; snowmelt; episodic acidification; beaver pond ID LOCH FLEET; WATER CHEMISTRY; LAKES; SOIL; MITIGATION; UPLAND; STRATEGIES; RESPONSES; PROJECT; ACIDITY AB During the fall of 1989 7.7Mg/ha of calcium carbonate was applied on two tributary catchments (40 ha and 60 ha) to Woods Lake, a small (25 ha) acidic headwater lake in the western Adirondack region of New York. Stream-water chemistry in both catchment tributaries responded immediately. Acid-neutralizing capacity (ANC) increased by more than 200 mu eq/L in one of the streams and more than 1000 mu eq/L in the other, from pre liming values which ranged from -25 to +40 mu eq/L. The increase in ANC was primarily due to increases in dissolved Ca2+ concentrations. Most of the initial response of the streams was due to the dissolution of calcite that fell directly into the stream channels and adjacent wetlands. A small beaver impoundment and associated wetlands were probably responsible for the greater response observed in one of the streams. After the liming of subcatchment IV (60 ha), Ca2+ concentrations increased with increasing stream discharge in the stream during fall rain events, suggesting a contribution from calcite dissolved within the soil and transported to the stream by surface runoff or shallow interflow. Concentrations of other ions not associated with the calcite (e.g. Na+) decreased during fall rain events, presumably due to mixing of solute-rich base flow with more dilute shallow interflow. The strong relation between changes in Ca2+ and changes in NO3- concentrations during spring snowmelt, (r(2) = 0.93, slope = 0.96, on an equivalent basis) suggests that both solutes had a common source in the organic horizon of the soil. Increases in NO3- concentrations during snowmelt were balanced by increases in Ca2+ that was released either directly from the calcite or from exchange sires, mitigating episodic acidification of the stream. However, high ambient NO3- concentrations and relatively low ambient Ca2+ concentrations in the stream during the spring caused the stream to become acidic despite the CaCO3 treatment. In stream WO2 (40ha), Ca2+ concentrations were much higher than in stream WO4 because of the dissolution of calcite which fell directly into the upstream beaver pond and its associated wetlands. Calcium concentrations decreased as both NO3- concentrations and stream discharge increased, due to the dilution of Ca-enriched beaver pond water by shallow interflow. Despite this dilution, Ca2+ concentrations were high enough to more than balance strong acid anion (SO42-, NO3-, Cl-) concentrations, resulting in a positive ANC in this stream throughout the year. These data indicate that liming of wetlands and beaver ponds is more effective than whole catchment liming in neutralizing acidic surface waters. C1 US GEOL SURVEY,TROY,NY 12180. UNIV MASSACHUSETTS,DEPT GEOL & GEOG,AMHERST,MA 01002. SYRACUSE UNIV,DEPT CIVIL & ENVIRONM ENGN,SYRACUSE,NY 13244. RP Newton, RM (reprint author), SMITH COLL,DEPT GEOL,NORTHAMPTON,MA 01063, USA. RI Burns, Douglas/A-7507-2009; Driscoll, Charles/F-9832-2014; OI Driscoll, Charles/0000-0003-2692-2890 NR 33 TC 16 Z9 16 U1 2 U2 7 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD MAR PY 1996 VL 32 IS 3 BP 299 EP 322 DI 10.1007/BF02187143 PG 24 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA UT830 UT WOS:A1996UT83000007 ER PT J AU Burns, DA AF Burns, DA TI The effects of liming an Adirondack lake watershed on downstream water chemistry - Effects of liming on stream chemistry SO BIOGEOCHEMISTRY LA English DT Article DE acidic precipitation; Adirondack Mountains; calcium carbonate; liming; snowmelt; stream acidification ID ACID-NEUTRALIZING CAPACITY; ORGANIC-ACIDS; NEW-YORK; ACIDIFICATION; SNOWMELT; ONTARIO; REGION AB Calcite treatment of chronically acidic lakes has improved fish habitat, but the effects on downstream water quality have not previously been examined. In this study, the spatial and temporal effects of watershed CaCO3 treatment on the chemistry of a lake outlet stream in the Adirondack Mountains of New York were examined. Before CaCO3 treatment, the stream was chronically acidic. During spring snowmelt before treatment, pH and acid-neutralizing capacity (ANC) in the outlet stream declined, and NO, and inorganic monomeric aluminum (Al-IM) concentrations increased sharply. During that summer, SO42- and NO3-, concentrations decreased downstream, and dissolved organic carbon (DOG) concentrations and ANC increased, in association with the seasonal increase in decomposition of organic matter and the attendant SO42--reduction process. A charge-balance ANC calculation closely matched measured downstream changes in ANC in the summer and indicated that SO42--reduction was the major process contributing to summer increases in ANC. Increases in Ca2+ concentration and ANC began immediately after CaCO3 application, and within 3 months, exceeded their pretreatment values by more than 130 mu eq/L. Within 2 months after treatment, downstream decreases in Ca2+ concentration, ANC, and pH, were noted. Stream mass balances between the lake and the sampling site 1.5 km downstream revealed that the transport of all chemical constituents was dominated by conservative mixing with tributaries and ground water; however, non-conservative processes resulted in significant Ca2+ losses during the 13-month period after CaCO3 treatment. Comparison of substrate samples from the buffered outlet stream with those from its untreated tributaries showed that the percentage of cation-exchange sites occupied by Ca2+, as well as non-exchangeable Ca, were higher in the outlet-stream substrate than in tributary-stream substrate. Mass-balance data for Ca2+, H+, Al-IM, and DOC revealed net downstream losses of these constituents and indicated that a reasonable set of hypothesized reactions involving Al-IM, HCO3-, Ca2+, SO42-, NO3-, and DOC could have caused the measured changes in stream acid/base chemistry. In the summer, the sharp decrease in ANC continued despite significant downstream decreases in SO42- concentrations. After CaCO3 treatment, reduction of SO42- was only a minor contributor to ANC changes relative to those caused by Ca2+ dilution from acidic tributaries and acidic ground water, and Ca2+ interactions with stream substrate. RP Burns, DA (reprint author), US GEOL SURVEY,425 JORDAN RD,TROY,NY 12180, USA. RI Burns, Douglas/A-7507-2009 NR 30 TC 9 Z9 9 U1 1 U2 5 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0168-2563 J9 BIOGEOCHEMISTRY JI Biogeochemistry PD MAR PY 1996 VL 32 IS 3 BP 339 EP 362 DI 10.1007/BF02187145 PG 24 WC Environmental Sciences; Geosciences, Multidisciplinary SC Environmental Sciences & Ecology; Geology GA UT830 UT WOS:A1996UT83000009 ER PT J AU Hickson, CJ Moore, JG Calk, L Metcalfe, P AF Hickson, CJ Moore, JG Calk, L Metcalfe, P TI Intraglacial volcanism in the Wells Gray Clearwater volcanic field, east-central British Columbia, Canada (vol 32, pg 838, 1995) SO CANADIAN JOURNAL OF EARTH SCIENCES LA English DT Correction C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP GEOL SURVEY CANADA, 100 W PENDER ST, VANCOUVER, BC V6B 1R8, CANADA. NR 1 TC 0 Z9 0 U1 0 U2 0 PU CANADIAN SCIENCE PUBLISHING, NRC RESEARCH PRESS PI OTTAWA PA 65 AURIGA DR, SUITE 203, OTTAWA, ON K2E 7W6, CANADA SN 0008-4077 EI 1480-3313 J9 CAN J EARTH SCI JI Can. J. Earth Sci. PD MAR PY 1996 VL 33 IS 3 BP 509 EP 509 DI 10.1139/e96-039 PG 1 WC Geosciences, Multidisciplinary SC Geology GA UL407 UT WOS:A1996UL40700012 ER PT J AU Schuster, RL Nieto, AS ORourke, TD Crespo, E PlazaNieto, G AF Schuster, RL Nieto, AS ORourke, TD Crespo, E PlazaNieto, G TI Mass wasting triggered by the 5 March 1987 Ecuador earthquakes SO ENGINEERING GEOLOGY LA English DT Article ID LANDSLIDES AB On 5 March 1987, two earthquakes (M(s) = 6.1 and M(s) = 6.9) occurred about 25 km north of Reventador Volcano, along the eastern slopes of the Andes Mountains in northeastern Ecuador. Although the shaking damaged structures in towns and villages near the epicentral area, the economic and social losses directly due to earthquake shaking were small compared to the effects of catastrophic earthquake-triggered mass wasting and flooding. About 600 mm of rain fell in the region in the month preceding the earthquakes; thus, the surficial soils had high moisture contents. Slope failures commonly started as thin slides, which rapidly turned into fluid debris avalanches and debris flows. The surficial soils and thick vegetation covering them flowed down the slopes into minor tributaries and then were carried into major rivers. Rock and earth slides, debris avalanches, debris and mud flows, and resulting floods destroyed about 40 km of the Trans-Ecuadorian oil pipeline and the only highway from Quite to Ecuador's northeastern rain forests and oil fields. Estimates of total volume of earthquake-induced mass wastage ranged from 75-110 million m(3). Economic losses were about US$ 1 billion. Nearly all of the approximately 1000 deaths from the earthquakes were a consequence of mass wasting and/or flooding. RP Schuster, RL (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 31 TC 16 Z9 17 U1 2 U2 4 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0013-7952 J9 ENG GEOL JI Eng. Geol. PD MAR PY 1996 VL 42 IS 1 BP 1 EP 23 DI 10.1016/0013-7952(95)00024-0 PG 23 WC Engineering, Geological; Geosciences, Multidisciplinary SC Engineering; Geology GA UG484 UT WOS:A1996UG48400001 ER PT J AU Piatt, JJ Backhus, DA Capel, PD Eisenreich, SJ AF Piatt, JJ Backhus, DA Capel, PD Eisenreich, SJ TI Temperature-dependent sorption of naphthalene, phenanthrene and pyrone to low organic carbon aquifer sediments SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCYCLIC AROMATIC-HYDROCARBONS; LOCAL EQUILIBRIUM ASSUMPTION; NONEQUILIBRIUM SORPTION; HYDROPHOBIC POLLUTANTS; AQUEOUS SOLUBILITY; NATURAL SEDIMENTS; SOLUTE TRANSPORT; CHEMICALS; SOILS; WATER AB Sorption experiments were conducted with naphthalene, phenanthrene, and pyrene on low organic carbon sediments at 4 and 26 degrees C using batch and column techniques. Experimental controls ensured the absence of biologic and photolytic activity and colloid-free solution supernatants. Equilibrium distribution coefficients (K-d) increased 1.1-1.6 times with a decrease in temperature of 22 degrees C. Fraction instantaneous sorption (A values did not change significantly with a decrease in temperature of 22 degrees C. Desorption rate constants (k(2)) decreased 1.2-2.6 times with a decrease in temperature of 22 degrees C. Times to equilibrium were at least 40 h. The magnitude of observed K-d and k(2) values and the effect of temperature on K-d (e.g., low enthalpy of sorption) are consistent with sorbate partitioning between the aqueous phase and small amounts of organic matter(f(oc) = 0.02%) on the sediments. The temperature dependence of K-d and k(2) may be small as compared to the effects of heterogeneities in field-scale aquifer systems. Thus, thermal gradients may not be of major importance in most saturated subsurface regimes when predicting solute transport. However, aquifer remediation pump-and-treat times could be decreased because increased temperature decreases both retardation and tailing. C1 UNIV MINNESOTA,GRAY FRESHWATER BIOL INST,NAVARRE,MN 55392. UNIV MINNESOTA,DEPT CIVIL ENGN,NAVARRE,MN 55392. US GEOL SURVEY,DIV WATER RESOURCES,NAVARRE,MN 55392. NR 65 TC 82 Z9 88 U1 1 U2 19 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1996 VL 30 IS 3 BP 751 EP 760 DI 10.1021/es9406288 PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TX751 UT WOS:A1996TX75100026 ER PT J AU Salmon, LG Cass, GR Kozlowski, R Hejda, A Spiker, EC Bates, AL AF Salmon, LG Cass, GR Kozlowski, R Hejda, A Spiker, EC Bates, AL TI Air pollutant intrusion into the Wieliczka Salt Mine SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SOUTHERN CALIFORNIA MUSEUMS; GAS-AEROSOL EQUILIBRIUM; SULFUR-DIOXIDE; NITRIC-ACID; LOS-ANGELES; COMBUSTION; SULFIDES; OXIDE AB The Wieliczka Salt Mine World Cultural Heritage Site contains many rock salt sculptures that are threatened by water vapor condensation from the mine ventilation air. Gaseous and particulate air pollutant concentrations have been measured both outdoors and within the Wieliczka Salt Mine, along with pollutant deposition fluxes to surfaces within the mine. One purpose of these measurements was to determine whether or not low deliquescence point ionic materials (e.g., NH4NO3) are accumulating on surfaces to an extent that would exacerbate the water va por condensation problems in the mine. It was found that pollutant gases including SO2 and HNO3 present in outdoor air are removed rapidly and almost completely from the air within the mine by deposition to surfaces. Sulfur isotope analyses confirm the accumulation of air pollutant-derived sulfur in liquid dripping from surfaces within the mine. Particle deposition onto interior surfaces in the mine is apparent, with resulting soiling of some of those sculptures that have been carved from translucent rock salt. Water accumulation by salt sculpture surfaces was studied both experimentally and by approximate thermodynamic calculations. Both approaches suggest that the pollutant deposits on the sculpture surfaces lower the relative humidity (RH) at which a substantial amount of liquid water will accumulate by 1% to several percent. The extraordinarily low SO2 concentrations within the mine may explain the apparent success of a respiratory sanatorium located deep within the mine. C1 CALTECH,DEPT ENVIRONM ENGN SCI,PASADENA,CA 91125. POLISH ACAD SCI,INST CATALYSIS & SURFACE CHEM,KRAKOW,POLAND. US GEOL SURVEY,RESTON,VA 22092. NR 20 TC 1 Z9 1 U1 0 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1996 VL 30 IS 3 BP 872 EP 880 DI 10.1021/es950306j PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TX751 UT WOS:A1996TX75100041 ER PT J AU Battaglin, WA Hay, LE AF Battaglin, WA Hay, LE TI Effects of sampling strategies on estimates of annual mean herbicide concentrations in midwestern rivers SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID SURFACE WATERS; UNITED-STATES AB The effects of 10 sampling strategies on estimates of annual mean concentrations of the herbicides atrazine, alachlor, and cyanazine in selected midwestern rivers were tested. The accuracy of the strategies was computed by comparing time-weighted annual mean herbicide concentrations calculated from water samples collected from 17 locations on midwestern rivers, with simulated annual mean concentrations calculated for each sampling strategy, using Monte Carlo simulations. Monthly sampling was the most accurate strategy tested. The U.S. Environmental Protection Agency requires quarterly sampling for municipalities using surface water as a source of drinking water. Due to the seasonality of herbicide occurrence and transport, quarterly sampling underestimates annual mean herbicide concentrations in over 40% of the simulations. Three of the strategies tested showed that, relative to quarterly sampling, a more accurate representation of annual mean concentrations could be obtained by sampling more frequently during spring and early summer runoff and assuming zero herbicide concentration during late summer and winter months. RP Battaglin, WA (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,BOX 25046,MS 406,DFC,LAKEWOOD,CO 80225, USA. NR 47 TC 17 Z9 17 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1996 VL 30 IS 3 BP 889 EP 896 DI 10.1021/es950351r PG 8 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TX751 UT WOS:A1996TX75100043 ER PT J AU Kimbrough, RA Litke, DW AF Kimbrough, RA Litke, DW TI Pesticides in streams draining agricultural and urban areas in Colorado SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID HERBICIDES; WATER; RIVER AB A study was conducted from April 1993 through April 1994 to describe and compare the occurrence and distribution of pesticides in streams in a small agricultural and a small urban area in Colorado. Twenty-five water samples collected at least monthly at the mouths of two tributary streams of the South Platte River were analyzed for 47 pesticides. The results indicate that both agricultural and urban areas are probable sources for pesticides in streams. In the agricultural area, 30 pesticides were detected, and in the urban area, 22 pesticides were detected in one or more samples. Most often, the more frequently detected pesticides in both areas also were some of the more commonly used pesticides. In both areas, pesticide concentrations were higher during the summer (application period) with maximum concentrations generally occurring in storm runoff. The year-round detection of some pesticides in both areas at consistently low concentrations, regardless of season or streamflow volume, could indicate that these compounds persist in the shallow alluvial aquifer year-round. RP Kimbrough, RA (reprint author), US GEOL SURVEY,DENVER FED CTR,POB 25046,MS 415,DENVER,CO 80225, USA. NR 27 TC 41 Z9 41 U1 0 U2 6 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1996 VL 30 IS 3 BP 908 EP 916 DI 10.1021/es950353b PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TX751 UT WOS:A1996TX75100045 ER PT J AU Horowitz, AJ Lum, KR Garbarino, JR Hall, GEM Lemieux, C Demas, CR AF Horowitz, AJ Lum, KR Garbarino, JR Hall, GEM Lemieux, C Demas, CR TI Problems associated with using filtration to define dissolved trace element concentrations in natural water samples SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID MASS-BALANCE; RIVER WATER; TRENDS; METALS AB Field and laboratory experiments indicate that a number of factors associated with filtration other than just pore size (e.g., diameter, manufacturer, volume of sample processed, amount of suspended sediment in the sample) can produce significant variations in the ''dissolved'' concentrations of such elements as Fe, Al, Cu, Zn, Pb, Co, and Ni. The bulk of these variations result from the inclusion/exclusion of colloidally associated trace elements in the filtrate, although dilution and sorption/desorption from filters also may be factors. Thus, dissolved trace element concentrations quantitated by analyzing filtrates generated by processing whole water through similar pore-sized filters may not be equal or comparable. As such, simple filtration of unspecified volumes of natural water through unspecified 0.45-mu m membrane filters may no longer represent an acceptable operational definition for a number of dissolved chemical constituents. C1 ENVIRONM CANADA,CTR ST LAURENT,MONTREAL,PQ H2Y 2E7,CANADA. GEOL SURVEY CANADA,OTTAWA,ON K1A 0E8,CANADA. US GEOL SURVEY,BATON ROUGE,LA 70816. US GEOL SURVEY,BRANCH ANALYT SERV,ARVADA,CO 80002. RP Horowitz, AJ (reprint author), US GEOL SURVEY,PEACHTREE BUSINESS CTR,3039 AMWILER RD,ATLANTA,GA 30360, USA. NR 23 TC 99 Z9 99 U1 2 U2 17 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD MAR PY 1996 VL 30 IS 3 BP 954 EP 963 DI 10.1021/es950407h PG 10 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TX751 UT WOS:A1996TX75100051 ER PT J AU Kutina, J Schulz, KJ AF Kutina, J Schulz, KJ TI IGCP project 354: Economic super-accumulations of metals in the lithosphere - Reston, Virginia, USA, 5-7 October 1995 SO EPISODES LA English DT Editorial Material C1 US GEOL SURVEY,RESTON,VA 22092. RP Kutina, J (reprint author), AMERICAN UNIV,DEPT CHEM,WASHINGTON,DC 20016, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT UNION GEOLOGICAL SCIENCES PI KEYWORTH PA C/O BRITISH GEOLOGICAL SURVEY, KEYWORTH, NOTTINGHAM, ENGLAND NG12 5GG SN 0705-3797 J9 EPISODES JI Episodes PD MAR-JUN PY 1996 VL 19 IS 1-2 BP 24 EP 25 PG 2 WC Geosciences, Multidisciplinary SC Geology GA VT836 UT WOS:A1996VT83600006 ER PT J AU Kaeding, LR Boltz, GD Carty, DG AF Kaeding, LR Boltz, GD Carty, DG TI Lake trout discovered in Yellowstone Lake threaten native cutthroat trout SO FISHERIES LA English DT Article ID ONTARIO; PREY AB On 30 July 1994, lake trout (Salvelinus namaycush) were discovered in Yellowstone Lake in Yellowstone National Park, Wyoming, the core of the remaining undisturbed natural habitat for native Yellowstone cutthroat trout (Oncorhynchus clarki bouvieri). Data from this and other lake trout subsequently caught by anglers and the U.S. Fish and Wildlife Service suggest lake trout have reproduced in Yellowstone Lake since at least 1989 and now number in the thousands, perhaps tens of thousands. A highly piscivorous, nonnative species, lake trout will probably thrive in Yellowstone Lake and reduce the lake's cutthroat trout stocks substantially unless preventive management actions are taken. A team of scientists that convened in February 1995 to discuss the lake trout problem concluded that there is little chance lake trout can be eliminated from Yellowstone Lake. The team projected a decline of 90% or more in cutthroat trout numbers in 20 years-100 years if the lake trout population is not controlled. The team considered mechanical removal methods, either gillnetting or some combination of gillnetting and trapping, to be the management actions most likely to control lake trout. RP Kaeding, LR (reprint author), US FISH & WILDLIFE SERV,YELLOWSTONE FISHERY ASSISTANCE OFF,POB 184,YELLOWSTONE NATL PK,WY 82190, USA. NR 25 TC 26 Z9 26 U1 4 U2 15 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD MAR PY 1996 VL 21 IS 3 BP 16 EP 20 DI 10.1577/1548-8446(1996)021<0016:LTDIYL>2.0.CO;2 PG 5 WC Fisheries SC Fisheries GA TX589 UT WOS:A1996TX58900003 ER PT J AU Starnes, LB Jiminez, GC Dodge, D Huntsman, G Janik, P Lloyd, J Prosser, N Royce, W Taylor, WW AF Starnes, LB Jiminez, GC Dodge, D Huntsman, G Janik, P Lloyd, J Prosser, N Royce, W Taylor, WW TI North American Fisheries Policy SO FISHERIES LA English DT Editorial Material RP Starnes, LB (reprint author), US FISH & WILDLIFE SERV,POB 1306,ALBUQUERQUE,NM 87103, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0363-2415 J9 FISHERIES JI Fisheries PD MAR PY 1996 VL 21 IS 3 BP 26 EP 29 PG 4 WC Fisheries SC Fisheries GA TX589 UT WOS:A1996TX58900005 ER PT J AU Johnson, SY Potter, CJ Armentrout, JM Miller, JJ Finn, C Weaver, CS AF Johnson, SY Potter, CJ Armentrout, JM Miller, JJ Finn, C Weaver, CS TI The southern Whidbey Island fault: An active structure in the Puget Lowland, Washington SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID OLYMPIC SUBDUCTION COMPLEX; COAST RANGE; PLATE CONVERGENCE; BRITISH-COLUMBIA; VANCOUVER-ISLAND; PACIFIC; DEFORMATION; NORTHWEST; OREGON; UPLIFT AB Information from seismic-reflection profiles, outcrops, boreholes, and potential field surveys is used to interpret the structure and history of the southern Whidbey Island fault in the Puget Lowland of western Washington, This northwest-trending fault comprises a broad (as wide as 6-11 km), steep, northeast-dipping zone that includes several splays with inferred strike-slip, reverse, and thrust displacement, Transpressional deformation along the southern Whidbey Island fault is indicated by along-strike variations in structural style and geometry, positive flower structure, local unconformities, out-of-plane displacements, and juxtaposition of correlative sedimentary units with different histories. The southern Whidbey Island fault represents a segment of a boundary between two major crustal blocks, The Cascade block to the northeast is floored by diverse assemblages of pre-Tertiary rocks; the Coast Range block to the southwest is floored by lower Eocene marine basaltic rocks of the Crescent Formation, The fault probably originated during the early Eocene as a dextral strike-slip fault along the eastern side of a continental-margin rift, Bending of the fault and transpressional deformation began during the late middle Eocene and continues to the present, Oblique convergence and clockwise rotation along the continental margin are the inferred driving forces for ongoing deformation. Evidence for Quaternary movement on the southern Whidbey Island fault includes (1) offset and disrupted upper Quaternary strata imaged on seismic-reflection profiles; (2) borehole data that suggests as much as 420 m of structural relief on the Tertiary-Quaternary boundary in the fault zone; (3) several meters of displacement along exposed faults in upper Quaternary sediments; (4) late Quaternary folds with limb dips of as much as approximate to 9 degrees; (5) large-scale liquefaction features in upper Quaternary sediments within the fault zone; and (6) minor historical seismicity, The southern Whidbey Island fault should be considered capable of generating large earthquakes (M(s) greater than or equal to 7) and represents a potential seismic hazard to residents of the Puget Lowland. C1 MOBIL RES & DEV CORP,DALLAS,TX 75265. UNIV WASHINGTON,DEPT GEOPHYS,US GEOL SURVEY,SEATTLE,WA 98195. RP Johnson, SY (reprint author), US GEOL SURVEY,MS 966,POB 25046,FED CTR,DENVER,CO 80225, USA. NR 70 TC 50 Z9 50 U1 0 U2 3 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD MAR PY 1996 VL 108 IS 3 BP 334 EP 354 DI 10.1130/0016-7606(1996)108<0334:TSWIFA>2.3.CO;2 PG 21 WC Geosciences, Multidisciplinary SC Geology GA TY592 UT WOS:A1996TY59200006 ER PT J AU Beaudoin, BC Godfrey, NJ Klemperer, SL Lendl, C Trehu, AM Henstock, TJ Levander, A Holl, JE Meltzer, AS Luetgert, JH Mooney, WD AF Beaudoin, BC Godfrey, NJ Klemperer, SL Lendl, C Trehu, AM Henstock, TJ Levander, A Holl, JE Meltzer, AS Luetgert, JH Mooney, WD TI Transition from slab to slabless: Results from the 1993 Mendocino triple junction seismic experiment SO GEOLOGY LA English DT Article ID ANDREAS FAULT SYSTEM; NORTHERN CALIFORNIA; VELOCITY STRUCTURE; VOLCANIC-ROCKS; GORDA PLATE; GEOMETRY; LITHOSPHERE; EVOLUTION; IMAGES; BASIN AB Three seismic refraction-reflection profiles, part of the Mendocino triple junction seismic experiment, allow us to compare and contrast crust and upper mantle of the North American margin before and after it is modified by passage of the Mendocino triple junction, Upper crustal velocity models reveal an asymmetric Great Valley basin overlying Sierran or ophiolitic rocks at the latitude of Fort Bragg, California,nd overlying Sierran or Klamath rocks near Redding, California, In addition, the upper crustal velocity structure indicates that Franciscan rocks underlie the Klamath terrane east of Eureka, California, The Franciscan complex is, on average, laterally homogeneous and is thickest in the triple junction region, North of the triple junction, the Gorda slab can be traced 150 km inboard from the Cascadia subduction zone, South of the triple junction, strong precritical reflections indicate partial melt and/or metamorphic fluids at the base of the crust or in the upper mantle, Breaks in these reflections are correlated with the Maacama and Bartlett Springs faults, suggesting that these faults extend at least to the mantle, We interpret our data to indicate tectonic thickening of the Franciscan complex in response to passage of the Mendocino triple junction and an associated thinning of these rocks south of the triple junction due to assimilation into melt triggered by upwelling asthenosphere, The region of thickened Franciscan complex overlies a zone of increased scattering, intrinsic attenuation, or both, resulting from mechanical mixing of lithologies and/or partial melt beneath the onshore projection of the Mendocino fracture zone, Our data reveal that we have crossed the southern edge of the Gorda slab and that this edge and/or the overlying North American crust may have fragmented because of the change in stress presented by the edge. C1 OREGON STATE UNIV,DEPT OCEAN & ATMOSPHER SCI,CORVALLIS,OR 97331. RICE UNIV,DEPT GEOL & GEOPHYS,HOUSTON,TX 77251. LEHIGH UNIV,DEPT EARTH & ENVIRONM SCI,BETHLEHEM,PA 18015. US GEOL SURVEY,MENLO PK,CA 94025. RP Beaudoin, BC (reprint author), STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305, USA. RI Klemperer, Simon/A-5919-2012; Wright, Dawn/A-4518-2011; Henstock, Timothy/C-3583-2014; Levander, Alan/A-3543-2011; OI Wright, Dawn/0000-0002-2997-7611; Henstock, Timothy/0000-0002-2132-2514; Levander, Alan/0000-0002-1048-0488; Klemperer, Simon/0000-0001-7050-1829 NR 30 TC 42 Z9 42 U1 0 U2 7 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD MAR PY 1996 VL 24 IS 3 BP 195 EP 199 DI 10.1130/0091-7613(1996)024<0195:TFSTSR>2.3.CO;2 PG 5 WC Geology SC Geology GA TY589 UT WOS:A1996TY58900001 ER PT J AU Ludwig, KR Muhs, DR Simmons, KR Halley, RB Shinn, EA AF Ludwig, KR Muhs, DR Simmons, KR Halley, RB Shinn, EA TI Sea-level records at similar to 80 ka from tectonically stable platforms: Florida and Bermuda SO GEOLOGY LA English DT Article ID REEF TRACTS; SERIES AB Studies from tectonically active coasts on New Guinea and Barbados have suggested that sea level at similar to 80 ka was significantly lower than present, whereas data from the Atlantic and Pacific coasts of North America indicate an similar to 80 ha sea level close to that of the present, We determined ages of corals from a shallow submerged reef off the Florida Keys and an emergent marine deposit on Bermuda. Both localities are on tectonically stable platforms distant from plate boundaries. Uranium-series ages show that corals at both localities grew during the similar to 80 ha sea-level highstand, and geologic data show that sea level at that time was no lower than 7-9 m below present (Florida) and may hale been 1-2 m above present (Bermuda). The ice-volume discrepancy of the 80 ka sea-level estimates is greater than the volume of the Greenland or West Antarctic ice sheets, Comparison of our ages with high-latitude insolation values indicates that the sea-level stand near the present at similar to 80 ha could have been orbitally forced. C1 US GEOL SURVEY,CTR COASTAL GEOL,ST PETERSBURG,FL 33701. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 21 TC 83 Z9 87 U1 1 U2 9 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD MAR PY 1996 VL 24 IS 3 BP 211 EP 214 DI 10.1130/0091-7613(1996)024<0211:SLRAKF>2.3.CO;2 PG 4 WC Geology SC Geology GA TY589 UT WOS:A1996TY58900005 ER PT J AU Dieterich, JH Okubo, PG AF Dieterich, JH Okubo, PG TI An unusual pattern of recurring seismic quiescence at Kalapana, Hawaii SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID KILAUEA VOLCANO; SOUTH FLANK; EARTHQUAKE; MAGMA AB An unusual pattern of recurring seismic quiescence is observed in the Kalapana, Hawaii region of Kilauea Volcano. Statistically significant intervals of quiescence preceded the Kalapana earthquakes of 1975 (M7.2) and 1989 (M6.1) and a third quiescence is presently underway. The sensitivity of the volcano flank to continuing magmatic activity in the nearby east rift zone complicates interpretation of these observations. The current quiescence episode may be caused by magmatic processes in the east rift zone or by changes within the flank of Kilauea. The latter possibility, if correct, may represent a precursor to another earthquake. C1 US GEOL SURVEY,HAWAIIAN VOLCANO OBSERV,HAWAII NATL PK,HONOLULU,HI 96718. RP Dieterich, JH (reprint author), US GEOL SURVEY,BRANCH EARTHQUAKE GEOL & GEOPHYS,MAIL STOP 977,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 18 TC 13 Z9 13 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 1 PY 1996 VL 23 IS 5 BP 447 EP 450 DI 10.1029/96GL00009 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TZ786 UT WOS:A1996TZ78600009 ER PT J AU Evans, JR Foulger, GR Julian, BR Miller, AD AF Evans, JR Foulger, GR Julian, BR Miller, AD TI Crustal shear-wave splitting from local earthquakes in the Hengill triple junction, southwest Iceland SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID PREDICTION AB The Hengill region in SW Iceland is an unstable ridge-ridge-transform triple junction between an active and a waning segment of the mid-Atlantic spreading center and a transform that is transgressing southward. The triple junction contains active and extinct spreading segments and a widespread geothermal area. We evaluated shear-wave birefringence for locally recorded upper-crustal earthquakes using an array of 30 three-component digital seismographs. Fast-polarization directions, phi, are mostly NE to NNE, subparallel to the spreading axis and probably caused by fissures and microcracks related to spreading. However, there is significant variability in phi throughout the array. The lag from fast to slow S is not proportional to earthquake depth (ray length), being scattered at all depths. The average wave-speed difference between qS1 and qS2 in the upper 2-5 km of the crust is 2-5%. Our results suggest considerable heterogeneity or strong S scattering. C1 UNIV DURHAM,DEPT GEOL SCI,DURHAM DH1 3LE,ENGLAND. RP Evans, JR (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS-977,MENLO PK,CA 94025, USA. NR 12 TC 12 Z9 12 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 1 PY 1996 VL 23 IS 5 BP 455 EP 458 DI 10.1029/96GL00261 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TZ786 UT WOS:A1996TZ78600011 ER PT J AU Savage, JC Byerlee, JD Lockner, DA AF Savage, JC Byerlee, JD Lockner, DA TI Is internal friction friction? SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB Mogi [1974] proposed a simple model of the incipient rupture surface to explain the Coulomb failure criterion. We show here that this model can plausibly be extended to explain the Mohr failure criterion. In Mogi's model the incipient rupture surface immediately before fracture consists of areas across which material integrity is maintained (intact areas) and areas across which it is not (cracks). The strength of the incipient rupture surface is made up of the inherent strength of the intact areas plus the frictional resistance to sliding offered by the cracked areas. Although the coefficient of internal friction (slope of the strength versus normal stress curve) depends upon both the frictional and inherent strengths, the phenomenon of internal friction call be identified with the frictional part. The curvature of the Mohr failure envelope is interpreted as a consequence of differences in damage (cracking) accumulated in prefailure loading at different confining pressures. RP Savage, JC (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. NR 8 TC 26 Z9 28 U1 0 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD MAR 1 PY 1996 VL 23 IS 5 BP 487 EP 490 DI 10.1029/96GL00241 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TZ786 UT WOS:A1996TZ78600019 ER PT J AU Eaton, GP AF Eaton, GP TI What's ahead for the USGS? SO GEOTIMES LA English DT Article RP Eaton, GP (reprint author), US GEOL SURVEY,NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD MAR PY 1996 VL 41 IS 3 BP 24 EP 26 PG 3 WC Geosciences, Multidisciplinary SC Geology GA UW267 UT WOS:A1996UW26700007 ER PT J AU Vroblesky, DA Rhodes, LC Robertson, JF Harrigan, JA AF Vroblesky, DA Rhodes, LC Robertson, JF Harrigan, JA TI Locating VOC contamination in a fractured-rock aquifer at the ground-water/surface-water interface using passive vapor collectors SO GROUND WATER LA English DT Article ID ZONES AB Chlorinated organic solvents introduced to unlined lagoons at an industrial waste-water treatment plant in the Inner Piedmont of South Carolina resulted in ground-water contamination of a fractured-rock aquifer. Part of the ground-water contamination discharges to Little Rocky Creek, downgradient from the waste-water treatment plant. Passive vapor collectors were buried in the bottom sediment of the creek to locate areas where ground water contaminated with volatile organic compounds was discharging to the creek. High concentrations of volatile organic compounds (VOCs) were found in passive vapor collectors in an area where VOCs were known to be discharging from ground water to surface water. This area was also a site where very low frequency electromagnetic anomalies (interpreted as fracture zones) intersected the creek or converged near the creek. The data show that passive vapor collectors in bottom sediment of Little Rocky Creek provided information on the location of fractures that were discharging contaminated ground water to surface water. C1 RUST ENVIRONM & INFRASTRUCT,GREENVILLE,SC 29615. RP Vroblesky, DA (reprint author), US GEOL SURVEY,STEPHENSON CTR,720 GRACERN RD,SUITE 129,COLUMBIA,SC 29210, USA. NR 20 TC 22 Z9 22 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1996 VL 34 IS 2 BP 223 EP 230 DI 10.1111/j.1745-6584.1996.tb01882.x PG 8 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TY223 UT WOS:A1996TY22300005 ER PT J AU Folger, PF Poeter, E Wanty, RB Frishman, D Day, W AF Folger, PF Poeter, E Wanty, RB Frishman, D Day, W TI Controls on Rn-222 variations in a fractured crystalline rock aquifer evaluated using aquifer tests and geophysical logging SO GROUND WATER LA English DT Article ID HYDRAULIC CONDUCTIVITY TENSOR; FIELD DETERMINATION; ANISOTROPIC MEDIA; FLOW; RADON; WATER; GROUNDWATER; TRANSPORT; COLORADO; USA AB Concentrations of Rn-222 in ground water may vary considerably within megascopically homogeneous rocks over relatively short distances. Calculations indicate that different hydraulic apertures of water-bearing fractures may account for variations in dissolved Rn-222 concentration measured in domestic water wells completed in fractured Pikes Peak Granite, assuming that all other factors influencing dissolved Rn-222 concentrations are constant. Concentrations of dissolved Rn-222 range from 124 to 840 kBq m(-3) [3,360 to 22,700 picocuries per liter (pCi L(-1))] within a 2.5 km(2) well field, Aquifer tests show that transmissivities range from 0.072 to 160 m(2) day(-1) within the well field, Acoustic televiewer and heat-pulse now meter logging of four wells reveals that, despite tens to hundreds of fractures that intersect each well, a single fracture supplies all the flow to three wells, and one fracture provides 65% of the flow to the fourth well, Aquifer tests indicate that two pairs of the four wells are hydraulically connected, Type-curve interpretation of early-time data from aquifer tests reveals classic half-slope behavior on log-log plots of drawdown versus time for two wells, suggesting linear flow to a single fracture, Drawdown versus time for the other two wells indicates radial or pseudo-radial flow, which suggests a higher degree of fracture interconnectivity near those boreholes. Hydraulic apertures calculated using the cubic law are 0.024 and 0.038 cm for producing fractures in the first hydraulically connected well pair and 0.011 and 0.020 cm for flowing fractures in the second well pair, Assuming uniform distribution of Ra-226 along fracture walls and long residence time of water relative to Rn-222 decay, the ratio of fracture apertures should equal the inverse ratio of Rn-222 concentration in each well, Assuming 50% error in hydraulic aperture estimation and 10% analytical uncertainty in Rn-222 measurement, differences in 222Rn concentration between wells in the hydraulically connected pairs can be attributed solely to differences in hydraulic aperture. Different hydraulic apertures, however, do not explain different Rn-222 concentrations between well pairs, Allowing for measurement error, a cubic meter of rock transfers from 1.3 to 20 times more Rn-222 to ground water in the first pair of wells than in the second pair, Nonuniform distribution of Ra-226 along fracture walls, heterogeneous emanating power in the rock-water system, or short ground-water residence time along the transmissive fracture network may account for the difference between well pairs. C1 COLORADO SCH MINES,DEPT GEOL & GEOL ENGN,GOLDEN,CO 80401. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Folger, PF (reprint author), US SENATE,OFF SENATOR PETE V DOMENICI,WASHINGTON,DC 20510, USA. NR 50 TC 14 Z9 14 U1 0 U2 1 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1996 VL 34 IS 2 BP 250 EP 261 DI 10.1111/j.1745-6584.1996.tb01885.x PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TY223 UT WOS:A1996TY22300008 ER PT J AU Church, PE Granato, GE AF Church, PE Granato, GE TI Bias in ground-water data caused by well-bore flow in long-screen wells SO GROUND WATER LA English DT Article ID MONITORING WELLS; SAMPLES AB The results of a field experiment comparing water-quality constituents, specific conductance, geophysical measurements, and well-bore hydraulics in two long-screen wells and adjacent vertical clusters of short-screen wells show bias in ground-water data caused by well-bore flow in long-screen wells, The well screen acts as a conduit for vertical flow because it connects zones of different head and transmissivity, even in a relatively homogeneous, unconfined, sand and gravel aquifer where such zones are almost indistinguishable. Flow in the well bore redistributes water and solutes in the aquifer adjacent to the well, increasing the risk of bias in water-quality samples, failure of plume detection, and cross-contamination of the aquifer, At one site, downward flow from a contaminated zone redistributes solutes over the entire length of the long-screen well, At another site, upward flow from an uncontaminated zone masks the presence of a road salt plume, Borehole induction logs, conducted in a fully penetrating short-screen well, can provide a profile of solutes in the aquifer that is not attainable in long-screen wells, In this study, the induction-log profiles show close correlation with data from analyses of water-quality samples from the short-screen wells; however, both of these data sets differ markedly from the biased water-quality samples from the long-screen wells, Therefore, use of induction logs in fully cased wells for plume detection and accurate placement of short-screen wells is a viable alternative to use of long screen wells for water-quality sampling. RP Church, PE (reprint author), US GEOL SURVEY,28 LORD RD,MARLBOROUGH,MA 01752, USA. NR 24 TC 52 Z9 55 U1 1 U2 5 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1996 VL 34 IS 2 BP 262 EP 273 DI 10.1111/j.1745-6584.1996.tb01886.x PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TY223 UT WOS:A1996TY22300009 ER PT J AU Barlow, PM Wagner, BJ Belitz, K AF Barlow, PM Wagner, BJ Belitz, K TI Pumping strategies for management of a shallow water table: The value of the simulation-optimization approach SO GROUND WATER LA English DT Article ID GROUNDWATER-MANAGEMENT; IRRIGATED AGRICULTURE; SURFACE-WATER; SYSTEMS; MODEL; SALINE AB The simulation-optimization approach is used to identify ground-water pumping strategies for control of the shallow water table in the western San Joaquin Valley, California, where shallow ground water threatens continued agricultural productivity. The approach combines the use of ground-water flow simulation with optimization techniques to build on and refine pumping strategies identified in previous research that used flow simulation alone. Use of the combined simulation-optimization model resulted in a 20 percent reduction in the area subject to a shallow water table over that identified by use of the simulation model alone. The simulation-optimization model identifies increasingly more effective pumping strategies for control of the water table as the complexity of the problem increases; that is, as the number of subareas in which pumping is to be managed increases, the simulation-optimization model is better able to discriminate areally among subareas to determine optimal pumping locations. The simulation-optimization approach provides an improved understanding of controls on the ground-water flow system and management alternatives that can be implemented in the valley. In particular, results of the simulation-optimization model indicate that optimal pumping strategies are constrained by the existing distribution of wells between the semiconfined and confined zones of the aquifer, by the distribution of sediment types (and associated hydraulic conductivities) in the western valley, and by the historical distribution of pumping throughout the western valley. C1 US GEOL SURVEY,MENLO PK,CA 94025. DARTMOUTH COLL,DEPT EARTH SCI,HANOVER,NH 03755. RP Barlow, PM (reprint author), US GEOL SURVEY,28 LORD RD,MARLBOROUGH,MA 01752, USA. NR 41 TC 16 Z9 18 U1 0 U2 3 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD MAR-APR PY 1996 VL 34 IS 2 BP 305 EP 317 DI 10.1111/j.1745-6584.1996.tb01890.x PG 13 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TY223 UT WOS:A1996TY22300013 ER PT J AU Plotkin, PT Owens, DW Byles, RA Patterson, R AF Plotkin, PT Owens, DW Byles, RA Patterson, R TI Departure of male olive ridley turtles (Lepidochelys olivacea) from a nearshore breeding ground SO HERPETOLOGICA LA English DT Article DE Lepidochelys olivacea; breeding ground; reproductive behavior; telemetry ID CHELONIA-MYDAS; SEA TURTLES AB Between 1990 and 1993, adult male olive ridley turtles (Lepidochelys olivacea) were captured at their breeding ground, in the Gulf of Papagayo, on the Pacific coast of Costa Rica. We attached radio (VHF) and satellite (UHF) transmitters to 11 reproductively active males (as verified by serum testosterone measurements and laparoscopy) to monitor their movements in and from the breeding ground. Telemetered males departed the Gulf of Papagayo by late September, which coincided with a notable decrease in the number of males that we observed in the breeding ground and with the mid-season peak in the number of females emerging to lay eggs at Nancite Beach. We suggest that males of L. olivacea depart nearshore breeding grounds at mid-season because most of the females already have mated. C1 TEXAS A&M UNIV, DEPT BIOL, COLLEGE STN, TX 77843 USA. US FISH & WILDLIFE SERV, ALBUQUERQUE, NM 87103 USA. NR 21 TC 25 Z9 34 U1 1 U2 6 PU HERPETOLOGISTS LEAGUE PI EMPORIA PA EMPORIA STATE UNIV, DIVISION BIOLOGICAL SCIENCES, 1200 COMMERCIAL ST, EMPORIA, KS 66801-5087 USA SN 0018-0831 EI 1938-5099 J9 HERPETOLOGICA JI Herpetologica PD MAR PY 1996 VL 52 IS 1 BP 1 EP 7 PG 7 WC Zoology SC Zoology GA VG888 UT WOS:A1996VG88800001 ER PT J AU Belton, MJS Chapman, CR Klaasen, KP Harch, AP Thomas, PC Veverka, J McEwen, AS Pappalardo, RT AF Belton, MJS Chapman, CR Klaasen, KP Harch, AP Thomas, PC Veverka, J McEwen, AS Pappalardo, RT TI Galileo's encounter with 243 Ida: An overview of the imaging experiment SO ICARUS LA English DT Article AB We provide an overview of the execution, data, and results of the solid state imaging (SSI) experiment at the encounter of the Galileo spacecraft with the asteroid 243 Ida. Ninety-six images of the asteroid, representing 18 time samples during a rotation period (4.633 h), were transmitted to Earth as a result of the UT 1993 August 28.70284 encounter. This provided coverage of similar to 95% of the surface and achieved ground resolutions as high as 25 m/pixel. Coverage of most of Ida's surface is available in four colors, with limited regions in five colors, at resolutions up to 105 m/pixel. A natural satellite of Ida, called Dactyl, was discovered in a prograde (with respect to Ida's spin), near-equatorial, orbit moving slowly (similar to 6 m/sec) with a separation of 85 km from Ida. Ida's shape is highly irregular; by comparison, Dactyl's global topography is quite smooth. The best fit ellipsoid to Ida's shape has principal dimensions 59.8 x 25.4 x 18.6 km, mean radius 15.7 km, and volume 16,100 +/- 1900 km(3). Dactyl's mean radius is only 0.7 km. Ida's spin axis (right ascension: 348.76 degrees +/- 7.5 degrees; declination: 87.10 degrees +/- 0.4 degrees; J2000) was found to align with the principal axis of inertia to within the error of measurement. This is consistent with a homogeneous density distribution. Dactyl's rotation rate is unknown, but its long axis was pointed in the direction of Ida at the time of observation, suggesting synchronism of its orbital motion and spin. Constraints on Dactyl's orbit yield 4.2 +/- 0.6 x 10(19) g for Ida's mass and 2.6 +/- 0.5 g/cm(3) for its bulk density. Unless Ida's bulk porosity is exceptionally high, Ida has moderate to low NiFe content. Subtle color variations across the surface of Ida are associated with fresh craters, but, unlike the case for Asteroid 951 Gaspra, are not correlated with topographic features such as ridges. This difference may be a reflection of a deeper and/or more mobile regolith on Ida. Dactyl's spectral reflectance is similar to, but quantitatively distinct from the surface of Ida itself. This difference may reflect compositional differences between Dactyl and Ida, which in turn may have originated in an only partially differentiated Koronis parent body. Results on the origin, collisional history, and geology of Ida and Dactyl are the subject of many of the papers in this special issue. There is general agreement that these asteroids originated in the catastrophic breakup of the Koronis parent body and that the formation of asteroid-satellite systems may be relatively common in such events. The age and collisional history of the pair present a dilemma: using standard interpretations of the cratering record on Ida's surface, an age > 1 byr. is indicated. However, the lifetime of Dactyl against collisional disruption is many times less than this. Novel ideas are presented concerning the collisional history of these two small objects that may resolve this dilemma. These ideas result from analysis of the geological record on the surface of Ida, Dactyl, and, by comparison, Gaspra-all of which are examined in this special issue. The execution of the Galileo flybys of Gaspra, Ida, and Dactyl provide important lessons for future flybys of small bodies. We present our views on the limitations faced by the Galileo imaging experimenters and indicate how future missions can be made more quantitative and productive through the application of innovative electronic control systems and detector technology. (C) 1996 Academic Press, Inc. C1 PLANETARY SCI INST,TUCSON,AZ 85705. CALTECH,JET PROP LAB,PASADENA,CA 91109. CORNELL UNIV,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853. US GEOL SURVEY,FLAGSTAFF,AZ 86001. ARIZONA STATE UNIV,DEPT GEOL,TEMPE,AZ 85287. RP Belton, MJS (reprint author), NATL OPT ASTRON OBSERV,TUCSON,AZ 85719, USA. NR 33 TC 42 Z9 43 U1 0 U2 4 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD MAR PY 1996 VL 120 IS 1 BP 1 EP 19 DI 10.1006/icar.1996.0032 PG 19 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UF009 UT WOS:A1996UF00900001 ER PT J AU Helfenstein, P Veverka, J Thomas, PC Simonelli, DP Klaasen, K Johnson, TV Fanale, F Granahan, J McEwen, AS Belton, M Chapman, C AF Helfenstein, P Veverka, J Thomas, PC Simonelli, DP Klaasen, K Johnson, TV Fanale, F Granahan, J McEwen, AS Belton, M Chapman, C TI Galileo photometry of asteroid 243 Ida SO ICARUS LA English DT Article ID BIDIRECTIONAL REFLECTANCE SPECTROSCOPY AB Galileo imaging observations over phase angles 19.5 degrees to 109.8 degrees are combined with near-opposition Earth-based data to derive the photometric properties of Ida. To first order these properties are uniform over the surface and well modeled at lambda = 0.55 mu m by Hapke parameters <(omega)over tilde>, = 0.22, h = 0.020, B-0 = 1.5, g = -0.33, and theta = 18 degrees with corresponding geometric albedo p = 0.21+/-(0.03)(0.01): and Bond albedo A(B) = 0.081+/-(0.017)(0.008). Ida's photometric properties are more similar to those of ''average S-asteroids'' (P. Helfenstein and J. Veverka 1989, Asteroids II, Univ. of Arizona Press, Tucson) than are those of 951 Gaspra. Two primary color units are identified on Ida: Terrain A exhibits a spectrum with relatively shallower 1-mu m absorption and a relatively steeper red spectral slope than average Ida, while Terrain B has a deeper 1-mu m absorption and a less steep red slope. The average photometric properties of Ida and Terrain A are similar while those of Terrain B differ mostly in having a slightly higher value of <(omega)over tilde>(0) (0.22 versus 0.21), suggesting that Terrain B consists of slightly brighter, more transparent regolith particles. Galileo observations of Ida's satellite Dactyl over phase angles 19.5 degrees to 47.6 degrees suggest photometric characteristics similar to those of Ida, the major difference being Dactyl's slightly lower albedo (0.20 compared to 0.21). (C) 1996 Academic Press, Inc. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV HAWAII,INST GEOPHYS,HONOLULU,HI 96822. US GEOL SURVEY,FLAGSTAFF,AZ 86001. KITT PEAK NATL OBSERV,NATL OPT ASTRON OBSERV,TUCSON,AZ 85726. PLANETARY SCI INST,TUCSON,AZ 85705. RP Helfenstein, P (reprint author), CORNELL UNIV,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853, USA. NR 19 TC 84 Z9 85 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD MAR PY 1996 VL 120 IS 1 BP 48 EP 65 DI 10.1006/icar.1996.0036 PG 18 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UF009 UT WOS:A1996UF00900005 ER PT J AU Veverka, J Helfenstein, P Lee, P Thomas, P McEwen, A Belton, M Klaasen, K Johnson, TV Granahan, J Fanale, F Geissler, P Head, JW AF Veverka, J Helfenstein, P Lee, P Thomas, P McEwen, A Belton, M Klaasen, K Johnson, TV Granahan, J Fanale, F Geissler, P Head, JW TI Ida and Dactyl: Spectral reflectance and color variations SO ICARUS LA English DT Article ID METAL AB Galileo SSI color data between 0.4 and 1.0 mu m demonstrate that both Ida and Dactyl are S-type asteroids with similar, but distinct spectra, Small but definite color variations are also observed on Ida itself and involve both the blue part of the spectrum and the depth of the 1-mu m pyroxene-olivine band. Ida's surface can be classified into two color terrains: Terrain A has a shadower 1-mu m absorption and a steeper visible red slope than does Terrain B. Qualitatively, the color-albedo systematics of these two terrains follow those noted for color units on Gaspra and the variations in 1-mu m band depth with weathering described by Gaffey et al. (Gaffey, M. J., J. F. Bell, R. H. Brown, T, H. Burbine, J. Piatek, K. L. Reed, and D. A. Chaky 1993. Icarus 106, 573-602). Terrain A, with its slightly lower albedo, its shallower 1-mu m band, and its slightly steeper visible red slope relative to Terrain B could be interpreted as the ''more processed,'' ''more mature,'' or the ''more weathered'' of the two terrains. Consistent with this interpretation is that Terrain A appears to be the ubiquitous background on most of Ida, while Terrain B is correlated with some small craters as well as with possible ejecta from the 10-km Azzurra impact structure. Because of these trends, it is less likely that differences between Terrains A and B are caused by an original compositional inhomogeneity within the body of Ida, although they do fail within the range known to occur within the Koronis family. The spectrum of Dactyl is similar to, but definitely different from, that of Terrain B on Ida. It does not conform to the pattern that obtains between the colors and albedos of Terrains A and B: the satellite's 1-mu m band is deeper than that of Terrain B, but its albedo is lower, rather than higher, By itself, the deeper band depth could be interpreted, following Gaffey et at, to mean that Dactyl is a less weathered version of Terrain B on Ida, but such an interpretation is at odds with Dactyl's redder spectral slope. Thus, the explanation for the color difference between Dactyl and Ida is likely to be different from that which accounts for the differences between the two terrains on Ida. Given that Dactyl and Ida have very similar photometric properties (Helfenstein, P., J. Veverka, P. C. Thomas, D. P. Simonelli, K. Klassen, T. V. Johnson, F. Fanale, J. Granahan, A. S. McEwen, M. J. S. Belton, and C. R. Chapman 1996 Icarus 120, 48-65), thus ruling out any dramatic texture differences between the two surfaces, the most likely explanation is that the satellite has a slightly different composition (more pyroxene?) than Ida. The spectral difference is within the range reported by Binzel et al. (Binzel, R. P., S. Xu, and S. J. Bus 1993. Icarus 106, 608-611.) for members of the Koronis family, and could be caused by compositional inhomogeneities of the Koronis parent body rather than by post-breakup regolith processes. (C) 1996 Academic Press, Inc. C1 US GEOL SURVEY,FLAGSTAFF,AZ 86001. NATL OPT ASTRON OBSERV,TUCSON,AZ 85726. CALTECH,JET PROP LAB,PASADENA,CA 91109. UNIV HAWAII,INST GEOPHYS,HONOLULU,HI 96822. UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721. BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. RP Veverka, J (reprint author), CORNELL UNIV,SPACE SCI BLDG,ITHACA,NY 14853, USA. NR 32 TC 33 Z9 33 U1 0 U2 0 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD MAR PY 1996 VL 120 IS 1 BP 66 EP 76 DI 10.1006/icar.1996.0037 PG 11 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UF009 UT WOS:A1996UF00900006 ER PT J AU Sullivan, R Greeley, R Pappalardo, R Asphaug, E Moore, JM Morrison, D Belton, MJS Carr, M Chapman, CR Geissler, P Greenberg, R Granahan, J Head, JW Kirk, R McEwen, A Lee, P Thomas, PC Veverka, J AF Sullivan, R Greeley, R Pappalardo, R Asphaug, E Moore, JM Morrison, D Belton, MJS Carr, M Chapman, CR Geissler, P Greenberg, R Granahan, J Head, JW Kirk, R McEwen, A Lee, P Thomas, PC Veverka, J TI Geology of 243 Ida SO ICARUS LA English DT Article ID IMPACT CRATERS; SOLAR-SYSTEM; PHOBOS; EJECTA; DEIMOS; SPECTROSCOPY; REGOLITHS; ORIGIN; MODEL; MOON AB The surface of 243 Ida is dominated by the effects of impacts. No complex crater morphologies are observed. A complete range of crater degradation states is present, which also reveals optical maturation of the surface (darkening and reddening of materials with increasing exposure age), Regions of bright material associated with the freshest craters might be ballistically emplaced deposits or the result of seismic disturbance of loosely-bound surface materials. Diameter/depth ratios for fresh craters on Ida are similar to 1:6.5, similar to Gaspra results, but greater than the 1:5 ratios common on other rocky bodies. Contributing causes include rim degradation by whole-body ''ringing,'' relatively thin ejecta blankets around crater rims, or an extended strength gradient in near-surface materials due to low gravitational self-packing, Grooves probably represent expressions in surface debris of reactivated fractures in the deeper interior, Isolated positive relief features as large as 150 m are probably ejecta blocks related to large impacts. Evidence for the presence of debris on the surface includes resolved ejecta blocks, mass-wasting scars, contrasts in color and albedo of fresh crater materials, and albedo streaks oriented down local slopes. Color data indicate relatively uniform calcium abundance in pyroxenes and constant pyroxene/olivine ratio. A large, relatively blue unit across the northern polar area is probably related to regolith processes involving ejecta from Azzurra rather than representing internal compositional heterogeneity. A small number of bluer, brighter craters are randomly distributed across the surface, unlike on Gaspra where these features are concentrated along ridges. This implies that debris on Ida is less mobile and/or consistently thicker than on Gaspra. Estimates of the average depth of mobile materials derived from chute depths (20-60 m), grooves (greater than or equal to 30 m), and shallowing of the largest degraded craters (20-50 m minimum, similar to 100 m maximum) suggest a thickness of potentially mobile materials of similar to 50 m, and a typical thickness for the debris layer of 50-100 m. (C) 1996 Academic Press, Inc. C1 NASA,AMES RES CTR,DIV SPACE SCI,MOFFETT FIELD,CA 94035. NATL OPT ASTRON OBSERV,TUCSON,AZ 85719. US GEOL SURVEY,BRANCH ASTROGEOL STUDIES,MENLO PK,CA 94025. PLANETARY SCI INST,TUCSON,AZ 85705. UNIV ARIZONA,LUNAR & PLANETARY LAB,TUCSON,AZ 85721. UNIV HAWAII MANOA,HAWAII INST GEOPHYS,HONOLULU,HI 96822. BROWN UNIV,DEPT GEOL SCI,PROVIDENCE,RI 02912. US GEOL SURVEY,FLAGSTAFF,AZ 86001. CORNELL UNIV,CTR RADIOPHYS & SPACE RES,ITHACA,NY 14853. RP Sullivan, R (reprint author), ARIZONA STATE UNIV,DEPT GEOL,BOX 871404,TEMPE,AZ 85287, USA. NR 99 TC 86 Z9 86 U1 1 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD MAR PY 1996 VL 120 IS 1 BP 119 EP 139 DI 10.1006/icar.1996.0041 PG 21 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA UF009 UT WOS:A1996UF00900010 ER PT J AU Ruppert, L Finkelman, R Boti, E Milosavljevic, M Tewalt, S Simon, N Dulong, F AF Ruppert, L Finkelman, R Boti, E Milosavljevic, M Tewalt, S Simon, N Dulong, F TI Origin and significance of high nickel and chromium concentrations in Pliocene lignite of the Kosovo Basin, Serbia SO INTERNATIONAL JOURNAL OF COAL GEOLOGY LA English DT Article AB Trace element data from 59 Pliocene lignite cores from the lignite field in the Kosovo Basin, southern Serbia, show localized enrichment of Ni and Cr (33-304 ppm and 8-176 ppm, respectively, whole-coal basis). Concentrations of both elements decrease from the western and southern boundaries of the lignite field. Low-temperature ash and polished coal pellets of selected bench and whole-coal samples were analyzed by X-ray diffraction and scanning electron microscopy with energy-dispersive X-ray analyses, These analyses show that most of the Ni and Cr are incorporated in detrital and, to a lesser degree, in authigenic minerals, The Ni- and Cr-bearing detrital minerals include oxides, chromites, serpentine-group minerals and rare mixed-layer clays. Possible authigenic minerals include Ni-Fe sulfates and sulfides, Analyses of three lignite samples by a supercritical fluid extraction technique indicate that some (1-11%) of the Ni is organically bound. Ni- and Cr-bearing oxides, mixed-layer clays, chromites and serpentine-group minerals were also identified in weathered and fresh samples of laterite developed on serpentinized Paleozoic peridotite at the nearby Glavica and Cikatovo Ni mines. These mines are located along the western and northwestern rim, respectively, of the Kosovo Basin, where Ni contents are highest. The detrital Ni- and Cr-bearing minerals identified in lignite samples from the western part of the Kosovo Basin may have been transported into the paleoswamp by rivers that drained the two Paleocene laterites. Some Ni may have been transported directly into the paleoswamp in solution or, alternatively, Ni may have been leached from detrital minerals by acidic peat water and adsorbed onto organic matter and included into authigenic mineral phases. No minable source of Ni and Cr is known in the southern part of the lignite field; however, the mineral and chemical data from the lignite and associated rocks suggest that such a source area may exist. C1 ELECTROECON KOSOVO INST SCI RES & DEV,YU-38000 PRISHTINA,YUGOSLAVIA. RP Ruppert, L (reprint author), US GEOL SURVEY,NATL CTR,MS 956,RESTON,VA 22092, USA. OI Ruppert, Leslie/0000-0002-7453-1061 NR 15 TC 30 Z9 32 U1 0 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-5162 J9 INT J COAL GEOL JI Int. J. Coal Geol. PD MAR PY 1996 VL 29 IS 4 BP 235 EP 258 DI 10.1016/0166-5162(95)00031-3 PG 24 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA UF303 UT WOS:A1996UF30300002 ER PT J AU Flores, RM Sykes, R AF Flores, RM Sykes, R TI Depositional controls on coal distribution and quality in the Eocene Brunner Coal Measures, Buller Coalfield, South Island, New Zealand SO INTERNATIONAL JOURNAL OF COAL GEOLOGY LA English DT Article ID FLUVIAL DEPOSITS; FACIES; RIVER AB The Buller Coalfield on the West Coast of the South Island, New Zealand, contains the Eocene Brunner Coal Measures. The coal measures unconformably overlie Paleozoic-Cretaceous basement rocks and are conformably overlain by, and laterally interfinger with, the Eocene marine Kaiata Formation. This study examines the lithofacies frameworks of the coal measures in order to interpret their depositional environments. The lower part of the coal measures is dominated by conglomeratic lithofacies that rest on a basal erosional surface and thicken in paleovalleys incised into an undulating peneplain surface. These lithofacies are overlain by sandstone, mudstone and organic-rich lithofacies of the upper part of the coal measures. The main coal seam of the organic-rich lithofacies is thick (10-20 m), extensive, locally split, and locally absent. This seam and associated coal seams in the Buller Coalfield are of low- to high-volatile bituminous rank (vitrinite reflectance between 0.65% and 1.75%). The main seam contains a variable percentage of ash and sulphur, These values are related to the thickening and areal distribution of the seam, which in turn, were controlled by the nature of elastic deposition and peat-forming mire systems, marine transgression and local tidal incursion. The conglomeratic lithofacies represent deposits of trunk and tributary braided streams that rapidly aggraded incised paleovalleys during sea-level stillstands. The main seam represents a deposit of raised mires that initially developed as topogenous mires on abandoned margins of inactive braidbelts. Feat accumulated in mires as a response to a rise in the water table, probably initially due to gradual sea-level rise and climate, and the resulting raised topography served as protection from floods. The upper part of the coal measures consists of sandstone lithofacies of fluvial origin and bioturbated sandstone, mudstone and organic-rich lithofacies, which represent deposits of paralic (deltaic, barrier shoreface, tidal and mire) and marine environments. The fluvial sandstone lithofacies accumulated in channels during a sea-level stillstand. The channels were infilled by coeval braided and meandering streams prior to transgression. Continued transgression, ranging from tidal channel-estuarine incursions to widespread but uneven paleoshoreline encroachment, accompanied by moderate basin subsidence, is marked by a stacked, back-stepping geometry of bioturbated sandstone and marine mudstone lithofacies. Final retrogradation (sea-level highstand) is marked by backfilling of estuaries and by rapid landward deposition of the marine Kaiata Formation in the late Eocene. C1 INST GEOL & NUCL SCI LTD,LOWER HUTT,NEW ZEALAND. RP Flores, RM (reprint author), US GEOL SURVEY,BOX 25046,MS 972,DENVER,CO 80225, USA. NR 73 TC 17 Z9 17 U1 1 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-5162 J9 INT J COAL GEOL JI Int. J. Coal Geol. PD MAR PY 1996 VL 29 IS 4 BP 291 EP 336 DI 10.1016/0166-5162(95)00028-3 PG 46 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA UF303 UT WOS:A1996UF30300005 ER PT J AU Elder, WP AF Elder, WP TI Bivalves and gastropods from the middle Campanian Anacacho limestone, south central Texas SO JOURNAL OF PALEONTOLOGY LA English DT Review ID AMMONITES AB The Anacacho Limestone was deposited during the Campanian and represents two depositional intervals, one of early Campanian and one of middle Campanian age. These two intervals correspond to periods of major eustatic sea level rise. This study focuses on the molluscan paleontology of the middle Campanian interval in the eastern part of the Anacacho exposure belt in Medina County, Texas. Molluscan assemblages in this area are indicative of inner to mid-shelf environments. No significant reef components are present. These eastern Anacacho deposits are interpreted to represent more offshore, deeper water environments than those to the southwest, where reef and lagoonal deposits have been reported. Analysis of the macrofossil components from these eastern localities has expanded the number of invertebrate species known from the Anacacho Limestone by nearly three-fold. This increase in diversity, based on a small amount of new work, suggests that many more taxa are yet to be identified, particularly in the western part of the exposure belt in Uvalde and Kinney Counties. This paper documents the bivalve and gastropod fauna, discussing and illustrating 24 bivalve taxa and 11 gastropod species. Two new bivalve species are named, Panopea anacachoensis new species and Spondylus siccus new species, and two potentially new gastropod species are identified but not named herein due to inadequate material. This paper expands the distribution of many eastern Gulf Coast and Atlantic Coast taxa westward into Texas and shows strong ties between the Anacacho fauna and that of the Campanian Tar Heel and Bladen Formations of the Black Creek Group in North Carolina. The taxonomic ties between these two areas probably reflect the thorough documentation of the North Carolina fauna, which is the best documented Campanian bivalve fauna in the Gulf or Atlantic Coast regions. RP Elder, WP (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 915, MENLO PK, CA 94025 USA. NR 152 TC 9 Z9 10 U1 0 U2 1 PU PALEONTOLOGICAL SOC INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044 USA SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD MAR PY 1996 VL 70 IS 2 BP 247 EP 271 PG 25 WC Paleontology SC Paleontology GA UE828 UT WOS:A1996UE82800007 ER PT J AU Gellis, AC AF Gellis, AC TI Gullying at the petroglyph national monument, New Mexico SO JOURNAL OF SOIL AND WATER CONSERVATION LA English DT Article ID COLORADO AB Fifty gullies were mapped along a 32 km (20 mi) escarpment in the Petroglyph National Monument, New Mexico, of which 14 were located along dirt roads, 7 along foot and bicycle trails, 18 on undisturbed hillslopes, and 11 part of a natural channel network. The dirt road and foot and bicycle trails channel surface runoff and increase erosion. Thirty of 50 gullies assessed received runoff from the dirt road. Ten gullies mapped in 1991 were not evident on 1987 aerial photographs and may have been formed during 1987 to 1991. Natural factors such as high-intensity rain storms during the intervening period, were thought to have initiated or increased erosion and gullying in the National Monument. Analyses of storm data during this period indicated that most storms had recurrence intervals of 2 years or less for rainfall intensity measured in millimeters per 30-minute, 1-hour and 2-hour durations. An exception was a storm on July 28, 1987, that for a 1-hour period had a recurrence interval of 25 years. However, the rainfall for this storm was highly localized falling in the southern portion of the monument and not in the vicinity of the 10 new gullies. Results from this study show the sensitivity of semiarid landscapes to certain forms of development, such that storms with recurrence intervals of 2 years or less might cause considerable erosion. RP Gellis, AC (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,4501 INDIAN SCH RD NE,SUITE 200,ALBUQUERQUE,NM 87110, USA. NR 9 TC 3 Z9 3 U1 0 U2 4 PU SOIL WATER CONSERVATION SOC PI ANKENY PA 7515 N E ANKENY RD, ANKENY, IA 50021-9764 SN 0022-4561 J9 J SOIL WATER CONSERV JI J. Soil Water Conserv. PD MAR-APR PY 1996 VL 51 IS 2 BP 155 EP 159 PG 5 WC Ecology; Soil Science; Water Resources SC Environmental Sciences & Ecology; Agriculture; Water Resources GA TZ904 UT WOS:A1996TZ90400012 ER PT J AU DSilva, AM Maughan, OE AF DSilva, AM Maughan, OE TI Optimum density of red tilapia Oreochromis mossambicus x O-urolepis hornorum in a pulsed-flow culture system SO JOURNAL OF THE WORLD AQUACULTURE SOCIETY LA English DT Article AB Densities of 9 tilapia (hybrid Oreochromis mossambicus x O. urolepis hornorum)/m(3) gave the highest production among five densities(1, 3, 6, 9, and 12 fish/m(3)) rested in a pulsed-flow culture system. Culture of fish in irrigation ditches may have great potential for integrating fish farming with irrigated agriculture. Each 1,000 meters of ditch could potentially produce up to 1,400 kg of tilapia during a 112-d growing season. RP DSilva, AM (reprint author), UNIV ARIZONA,US FISH & WILDLIFE SERV,ARIZONA COOPERAT FISH & WILDLIFE RES UNIT,104 BIOL SCI E,TUCSON,AZ 85721, USA. NR 11 TC 3 Z9 4 U1 0 U2 0 PU WORLD AQUACULTURE SOCIETY PI BATON ROUGE PA LOUISIANA STATE UNIV, 143 J M PARKER COLISEUM, BATON ROUGE, LA 70803 SN 0893-8849 J9 J WORLD AQUACULT SOC JI J. World Aquacult. Soc. PD MAR PY 1996 VL 27 IS 1 BP 126 EP 129 DI 10.1111/j.1749-7345.1996.tb00603.x PG 4 WC Fisheries SC Fisheries GA UM235 UT WOS:A1996UM23500017 ER PT J AU Melching, CS Yoon, CG AF Melching, CS Yoon, CG TI Key sources of uncertainty in QUAL2E model of Passaic River SO JOURNAL OF WATER RESOURCES PLANNING AND MANAGEMENT-ASCE LA English DT Article ID WATER AB Application of stream water-quality models in decision making has been hampered by a lack of data appropriate for minimization of model-simulation uncertainty. A method for determining data needed to reduce model-prediction uncertainty is illustrated in this paper. First-order reliability analysis is applied to determine (1) the model parameters that significantly affect model-prediction uncertainty; and (2) the constituents for which model-prediction uncertainty is unacceptable. Additional data are required to reduce uncertainty in the parameters that significantly affect constituents with high prediction uncertainty and consequently in model prediction. The method is demonstrated for multiconstituent water-quality modeling on the Passaic River in New Jersey applying QUAL2E. The model-prediction uncertainty of dissolved oxygen, biochemical oxygen demand, ammonia, and chlorphyll a is considered. For this example, only the reaeration rate and the algal maximum-specific-growth rate contribute significant uncertainty to model prediction. The effect of reducing the uncertainty in the reaeration rate and algal maximum-specific-growth rate on the uncertainty on predicted dissolved oxygen and chlorphyll a, respectively, is demonstrated. C1 KONKUK UNIV, DEPT AGR ENGN, SEOUL 133701, SOUTH KOREA. RP Melching, CS (reprint author), US GEOL SURVEY, DIV WATER RESOURCES, 102 E MAIN, 4TH FLOOR, URBANA, IL 61801 USA. NR 28 TC 69 Z9 72 U1 1 U2 12 PU ASCE-AMER SOC CIVIL ENGINEERS PI RESTON PA 1801 ALEXANDER BELL DR, RESTON, VA 20191-4400 USA SN 0733-9496 J9 J WATER RES PL-ASCE JI J. Water Resour. Plan. Manage.-ASCE PD MAR-APR PY 1996 VL 122 IS 2 BP 105 EP 113 DI 10.1061/(ASCE)0733-9496(1996)122:2(105) PG 9 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA TX198 UT WOS:A1996TX19800004 ER PT J AU Celebi, M AF Celebi, M TI Comparison of damping in buildings under low-amplitude and strong motions SO JOURNAL OF WIND ENGINEERING AND INDUSTRIAL AERODYNAMICS LA English DT Article; Proceedings Paper CT Meeting on Structural Damping - International Wind Engineering Forum CY SEP 08, 1995 CL ATSUGI, JAPAN SP Int Wind Engn Forum, Kanagawa Acad Sci & Technol, Architectural Inst Japan, Bldg Ctr Japan, Japan Assoc Wind Engn, Japan Soc Civil Engineers DE ambient vibration; ARX (autoregressive extra input) model; damping; Loma Prieta earthquake; low-amplitude vibration; natural frequency; soil-structure interaction; strong motion; system identification AB This paper presents a comprehensive assessment of damping values and other dynamic characteristics of five buildings using strong-motion and low-amplitude (ambient vibration) data. The strong-motion dynamic characteristics of five buildings within the San Francisco Bay area are extracted from recordings of the 17 October 1989 Loma Prieta earthquake (LPE). Ambient vibration response characteristics for the same five buildings were inferred using data collected in 1990 following LPE. Additional earthquake data other than LPE for one building and ambient vibration data collected before LPE for two other buildings provide additional confirmation of the results obtained. For each building, the percentages of critical damping and the corresponding fundamental periods determined from low-amplitude test data are appreciably lower than those determined from strong-motion recordings. These differences are attributed mainly to soil-structure interaction and other non-linear behavior affecting the structures during strong shaking. Significant contribution of radiation damping to the effective damping of a specific building is discussed in detail. RP Celebi, M (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD MS 977,MENLO PK,CA 94025, USA. NR 20 TC 28 Z9 33 U1 0 U2 3 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0167-6105 J9 J WIND ENG IND AEROD JI J. Wind Eng. Ind. Aerodyn. PD MAR PY 1996 VL 59 IS 2-3 BP 309 EP 323 DI 10.1016/0167-6105(96)00014-1 PG 15 WC Engineering, Civil; Mechanics SC Engineering; Mechanics GA UQ689 UT WOS:A1996UQ68900015 ER PT J AU Poag, CW AF Poag, CW TI Structural outer rim of Chesapeake Bay impact crater: Seismic and bore hole evidence SO METEORITICS & PLANETARY SCIENCE LA English DT Article ID RECORD AB Nine seismic-reflection profiles and four continuous core holes define the gross structural and stratigraphic framework of the outer rim of the Chesapeake Bay impact crater. The rim is manifested as a 90 km diameter ring of terraced normal-fault blocks, which forms a similar to 320 m-1200 m high rim escarpment. The top of the rim escarpment is covered by a 20 m-30 m thick ejecta blanket. The escarpment encircles a flat-floored annular trough, which is partly filled with an similar to 250 m thick breccia lens (Exmore breccia). The Exmore breccia overlies a 200 m-800 m thick interval of slumped sedimentary megablocks, which, in turn, rests on crystalline basement rocks. All postimpact strata (upper Eocene to Quaternary) sag structurally into the annular trough, and most units also thicken as they cross the rim into the crater. Postimpact compaction and subsidence of the Exmore breccia have created extensive normal faulting in overlying strata. RP Poag, CW (reprint author), US GEOL SURVEY,WOODS HOLE,MA 02543, USA. NR 34 TC 36 Z9 37 U1 0 U2 3 PU METEORITICAL SOC PI FAYETTEVILLE PA DEPT CHEMISTRY/BIOCHEMISTRY, UNIV ARKANSAS, FAYETTEVILLE, AR 72701 SN 0026-1114 J9 METORIT PLANET SCI JI Meteorit. Planet. Sci. PD MAR PY 1996 VL 31 IS 2 BP 218 EP & PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UA636 UT WOS:A1996UA63600009 ER PT J AU Geist, E Yoshioka, S AF Geist, E Yoshioka, S TI Source parameters controlling the generation and propagation of potential local tsunamis along the Cascadia margin SO NATURAL HAZARDS LA English DT Article DE tsunamis; Cascadia; source parameters; earthquakes; hazard assessment ID EARTHQUAKE SOURCE PARAMETERS; NORTHWESTERN UNITED-STATES; 1946 NANKAIDO EARTHQUAKE; SUBDUCTION ZONE; PACIFIC-NORTHWEST; DISPLACEMENT-FIELDS; CONTINENTAL-MARGIN; BENEATH WASHINGTON; STRUCTURAL TRENDS; LANDER EARTHQUAKE AB The largest uncertainty in assessing hazards from local tsunamis along the Cascadia margin is estimating the possible earthquake source parameters. We investigate which source parameters exert the largest influence on tsunami generation and determine how each parameter affects the amplitude of the local tsunami. The following source parameters were analyzed: (1) type of faulting characteristic of the Cascadia subduction zone, (2) amount of slip during rupture, (3) slip orientation, (4) duration of rupture, (5) physical properties of the accretionary wedge, and (6) influence of secondary faulting. The effect of each of these source parameters on the quasi-static displacement of the ocean floor is determined by using elastic three-dimensional, finite-element models. The propagation of the resulting tsunami is modeled both near the coastline using the two-dimensional (x-t) Peregrine equations that includes the effects of dispersion and near the source using the three-dimensional (x-y-t) linear longwave equations. The source parameters that have the largest influence on local tsunami excitation are the shallowness of rupture and the amount of slip. In addition, the orientation of slip has a large effect on the directivity of the tsunami, especially for shallow dipping faults, which consequently has a direct influence on the length of coastline inundated by the tsunami. Duration of rapture, physical properties of the accretionary wedge, and secondary faulting all affect the excitation of tsunamis but to a lesser extent than the shallowness of rupture and the amount and orientation of slip. Assessment of the severity of the local tsunami hazard should take into account that relatively large tsunamis can be generated from anomalous 'tsunami earthquakes' that rupture within the accretionary wedge in comparison to interplate thrust earthquakes of similar magnitude. C1 EHIME UNIV,FAC SCI,DEPT EARTH SCI,MATSUYAMA,EHIME,JAPAN. RP Geist, E (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 99 TC 22 Z9 23 U1 0 U2 3 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0921-030X J9 NAT HAZARDS JI Nat. Hazards PD MAR PY 1996 VL 13 IS 2 BP 151 EP 177 DI 10.1007/BF00138481 PG 27 WC Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences; Water Resources SC Geology; Meteorology & Atmospheric Sciences; Water Resources GA UJ449 UT WOS:A1996UJ44900004 ER PT J AU Hobden, BJ Houghton, BF Lanphere, MA Nairn, IA AF Hobden, BJ Houghton, BF Lanphere, MA Nairn, IA TI Growth of the Tongariro volcanic complex: New evidence from K-Ar age determinations SO NEW ZEALAND JOURNAL OF GEOLOGY AND GEOPHYSICS LA English DT Article DE Tongariro volcano; K-Ar age determinations AB New K-Ar age determinations indicate that the exposed portion of the Tongariro volcanic complex has grown steadily since at least 275 ka, with intervals of vigorous cone growth at 210-200, 130-70, and 25 ka to the present day. C1 INST GEOL & NUCL SCI LTD,WAIRAKEI RES CTR,TAUPO,NEW ZEALAND. US GEOL SURVEY,BRANCH ISOTOPE GEOL,MENLO PK,CA 94305. RP Hobden, BJ (reprint author), UNIV CANTERBURY,DEPT GEOL,PRIVATE BAG 4800,CHRISTCHURCH,NEW ZEALAND. NR 7 TC 32 Z9 32 U1 0 U2 1 PU SIR PUBLISHING PI WELLINGTON PA PO BOX 399, WELLINGTON, NEW ZEALAND SN 0028-8306 J9 NEW ZEAL J GEOL GEOP JI N. Z. J. Geol. Geophys. PD MAR PY 1996 VL 39 IS 1 BP 151 EP 154 PG 4 WC Geology; Geosciences, Multidisciplinary SC Geology GA UM147 UT WOS:A1996UM14700014 ER PT J AU Light, DL AF Light, DL TI Film cameras or digital sensors? The challenge ahead for aerial imaging SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID SYSTEM AB Cartographic aerial cameras continue to play the key role in producing quality products for the aerial photography business, and specifically for the National Aerial Photography Program (NAPP). One NAPP photograph taken with cameras capable of 39 lp/mm system resolution can contain the equivalent of 432 million pixels at 11 mu m spot size, and the cost is less than $75 per photograph to scan and output the pixels on a magnetic storage medium. On the digital side, solid state charge coupled device linear and area arrays can yield quality resolution (7 to 12 mu m detector size) and a broader dynamic range. If linear arrays are to compete with film cameras, they will require precise attitude and positioning of the aircraft so that the lines of pixels can be unscrambled and put into a suitable homogeneous scene that is acceptable to an interpreter. Area arrays need to be much larger than currently available to image scenes competitive in size with film cameras. Analysis of the relative advantages and disadvantages of the two systems show that the analog approach is more economical at present. However, as arrays become larger, attitude sensors become more refined, global positioning system coordinate readouts become commonplace, and storage capacity becomes more affordable, the digital camera may emerge as the imaging system for the future. Several technical challenges must be overcome if digital sensors are to advance to where they can support mapping, charting and geographic information system applications. RP Light, DL (reprint author), US GEOL SURVEY,511 NATL CTR,RESTON,VA 22092, USA. NR 18 TC 14 Z9 14 U1 0 U2 2 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD MAR PY 1996 VL 62 IS 3 BP 285 EP 291 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA TZ195 UT WOS:A1996TZ19500005 ER PT J AU Thompson, DM Wohl, EE Jarrett, RD AF Thompson, DM Wohl, EE Jarrett, RD TI Revised velocity-reversal and sediment-sorting model for a high-gradient, pool-riffle stream SO PHYSICAL GEOGRAPHY LA English DT Article DE channel morphology; fluvial geomorphology; velocity reversal; pool-riffle streams; recirculating eddy ID BEDLOAD TRANSPORT; SEQUENCES; RIVER; BED; ENTRAINMENT; HYPOTHESIS; MORPHOLOGY; SIZE AB Sediment-sorting processes related to varying channel-bed morphology were investigated from April to November 1993 along a 1-km pool-riffle and step-pool reach of North Saint Vrain Creek, a small mountain stream in the Rocky Mountains of northern Colorado. Measured cross-sectional areas of flow were used to suggest higher velocities in pools than in riffles at high flow. Three hundred and sixteen tracer particles, ranging in size from 16 mm to 256 mm, were placed in two separate pool-riffle-pool sequences and used to assess sediment-sorting patterns and sediment-transport competence variations. Tracer-particle depositional evidence indicated higher sediment-transport competence in pools than in riffles at high flow. Pool-riffle sediment sorting may be created by velocity reversals, and more localized sorting results from gravitational forces along the upstream sloping portion of the channel bed located at the downstream end of pools. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Thompson, DM (reprint author), COLORADO STATE UNIV,DEPT EARTH RESOURCES,FT COLLINS,CO 80523, USA. RI Thompson, Douglas /O-2434-2014 OI Thompson, Douglas /0000-0003-1137-4326 NR 36 TC 32 Z9 32 U1 2 U2 10 PU V H WINSTON & SON INC PI PALM BEACH PA 360 SOUTH OCEAN BLVD, PH-B, PALM BEACH, FL 33480 SN 0272-3646 J9 PHYS GEOGR JI Phys. Geogr. PD MAR-APR PY 1996 VL 17 IS 2 BP 142 EP 156 PG 15 WC Environmental Sciences; Geography, Physical; Geosciences, Multidisciplinary; Meteorology & Atmospheric Sciences SC Environmental Sciences & Ecology; Physical Geography; Geology; Meteorology & Atmospheric Sciences GA UU148 UT WOS:A1996UU14800003 ER PT J AU Langer, CJ Hartzell, S AF Langer, CJ Hartzell, S TI Rupture distribution of the 1977 western Argentina earthquake SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Article ID GEOMETRY AB Teleseismic P and SH body waves are used in a finite-fault, waveform inversion for the rupture history of the 23 November 1977 western Argentina earthquake. This double event consists of a smaller foreshock (M(0) = 5.3 x 10(26) dyn-cm) followed about 20 s later by a larger main shock (M(0) = 1.5 x 10(27) dyn-cm). Our analysis indicates that these two events occurred on different fault segments: with the foreshock having a strike, dip, and average rake of 345 degrees, 45 degrees E, and 50 degrees, and the main shock 10 degrees, 45 degrees E, and 80 degrees, respectively. The foreshock initiated at a depth of 17 km and propagated updip and to the north. The main shock initiated at the southern end of the foreshock zone at a depth of 25 to 30 km, and propagated updip and unilaterally to the south. The north-south separation of the centroids of the moment release for the foreshock and main shock is about 60 km. The apparent triggering of the main shock by the foreshock is similar to other earthquakes that have involved the failure of multiple fault segments, such as the 1992 Landers, California, earthquake. Such occurrences argue against the use of individual, mapped, surface fault or fault-segment lengths in the determination of the size and frequency of future earthquakes. C1 US GEOL SURVEY,BRANCH EARTHQUAKE & LANDSLIDE HAZARDS,DENVER,CO 80225. NR 19 TC 17 Z9 21 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD MAR PY 1996 VL 94 IS 1-2 BP 121 EP 132 DI 10.1016/0031-9201(95)03080-8 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UH065 UT WOS:A1996UH06500007 ER PT J AU Kuksenko, V Tomilin, N Damaskinskaya, E Lockner, D AF Kuksenko, V Tomilin, N Damaskinskaya, E Lockner, D TI A two-stage model of fracture of rocks SO PURE AND APPLIED GEOPHYSICS LA English DT Article DE fracture; fault nucleation; critical crack density; hierarchic failure; earthquakes; thermal activation ID TIME-DEPENDENT SIMULATIONS; MULTIPLE-CRACK MODEL; BRITTLE-FRACTURE; GRANITE AB In this paper we propose a two-stage model of rock fracture. In the first stage, cracks or local regions of failure are uncorrelated and occur randomly throughout the rock in response to loading of pre-existing flaws. As damage accumulates in the rock, there is a gradual increase in the probability that large clusters of closely spaced cracks or local failure sites will develop. Based on statistical arguments, a critical density of damage will occur where clusters of flaws become large enough to lead to larger-scale failure of the rock (stage two). While crack interaction and cooperative failure is expected to occur within clusters of closely spaced cracks, the initial development of clusters is predicted based on the random variation in pre-existing flaw populations. Thus the onset of the unstable second stage in the model can be computed from the generation of random, uncorrelated damage. The proposed model incorporates notions of the kinetic (and therefore time-dependent) nature of the strength of solids as well as the discrete hierarchic structure of rocks and the flaw populations that lead to damage accumulation. The advantage offered by this model is that its salient features are valid for fracture processes occurring over a wide range of scales including earthquake processes. A notion of the rank of fracture (fracture size) is introduced, and criteria are presented for both fracture nucleation and the transition of the failure process from one scale to another. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Kuksenko, V (reprint author), RUSSIAN ACAD SCI,AF IOFFE PHYS TECH INST,POLYTECHNICHSKAYA 26,ST PETERSBURG 194021,RUSSIA. RI Kuksenko, Victor/M-7793-2014 NR 38 TC 38 Z9 42 U1 0 U2 1 PU BIRKHAUSER VERLAG AG PI BASEL PA PO BOX 133 KLOSTERBERG 23, CH-4010 BASEL, SWITZERLAND SN 0033-4553 J9 PURE APPL GEOPHYS JI Pure Appl. Geophys. PD MAR PY 1996 VL 146 IS 2 BP 253 EP 263 DI 10.1007/BF00876492 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UE940 UT WOS:A1996UE94000003 ER PT J AU Occhietti, S Balescu, S Lamothe, M Clet, M Cronin, T Ferland, P Pichet, P AF Occhietti, S Balescu, S Lamothe, M Clet, M Cronin, T Ferland, P Pichet, P TI Late stage 5 glacio-isostatic sea in the St Lawrence valley, Canada and United States SO QUATERNARY RESEARCH LA English DT Article ID LAURENTIDE ICE-SHEET; QUEBEC; DEPOSITS; HISTORY; PERADE; LEVEL; NORTH; SITE AB Although post-glacial marine sediments of late Wisconsinan and early Holocene age are common in eastern Canada and the northeastern United States, remnants of older Pleistocene marine sediments are scarce. A fossiliferous marine clay that predates the classical Wisconsinan was recently discovered in the St. Lawrence Valley. A dominantly estuarine environment is inferred from the geochemistry of the shells (delta(18)O = -7.1) and from benthic foraminifer and ostracode assemblages, The clay indicates-a marine invasion (Cartier Sea) shallower and probably shorter than that during the upper late Wisconsinan Champlain Sea episode (12,000-9,500 yr B.P.). The pollen content shows that regional vegetation during the marine episode began as open tundra, then became a Betula and Alnus; crispa forest, reached a climatic optimum with Quercus, Corylus, and Abies, and concluded as a Pinus/Picea boreal forest. A corrected infrared stimulated luminescence age of 98,000 +/- 9000 yr is compatible with the epimerization ratio of shells. The Cartier Sea resulted from a post-glacial glacio-isostatic marine invasion in the St. Lawrence lowlands. It probably occurred during late stage 5 and is tentatively assigned to the transition of oxygen isotope substages 5b/5a. This marine episode dates to stage 5 of the preceding continental glacier which extended to middle latitudes in NE America. (C) 1996 University of Washington. C1 UNIV QUEBEC,GEETERAP,LAB IUMINESCENCE LUX,MONTREAL,PQ H3C 3P8,CANADA. CNRS,CTR GEOMORPHOL,F-14000 CAEN,FRANCE. US GEOL SURVEY,NATL CTR 970,RESTON,VA 22092. RP Occhietti, S (reprint author), UNIV QUEBEC,GEOTOP,CP 8888 CTR VILLE,MONTREAL,PQ H3C 3P8,CANADA. NR 39 TC 11 Z9 11 U1 1 U2 7 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD MAR PY 1996 VL 45 IS 2 BP 128 EP 137 DI 10.1006/qres.1996.0015 PG 10 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UK235 UT WOS:A1996UK23500003 ER PT J AU Koeberl, C Poag, CW Reimold, WU Brandt, D AF Koeberl, C Poag, CW Reimold, WU Brandt, D TI Impact origin of the chesapeake bay structure and the source of the North American tektites SO SCIENCE LA English DT Article ID SITE-612; QUARTZ; TEMPERATURES; COAST; ND AB Seismic profiles, drill core samples, and gravity data suggest that a complex impact crater similar to 35.5 million years old and 90 kilometers in diameter is buried beneath the lower Chesapeake Bay. The breccia that fills the structure contains evidence of shock metamorphism, including impact melt breccias and multiple sets of planar deformation features (shock lamellae) in quartz and feldspar. The age of the crater and the composition of some breccia clasts are consistent with the Chesapeake Bay impact structure being the source of the North American tektites. C1 UNIV WITWATERSRAND,DEPT GEOL,JOHANNESBURG 2050,SOUTH AFRICA. US GEOL SURVEY,WOODS HOLE,MA 02543. RP Koeberl, C (reprint author), UNIV VIENNA,INST GEOCHEM,ALTHANSTR 14,A-1090 VIENNA,AUSTRIA. NR 48 TC 136 Z9 139 U1 1 U2 6 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD MAR 1 PY 1996 VL 271 IS 5253 BP 1263 EP 1266 DI 10.1126/science.271.5253.1263 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TX695 UT WOS:A1996TX69500031 ER PT J AU Hunt, RJ Krabbenhoft, DP Anderson, MP AF Hunt, RJ Krabbenhoft, DP Anderson, MP TI Groundwater inflow measurements in wetland systems SO WATER RESOURCES RESEARCH LA English DT Article ID WATER-BALANCE; FLOW MODEL; LAKES; TRANSPORT; EXCHANGE; LAKEBEDS; SEEPAGE; PEAT AB Our current understanding of wetlands is insufficient to assess the effects of past and future wetland loss. While knowledge of wetland hydrology is crucial, groundwater flows are often neglected or uncertain. In this paper, groundwater inflows were estimated in wetlands in southwestern Wisconsin using traditional Darcy's law calculations and three independent methods that included (1) stable isotope mass balances, (2) temperature profile modeling, and (3) numerical water balance modeling techniques. Inflows calculated using Darcy's law were lower than inflows estimated using the other approaches and ranged from 0.02 to 0.3 cm/d. Estimates obtained using the other methods generally were higher (0.1 to 1.1 cm/d) and showed similar spatial trends. An areal map of groundwater flux generated by the water balance model demonstrated that areas of both recharge and discharge exist in what is considered a regional discharge area. While each method has strengths and weaknesses, the use of more than one method can reduce uncertainty in the estimates. C1 UNIV WISCONSIN,DEPT GEOL & GEOPHYS,MADISON,WI 53706. RP Hunt, RJ (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,6417 NORMANDY LABE,MADISON,WI 53719, USA. NR 70 TC 87 Z9 87 U1 2 U2 30 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAR PY 1996 VL 32 IS 3 BP 495 EP 507 DI 10.1029/95WR03724 PG 13 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TX708 UT WOS:A1996TX70800001 ER PT J AU Milly, PCD AF Milly, PCD TI Effects of thermal vapor diffusion on seasonal dynamics of water in the unsaturated zone SO WATER RESOURCES RESEARCH LA English DT Article ID DESERT SOILS; EVAPORATION; TRITIUM; TRACERS; LIQUID AB The response of water in the unsaturated zone to seasonal changes of temperature (T) is determined analytically using the theory of nonisothermal water transport in porous media, and the solutions are tested against field observations of moisture potential and bomb fallout isotopic (Cl-36 and H-3) concentrations. Seasonally varying land surface temperatures and the resulting subsurface temperature gradients induce thermal vapor diffusion. The annual mean vertical temperature gradient is close to zero; however, the annual mean thermal vapor flux is downward, because the temperature-dependent vapor diffusion coefficient is larger, on average, during downward diffusion (occurring at high T) than during upward diffusion (low T). The annual mean thermal vapor flux is shown to decay exponentially with depth; the depth (about 1 m) at which it decays to e(-1) of its surface value is one half of the corresponding decay depth for the amplitude of seasonal temperature changes; This depth-dependent annual mean flux is effectively a source of water, which must be balanced by a flux divergence associated with other transport processes. In a relatively humid environment the liquid fluxes greatly exceed the thermal vapor fluxes, so such a balance is readily achieved without measurable effect on the dynamics of water in the unsaturated zone. However, if the mean vertical water flux through the unsaturated zone is very small (<1 mm y(-1)), as it may be at many locations in a desert landscape, the thermal vapor flux must be balanced mostly by a matric-potential-induced upward flux of water. This return flux may include both vapor and liquid components. Below any near-surface zone of weather-related fluctuations of matric potential, maintenance of this upward flux requires an increase with depth in the annual mean matric potential; this theoretical prediction is supported by long-term field measurements in the Chihuahuan Desert. The analysis also makes predictions, confirmed by the field observations, regarding the seasonal variations of matric potential at a given depth. The conceptual model of unsaturated zone water transport developed here implies the possibility of near-surface trapping of any aqueous constituent introduced at the surface. RP Milly, PCD (reprint author), US GEOL SURVEY,NOAA,GEOPHYS FLUID DYNAM LAB,POB 308,PRINCETON,NJ 08542, USA. NR 24 TC 10 Z9 12 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAR PY 1996 VL 32 IS 3 BP 509 EP 518 DI 10.1029/95WR03489 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TX708 UT WOS:A1996TX70800002 ER PT J AU Rudolph, DL Kachanoski, RG Celia, MA LeBlanc, DR Stevens, JH AF Rudolph, DL Kachanoski, RG Celia, MA LeBlanc, DR Stevens, JH TI Infiltration and solute transport experiments in unsaturated sand and gravel, Cape Cod, Massachusetts: Experimental design and overview of results SO WATER RESOURCES RESEARCH LA English DT Article ID GRADIENT TRACER TEST; TIME DOMAIN REFLECTOMETRY; FIELD SCALE TRANSPORT; SOIL; VARIABILITY; METHODOLOGY; BROMIDE AB A series of infiltration and tracer experiments was conducted in unsaturated sand and gravel deposits on Cape God, Massachusetts, A network of 112 porous cup lysimeters and 168 time domain reflectometry (TDR) probes was deployed at depths from 0.25 to 2.0 m below ground surface along the centerline of a 2-m by 10-m test plot. The test plot was irrigated at rates ranging from 7.9 to 37.0 cm h(-1) through a sprinkler system. Transient and steady state water content distributions were monitored with the TDR probes and spatial properties of water content distributions were determined from the TDR data. The spatial variance of the water content tended to increase as the average water content increased. In addition, estimated horizontal correlation length scales for water content were significantly smaller than those estimated by previous investigators for saturated hydraulic conductivity. Under steady state flow conditions at each irrigation rate, a sodium chloride solution was released as a tracer at ground surface and tracked with both the lysimeter and TDR networks. Transect-averaged breakthrough curves at each monitoring depth were constructed both from solute concentrations measured in the water samples and flux concentrations inferred from the TDR measurements. Transport properties, including apparent solute velocities, dispersion coefficients, and total mass balances, were determined independently from both sets of breakthrough curves. The dispersion coefficients tended to increase with depth, reaching a constant value with the lysimeter data and appearing to increase continually with the TDR data. The variations with depth of the solute transport parameters, along with observations of water and solute mass balance and spatial distributions of water content, provide evidence of significant three-dimensional flow during the irrigation experiments. The TDR methods are shown to efficiently provide dense spatial and temporal data sets for both flow and solute transport in unsaturated sediments with minimal sediment and flow field disturbance. Combined implementation of lysimeters and TDR probes can enhance data interpretation particularly when three-dimensional flow conditions are anticipated. C1 PRINCETON UNIV,DEPT CIVIL ENGN & OPERAT RES,PRINCETON,NJ 08540. US GEOL SURVEY,DIV WATER RESOURCES,MARLBOROUGH,MA 01752. UNIV GUELPH,DEPT LAND RESOURCE SCI,GUELPH,ON N1G 2W1,CANADA. ENVIRON,PRINCETON,NJ. RP Rudolph, DL (reprint author), UNIV WATERLOO,WATERLOO CTR GROUNDWATER RES,WATERLOO,ON N2L 3G1,CANADA. NR 22 TC 27 Z9 27 U1 2 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAR PY 1996 VL 32 IS 3 BP 519 EP 532 DI 10.1029/95WR02972 PG 14 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TX708 UT WOS:A1996TX70800003 ER PT J AU Gu, RC McCutcheon, SC Wang, PF AF Gu, RC McCutcheon, SC Wang, PF TI Modeling reservoir density underflow and interflow from a chemical spill SO WATER RESOURCES RESEARCH LA English DT Article ID SIMULATION; LAKES; RIVER AB An integral simulation model has been developed for understanding and simulating the process of a density current and the transport of spilled chemicals in a stratified reservoir. The model is capable of describing flow behavior and mixing mechanisms in different flow regimes (plunging flow, underflow, and interflow). It computes flow rate, velocity, flow thickness, mixing parameterized by entrainment and dilution, depths of plunging, separation and intrusion, and time of travel. The model was applied to the Shasta Reservoir in northern California during the July 1991 Sacramento River chemical spill. The simulations were used to assist in the emergency response, confirm remediation measures, and guide data collection. Spill data that were available after the emergency response are used to conduct a postaudit of the model results. Predicted flow parameters are presented and compared with observed interflow intrusion depth, travel time, and measured concentrations of spilled chemicals. In the reservoir, temperature difference between incoming river flow and ambient lake water played a dominant role during the processes of flow plunging, separation, and intrusion. With the integral approach, the gross flow behavior can be adequately described and information useful in the analysis of contaminated flow in a reservoir after a spill is provided. C1 US EPA,NATL EXPOSURE RES LAB,ATHENS,GA 30605. US GEOL SURVEY,MENLO PK,CA 94025. RP Gu, RC (reprint author), IOWA STATE UNIV SCI & TECHNOL,COLL ENGN,DEPT CIVIL & CONSTRUCT ENGN,AMES,IA 50011, USA. NR 39 TC 19 Z9 21 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD MAR PY 1996 VL 32 IS 3 BP 695 EP 705 DI 10.1029/95WR03486 PG 11 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TX708 UT WOS:A1996TX70800018 ER PT J AU Korschgen, CE Kenow, KP Nissen, JM Wetzel, JF AF Korschgen, CE Kenow, KP Nissen, JM Wetzel, JF TI Canvasback mortality from illegal hunting on the Upper Mississippi River SO WILDLIFE SOCIETY BULLETIN LA English DT Article DE Aythya valisineria; canvasback; hunting; illegal hunting; mortality; Upper Mississippi River; Vallisneria americana; wildcelery AB To quantify the consequences of local hunting on illegal kill of canvasbacks (Aythya valisineria), we studied the behavior of hunters on a 646-ha area open to duck hunting (closed to canvasback hunting) on Lake Onalaska, Navigation Pool 7, Wisconsin, during the 1991 and 1992 waterfowl hunting seasons. Law enforcement officers observed 258 hunting parties for 419 hours. Of 94 hunting parties encountering canvasbacks, 41 (44%) shot at the ducks on 56 occasions, or 27% of 207 encounters observed, Based on a ratio estimator, there were 790 (95% CI = 376) attempts to shoot at canvasbacks on the Lake Onalaska study area during 1991 and 837 (95% CI = 390) during 1992. Mortality of canvasbacks, excluding crippling loss, was estimated to be 128 during 1991 and 166 during 1992. Thus, total canvasback losses may be higher than currently estimated on a flyway or national basis. This estimating technique offers a promising method for enumerating hunter take of protected and legal species. C1 US FISH & WILDLIFE SERV,UPPER MISSISSIPPI RIVER NATL WILDLIFE & FISH REFU,ONLASKA,WI 54650. WISCONSIN DEPT NAT RESOURCES,LA CROSSE,WI 54601. RP Korschgen, CE (reprint author), NATL BIOL SERV,POB 818,LA CROSSE,WI 54602, USA. NR 13 TC 1 Z9 1 U1 0 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0091-7648 J9 WILDLIFE SOC B JI Wildl. Soc. Bull. PD SPR PY 1996 VL 24 IS 1 BP 132 EP 139 PG 8 WC Biodiversity Conservation SC Biodiversity & Conservation GA UG779 UT WOS:A1996UG77900026 ER PT J AU Stein, RS AF Stein, RS TI Earthquakes - Being struck by a balance SO NATURE LA English DT Editorial Material RP Stein, RS (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 5 TC 0 Z9 0 U1 0 U2 0 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD FEB 29 PY 1996 VL 379 IS 6568 BP 768 EP 769 DI 10.1038/379768a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TX501 UT WOS:A1996TX50100028 ER PT J AU Johnson, JR Gaddis, L AF Johnson, JR Gaddis, L TI Modeling of fluidized ejecta emplacement over digital topography on Venus SO JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS LA English DT Article ID IMPACT CRATERS; MAGELLAN DATA; FLOW; MORPHOLOGY; OUTFLOWS; CHANNELS; VALLEYS AB The FLOW computer model of McEwen and Malin (1989) modified for application to the study of Venus fluidized ejecta blankets (FEBs) demonstrates that relatively low viscosities, yield strengths, and initial velocities are required to duplicate the observed flow paths of the outflow materials. The model calculates the velocities and simulated flow paths of gravity flows over Magellan topography, The model is formulated to determine flow movements from initial conditions, gravitational acceleration, and resistance to motion as described by Coulomb, viscous, and turbulent resistance forces. Successful duplication of observed FEB flow paths has been achieved for the FEB craters Addams, Isabella, and Cochran, When used as a simple energy-line model, the model requires low coefficients of friction to extend FEBs to near their observed termini in the synthetic aperture radar (SAR) imagery, although the resulting straight flow lines do not follow the observed flow paths well. For Bingham flow, the model requires low values of viscosity and yield strength which are more similar to pyroclastic or debris flows than basaltic lavas. Flows of 100-m depth require 1 to 2 orders of magnitude higher values of both viscosity and yield strength than 10-m-deep flows. The complicated nature of the flow lines for the low velocity model suggests that FEBs were probably emplaced under variably laminar and turbulent flow conditions, where underlying topography influenced both the direction and energy of flow materials. C1 US GEOL SURVEY,BRANCH ASTROGEOL,FLAGSTAFF,AZ 86001. UNIV ARIZONA,LUNAR & PLANETARY LAB,DEPT GEOSCI,TUCSON,AZ 85721. RI Johnson, Jeffrey/F-3972-2015 NR 35 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-PLANET JI J. Geophys. Res.-Planets PD FEB 25 PY 1996 VL 101 IS E2 BP 4673 EP 4682 DI 10.1029/95JE02361 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TX641 UT WOS:A1996TX64100013 ER PT J AU Miller, KG Mountain, GS AF Miller, KG Mountain, GS TI Drilling and dating New Jersey Oligocene-Miocene sequences: Ice volume, global sea level, and Exxon records SO SCIENCE LA English DT Article ID STRATIGRAPHIC SEQUENCES AB Oligocene to middle Miocene sequence boundaries on the New Jersey coastal plain (Ocean Drilling Project Leg 150X) and continental slope (Ocean Drilling Project Leg 150) were dated by integrating strontium isotopic stratigraphy, magnetostratigraphy, and biostratigraphy (planktonic foraminifera, nannofossils, dinocysts, and diatoms). the ages of coastal plain unconformities and slope seismic reflectors (unconformities or stratal breaks with no discernible hiatuses) match the ages of global delta(18)O increases (inferred glacioeustatic lowerings) measured in deep-sea sites. These correlations confirm a causal link between coastal plain and slope sequence boundaries: both formed during global sea-level lowerings, The ages of New Jersey sequence boundaries and global delta(18)O increases also correlate well with the Exxon Production Research sea-level records of Haq et al, and Vail et al., validating and refining their compilations. C1 COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964. TEXAS A&M UNIV,COLLEGE STN,TX 77845. LUND UNIV,S-22100 LUND,SWEDEN. INST SCI EVOLUT,MONTPELLIER 5,FRANCE. UNIV S CAROLINA,COLUMBIA,SC 29208. UNIV S FLORIDA,ST PETERSBURG,FL 33701. UNIV TEXAS,ARLINGTON,TX 76019. UNIV LILLE,F-59655 VILLENEUVE DASCQ,FRANCE. UNIV TORONTO,TORONTO,ON M5S 3B1,CANADA. UNIV TEXAS,AUSTIN,TX 78759. UNIV OXFORD,OXFORD OX1 3PR,ENGLAND. UNIV CALIF SANTA CRUZ,SANTA CRUZ,CA 95064. CHIBA UNIV,CHIBA 263,JAPAN. LOUISIANA STATE UNIV,BATON ROUGE,LA 70803. UNIV WESTERN AUSTRALIA,NEDLANDS,WA 6009,AUSTRALIA. CUNY QUEENS COLL,FLUSHING,NY 11367. UNIV NEWCASTLE UPON TYNE,NEWCASTLE TYNE NE1 7RU,TYNE & WEAR,ENGLAND. GEOL SURVEY JAPAN,TSUKUBA,IBARAKI 305,JAPAN. E CAROLINA STATE UNIV,GREENVILLE,NC 27858. FREE UNIV AMSTERDAM,AMSTERDAM,NETHERLANDS. UNIV COLOGNE,W-5000 COLOGNE,GERMANY. UNIV FREIBURG,INST GEOL,D-79104 FREIBURG,GERMANY. NEW JERSEY GEOL SURVEY,TRENTON,NJ 08625. US GEOL SURVEY,RESTON,VA 22092. US GEOL SURVEY,MENLO PK,CA 94025. RP Miller, KG (reprint author), RUTGERS STATE UNIV,DEPT GEOL SCI,PISCATAWAY,NJ 08855, USA. RI Fulthorpe, Craig/C-3066-2008; SAITO, Yoshiki/A-9167-2010 OI SAITO, Yoshiki/0000-0003-3212-6356 NR 34 TC 128 Z9 133 U1 1 U2 12 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD FEB 23 PY 1996 VL 271 IS 5252 BP 1092 EP 1095 DI 10.1126/science.271.5252.1092 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TW701 UT WOS:A1996TW70100030 ER PT J AU Loveland, JP Ryan, JN Amy, GL Harvey, RW AF Loveland, JP Ryan, JN Amy, GL Harvey, RW TI The reversibility of virus attachment to mineral surfaces SO COLLOIDS AND SURFACES A-PHYSICOCHEMICAL AND ENGINEERING ASPECTS LA English DT Article; Proceedings Paper CT Symposium on Colloidal and Interfacial Phenomena to Aquatic Environments, at the 209th National Meeting of the American-Chemical-Society CY APR 04-06, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Environm Chem DE colloids; colloid transport; ferric oxyhydroxide coating; PRD1; quartz surfaces; virus attachment; virus release; virus transport ID POROUS-MEDIA; COLLOIDAL PARTICLES; CHEMICAL PERTURBATIONS; WASTE-WATER; ADSORPTION; SOILS; FILTRATION; TRANSPORT; BACTERIOPHAGE; DETACHMENT AB Virus transport through groundwater is limited by attachment to mineral surfaces and inactivation. Current virus transport models do not consider the implications of the reversibility of virus attachment to minerals. To explore the reversibility of virus attachment to mineral surfaces, we attached PRD1, a bacteriophage considered to be a good model of enteric viruses, to quartz and ferric oxyhydroxide-coated quartz surfaces over a range of pH values in equilibrium ''static columns.'' Following attachment, we detached the viruses by replacing the pore solution with solutions of equal and higher pH. The extent of virus attachment followed an attachment ''edge'' that occurred at a pH value about 2.5-3.5 pH units above the pH(IEP) of the mineral surfaces. Viruses attached below this edge were irreversibly attached until the pH of the detachment solution exceeded the pH value of the attachment edge. Viruses attached above this edge were reversibly attached. Derjaguin-Landau-Verwey-Overbeek (DLVO) potential energy calculations showed that the attachment edge occurred at the pH at which the potential energy of the primary minimum was near zero, implying that the position of the primary minimum (attractive or repulsive) controlled the equilibrium distribution of the viruses. The results suggest that the reversibility of virus attachment must be considered in virus transport models for accurate predictions of virus travel time. C1 UNIV COLORADO,DEPT CIVIL ENVIRONM & ARCHITECTURAL ENGN,BOULDER,CO 80309. US GEOL SURVEY,DIV WATER RESOURCES,BOULDER,CO 80303. RI Ryan, Joseph/H-7025-2012; Harvey, Ronald/C-5783-2013 OI Harvey, Ronald/0000-0002-2791-8503 NR 67 TC 108 Z9 113 U1 3 U2 17 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0927-7757 J9 COLLOID SURFACE A JI Colloid Surf. A-Physicochem. Eng. Asp. PD FEB 20 PY 1996 VL 107 BP 205 EP 221 DI 10.1016/0927-7757(95)03373-4 PG 17 WC Chemistry, Physical SC Chemistry GA TW021 UT WOS:A1996TW02100014 ER PT J AU Pribnow, D Williams, CF Sass, JH Keating, R AF Pribnow, D Williams, CF Sass, JH Keating, R TI Thermal conductivity of water-saturated rocks from the KTB pilot hole at temperatures of 25 to 300 degrees C SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article AB The conductivitites of selected gneiss (two) and amphibolite (one) core samples have been measured under conditions of elevated temperature and pressure with a needle-probe. Water-saturated thermal conductivity measurements spanning temperatures from 25 to 300 degrees C and hydrostatic pressures of 0.1 and 34 MPa confirm the general decrease in conductivity with increasing temperature but deviate significantly from results reported from measurements on dry samples over the same temperature range. The thermal conductivity of water-saturated amphibolite decreases with temperature at a rate approximately 40% less than the rate for dry amphibolite, and the conductivity of water-saturated gneiss decreases at a rate approximately 20% less than the rate for dry gneiss. The available evidence points to thermal cracking as the primary cause of the more rapid decrease in dry thermal conductivity with temperature. The effects of thermal cracking were also observed in the water-saturated samples but resulted in a net decrease in room-temperature conductivity of less than 3%. These results highlight the importance of duplicating in-situ conditions when determining thermal conductivity for the deep crust. C1 US GEOL SURVEY,MENLO PK,CA 94025. US GEOL SURVEY,FLAGSTAFF,AZ 86001. RP Pribnow, D (reprint author), UNIV UTAH,DEPT GEOL & GEOPHYS,WBB 717,SALT LAKE CITY,UT 84112, USA. NR 15 TC 31 Z9 31 U1 0 U2 8 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 15 PY 1996 VL 23 IS 4 BP 391 EP 394 DI 10.1029/95GL00253 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TW551 UT WOS:A1996TW55100019 ER PT J AU vanGeen, A Husby, DM AF vanGeen, A Husby, DM TI Cadmium in the California current system: Tracer of past and present upwelling SO JOURNAL OF GEOPHYSICAL RESEARCH-OCEANS LA English DT Article ID NORTHEAST PACIFIC WATERS; COASTAL TRANSITION ZONE; SAN-FRANCISCO BAY; COPPER; DISTRIBUTIONS; PHYTOPLANKTON; FORAMINIFERA; NUTRIENTS; SEAWATER; NICKEL AB Over 100 samples were collected off the west coast of North America during 1991-1993 to determine the relation between wind-driven upwelling and nearshore concentrations of dissolved silicate (Si), phosphate (P), and cadmium (Cd). Highly enriched in deep water offshore, these constituents are sensitive indicators of upwelling. Coastal water was sampled from the shore in January and June 1992 at 12 sites distributed between 36 degrees and 48 degrees N latitude. In January the composition of nearshore water along this transect was fairly uniform: 5-15 mu mol/kg for Si, 0.5 to 1.0 mu mol/kg for P, and 0.1-0.3 nmol/kg for Cd. In June, elevated concentrations of Si (30 mu mol/kg), P (2.0 mu mol/kg), and Cd (0.6 nmol/kg) revealed a region of intense upwelling between 38 degrees and 40 degrees N. The pattern is broadly consistent with meridional gradients in coastal upwelling calculated from the long-term mean of alongshore winds compiled from ship reports. Nearshore water was also collected biweekly to monthly at two sites 3 km apart near San Francisco Bay (37.5 degrees N) during 1991-1993. The variability seen in the time series suggests that the composition of nearshore water integrates the effect of alongshore winds over timescales of several weeks. Seasonal variations in Si (5-50 mu mol/kg), P (0.5-2.5 mu mol/kg), and Cd (0.1-0.8 nmol/kg) concentrations were consistent with upwelling during spring and summer. Maximum Si, P, and Cd concentrations reached in May 1991 were consistent with advection to the very nearshore region from a depth of about 300 m relative to a vertical profile at a distance of 200 km from the coast. Nearshore Si, P, and Cd concentrations were reduced relative to 1991 in 1992 and, to a lesser extent, in 1993 due to weaker upwelling linked to the warm phase of the Fl Nino-Southern Oscillation. During periods of weaker upwelling or downwelling, variations in P, Si, and Cd concentrations became uncoupled. There is a good correlation between the coastal Cd time series near San Francisco Bay (37.5 degrees N) and a second order polynomial function of the the upwelling index of Bakun [1975] at 35 degrees N, filtered with a 30-day running mean (r(2) = 0.71, n=39). The index is a daily estimate of coastal upwelling calculated from 6-hourly mean atmospheric pressure distributions at 36 degrees N. From this function and a record of daily upwelling indices we infer a range of annually averaged coastal Cd concentrations of at least 0.3-0.5 nmol/kg since 1967. Cd/Ca ratios in shells of foraminifera from San Francisco Bay suggest that average coastal ed concentrations 3500-4500 years ago were at the upper end of this range. C1 NOAA,PACIFIC FISHERIES ENVIRONM GRP,SW FISHERIES SCI CTR,MONTEREY,CA 93942. US GEOL SURVEY,MENLO PK,CA 94025. RP vanGeen, A (reprint author), COLUMBIA UNIV,LAMONT DOHERTY GEOL OBSERV,PALISADES,NY 10964, USA. NR 50 TC 38 Z9 38 U1 0 U2 7 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0148-0227 J9 J GEOPHYS RES-OCEANS JI J. Geophys. Res.-Oceans PD FEB 15 PY 1996 VL 101 IS C2 BP 3489 EP 3507 DI 10.1029/95JC03302 PG 19 WC Oceanography SC Oceanography GA TW390 UT WOS:A1996TW39000005 ER PT J AU Durham, WB Stern, LA Kirby, SH AF Durham, WB Stern, LA Kirby, SH TI Rheology of water ices V and VI SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID GANYMEDE; EVOLUTION; CALLISTO AB We have measured the mechanical strength (sigma) of pure water ices V and VI under steady state deformation conditions. Constant displacement rate compressional tests were conducted in a gas apparatus at confining pressures from 400 < P < 800 MPa, temperatures from 209 < T < 270 K, and strain rates 7 x 10(-7) < epsilon < 7 x 10(-4) s(-1). Most of the results fit to an empirical flow law of the form epsilon = A sigma(n) exp (-(E* + PV*)/RT), where the four material constants A, n, E*, and V* are (for epsilon in inverse seconds and P and cr in megapascals) 10(23.0), 6.0, 136 kJ/mol, and 29 cm(3)/mol, respectively, for ice V; and 10(6.7), 4.5, 66 kJ/mol, and 11 cm(3)/mol, respectively, for ice VI. Ice VI may weaken to a mechanism of higher E* at T > 250 K. Ices V and VI are thus theologically distinct but by coincidence have approximately the same strength under the conditions chosen for these experiments. To avoid misidentification, these tests are therefore accompanied by careful observations of the occurrences and characteristics of phase changes. One sample each of ice V and VI was quenched at pressure to metastably retain the high-pressure phase and the acquired deformation microstructures; X ray diffraction analysis of these samples confirmed the phase identification. Surface replicas of the deformed and quenched samples suggest that ice V probably deforms largely by dislocation creep, while ice VI deforms by a more complicated process involving substantial grain size reduction through recrystallization. C1 US GEOL SURVEY, MS 977, MENLO PK, CA 94025 USA. RP Durham, WB (reprint author), LAWRENCE LIVERMORE NATL LAB, L-201, BOX 808, LIVERMORE, CA 94550 USA. NR 25 TC 14 Z9 14 U1 0 U2 6 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD FEB 10 PY 1996 VL 101 IS B2 BP 2989 EP 3001 DI 10.1029/95JB03542 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TV380 UT WOS:A1996TV38000016 ER PT J AU Guffanti, M Clynne, MA Muffler, LPJ AF Guffanti, M Clynne, MA Muffler, LPJ TI Thermal and mass implications of magmatic evolution in the Lassen volcanic region, California, and minimum constraints on basalt influx to the lower crust SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID ISLAND-ARC; NORTHERN CALIFORNIA; PHASE-RELATIONS; CASCADE RANGE; SUBDUCTION; GENERATION; EARTHQUAKES; EXTENSION; ELEMENT; OLIVINE AB We have analyzed the heat and mass demands of a petrologic model of basalt-driven magmatic evolution in which variously fractionated mafic magmas mix with silicic partial melts of the lower crust. We have formulated steady state heat budgets for two volcanically distinct areas in the Lassen region: the large, late Quaternary, intermediate to silicic Lassen volcanic center and the nearby, coeval, less evolved Caribou volcanic field. Ar Caribou volcanic field, heat provided by cooling and fractional crystallization of 52 km(3) of basalt is more than sufficient to produce 10 km(3) of rhyolitic melt by partial melting of lower crust. Net heat added by basalt intrusion at Caribou volcanic field is equivalent to an increase in lower crustal heat flow of similar to 7 mW m(-2), indicating that the field is not a major crustal thermal anomaly. Addition of cumulates from fractionation is offset by removal of erupted partial melts. A minimum basalt influx of 0.3 km(3) (km(2) Ma)(-1) is needed to supply Caribou volcanic field. Our methodology does not fully account for an influx of basalt that remains in the crust as derivative intrusives. On the basis of comparison to deep heat flow, the input of basalt could be similar to 3 to 7 times the amount we calculate. At Lassen volcanic center, at least 203 km(3) of mantle-derived basalt is needed to produce 141 km(3) of partial melt and drive the volcanic system. Partial melting mobilizes lower crustal material, augmenting the magmatic volume available for eruption at Lassen volcanic center; thus the erupted volume of 215 km(3) exceeds the calculated basalt input of 203 km(3). The minimum basalt input of 1.6 km(3) (km(2) Ma)(-1) is >5 times the minimum influx to the Caribou volcanic field. Basalt influx high enough to sustain considerable partial melting, coupled with locally high extension rate, is a crucial factor in development of Lassen volcanic center; in contrast, Caribou volcanic field has failed to develop into a large silicic center primarily because basalt supply there has been insufficient. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. RP US GEOL SURVEY, 922 NATL CTR, 12201 SUNRISE VALLEY DR, RESTON, VA 22092 USA. NR 40 TC 22 Z9 26 U1 2 U2 5 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD FEB 10 PY 1996 VL 101 IS B2 BP 3003 EP 3013 DI 10.1029/95JB03463 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TV380 UT WOS:A1996TV38000017 ER PT J AU Snay, RA Cline, MW Philipp, CR Jackson, DD Feng, YJ Shen, ZK Lisowski, M AF Snay, RA Cline, MW Philipp, CR Jackson, DD Feng, YJ Shen, ZK Lisowski, M TI Crustal velocity field near the big bend of California's San Andreas fault SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID WESTERN TRANSVERSE RANGES; GLOBAL POSITIONING SYSTEM; SOUTHERN CALIFORNIA; REGIONAL DEFORMATION; GEODETIC MEASUREMENT; VENTURA-BASIN; EARTH MODEL; KERN COUNTY; STRAIN; PLATE AB We use geodetic data spanning the 1920-1992 interval to estimate the horizontal velocity field near the big bend segment of California's San Andreas fault (SAF). More specifically, we estimate a horizontal velocity vector for each node of a two-dimensional grid that has a 15-min-by-15-min mesh and that extends between latitudes 34.0 degrees N and 36.0 degrees N and longitudes 117.5 degrees W and 120.5 degrees W. For this estimation process, we apply bilinear interpolation to transfer crustal deformation information from geodetic sites to the grid nodes. The data include over a half century of triangulation measurements, over two decades of repeated electronic distance measurements, a decade of repeated very long baseline interferometry measurements, and several years of Global Positioning System measurements. Magnitudes for our estimated velocity vectors have formal standard errors ranging from 0.7 to 6.8 mm/yr. Our derived velocity field shows that (1) relative motion associated with the SAF exceeds 30 mm/yr and is distributed on the Earth's surface across a band (>100 km wide) that is roughly centered on this fault; (2) when velocities are expressed relative to a fixed North America plate, the motion within our primary study region has a mean orientation of N44 degrees W +/- 2 degrees and the surface trace of the SAF is congruent in shape to nearby contours of constant speed yet this trace is oriented between 5 degrees and 10 degrees counterclockwise relative to these contours; and (3) large strain rates (shear rates > 150 nrad/yr and/or areal dilatation rates < -150 nstr/yr) exist near the Garlock fault, near the White Wolf fault, and in the Ventura basin. C1 UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. US GEOL SURVEY, HAWAIIAN VOLCANO OBSERV, HILO, HI 96718 USA. RP Snay, RA (reprint author), NOAA, NATL GEODET SURVEY, 1315 EW HIGHWAY, SILVER SPRING, MD 20910 USA. NR 54 TC 19 Z9 19 U1 0 U2 0 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD FEB 10 PY 1996 VL 101 IS B2 BP 3173 EP 3185 DI 10.1029/95JB02394 PG 13 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TV380 UT WOS:A1996TV38000029 ER PT J AU Rathbun, RE AF Rathbun, RE TI Speciation of trihalomethane mixtures for the Mississippi, Missouri, and Ohio Rivers SO SCIENCE OF THE TOTAL ENVIRONMENT LA English DT Article DE trihalomethane; chloroform; chlorination; Mississippi River; Missouri River; Ohio River ID DRINKING-WATER AB Trihalomethane formation potentials were determined for the chlorination of water samples from the Mississippi, Missouri, and Ohio Rivers. Samples were collected during the summer and fall of 1991 and the spring of 1992 at 12 locations on the Mississippi from New Orleans, LA, to Minneapolis, MN, and on the Missouri and Ohio 1.6 km upstream from their confluences with the Mississippi. Formation potentials were determined as a function of pH and initial free-chlorine concentration. Chloroform concentrations decreased with distance downstream and approximately paralleled the decrease of the dissolved organic-carbon concentration. Bromide concentrations were 3.7-5.7 times higher for the Missouri and 1.4-1.6 times higher for the Ohio than for the Mississippi above their confluences, resulting in an overall increase of the bromide concentration with distance downstream. Variations of the concentrations of the brominated trihalomethanes with distance downstream approximately paralleled the variation of the bromide concentration. Concentrations of all four trihalomethanes increased as the pH increased. Concentrations of chloroform and bromodichloromethane increased slightly and the concentration of bromoform decreased as the initial free-chlorine concentration increased; the chlorodibromomethane concentration had little dependence on the free-chlorine concentration. RP Rathbun, RE (reprint author), US GEOL SURVEY, 5293 WARD RD, ARVADA, CO 80002 USA. NR 21 TC 13 Z9 13 U1 0 U2 7 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0048-9697 EI 1879-1026 J9 SCI TOTAL ENVIRON JI Sci. Total Environ. PD FEB 9 PY 1996 VL 180 IS 2 BP 125 EP 135 DI 10.1016/0048-9697(95)04938-X PG 11 WC Environmental Sciences SC Environmental Sciences & Ecology GA TY410 UT WOS:A1996TY41000004 ER PT J AU Rathbun, RE AF Rathbun, RE TI Trihalomethane and nonpurgeable total organic-halide formation potentials of the Mississippi River SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article AB Trihalomethane and nonpurgeable total organic-halide formation potentials were determined for water samples from 12 sites along the Mississippi River from Minneapolis, MN, to New Orleans, LA, for the summer and fall of 1991 and the spring of 1992. The formation potentials increased with distance upstream, approximately paralleling the increase of the dissolved organic-carbon concentration. The pH and the dissolved organic-carbon and free-chlorine concentrations were significant variables in the prediction of the formation potentials. The trihalomethane formation potential increased as the pH increased, whereas the nonpurgeable total organic-halide formation potential decreased. All formation potentials increased as the dissolved organic-carbon and free-chlorine concentrations increased, with the dissolved organic-carbon concentration having a much greater effect. RP Rathbun, RE (reprint author), US GEOL SURVEY, 5293 WARD RD, ARVADA, CO 80002 USA. NR 17 TC 3 Z9 3 U1 0 U2 3 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-4341 EI 1432-0703 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD FEB PY 1996 VL 30 IS 2 BP 156 EP 162 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TT081 UT WOS:A1996TT08100002 ER PT J AU Custer, TW Sparks, DW Sobiech, SA Hines, RK Melancon, MJ AF Custer, TW Sparks, DW Sobiech, SA Hines, RK Melancon, MJ TI Organochlorine accumulation by sentinel mallards at the Winston-Thomas sewage treatment plant, Bloomington, Indiana SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID POLYCHLORINATED-BIPHENYLS PCBS; ARYL-HYDROCARBON HYDROXYLASE; NEW-YORK-STATE; HERRING GULL; INDUCTION; CONTAMINANTS; SEDIMENTS; EMBRYOS; MEXICO; MIREX AB Farm-raised 12-month-old female mallards (Anas platyrhynchos) were released at the Winston-Thomas sewage treatment plant, Bloomington, Indiana. Five mallards were sacrificed at the start of the study and at approximately 10-day intervals through day 100. Concentrations of polychlorinated biphenyls (PCBs) in carcasses increased linearly with time of exposure and exceeded 16 mu g/g wet weight by day 100; PCBs in breast muscle exceeded 3.9 mu g/g by day 100. These PCB values are among the highest recorded for wild or sentinel waterfowl. PCB concentrations in breast muscle (26-523 mu g/g lipid weight) were 50-1,000 times greater than human consumption guidelines for edible poultry in Canada (0.5 mu g/g lipid weight) and 9-176 times greater than consumption guidelines for edible poultry in the United States (3.0 mu g/g lipid weight). Additionally, PCB concentrations in carcass and breast muscle exceeded the threshold of the Great Lakes Sport Fish Consumption Advisory 'do not eat' category (1.9 mu g/g wet weight) by day 20 and day 50, respectively. Hepatic cytochrome P450-associated monooxygenases including BROD (benzyloxyresorufin-O-dealkylase), EROD (ethoxyresorufin-O-dealkylase), and PROD (pentoxyresorufin-O-dealkylase) were induced over 5-fold compared to reference mallards. BROD, EROD, and PROD were each significantly correlated to total PCBs and to the toxicity of selected PCB congeners, relative to 2,3,7,8-tetrachlorodibenzo-p-dioxin. C1 US FISH & WILDLIFE SERV,HABITAT ENHANCEMENT FIELD OFF,BLOOMINGTON,IN 47403. NATL BIOL SERV,PATUXENT ENVIRONM SCI CTR,LAUREL,MD 20708. RP Custer, TW (reprint author), NATL BIOL SERV,UPPER MISSISSIPPI SCI CTR,POB 818,LA CROSSE,WI 54602, USA. OI Custer, Thomas/0000-0003-3170-6519 NR 37 TC 16 Z9 17 U1 4 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD FEB PY 1996 VL 30 IS 2 BP 163 EP 169 PG 7 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TT081 UT WOS:A1996TT08100003 ER PT J AU Naftz, DL Klusman, RW Michel, RL Schuster, PF Reddy, MM Taylor, HE Yanosky, TM McConnaughey, EA AF Naftz, DL Klusman, RW Michel, RL Schuster, PF Reddy, MM Taylor, HE Yanosky, TM McConnaughey, EA TI Little ice age evidence from a south-central North America ice core, USA SO ARCTIC AND ALPINE RESEARCH LA English DT Article ID STRATIGRAPHY; CALIBRATION; CAP AB In the past, ice-core records from mid-latitude glaciers in alpine areas of the continental United States were considered to be poor candidates for paleoclimate records because of the influence of meltwater on isotopic stratigraphy. To evaluate the existence of reliable paleoclimatic records, a 160-m ice core, containing about 250 yr of record was obtained from Upper Fremont Glacier, at an altitude of 4000 m in the Wind River Range of south-central North America. The delta(18)O (SMOW) profile from the core shows a -0.95 parts per thousand shift to lighter values in the interval from 101.8 to 150 m below the surface, corresponding to the latter part of the Little Ice Age (LIA). Numerous high-amplitude oscillations in the section of the core from 101.8 to 150 m cannot be explained by site-specific lateral variability and probably reflect increased seasonality or better preservation of annual signals as a result of prolonged cooler temperatures that existed in this alpine setting. An abrupt decrease in these large amplitude oscillations at the 101.8-m depth suggests a sudden termination of this period of lower temperatures which generally coincides with the termination of the LIA. Three common features in the delta(18)O profiles between Upper Fremont Glacier and the better dated Quelccaya Ice Cap cores indicate a global paleoclimate linkage, further supporting the first documented occurrence of the LIA in an ice-core record from a temperate glacier in southcentral North America. C1 COLORADO SCH MINES, DEPT CHEM & GEOCHEM, GOLDEN, CO 80401 USA. COLORADO SCH MINES, DIV ENVIRONM SCI & ENGN, GOLDEN, CO 80401 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. US GEOL SURVEY, BOULDER, CO 80303 USA. US GEOL SURVEY, NATL CTR, RESTON, VA 22092 USA. US GEOL SURVEY, DENVER FED CTR, DENVER, CO 80225 USA. RP US GEOL SURVEY, 1745 WEST, 1700 SOUTH, SALT LAKE CITY, UT 84104 USA. NR 26 TC 23 Z9 23 U1 2 U2 3 PU INST ARCTIC ALPINE RES PI BOULDER PA UNIV COLORADO, BOULDER, CO 80309 USA SN 0004-0851 J9 ARCTIC ALPINE RES JI Arct. Alp. Res. PD FEB PY 1996 VL 28 IS 1 BP 35 EP 41 DI 10.2307/1552083 PG 7 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA TZ759 UT WOS:A1996TZ75900004 ER PT J AU Brunstein, FC AF Brunstein, FC TI Climatic significance of the bristlecone pine latewood frost-ring record at Almagre Mountain, Colorado, USA SO ARCTIC AND ALPINE RESEARCH LA English DT Article ID VOLCANIC-ERUPTIONS; AD AB From 1900 to 1993, latewood frost rings occurred in 1903, 1912, 1941, 1961, and 1965 in 10 to 21% of the sampled bristlecone pines at Almagre Mountain, Colorado. In early to mid September in each of those years, a severe outbreak of unseasonably cold air from higher latitudes produced a memorable or historic late-summer snowstorm in the western United States. Record subfreezing temperatures during these snowstorms probably caused the latewood frost rings, shortened (by about 1 mo in 1912) already colder than normal growing seasons, and caused crop damage in parts of the Western United States. Latewood frost rings recorded in relatively high percentages of the sampled trees (such as the 1805 event in 61% of sampled trees) were probably caused by multiple severe outbreaks of unseasonably cold air from higher latitudes that occurred from early September (possibly as early as mid- or late August) to mid-September. Analyses of 1900-1992 temperature data for two widely separated Colorado stations, Fort Collins and Colorado Springs, show that average summer (June-September) temperatures during latewood frost-ring years in this century were 1.5 and 2.0 degrees C cooler than normal, respectively. Mountain snowpack probably persisted through these cool summers and was subsequently buried by the earlier than normal snowfall in September. Latewood frost-ring, ring-width, historical, and other data suggest that severe to cataclysmic volcanic eruptions from 1812 to 1835 triggered (1) an extended period of climatic cooling from as early as 1816 or 1817 through the early 1850s in the Southern Rocky Mountains, (2) catastrophic winters in Colorado and Wyoming in 1842-43 and 1844-45, and in the Great Salt Lake Basin in 1836-37, that caused large-scale destruction of bison and other large plains animals, and (3) Little Ice Age alpine glacial advances in about 1850-60 in the western United States. RP US GEOL SURVEY, FED CTR, BOX 25046, MAIL STOP 902, DENVER, CO 80225 USA. NR 51 TC 27 Z9 29 U1 2 U2 6 PU INST ARCTIC ALPINE RES PI BOULDER PA UNIV COLORADO, BOULDER, CO 80309 USA SN 0004-0851 J9 ARCTIC ALPINE RES JI Arct. Alp. Res. PD FEB PY 1996 VL 28 IS 1 BP 65 EP 76 DI 10.2307/1552087 PG 12 WC Environmental Sciences; Geography SC Environmental Sciences & Ecology; Geography GA TZ759 UT WOS:A1996TZ75900008 ER PT J AU Stanley, WD Johnson, SY Qamar, AI Weaver, CS Williams, JM AF Stanley, WD Johnson, SY Qamar, AI Weaver, CS Williams, JM TI Tectonics and seismicity of the southern Washington Cascade range SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID BENEATH WASHINGTON; WESTERN WASHINGTON; VOLCANIC-ROCKS; FAULT; ROTATION; TRANSPRESSION; SEDIMENTARY; SUBDUCTION; GEOMETRY; BASEMENT AB Geophysical, geological, and seismicity data are combined to develop a transpressional strain model for the southern Washington Cascades region. We use this model to explain oblique fold and fault systems, transverse faults, and a linear seismic zone just west of Mt. Rainier known as the western Rainier zone. We also attempt to explain a concentration of earthquakes that connects the northwest-trending Mount St. Helens seismic zone to the north-trending western Rainier zone. Our tectonic model illustrates the pervasive effects of accretionary processes, combined with subsequent transpressive forces generated by oblique subduction, on Eocene to present crustal processes, such as seismicity and volcanism. C1 UNIV WASHINGTON,GEOPHYS PROGRAM,US GEOL SURVEY,SEATTLE,WA 98195. RP Stanley, WD (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS964,DENVER,CO 80225, USA. NR 62 TC 21 Z9 21 U1 3 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 BP 1 EP 18 PN A PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ064 UT WOS:A1996TZ06400001 ER PT J AU Carver, D Hartzell, SH AF Carver, D Hartzell, SH TI Earthquake site response in Santa Cruz, California SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID GROUND MOTION; FRANCISCO-BAY AB Aftershocks of the 1989 Loma Prieta, California, earthquake are used to estimate site response in a 12-km(2) area centered on downtown Santa Cruz. A total of 258 S-wave records from 36 aftershocks recorded at 33 sites are used in a linear inversion for site-response spectra. The inversion scheme takes advantage of the redundancy of the large data set for which several aftershocks are recorded at each site. The scheme decomposes the observed spectra into source, path, and site terms. The path term is specified before the inversion. The undetermined degree of freedom in the decomposition into source and site spectra is removed by specifying the site-response factor to be approximately 1.0 at two sites on crystalline bedrock. The S-wave site responses correlate well with the surficial geology and observed damage pattern of the mainshock. The site-response spectra of the floodplain sites, which include the heavily damaged downtown area, exhibit significant peaks. The largest peaks are between 1 and 4 Hz. Five floodplain sites have amplification factors of 10 or greater. Most of the floodplain site-response spectra also have a smaller secondary peak between 6 and 8 Hz. Residential areas built on marine terraces above the flood-plain experienced much less severe damage. Site-response spectra for these areas also have their largest peaks between 1 and 4 Hz, but the amplification is generally below 6, Several of these sites also have a secondary peak between 6 and 8 Hz. The response peaks seen at nearly all sites between 1 and 4 Hz are probably caused by the natural resonance of the sedimentary rock column. The higher amplifications at floodplain sites may be caused by surface waves generated at the basin margins. The secondary peak between 6 and 8 Hz at many sites may be a harmonic of the 1- to 4-Hz peaks. We used waveforms from a seven-station approximately linear array located on the floodplain to calculate the apparent velocity and azimuth of propagation of coherent arrivals within moving windows of the S-wave codas. The initial windows give results that are consistent with direct S-wave arrivals. The apparent velocities are high (greater than 4.0 km/sec), and azimuths are from the source. Waves arriving later than 2 sec after the direct S waves have apparent velocities of less than 1 km/sec, indicating that they are surface waves, and arrive from divergent azimuths. This analysis indicates that after the direct S-wave arrival, long-duration shaking comes from surface waves that are generated at the basin margin and reverberate in the floodplain sediments. RP Carver, D (reprint author), US GEOL SURVEY,BRANCH EARTHQUAKE & LANDSLIDE HAZARDS,BOX 25046,DENVER,CO 80225, USA. NR 21 TC 10 Z9 11 U1 0 U2 3 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 BP 55 EP 65 PN A PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ064 UT WOS:A1996TZ06400005 ER PT J AU Rogers, AM Perkins, DM AF Rogers, AM Perkins, DM TI Monte Carlo simulation of peak-acceleration attenuation using a finite-fault uniform-patch model including isochrone and extremal characteristics SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID HIGH-FREQUENCY RADIATION; STRESS DROP; EARTHQUAKES; RUPTURE; MICHOACAN; MEXICO AB A finite-fault statistical model of the earthquake source is used to confirm observed magnitude and distance saturation scaling in a large peak-acceleration data set. This model allows us to determine the form of peak-acceleration attenuation curves without a priori assumptions about their shape or scaling properties. The source is composed of patches having uniform size and statistical properties. The primary source parameters are the patch peak-acceleration distribution mean, the distribution standard deviation, the patch size, and patch-rupture duration. Although our model assumes no scaling of peak acceleration with magnitude at the patch, the peak-acceleration attenuation curves, nevertheless, strongly scale with magnitude (da(p)/dM) not equal 0, and the scaling is distance dependent (da(p)/dM) proportional to f(r). The distance-dependent magnitude scaling arises from two principal sources in the model. For a propagating rupture, loci exist on the fault from which radiated energy arrives at a particular station at the same time. These loci are referred to as isochrones. As fault size increases, the length of the isochrones and, hence, the number of additive pulses increase. Thus, peak accelerations increase with magnitude. The second effect, which arises in a completely different manner, is due to extreme-value properties. That is, as the fault size increases, the number of patches on the fault and the number of peak values at the station increase. Because these attenuated pulses are produced by a statistical distribution at the patch, the largest value will depend on the total number of peak values available on the seismogram. We refer to this result as the extremal effect, because it is predicted by the theory of extreme values. Both the extremal and isochrone effects are moderated by attenuation and distance to the fault, leading to magnitude- and distance-dependent peak-acceleration scaling. Remarkably, the scaling produced by both effects is very similar, although the underlying mechanisms are completely different. Because this model approximates data characteristics we have observed in an earlier study, we adjusted the parameters of the model to fit a set of smoothed peak accelerations from earthquakes worldwide. These data have not been preselected for particular magnitude or distance ranges and contain earthquake records for magnitudes ranging from about M 3 to M 8 and distance ranging from a few kilometers to about 400 km. In fitting the data, we use a trial-and-error procedure, varying the mean and standard deviation of the patch peak-acceleration distribution, the patch size, and the pulse duration. The model explicitly includes triggering bias, and the triggering threshold is also a model parameter. The data can be approximated equally well by a model that includes the isochrone effect alone, the extremal effect alone, or both effects. Inclusion of both effects is likely to be closest to reality, but because both effects produce similar results, it is not possible to determine the relative contribution of each one. In any case, the model approximates the complex features of the observed data, including a decrease in magnitude scaling with increasing magnitude at short distances and increase in magnitude scaling with magnitude at large distances. RP Rogers, AM (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 966,DENVER,CO 80225, USA. NR 37 TC 9 Z9 9 U1 0 U2 0 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 BP 79 EP 92 PN A PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ064 UT WOS:A1996TZ06400008 ER PT J AU Gomberg, J Agnew, D AF Gomberg, J Agnew, D TI The accuracy of seismic estimates of dynamic strains: An evaluation using strainmeter and seismometer data from Pinon Flat Observatory, California SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID EARTHQUAKE AB The dynamic strains associated with seismic waves may play a significant role in earthquake triggering, hydrological and magmatic changes, earthquake damage, and ground failure. We determine how accurately dynamic strains may be estimated from seismometer data and elastic-wave theory by comparing such estimated strains with strains measured on a three-component long-base strainmeter system at Pinon Flat, California. We quantify the uncertainties and errors through cross-spectral analysis of data from three regional earthquakes (the M(0) = 4 x 10(17) N-m St. George, Utah; M(0) = 4 X 10(17) N-m Little Skull Mountain, Nevada; and M(0) 1 x 10(19) N-m Northridge, California, events at distances of 470, 345, and 206 km, respectively). Our analysis indicates that in most cases the phase of the estimated strain matches that of the observed strain quite well (to within the uncertainties, which are about +/-0.1 to +/-0.2 cycles). However, the amplitudes are often systematically off, at levels exceeding the uncertainties (about 20%); in one case, the predicted strain amplitudes are nearly twice those observed. We also observe significant epsilon(phi phi) strains (phi = tangential direction), which should be zero theoretically; in the worst case, the rms epsilon(phi phi) Strain exceeds the other nonzero components. These nonzero epsilon(phi phi) strains cannot be caused by deviations of the surface-wave propagation paths from the expected azimuth or by departures from the plane-wave approximation. We believe that distortion of the strain field by topography or material heterogeneities give rise to these complexities. C1 UNIV CALIF SAN DIEGO,IGPP A025,LA JOLLA,CA 92093. RP Gomberg, J (reprint author), MEMPHIS UNIV,CERI,US GEOL SURVEY,MEMPHIS,TN 38152, USA. NR 44 TC 35 Z9 35 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 BP 212 EP 220 PN A PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ064 UT WOS:A1996TZ06400019 ER PT J AU Wennerberg, L AF Wennerberg, L TI Simultaneous study of the source, path, and site effects on strong ground motion during the 1989 Loma Prieta earthquake: A preliminary result on pervasive nonlinear site effects - Comment SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-FRANCISCO; QUANTITATIVE DESCRIPTION; BARRIER MODEL; AMPLIFICATION; CALIFORNIA; PREDICTION; CODA C1 US GEOL SURVEY,MS 977,MENLO PK,CA 94025. NR 29 TC 10 Z9 10 U1 0 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 BP 259 EP 267 PN A PG 9 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ064 UT WOS:A1996TZ06400024 ER PT J AU Harp, EL Jibson, RW AF Harp, EL Jibson, RW TI Landslides triggered by the 1994 Northridge, California, earthquake SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article AB The 17 January 1994 Northridge, California, earthquake (M(W) = 6.7) triggered more than 11,000 landslides over an area of about 10,000 km(2). Most of the landslides were concentrated in a 1000-km(2) area that included the Santa Susana Mountains and the mountains north of the Santa Clara River valley. We mapped landslides triggered by the earthquake in the field and from 1:60,000-nominal-scale aerial photography provided by the U.S. Air Force and taken the morning of the earthquake; these mapped landslides were subsequently digitized and plotted in a GIS-based format. Most of the triggered landslides were shallow (1- to 5-m thick), highly disrupted falls and slides within weakly cemented Tertiary to Pleistocene elastic sediment. Average volumes of these types of landslides were less than 1000 m(3), but many had volumes exceeding 100,000 m(3). The larger disrupted slides commonly had runout paths of more than 50 m, and a few traveled as far as 200 m from the bases of steep parent slopes. Deeper (>5-m thick) rotational slumps and block slides numbered in the tens to perhaps hundreds, a few of which exceeded 100,000 m(3) in volume; Most of these were reactivations of previously existing landslides. The largest single landslide triggered by the earthquake was a rotational slump/block slide having a volume of 8 x 10(6) m(3). Analysis of the mapped landslide distribution with respect to variations in (1) landslide susceptibility and (2) strong shaking recorded by hundreds of instruments will form the basis of a seismic landslide hazard analysis of the Los Angeles area. RP Harp, EL (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 11 TC 90 Z9 108 U1 0 U2 9 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 SU S BP S319 EP S332 PN B PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ652 UT WOS:A1996TZ65200023 ER PT J AU Hartzell, S Leeds, A Frankel, A Michael, J AF Hartzell, S Leeds, A Frankel, A Michael, J TI Site response for urban Los Angeles using aftershocks of the Northridge earthquake SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID LOMA-PRIETA EARTHQUAKE; SAN-FRANCISCO-BAY; GROUND RESPONSE; MOTIONS AB Ground-motion records from aftershocks of the 1994 Northridge earthquake are used to estimate site response in the urban Los Angeles area. Over 1300 shear-wave records from 61 sources and 90 sites are used in a linear inversion for source and site-response spectra. The methodology makes no assumptions about the shape of the source spectrum. To obtain a stable unique inverse, a Q model and geometrical spreading factor are assumed. In addition, the site response at a hardrock site is constrained to be approximately 1.0 with a kappa of 0.02. The site-response spectra compare favorably with the results of previous and on-going investigations in Los Angeles. A couple of first-order effects are lower site response in the surrounding mountains, dominated by Mesozoic and Tertiary rocks, and higher values in the San Fernando and Los Angeles Basins, containing surficial Pleistocene and Holocene alluvial deposits. Results show good correlation of high site-response spectral values with localized areas of severe damage (Interstate 10 collapse, Sherman Oaks, Northridge, Interstate 5/14 collapse). However, widespread trends in site response across the sedimentary basins are not obvious. The data suggest that site responses are lower near the southern margin of the San Fernando Valley for sources to the north, due to north-dipping sedimentary structures. But the general pattern of site response is characterized by high variability on length scales less than a kilometer. Variations of a factor of 2 in site response are observed over the length scale of 200 m and for the same surficial geologic unit. For some of the alluvial basin sites, surface-wave generation is a significant contributor to elevated site response at lower frequencies, below 2 Hz. The total damage pattern for the Northridge earthquake is influenced by strong source directivity to the north and strong local site effects. The correlation of weak-motion site-response estimates with areas of significant damage demonstrates the value of these field measurements in future urban planning and in the reduction of seismic risk in urban areas. RP Hartzell, S (reprint author), US GEOL SURVEY,BRANCH EARTHQUAKE & LANDSLIDE HAZARDS,BOX 25046,MS 966,DENVER,CO 80225, USA. NR 41 TC 53 Z9 58 U1 0 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 SU S BP S168 EP S192 PN B PG 25 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ652 UT WOS:A1996TZ65200014 ER PT J AU Hudnut, KW Shen, Z Murray, M McClusky, S King, R Herring, T Hager, B Feng, Y Fang, P Donnellan, A AF Hudnut, KW Shen, Z Murray, M McClusky, S King, R Herring, T Hager, B Feng, Y Fang, P Donnellan, A TI Co-seismic displacements of the 1994 Northridge, California, earthquake SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SAN-ANDREAS FAULT; CRUSTAL DEFORMATION; GEODETIC MEASUREMENT; SOUTHERN CALIFORNIA; VENTURA-BASIN; PARKFIELD; SEQUENCE; REGION; SPACE AB The 17 January 1994 Northridge, California, earthquake significantly deformed the Earth's crust in the epicentral region, Displacements of 66 survey stations determined from Global Positioning System (GPS) observations collected before and after the earthquake show that individual stations were uplifted by up to 417 +/- 5 mm and displaced horizontally by up to 216 +/- 3 mm. Using these displacements, we estimate parameters of a uniform-slip model. Fault geometry and slip are estimated independent of seismological information, using Monte Carlo optimization techniques that minimize the model residuals, The plane that best fits the geodetic data lies 1 to 2 km above the plane indicated by aftershock seismicity. Modeling for distributed slip on a coplanar, yet larger model fault indicates that a high-slip patch occurred up-dip and northwest of the mainshock hypocenter and that less than 1 m of slip occurred in the uppermost 5 km of the crust. This finding is consistent with the lack of clear surface rupture and with the notion that the intersection with the fault that ruptured in 1971 formed the up-dip terminus of slip in the Northridge earthquake. Displacements predicted by either of these simple models explain most of the variance in the data within 50 km of the epicenter. On average, however, the scatter of the residuals is twice the data uncertainties, and in some areas, there is significant systematic misfit to either model. The co-seismic contributions of aftershocks are insufficient to explain this mismatch, indicating that the source geometry is more complicated than a single rectangular plane. C1 UNIV CALIF LOS ANGELES, DEPT EARTH & SPACE SCI, LOS ANGELES, CA 90024 USA. US GEOL SURVEY, MENLO PK, CA 94025 USA. MIT, DEPT EARTH ATMOSPHER & PLANETARY SCI, CAMBRIDGE, MA 02146 USA. UNIV CALIF SAN DIEGO, SCRIPPS INST OCEANOG, INST GEOPHYS & PLANETARY PHYS, LA JOLLA, CA 92093 USA. CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP Hudnut, KW (reprint author), US GEOL SURVEY, 525 S WILSON AVE, PASADENA, CA 91106 USA. RI Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010 OI Hudnut, Kenneth/0000-0002-3168-4797; NR 60 TC 59 Z9 62 U1 1 U2 2 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 USA SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 SU S BP S19 EP S36 PN B PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ652 UT WOS:A1996TZ65200003 ER PT J AU Somerville, P Saikia, C Wald, D Graves, R AF Somerville, P Saikia, C Wald, D Graves, R TI Implications of the Northridge earthquake for strong ground motions from thrust faults SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID SIMULATION AB The peak accelerations recorded on alluvial sites during the Northridge earthquake were about 50% larger than the median value predicted by current empirical attenuation relations at distances less than about 30 km. This raises the question of whether the ground motions from the Northridge earthquake are anomalous for thrust events or are representative of ground motions expected in future thrust earthquakes. Since the empirical data base contains few strong-motion records close to large-thrust earthquakes, it is difficult to assess whether the Northridge ground motions are anomalous based on recorded data alone. For this reason, we have used a broadband strong-motion simulation procedure to help assess whether the ground motions were anomalous. The simulation procedure has been validated against a large body of strong-motion data from California earthquakes, and so we expect it to produce accurate estimates of ground motions for any given rupture scenario, including blind-thrust events for which no good precedent existed in the strong-motion data base until the occurrence of the Northridge earthquake. The ground motions from the Northridge earthquake and our simulations of these ground motions have a similar pattern of departure from empirical attenuation relations for thrust earthquakes: the peak accelerations are at about the 84th percentile level for distances within 20 to 30 km and follow the median level for larger distances. This same pattern of departure from empirical attenuation relations was obtained in our simulations of the peak accelerations of an Elysian Park blind-thrust event prior to the occurrence of the Northridge earthquake. Since we are able to model this pattern with broadband simulations, and had done so before the Northridge earthquake occurred, this suggests that the Northridge strong-motion records are not anomalous and are representative of ground motions close to thrust faults. Accordingly, it seems appropriate to include these recordings in strong-motion data sets that are used to develop empirical ground-motion attenuation relations for thrust faults and to use this augmented data set as the basis for evaluating the need for modifications in design coefficients in the seismic provisions of building codes. C1 US GEOL SURVEY,PASADENA,CA 91106. RP Somerville, P (reprint author), WOODWARD CLYDE FED SERV,566 EL DORADO ST,PASADENA,CA 91101, USA. RI Graves, Robert/B-2401-2013 NR 33 TC 23 Z9 24 U1 2 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 SU S BP S115 EP S125 PN B PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ652 UT WOS:A1996TZ65200010 ER PT J AU Spudich, P Hellweg, M Lee, WHK AF Spudich, P Hellweg, M Lee, WHK TI Directional topographic site response at Tarzana observed in aftershocks of the 1994 Northridge, California, earthquake: Implications for mainshock motions SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID GROUND MOTION; AMPLIFICATION; RESONANCES AB The Northridge earthquake caused 1.78 g acceleration in the east-west direction at a site in Tarzana, California, located about 6 km south of the mainshock epicenter. The accelerograph was located atop a hill about 15-m high, 500-m long, and 130-m wide, striking about N78 degrees E. During the aftershock sequence, a temporary array of 21 three-component geophones was deployed in six radial lines centered on the accelerograph, with an average sensor spacing of 35 m. Station C00 was located about 2 m from the accelerograph, We inverted aftershock spectra to obtain average relative site response at each station as a function of direction of ground motion. We identified a 3.2-Hz resonance that is a transverse oscillation of the hill (a directional topographic effect). The top/base amplification ratio at 3.2 Hz is about 4.5 for horizontal ground motions oriented approximately perpendicular to the long axis of the hill and about 2 for motions parallel to the hill. This resonance is seen most strongly within 50 m of C00. Other resonant frequencies were also observed, A strong lateral variation in attenuation, probably associated with a fault, caused substantially lower motion at frequencies above 6 Hz at the east end of the hill. There may be some additional scattered waves associated with the fault zone and seen at both the base and top of the hill, causing particle motions (not spectral ratios) at the top of the hill to be rotated about 20 degrees away from the direction transverse to the hill. The resonant frequency, but not the amplitude, of our observed topographic resonance agrees well with theory, even for such a low hill. Comparisons of our observations with theoretical results indicate that the 3D shape of the hill and its internal structure are important factors affecting its response. The strong transverse resonance of the hill does not account for the large east-west mainshock motions. Assuming linear soil response, mainshock east-west motions at the Tarzana accelerograph were amplified by a factor of about 2 or less compared with sites at the base of the hill. Probable variations in surficial shear-wave velocity do not account for the observed differences among mainshock acceleration observed at Tarzana and at two different sites within 2 km of Tarzana. RP Spudich, P (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 26 TC 106 Z9 109 U1 1 U2 4 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 SU S BP S193 EP S208 PN B PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ652 UT WOS:A1996TZ65200015 ER PT J AU Wald, DJ Heaton, TH Hudnut, KW AF Wald, DJ Heaton, TH Hudnut, KW TI The slip history of the 1994 Northridge, California, earthquake determined from strong-motion, teleseismic, GPS, and leveling data SO BULLETIN OF THE SEISMOLOGICAL SOCIETY OF AMERICA LA English DT Article ID RUPTURE; INVERSION AB We present a rupture model of the Northridge earthquake, determined from the joint inversion of near-source strong ground motion recordings, P and SH teleseismic body waves, Global Positioning System (GPS) displacement vectors, and permanent uplift measured along leveling lines. The fault is defined to strike 122 degrees and dip 40 degrees to the south-southwest. The average rake vector is determined to be 101 degrees, and average slip is 1.3 m; the peak slip reaches about 3 m. Our estimate of the seismic moment is 1.3 +/- 0.2 x 10(26) dyne-cm (potency of 0.4 km(3)). The rupture area is small relative to the overall aftershock dimensions and is approximately 15 km along strike, nearly 20 km in the dip direction, and there is no indication of slip shallower than about 5 to 6 km. The up-dip, strong-motion velocity waveforms are dominated by large S-wave pulses attributed to source directivity and are comprised of at least 2 to 3 distinct arrivals (a few seconds apart). Stations at southern azimuths indicate two main S-wave arrivals separated longer in time (about 4 to 5 sec). These observations are best modeled with a complex distribution of subevents: The initial S-wave arrival comes from an asperity that begins at the hypocenter and extends up-dip and to the north where a second, larger subevent is centered (about 12 km away). The secondary S arrivals at southern azimuths are best fit with additional energy radiation from another high slip region at a depth of 19 km, 8 km west of the hypocenter. The resolving power of the individual data sets is examined by predicting the geodetic (GPS and leveling) displacements with the dislocation model determined from the waveform data, and vice versa, and also by analyzing how well the teleseismic solution predicts the recorded strong motions. The general features of the geodetic displacements are not well predicted from the model determined independently from the strong-motion data; likewise, the slip model determined from geodetic data does not adequately reproduce the strong-motion characteristics. Whereas a particularly smooth slip pattern is sufficient to satisfy the geodetic data, the strong-motion and teleseismic data require a more heterogeneous slip distribution in order to reproduce the velocity amplitudes and frequency content. Although the teleseismic model can adequately reproduce the overall amplitude and frequency content of the strong-motion velocity recordings, it does a poor job of predicting the geodetic data. Consequently, a robust representation of the slip history and heterogeneity requires a combined analysis of these data sets. RP Wald, DJ (reprint author), US GEOL SURVEY,525 S WILSON AVE,PASADENA,CA 91106, USA. RI Hudnut, Kenneth/B-1945-2009; Hudnut, Kenneth/G-5713-2010 OI Hudnut, Kenneth/0000-0002-3168-4797; NR 29 TC 179 Z9 188 U1 2 U2 21 PU SEISMOLOGICAL SOC AMER PI EL CERRITO PA PLAZA PROFESSIONAL BLDG, SUITE 201, EL CERRITO, CA 94530 SN 0037-1106 J9 B SEISMOL SOC AM JI Bull. Seismol. Soc. Amer. PD FEB PY 1996 VL 86 IS 1 SU S BP S49 EP S70 PN B PG 22 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ652 UT WOS:A1996TZ65200005 ER PT J AU Goldstein, RM Brigham, ME Stauffer, JC AF Goldstein, RM Brigham, ME Stauffer, JC TI Comparison of mercury concentrations in liver, muscle, whole bodies, and composites of fish from the Red River of the North SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article ID PRECAMBRIAN SHIELD LAKES; FRESHWATER FISHES; YELLOW PERCH; ACCUMULATION; MANITOBA; TOXICITY; ONTARIO; TROUT; PIKE AB Carp (Cyprinus carpio) from four sites and channel catfish (Ictalurus punctatus) from one site in the Red River of the North in 1994 were analyzed for total mercury content. In carp, mercury concentrations differed among liver, muscle, and whole bodies (0.11, 0.31, and 0.18 mu g/g wet weight, respectively), between large and small size groups, but not location. Mercury distribution in channel catfish tissues differed from that in carp. Liver and muscle tissue had similar mean concentrations; each was higher than whole-body concentrations (0.16, 0.18, and 0.11 mu g/g, respectively). Mercury concentrations were not significantly different between the two size groups of channel catfish. Weighted-mean mercury concentrations from seven individual fish agreed closely (usually within 10%) with concentrations determined on physical composites of the same fish. The ratio of mercury in whole bodies to mercury in muscle was similar for both carp and channel catfish. Historical data indicate that this ratio may be applicable to other species and locations. The ratio of mercury in livers to whole bodies and muscle differed between carp and channel catfish, which may reflect physiological differences between different trophic groups. RP Goldstein, RM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,2280 WOODALE DR,MOUNDS VIEW,MN 55112, USA. OI Brigham, Mark/0000-0001-7412-6800 NR 43 TC 71 Z9 77 U1 0 U2 12 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PD FEB PY 1996 VL 53 IS 2 BP 244 EP 252 DI 10.1139/cjfas-53-2-244 PG 9 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA UK632 UT WOS:A1996UK63200002 ER PT J AU Jiang, SY Palmer, MR AF Jiang, SY Palmer, MR TI Mn-rich ilmenite from the Sullivan Pb-Zn-Ag deposit, British Columbia SO CANADIAN MINERALOGIST LA English DT Article DE manganese; ilmenite; hydrothermal; metamorphic; Pb-Zn-Ag deposit; Sullivan mine; British Columbia ID SOLID-SOLUTION; BROKEN-HILL; ECANDREWSITE; METAMORPHISM; AUSTRALIA; ROCKS AB Electron-microprobe analyses of 76 ilmenite grains from 13 locations in the footwall, hanging wall, and ore zone of the Sullivan Pb-Zn-Ag deposit, Kimberley, British Columbia, and from regionally developed tourmalinite of the Middle Proterozoic Aldridge Formation show two different modes that reflect two stages of formation. The first stage of ilmenite formation occurred as a result of, greenschist-facies regional metamorphism, which also produced the associated Mn-rich garnet. Ilmenite from this stage forms inclusions within garnet and has a relatively low Mn content (<5.5 wt% MnO), owing to the preferential partitioning of Mn into the garnet. A second metamorphic or hydrothermal event resulted in the formation of ilmenite-bearing veinlets (+ chlorite + quartz + sulfides) that cut garnet and associated biotite. This latter type of ilmenite has a higher Mn content (up to 16.7 wt% MnO) that reflects remobilization of Mn within the local environment. Both types of Mn-rich ilmenite are considered to be derived from Mn originally concentrated in pools of dense brine that formed during synsedimentary, submarine-exhalative mineralization. C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP Jiang, SY (reprint author), UNIV BRISTOL,DEPT GEOL,WILLS MEM BLDG,BRISTOL BS8 1RJ,AVON,ENGLAND. RI Palmer, Martin/I-6765-2012 OI Palmer, Martin/0000-0003-1660-3714 NR 23 TC 7 Z9 8 U1 1 U2 4 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD FEB PY 1996 VL 34 BP 29 EP 36 PN 1 PG 8 WC Mineralogy SC Mineralogy GA UC457 UT WOS:A1996UC45700004 ER PT J AU Roberts, AC Grice, JD Groat, LA Criddle, AJ Gault, RA Erd, RC Moffatt, EA AF Roberts, AC Grice, JD Groat, LA Criddle, AJ Gault, RA Erd, RC Moffatt, EA TI Jensenite, Cu3Te6+O6 center dot 2H(2)O, a new mineral species from the Centennial Eureka mine, Tintic district, Juab county, Utah SO CANADIAN MINERALOGIST LA English DT Article DE jensenite; new mineral species; tricopper tellurate dihydrate; X-ray data; electron-microprobe data; reflectance data; Centennial Eureka mine; Juab County; Utah AB Jensenite, ideally Cu3Te6+O6 . 2H(2)O, is monoclinic, P2(1)/n (14), with unit-cell parameters refined from powder data: a 9.204(2), b 9.170(2), c 7.584(1) Angstrom, beta 102.32(3)degrees, V 625.3(3) Angstrom(3), a:b:c 1.0037:1:0.8270, Z = 4. The strongest six reflections of the X-ray powder-diffraction pattern [d in Angstrom(I)(hkl)] are: 6.428(100)((1) over bar 01,110), 3.217(70)((2) over bar 02), 2.601(40)(202), 2.530(50)(230), 2.144(35)((3) over bar 31) and 1.750(35)((4) over bar 32). The mineral is found on the dumps of the Centennial Eureka mine, Juab County, Utah, where it occurs as isolated crystals or as groups of crystals on drusy white quartz. Associated minerals are mcalpineite, xocomecatlite and unnamed Cu(Mg,Cu,Fe,Zn)(2)Te6+O6 . 6H(2)O. Individual crystals of jensenite are subhedral to euhedral, and form simple rhombs that are nearly equant. Some crystals are slightly elongate [101], with a length-to-width ratio up to 2:1. The largest crystal is approximately 0.4 mm in size; the average size is between 0.1 and 0.2 mm. Cleavage {(1) over bar 01} fair. Forms are: {(1) over bar 01} major; {110} medium; {100} minor; (301), {201}, {203}, {(1) over bar 02}, {010} very small. The mineral is transparent, emerald green, with a less intense streak of the same color and an uneven fracture. Jensenite is adamantine, brittle and nonfluorescent; H (Mohs) 3-4; D (calc.) 4.78 for the idealized formula, 4.76 g/cm(3) for the empirical formula. In a polished section, jensenite is very weakly bireflectant and nonpleochroic. In reflected plane-polarized light in air, it is a nondescript grey, and in oil, it is a much darker grey in color with a brownish tint, with ubiquitous bright green internal reflections. Anisotropy is not detectable. Measured values of reflectance, in air and in oil, are tabulated. Electron-microprobe analyses yielded CuO 50.91, ZnO 0.31, TeO3 38.91, H2O (calc.) [8.00], total [98.13] wt.%. The empirical formula, derived from crystal-structure analysis and electron-microprobe analyses, is (Cu2.92Zn0.02Sigma 2.94Te1.016+O5.97. 2.03H(2)O), based on O = 8. The mineral name honors Martin C. Jensen, Reno, Nevada, who discovered the mineral. C1 CANADIAN MUSEUM NAT,DIV RES,OTTAWA,ON K1P 6P4,CANADA. UNIV BRITISH COLUMBIA,DEPT GEOL SCI,VANCOUVER,BC V6T 1Z4,CANADA. NAT HIST MUSEUM,DEPT MINERAL,LONDON SW7 5BD,ENGLAND. US GEOL SURVEY,MENLO PK,CA 94025. CANADIAN CONSERVAT INST,OTTAWA,ON K1A 0M5,CANADA. RP Roberts, AC (reprint author), GEOL SURVEY CANADA,601 BOOTH ST,OTTAWA,ON K1A 0E8,CANADA. NR 10 TC 12 Z9 12 U1 1 U2 1 PU MINERALOGICAL ASSOC CANADA PI NEPEAN PA CITYVIEW 78087, NEPEAN ON K2G 5W2, CANADA SN 0008-4476 J9 CAN MINERAL JI Can. Mineral. PD FEB PY 1996 VL 34 BP 49 EP 54 PN 1 PG 6 WC Mineralogy SC Mineralogy GA UC457 UT WOS:A1996UC45700006 ER PT J AU Modde, T Burnham, KP Wick, EJ AF Modde, T Burnham, KP Wick, EJ TI Population status of the razorback sucker in the middle Green River (USA) SO CONSERVATION BIOLOGY LA English DT Article ID LOWER COLORADO RIVER; XYRAUCHEN-TEXANUS; HABITAT; POWER; BASIN; UTAH AB The razorback sucker, Xyrauchen texanus, in the middle Green River (U.S.A.) has been described as a static population consisting of old individuals that will eventually disappear through attrition. Capture data between 1980 and 1992 indicated a constant length frequency despite a slow but positive Growth rate of individual fish. Abundance and survival estimates indicated that the population of razorback sucker in the middle Green River is precariously low brat dynamic. Although high variation existed among survival estimates, no significant decrease in the population between 1982 and 1992 could be detected. The low level of recruitment occurring in the razorback sucker population of the middle Green River was related to high-flow years, indicating that floodplain habitats may be necessary for survival of the species. C1 NATL BIOL SERV, COLORADO COOPERAT FISH & WILDLIFE RES UNIT, FT COLLINS, CO 80523 USA. NATL PK SERV, COLORADO COOPERAT RES UNIT, FT COLLINS, CO 80523 USA. RP US FISH & WILDLIFE SERV, COLORADO RIVER FISH PROJECT, 266 W 100 N, VERNAL, UT 84078 USA. NR 41 TC 39 Z9 40 U1 1 U2 6 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0888-8892 EI 1523-1739 J9 CONSERV BIOL JI Conserv. Biol. PD FEB PY 1996 VL 10 IS 1 BP 110 EP 119 DI 10.1046/j.1523-1739.1996.10010110.x PG 10 WC Biodiversity Conservation; Ecology; Environmental Sciences SC Biodiversity & Conservation; Environmental Sciences & Ecology GA TX280 UT WOS:A1996TX28000020 ER PT J AU Barnes, CG Petersen, SW Kistler, RW Murray, R Kays, MA AF Barnes, CG Petersen, SW Kistler, RW Murray, R Kays, MA TI Source and tectonic implications of tonalite-trondhjemite magmatism in the Klamath Mountains SO CONTRIBUTIONS TO MINERALOGY AND PETROLOGY LA English DT Article ID TRACE-ELEMENT GEOCHEMISTRY; SOUTHWESTERN OREGON; JOSEPHINE OPHIOLITE; SUBDUCTED LITHOSPHERE; ARCHEAN TRONDHJEMITES; NORTHERN CALIFORNIA; ZIRCON SATURATION; DACITE GENESIS; STABLE ISOTOPE; ARC AB In the Klamath Mountains, voluminous tonalite-trondhjemite magmatism was characteristic of a short period of time from about 144 to 136 Ma (Early Cretaceous). It occurred about 5 to 10 m.y. after the similar to 165 to 159 Ma Josephine ophiolite was thrust beneath older parts of the province during the Nevadan orogeny (thrusting from similar to 155 to 148 Ma). The magmatism also corresponds to a period of slow or no subduction. Most of the plutons crop out in the south-central Klamath Mountains in California, but one occurs in Oregon at the northern end of the province. Compositionally extended members of the suite consist of precursor gabbroic to dioritic rocks followed by later, more voluminous tonalitic and trondhjemitic intrusions. Most plutons consist almost entirely of tonalite and trondhjemite. Poorly-defined concentric zoning is common. Tonalitic rocks are typically of the low-Al type but trondhjemites are generally of the high-Al type, even those that occur in the same pluton as low-Al tonalite. The suite is characterized by low abundances of K2O, Rb, Zr, and heavy rare earth elements. Sr contents are generally moderate (similar to 450 ppm) by comparison with Sr-rich are lavas interpreted to be slab melts (up to 2000 ppm). Initial Sr-87/Sr-86, delta(18)O, and epsilon(Nd) are typical of mantle-derived magmas or of crustally-derived magmas with a metabasic source. Compositional variation within plutons can be modeled by variable degrees of partial melting of a heterogeneous metabasaltic source (transitional mid-ocean ridge to island are basalt), but not by fractional crystallyzation of a basaltic parent. Melting models require a residual assemblage of dinopyroxene+garnet+/-plagioclase+/-amphibole; residual plagioclase suggests a deep crustal origin rather than melting of a subducted slab. Such models are consistent with the metabasic part of the Josephine ophiolite as the source. Because the Josephine ophiolite was at low T during Nevadan thrusting, an external heat source was probably necessary to achieve significant degrees of melting; heat was probably extracted from mantle-derived basaltic melts, which were parental to the mafic precursors of the tonalite-trondhjemite suite. Thus, under appropriate tectonic and thermal conditions, heterogeneous mafic crustal rocks can melt to form both low- and high-Al tonalitic and trondhjemitic magmas; slab melting is not necessary. C1 WESTINGHOUSE HANFORD CO,RICHLAND,WA 99352. US GEOL SURVEY,MENLO PK,CA 94025. UNIV OREGON,DEPT GEOL SCI,EUGENE,OR 97403. RP Barnes, CG (reprint author), TEXAS TECH UNIV,DEPT GEOSCI,LUBBOCK,TX 79409, USA. NR 71 TC 82 Z9 92 U1 0 U2 10 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0010-7999 J9 CONTRIB MINERAL PETR JI Contrib. Mineral. Petrol. PD FEB PY 1996 VL 123 IS 1 BP 40 EP 60 DI 10.1007/s004100050142 PG 21 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA TW382 UT WOS:A1996TW38200003 ER PT J AU Baker, J Snee, L Menzies, M AF Baker, J Snee, L Menzies, M TI A brief Oligocene period of flood volcanism in Yemen: Implications for the duration and rate of continental flood volcanism at the Afro-Arabian triple junction SO EARTH AND PLANETARY SCIENCE LETTERS LA English DT Article DE Yemen; Ethiopia; triple junctions; flood basalts; K/Ar; Ar-40/Ar-39; Oligocene ID CRETACEOUS TERTIARY BOUNDARY; THOLEIITIC MAGMATISM; TRIASSIC BOUNDARY; ETHIOPIAN PLATEAU; BASALT PROVINCE; RAPID ERUPTION; SIBERIAN TRAPS; MANTLE SOURCES; AGE; RIFT AB Ar-40/Ar-39 dating of mineral separates and whole-rock (WR) samples has established that basaltic continental flood volcanism (CFV) began between 30.9 and 29.2 Ma in northwestern and southwestern Yemen, respectively. Rhyolitic volcanism commenced at 29.3-29.0 Ma throughout Yemen. Lower basaltic lavas were erupted every 10-100 kyr, whereas upper bimodal volcanic units were erupted every 100-500 kyr, which reflects generation of rhyolitic magmas from basalts that resided for longer periods in lithospheric magma chambers than during the early phase of exclusively mafic magmatism. The youngest dated flood volcanic units were erupted between 26.9 and 26.5 Ma throughout Yemen. The duration of preserved CFV defined by Ar-40/Ar-39 dating (4.4 myr) contrasts with the wide range of WR K-Ar dates previously obtained in Yemen (> 50 myr). Ar-40/Ar-39 step-heating studies of WR samples has shown that this discrepancy is due to the disturbed Ar systematics of volcanic samples. Most samples have experienced post-crystallization loss of radiogenic Ar and/or contain excess Ar, with only ca. 25% of the WR K-Ar dates within 1-2 myr of true crystallization ages. WR K-Ar data can be screened for reliability using the radiogenic Ar yield and K-40/Ar-36. ratio, which reflect the Ar retentivity of the sample, the likelihood that alteration has disturbed a sample's Ar systematics, and the susceptibility of the sample to a finite amount of Ar loss or the presence of a finite amount of excess Ar. Examination of existing WR K-Ar data in the Ethiopian part of this flood volcanic province, using these parameters, suggests that much of these data are also misleading. Two phases of flood volcanism are inferred in Ethiopia and Eritrea at 38-30 Ma and ca. 20 Ma. The older phase is equivalent to that in Yemen, and is consistent with the progression in basal volcanic ages obtained in Yemen moving from north to south. The younger phase is related to the onset of upper crustal extension and incipient Red Sea-Gulf of Aden rifting. The sequence of events - surface uplift (?), flood magmatism and subsequent upper crustal extension - in Yemen is consistent with the involvement of a mantle plume at the Afro-Arabian triple junction. However, the overall eruption rate for this flood volcanic province is only 0.03 km(3)/yr, much slower than that postulated for other plume-related provinces such as the Deccan or Siberian Traps, but perhaps comparable to the Parand-Etendeka province, which also contains significant amounts of rhyolitic volcanic products like those of Yemen-Ethiopia. The highly variable eruption rates in individual provinces must reflect the very different character of individual plumes, or the control of lithospheric structure and plate tectonic stresses on the surface manifestations of plumes. The long duration of CFV and large amounts of rhyolitic volcanism at the Afro-Arabian triple junction may be attributed to the relatively slow separation of the African and Arabian plates compared with, for example, the rifting of India and the Deccan Traps. C1 US GEOL SURVEY,BRANCH ISOTOPE GEOL,DENVER,CO 80225. RP Baker, J (reprint author), UNIV LONDON ROYAL HOLLOWAY & BEDFORD NEW COLL,DEPT GEOL,EGHAM TW20 0EX,SURREY,ENGLAND. RI Baker, Joel/A-3477-2008; OI Baker, Joel/0000-0001-6371-5060 NR 51 TC 167 Z9 167 U1 2 U2 6 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0012-821X J9 EARTH PLANET SC LETT JI Earth Planet. Sci. Lett. PD FEB PY 1996 VL 138 IS 1-4 BP 39 EP 55 DI 10.1016/0012-821X(95)00229-6 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TZ993 UT WOS:A1996TZ99300004 ER PT J AU Bethke, R Taylor, M Amstrup, S Messier, F AF Bethke, R Taylor, M Amstrup, S Messier, F TI Population delineation of polar bears using satellite collar data SO ECOLOGICAL APPLICATIONS LA English DT Article DE boundaries; Canadian Arctic; cluster analysis; harmonic contours; home ranger; polar bears; population delineation; radio collar; satellite data; spatial utilization ID FEMALE AB To produce reliable estimates of the size or vital rates of a given population, it is important that the boundaries of the population under study are clearly defined. This is particularly critical for large, migratory animals where levels of sustainable harvest are based on these estimates, and where small errors may have serious long-term consequences for the population. Once populations are delineated, rates of exchange between adjacent populations can be determined and accounted/corrected for when calculating abundance (e.g., based on mark-recapture data). Using satellite radio-collar locations for polar bears in the western Canadian Arctic, we illustrate one approach to delineating wildlife populations that integrates cluster analysis methods for determining group membership with home range plotting procedures to define spatial utilization. This approach is flexible with respect to the specific procedures used and provides an objective and quantitative basis for defining population boundaries. C1 US FISH & WILDLIFE SERV,ANCHORAGE,AK 99503. UNIV SASKATCHEWAN,DEPT BIOL,SASKATOON,SK S7N 0W0,CANADA. RP Bethke, R (reprint author), GOVT NW TERR,DEPT RENEWABLE RESOURCES,WILDLIFE MANAGEMENT DIV,600,5102-50 AVE,YELLOWKNIFE,NT X1A 3S8,CANADA. NR 20 TC 63 Z9 66 U1 2 U2 16 PU ECOLOGICAL SOC AMER PI WASHINGTON PA 2010 MASSACHUSETTS AVE, NW, STE 400, WASHINGTON, DC 20036 SN 1051-0761 J9 ECOL APPL JI Ecol. Appl. PD FEB PY 1996 VL 6 IS 1 BP 311 EP 317 DI 10.2307/2269574 PG 7 WC Ecology; Environmental Sciences SC Environmental Sciences & Ecology GA TU567 UT WOS:A1996TU56700038 ER PT J AU Thurman, EM Goolsby, DA Aga, DS Pomes, ML Meyer, MT AF Thurman, EM Goolsby, DA Aga, DS Pomes, ML Meyer, MT TI Occurrence of alachlor and its sulfonated metabolite in rivers and reservoirs of the midwestern United States: The importance of sulfonation in the transport of chloroacetanilide herbicides SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; SURFACE-WATER; SOIL; IMMUNOASSAY AB Alachlor and its metabolite, 2-[(2',6'-diethylphenyl)(methoxymethyl)amino]-2-oxoethanesulfonate (ESA), were identified in 76 reservoirs in the midwestern United States using immunoassay, liquid chromatography, and gas chromatography/mass spectrometry. The median concentration of ESA (0.48 mu g/L) exceeded the med lan concentration of alachlor (0.05 mu g/L), with highest values in the upper Midwest. ESA also was detected in the Mississippi River from the mouth to the headwaters at concentrations of 0.2-1.5 mu g/L, exceeding the concentration of alachlor. In a field runoff study, alachlor rapidly formed ESA. It is hypothesized that a glutathione conjugate forms, which later oxidizes in soil to ESA. The removal of the chlorine atom lessens the toxicity of the parent compound and increases runoff potential. It is hypothesized further that sulfonic acid metabolites of other chloroacetanilides, including acetochlor, butachlor, metolachlor, and propachlor, also occur in surface water. RP Thurman, EM (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. RI Thurman, Earl/B-5131-2011; OI Meyer, Michael/0000-0001-6006-7985 NR 28 TC 102 Z9 108 U1 3 U2 14 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1996 VL 30 IS 2 BP 569 EP 574 DI 10.1021/es950341q PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TT496 UT WOS:A1996TT49600048 ER PT J AU Aga, DS Thurman, EM Yockel, ME Zimmerman, LR Williams, TD AF Aga, DS Thurman, EM Yockel, ME Zimmerman, LR Williams, TD TI Identification of a new sulfenic acid metabolite of metolachlor in soil SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID TRANSFORMATION; GLUTATHIONE AB An ethanesulfonic acid metabolite of metolachlor (metolachlor ESA) was identified in soil-sample extracts by negative-ion, fast-atom bombardment mass spectrometry (FAB-MS) and FAB tandem mass spectrometry (FAB-MS/MS). Product-ion fragments from MS/MS analysis of the deprotonated molecular ion of metolachlor ESA in the soil extract can be reconciled with the structure of the synthesized standard. The elemental compositions of the (M - H)(-) ions of the metolachlor ESA standard and the soil-sample extracts were confirmed by high-resolution mass spectrometry. A dissipation study revealed that metolachlor ESA is formed in soil under field conditions corresponding to a decrease in the concentration of the parent herbicide, metolachlor. The identification of the sulfonated metabolite of metolachlor suggests that the glutathione conjugation pathway is a common detoxification pathway shared by chloroacetanilide herbicides. C1 UNIV KANSAS,MASS SPECTROMETRY LAB,LAWRENCE,KS 66045. RP Aga, DS (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. RI Thurman, Earl/B-5131-2011; Zimmerman, Lisa/K-6674-2012 NR 17 TC 67 Z9 68 U1 1 U2 12 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD FEB PY 1996 VL 30 IS 2 BP 592 EP 597 DI 10.1021/es9503600 PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TT496 UT WOS:A1996TT49600051 ER PT J AU Pereira, WE Domagalski, JL Hostettler, FD Brown, LR Rapp, JB AF Pereira, WE Domagalski, JL Hostettler, FD Brown, LR Rapp, JB TI Occurrence and accumulation of pesticides and organic contaminants in river sediment, water and clam tissues from the San Joaquin River and tributaries, California SO ENVIRONMENTAL TOXICOLOGY AND CHEMISTRY LA English DT Article DE water quality; pesticides; sediments; clams; bioaccumulation ID TECHNICAL CHLORDANE; MASS-SPECTROMETRY; BIOACCUMULATION; RESIDUES AB A study was conducted in 1992 to assess the effects of anthropogenic activities and land use on the water quality of the San Joaquin River and its major tributaries. This study focused on pesticides and organic contaminants, looking at distributions of contaminants in water, bed and suspended sediment, and the bivalve Corbicula fluminea. Results indicated that this river system is affected by agricultural practices and urban runoff. Sediments from Dry Creek contained elevated concentrations of polycyclic aromatic hydrocarbons (PAHs), possibly derived from urban runoff from the city of Modesto; suspended sediments contained elevated amounts of chlordane. Trace levels of triazine herbicides atrazine and simazine were present in water at most sites. Sediments, water, and bivalves from Orestimba Creek, a westside tributary draining agricultural areas, contained the greatest levels of DDT (1,1,1-trichloro-2,2-bis[p-chlorophenyl]ethane) and its degradates DDD (1,1-dichloro-2,2-bis[p-chlorophenyl]ethylene) and DDE(1, 1-dichloro-2,2-bis[p-chlorophenyl]ethyle). Sediment adsorption coefficients (K-alpha, and bioconcentration factors (BCF) in Corbicula of DDT, DDD, and DDE at Orestimba Creek were greater than predicted values. Streams of the western San Joaquin Valley can potentially transport significant amounts of chlorinated pesticides to the San Joaquin River, the delta, and San Francisco Bay. Organochlorine compounds accumulate in bivalves and sediment and may pose a problem to other biotic species in this watershed. RP Pereira, WE (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 38 TC 101 Z9 110 U1 0 U2 29 PU SETAC PRESS PI PENSACOLA PA 1010 NORTH 12TH AVE, PENSACOLA, FL 32501-3370 SN 0730-7268 J9 ENVIRON TOXICOL CHEM JI Environ. Toxicol. Chem. PD FEB PY 1996 VL 15 IS 2 BP 172 EP 180 DI 10.1897/1551-5028(1996)015<0172:OAAOPA>2.3.CO;2 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TU207 UT WOS:A1996TU20700016 ER PT J AU Carter, JL Fend, SV Kennelly, SS AF Carter, JL Fend, SV Kennelly, SS TI The relationships among three habitat scales and stream benthic invertebrate community structure SO FRESHWATER BIOLOGY LA English DT Article ID RIVER CONTINUUM CONCEPT; MACROINVERTEBRATE COMMUNITIES; ENVIRONMENTAL-FACTORS; LOTIC ECOSYSTEMS; UPLAND STREAMS; NORTH-AMERICA; CLASSIFICATION; PATTERNS; GEOMORPHOLOGY; ZONATION AB 1. The relationships between three habitat scales and lotic invertebrate species composition were investigated for the 15 540 km(2) Yakima River basin in south-central Washington, U.S.A. 2. The three spatial scales were sample (the sampled riffle), reach (a length of ten-twenty stream widths) and segment (a length of stream of nearly uniform slope and valley form having no change in stream order). 3. Physical variables were highly correlated between scales and expressed a relationship between altitude, basin form and small-scale physical structure. 4. Multiple discriminant function analyses indicated that segment- and reach-scale variables discriminated among species-defined groups better than sample-scale variables. 5. Species composition varied along a complex altitudinal gradient of changing basin form and resultant land use. 6. There was no clear relationship between species richness and altitude on a site basis. However, when viewed at the basin scale, maximum richness was observed at the transition between montane and valley sites. C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 62 TC 63 Z9 69 U1 0 U2 15 PU BLACKWELL SCIENCE LTD PI OXFORD PA OSNEY MEAD, OXFORD, OXON, ENGLAND OX2 0EL SN 0046-5070 J9 FRESHWATER BIOL JI Freshw. Biol. PD FEB PY 1996 VL 35 IS 1 BP 109 EP 124 DI 10.1046/j.1365-2427.1996.d01-450.x PG 16 WC Marine & Freshwater Biology SC Marine & Freshwater Biology GA TW366 UT WOS:A1996TW36600010 ER PT J AU Ryder, G Delano, JW Warren, PH Kallemeyn, GW Dalrymple, GB AF Ryder, G Delano, JW Warren, PH Kallemeyn, GW Dalrymple, GB TI A glass spherule of questionable impact origin from the Apollo 15 landing site: Unique target mare basalt SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID MOON ROCKS; PETROGENESIS; LIQUIDS; KREEP; AGE AB A 6 mm-diameter dark spherule, 15434,28, from the regolith on the Apennine Front at the Apollo 15 landing site has a homogeneous glass interior with a 200 mu m-thick rind of devitrified or crystallized melt. The rind contains abundant small fragments of Apollo 15 olivine-normative mare basalt and rare volcanic Apollo 15 green glass. The glass interior of the spherule has the chemical composition, including a high FeO content and high CaO/Al2O3, of a mare basalt. Whereas the major element and Sc, Ni, and Co abundances are similar to those of low-Ti mare basalts, the incompatible elements and Sr abundances are similar to those of high-Ti mare basalts. The relative abundance patterns of the incompatible trace elements are distinct from any other lunar mare basalts or KREEP; among these distinctions are a much steeper slope of the heavy rare earth elements. The 15434,28 glass has abundances of the volatile element Zn consistent with both impact glasses and crystalline mare basalts, but much lower than in glasses of mare volcanic origin. The glass contains siderophile elements such as Ir in abundances only slightly higher than accepted lunar indigenous levels, and some, such as Au, are just below such upper limits. The age of the glass, determined by the Ar-40/Ar-39 laser incremental heating technique, is 1647 +/- 11 Ma (2 sigma); it is expressed as an age spectrum of seventeen steps over 96% of the Ar-39 released, unusual for an impact glass. Trapped argon is negligible. The undamaged nature of the sphere demonstrates that it must have spent most of its life buried in regolith; Ar-38 cosmic ray exposure data suggest that it was buried at less than 2m but more than a few centimeters ifa single depth is appropriate. That the spherule solidified to a glass is surprising; for such a mare composition, cooling at about 50 degrees C s(-1) is required to avoid crystallization, and barely attainable in such a large spherule. The low volatile abundances, slightly high siderophile abundances, and the young age are perhaps all most consistent with an impact origin, but nonetheless not absolutely definitive. The 15434,28 glass is distinct from the common yellow impact glasses at the Apollo 15 landing site, in particular in its lower abundances of incompatible elements and much younger age. If we accept an impact origin, then the trace element relative abundances preclude both typical KREEP and the common Apollo 15 yellow impact glass from contributing more than a few percent of the incompatible elements to potential mixtures. The melted part of any target must have consisted almost entirely of a variety (or varieties) of mare basalt or glass distinct from any known mare basalts or glasses, including Apollo 15 yellow volcanic glass, or mixtures of them. However, the rind inclusions, similar to materials of local origin, do suggest a source near the Apollo 15 landing site. An impact melt cannot have dissolved much, if any, of such inclusions. A lack of regolith materials in the rind and in the melt component suggest an immature source terrain. Thus, even for an impact origin, there is the possibility (though not requirement) that the volcanic target is younger than most mare plains. The crater Hadley C, 25 km away, is a potential source. If the 15434,28 glass is instead directly of volcanic origin, it represents an extremely young mare magma of a type previously undiscovered on the Moon. C1 SUNY ALBANY,DEPT GEOL SCI,ALBANY,NY 12222. UNIV CALIF LOS ANGELES,INST GEOPHYS & PLANETARY PHYS,LOS ANGELES,CA 90024. US GEOL SURVEY,MENLO PK,CA 94025. RP Ryder, G (reprint author), LUNAR & PLANETARY INST,CTR ADV SPACE STUDIES,3600 BAY AREA BLVD,HOUSTON,TX 77058, USA. NR 59 TC 5 Z9 5 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD FEB PY 1996 VL 60 IS 4 BP 693 EP 710 DI 10.1016/0016-7037(95)00420-3 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TV810 UT WOS:A1996TV81000011 ER PT J AU Nelson, AR Jennings, AE Kashima, K AF Nelson, AR Jennings, AE Kashima, K TI An earthquake history derived from stratigraphic and microfossil evidence of relative sea-level change at Coos Bay, southern coastal Oregon SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID CASCADIA SUBDUCTION ZONE; WASHINGTON-STATE; TIDAL MARSHES; RISE; ZONATION; DIATOMS AB Much of the uncertainty in determining the number and magnitude of past great earthquakes in the Cascadia subduction zone of western North America stems from difficulties in using estuarine stratigraphy to infer the size and rate of late Holocene relative sea-level changes, A sequence of interbedded peaty and muddy intertidal sediment beneath a small, protected tidal marsh in a narrow inlet of Coos Bay, Oregon, records ten rapid to instantaneous rises in relative sea level, Each rise is marked by a contact that records an upward transition from peaty to muddy sediment, But only two contacts, dating from about 1700 and 2300 yr ago, show the site-nide extent and abrupt changes in lithology and foraminiferal and diatom assemblages that can be used to infer at least half a meter of sudden coseismic subsidence, Although the characteristics of a third, gradual contact do not differ from those of some contacts produced by nonseismic processes, regional correlation with other similar sequences and high-precision C-14 dating suggest that the third contact records a great plate-boundary earthquake about 300 yr ago, A fourth contact formed too slowly to have been caused by coseismic subsidence, Because lithologic and microfossil data are not sufficient to distinguish a coseismic from a nonseismic origin for the other six peat-mud contacts, we cannot determine earthquake recurrence intervals at this site, Similar uncertainties in great earthquake recurrence and magnitude prevail at similar sites elsewhere in the Cascadia subduction zone, except those with sequences showing changes in fossils indicative of >1 m of sudden subsidence, sand sheets deposited by tsunamis, or liquefaction features. C1 UNIV COLORADO,INST ARCTIC & ALPINE RES,BOULDER,CO 80309. KYUSHU UNIV,DEPT EARTH & PLANETARY SCI,FUKUOKA 810,JAPAN. RP Nelson, AR (reprint author), US GEOL SURVEY,BOX 25046,MS 966,DENVER,CO 80225, USA. NR 64 TC 74 Z9 76 U1 2 U2 6 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD FEB PY 1996 VL 108 IS 2 BP 141 EP 154 DI 10.1130/0016-7606(1996)108<0141:AEHDFS>2.3.CO;2 PG 14 WC Geosciences, Multidisciplinary SC Geology GA TT579 UT WOS:A1996TT57900002 ER PT J AU Ishman, SE Polyak, LV Poore, RZ AF Ishman, SE Polyak, LV Poore, RZ TI Amerasian Arctic Ocean SO GEOLOGY LA English DT Article ID BENTHIC FORAMINIFERA; SEA AB Four sediment cores collected from the Northwind and Mendeleyev ridges, Arctic Ocean, from 1089 m to 1909 m water depth, provide an oceanographic record extending back into the Matuyama reversed polarity chron, Benthic foraminiferal analyses show four prominent assemblage zones: Bolivina arctica, Cassidulina teretis, Bulimina aculeata, and Oridorsalis tener from the upper Matuyama reversed polarity chronozone through the Brunhes normal polarity chronozone. These assemblage zones represent depth-dependent benthic foraminiferal biofacies changes associated with oceanographic events that occurred in the Amerasian basin at similar to 780 and 300 ka, and indicate oceanographic influence from the North Atlantic. Recognition of these benthic assemblage zones in Arctic cores from the Alpha Ridge indicates that the benthic foraminiferal zonations in intermediate to deep water (>1000 m) Arctic cores may be more useful than preexisting lithostratigraphic zonations and should provide important information pertaining to the Quaternary paleoceanographic evolution of the Arctic Ocean. C1 BYRD POLAR RES CTR,COLUMBUS,OH 43210. US GEOL SURVEY,RESTON,VA 22092. RP Ishman, SE (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 22 TC 24 Z9 29 U1 0 U2 2 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD FEB PY 1996 VL 24 IS 2 BP 139 EP 142 DI 10.1130/0091-7613(1996)024<0139:EROQOC>2.3.CO;2 PG 4 WC Geology SC Geology GA TT580 UT WOS:A1996TT58000011 ER PT J AU Li, Y Craven, J Schweig, ES Obermeier, SF AF Li, Y Craven, J Schweig, ES Obermeier, SF TI Sand boils induced by the 1993 Mississippi River flood: Could they one day be misinterpreted as earthquake-induced liquefaction? SO GEOLOGY LA English DT Article AB In areas that are seismically active but lacking clear surficial faulting, many paleoearthquake studies depend on the interpretation of ancient liquefaction features (sand blows) as indicators of prehistoric seismicity. Sand blows, however, can be mimicked by nonseismic sand boils formed by water seeping beneath levees during floods. We examined sand boils induced by the Mississippi River flood of 1993 in order to compare their characteristics with sand blows of the New Madrid earthquakes of 1811-1812. We found a number of criteria that allow a distinction between the two types of deposits. (1) Earthquake-induced liquefaction deposits are broadly distributed about an epicentral area, whereas flood-induced sand boils are limited to a narrow band along a river's levee. (2) The conduits of most earthquake-induced sand blows are planar dikes, whereas the conduits of flood-induced sand boils are most commonly tubular. (3) Depression of the preearthquake ground surface is usual for sand blows, not for sand boils. (4) Flood-induced sand boils tend to be better sorted and much finer than sand-blow deposits. (5) Source beds for earthquake-induced deposits occur at a wide range of depths, whereas the source bed for sand boils is always near surface, (6) Materials removed from the walls surrounding the vent of a sand blow are seen inside sand blows, but are rarely seen inside sand boils. In general, flood-induced sand boils examined are interpreted to represent a less-energetic genesis than earthquake-induced liquefaction. C1 US GEOL SURVEY, MEMPHIS, TN 38152 USA. US GEOL SURVEY, RESTON, VA 22092 USA. RP MEMPHIS UNIV, CTR EARTHQUAKE RES & INFORMAT, MEMPHIS, TN 38152 USA. NR 22 TC 51 Z9 54 U1 1 U2 7 PU GEOLOGICAL SOC AMER, INC PI BOULDER PA PO BOX 9140, BOULDER, CO 80301-9140 USA SN 0091-7613 EI 1943-2682 J9 GEOLOGY JI Geology PD FEB PY 1996 VL 24 IS 2 BP 171 EP 174 DI 10.1130/0091-7613(1996)024<0171:SBIBTM>2.3.CO;2 PG 4 WC Geology SC Geology GA TT580 UT WOS:A1996TT58000019 ER PT J AU Wieczorek, GF Jager, S AF Wieczorek, GF Jager, S TI Triggering mechanisms and depositional rates of postglacial slope-movement processes in the Yosemite valley, California SO GEOMORPHOLOGY LA English DT Article ID NATIONAL-PARK AB We examined information collected from 395 reports of slope-movement events during about the past 150 years in Yosemite National Park, central Sierra Nevada, California, to identify the most prevalent types of slope movements and their triggering mechanisms. Rock slides and rock falls have been more numerous than debris slides, debris flows, and miscellaneous slumps. Rock falls have produced the largest cumulative volume of deposits. About half of slope movements had unreported or unrecognized triggering events. Earthquakes and rain storms individually accounted for the greatest cumulative volumes of deposits from recognized triggers of all types of historical slope movements; snowmelt, human activities and freeze-thaw conditions accounted for only a small proportion of the volumes from reported triggers. A comparison of the historical and postglacial average annual rates of deposition from slope-movement processes in a portion of the Yosemite Valley indicates that, during the period 1851-1992, slope-movement processes have been producing about half the average rate of deposits than during the past 15,000 years. C1 UNIV HEIDELBERG,INST GEOG,D-69120 HEIDELBERG,GERMANY. RP Wieczorek, GF (reprint author), US GEOL SURVEY,NATL CTR,MS 922,RESTON,VA 22092, USA. NR 38 TC 66 Z9 67 U1 0 U2 9 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD FEB PY 1996 VL 15 IS 1 BP 17 EP 31 DI 10.1016/0169-555X(95)00112-I PG 15 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UD535 UT WOS:A1996UD53500002 ER PT J AU Harris, RA Simpson, RW AF Harris, RA Simpson, RW TI In the shadow of 1857 - The effect of the great Ft Tejon earthquake on subsequent earthquakes in southern California SO GEOPHYSICAL RESEARCH LETTERS LA English DT Article ID SAN-ANDREAS FAULT; LANDER EARTHQUAKE; STATIC STRESS; SEQUENCE; SLIP; AFTERSHOCKS; DEFORMATION; SEISMICITY; SHEAR AB The great 1857 Fort Tejon earthquake is the largest earthquake to have hit southern California during the historic period. We investigated if seismicity patterns following 1857 could be due to static stress changes generated by the 1857 earthquake. When post-1857 earthquakes with unknown focal mechanisms were assigned strike-slip mechanisms with strike and rake determined by the nearest active fault, 13 of the 13 southern California M greater than or equal to 5.5 earthquakes between 1857 and 1907 were encouraged by the 1857 rupture. When post-1857 earthquakes in the Transverse Ranges with unknown focal mechanisms were assigned reverse mechanisms and all other events were assumed strike-slip, 11 of the 13 earthquakes were encouraged by the 1857 earthquake. These results show significant correlations between static stress changes and seismicity patterns. The correlation disappears around 1907, suggesting that tectonic loading began to overwhelm the effect of the 1857 earthquake early in the 20th century. RP Harris, RA (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. RI Harris, Ruth/C-4184-2013 OI Harris, Ruth/0000-0002-9247-0768 NR 30 TC 143 Z9 156 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0094-8276 J9 GEOPHYS RES LETT JI Geophys. Res. Lett. PD FEB 1 PY 1996 VL 23 IS 3 BP 229 EP 232 DI 10.1029/96GL00015 PG 4 WC Geosciences, Multidisciplinary SC Geology GA TU593 UT WOS:A1996TU59300006 ER PT J AU Byrnes, RA AF Byrnes, RA TI Mapping SO GEOTIMES LA English DT Article RP Byrnes, RA (reprint author), US GEOL SURVEY,516 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD FEB PY 1996 VL 41 IS 2 BP 27 EP 28 PG 2 WC Geosciences, Multidisciplinary SC Geology GA UW268 UT WOS:A1996UW26800014 ER PT J AU Gray, JE AF Gray, JE TI Exploration geochemistry SO GEOTIMES LA English DT Article RP Gray, JE (reprint author), US GEOL SURVEY,DENVER FED CTR,POB 25046,DENVER,CO 80225, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD FEB PY 1996 VL 41 IS 2 BP 33 EP 33 PG 1 WC Geosciences, Multidisciplinary SC Geology GA UW268 UT WOS:A1996UW26800021 ER PT J AU McCabe, PJ Shanley, KW AF McCabe, PJ Shanley, KW TI Sequence stratigraphy SO GEOTIMES LA English DT Article RP McCabe, PJ (reprint author), US GEOL SURVEY,DENVER FED CTR MS 972,BOX 25046,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 SN 0016-8556 J9 GEOTIMES JI Geotimes PD FEB PY 1996 VL 41 IS 2 BP 49 EP 49 PG 1 WC Geosciences, Multidisciplinary SC Geology GA UW268 UT WOS:A1996UW26800041 ER PT J AU Peters, NE AF Peters, NE TI Trends in water quality - Special issue of hydrological processes SO HYDROLOGICAL PROCESSES LA English DT Editorial Material RP Peters, NE (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,3039 AMWILER RD,SUITE 130,ATLANTA,GA 30360, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD FEB PY 1996 VL 10 IS 2 BP 125 EP 125 PG 1 WC Water Resources SC Water Resources GA TZ263 UT WOS:A1996TZ26300001 ER PT J AU Aulenbach, BT Hooper, RP Bricker, OP AF Aulenbach, BT Hooper, RP Bricker, OP TI Trends in the chemistry of precipitation and surface water in a national network of small watersheds SO HYDROLOGICAL PROCESSES LA English DT Article DE trends; water quality; chemistry of precipitation; statistical methods; seasonal variation; acid rain ID EASTERN-UNITED-STATES; STREAM CHEMISTRY; NORTH-AMERICA; PATTERNS; ACIDIFICATION AB Trends in precipitation and surface water chemistry at a network of 15 small watersheds (<10 km(2)) in the USA were evaluated using a statistical test for monotonic trends (the seasonal Kendall test) and a graphical smoothing technique for the visual identification of trends. Composite precipitation samples were collected weekly and surface water samples were collected at least monthly. Concentrations were adjusted before trend analysis, by volume for precipitation samples and by flow for surface water samples. A relation between precipitation and surface water trends was not evident either for individual inorganic solutes or for solute combinations, such as ionic strength, at most sites. The only exception was chloride, for which there was a similar trend at 60% of the sites. The smoothing technique indicated that short-term patterns in precipitation chemistry were not reflected in surface waters. The magnitude of the short-term variations in surface water concentration was generally larger than the overall long-term trend, possibly because flow adjustment did not adequately correct for climatic variability. Detecting the relation between precipitation and surface water chemistry trends may be improved by using a more powerful sampling strategy and by developing better methods of concentration adjustment to remove the effects of natural variation in surface waters. RP Aulenbach, BT (reprint author), US GEOL SURVEY,3039 AMWILER RD,SUITE 130,ATLANTA,GA 30360, USA. RI Aulenbach, Brent/A-5848-2008 OI Aulenbach, Brent/0000-0003-2863-1288 NR 30 TC 15 Z9 15 U1 1 U2 4 PU JOHN WILEY & SONS LTD PI W SUSSEX PA BAFFINS LANE CHICHESTER, W SUSSEX, ENGLAND PO19 1UD SN 0885-6087 J9 HYDROL PROCESS JI Hydrol. Process. PD FEB PY 1996 VL 10 IS 2 BP 151 EP 181 DI 10.1002/(SICI)1099-1085(199602)10:2<151::AID-HYP355>3.0.CO;2-K PG 31 WC Water Resources SC Water Resources GA TZ263 UT WOS:A1996TZ26300003 ER PT J AU Kargel, JS Pozio, S AF Kargel, JS Pozio, S TI The volcanic and tectonic history of enceladus SO ICARUS LA English DT Article ID SATURNS E-RING; ICY SATELLITES; PLANETOLOGICAL APPLICATIONS; TIDAL DISSIPATION; EVOLUTION; URANUS; LITHOSPHERE; METHANOL; MIRANDA; LIQUID AB Enceladus has a protracted history of impact cratering, cryovolcanism, and extensional, compressional, and probable strike-slip faulting. It is unique in having some of the outer Solar System's least and most heavily cratered surfaces. Enceladus' cratering record, tectonic features, and relief elements have been analyzed more comprehensively than done previously. Like few other icy satellites, Enceladus seems to have experienced major lateral lithospheric motions; it may be the only icy satellite with global features indicating probable lithospheric convergence and folding. Ridged plains, 500 km across, consist of a central labyrinthine ridge complex atop a broad dome surrounded by smooth plains and peripheral sinuous ridge belts. The ridged plains have few if any signs of extension, almost no craters, and an average age of just 10(7) to 10(8) years. Ridge belts have local relief ranging from 500 to 2000 m and tend to occur near the bottoms of broad regional troughs between swells. Our reanalysis of Peter Thomas' (Dermott, S. F., and P. C. Thomas, 1994, The determination of the mass and mean density of Enceladus from its observed shape, Icarus, 109, 241-257) limb profiles indicates that high peaks, probably ridge belts, also occur in unmapped areas. Sinuous ridges appear foldlike and are similar to terrestrial fold belts such as the Appalachians. If they are indeed folds, it may require that the ridged plains are mechanically (perhaps volcanically) layered. Regional topography suggests that folding may have occurred along zones of convective downwelling. The cratered plains, in contrast to the ridged plains, are heavily cratered and exhibit extensional structures but no obvious signs of compression. Cratered plains contain a possible strike-slip fault (Isbanir Fossa), along which two pairs of fractures seem to have 15 km of right-lateral offset. The oldest cratered plains might date from shortly after the formation of the saturnian system or the impact disruption and reaccretion of Enceladus. Another area of cratered plains has modified craters (e.g., Ali Baba and Aladdin), which some workers have explained by anomalous heat flow and viscous relaxation; lateral shear and shield-building volcanism also may have been important. A young rift-like structure (northern Samarkand Sulci) has few craters and a concentration of cracks or grabens and flattened, flooded, and rifted craters. Pit chains and cratered domes suggest explosive volcanism. Smooth plains may have formed by cryovolcanic equivalents of flood-basalt volcanism. Pure H2O would be difficult to extrude through an icy crust and is cosmochemically improbable as a cryovolcanic agent. Density relations rule out eutectic brine lavas on Enceladus, but NH3-H2O volcanism is possible. Current steady-state tidal dissipation may cause melting of ammonia hydrate at a depth of similar to 25 km if the crust is made of ammonia hydrate or similar to 100 km if it is made of water ice. (C) 1996 Academic Press, Inc. C1 REPARTO PLANETOL,I-00185 ROME,ITALY. RP Kargel, JS (reprint author), US GEOL SURVEY,FLAGSTAFF,AZ 86001, USA. NR 65 TC 59 Z9 60 U1 2 U2 15 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0019-1035 J9 ICARUS JI Icarus PD FEB PY 1996 VL 119 IS 2 BP 385 EP 404 DI 10.1006/icar.1996.0026 PG 20 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TY870 UT WOS:A1996TY87000010 ER PT J AU Stamer, JK AF Stamer, JK TI Water supply implications of herbicide sampling SO JOURNAL AMERICAN WATER WORKS ASSOCIATION LA English DT Article ID MIDWESTERN UNITED-STATES; STREAM-AQUIFER SYSTEM; SURFACE WATERS; ATRAZINE; NEBRASKA AB The temporal distribution of the herbicides alachlor, atrazine, cyanazine, and metolachlor was documented from September 1991 through August 1992 in the Platte River at Louisville, Neb., the drainage of the Central Nebraska Basins. Lincoln, Omaha, and other municipalities withdraw groundwater for public supplies from the adjacent alluvium, which is hydraulically connected to the Platte River. Data were collected, in part, to provide information to managers, planners, and public utilities on the likelihood of water supplies being adversely affected by these herbicides. Three computational procedures-monthly means, monthly subsampling, and quarterly subsampling-were used to calculate annual mean herbicide concentrations. When the sampling was conducted quarterly rather than monthly, alachlor and atrazine concentrations were more likely to exceed their respective maximum contaminant levels (MCLs) of 2.0 mu g/L and 3.0 mu g/L and cyanazine concentrations were more likely to exceed their health advisory level of 1.0 mu g/L. The US Environment Protection Agency has established a tentative MCL of 1.0 mu L for cyanazine; data indicate that cyanazine is likely to exceed this level under most hydrologic conditions. RP Stamer, JK (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. NR 31 TC 7 Z9 7 U1 0 U2 0 PU AMER WATER WORKS ASSN PI DENVER PA 6666 W QUINCY AVE, DENVER, CO 80235 SN 0003-150X J9 J AM WATER WORKS ASS JI J. Am. Water Work Assoc. PD FEB PY 1996 VL 88 IS 2 BP 76 EP 85 PG 10 WC Engineering, Civil; Water Resources SC Engineering; Water Resources GA TW061 UT WOS:A1996TW06100012 ER PT J AU Kappelman, J Swisher, CC Fleagle, JG Yirga, S Bown, TM Feseha, M AF Kappelman, J Swisher, CC Fleagle, JG Yirga, S Bown, TM Feseha, M TI Age of Australopithecus afarensis from Fejej, Ethiopia SO JOURNAL OF HUMAN EVOLUTION LA English DT Article ID NORTHERN KENYA; GEOCHRONOLOGY C1 UNIV TEXAS,CTR ASIAN STUDIES,AUSTIN,TX 78712. BERKELEY GEOCHRONOL CTR,BERKELEY,CA 94709. SUNY STONY BROOK,DEPT ANAT SCI,STONY BROOK,NY 11794. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. UNIV TEXAS,DEPT GEOL SCI,AUSTIN,TX 78712. RP Kappelman, J (reprint author), UNIV TEXAS,DEPT ANTHROPOL,AUSTIN,TX 78712, USA. NR 26 TC 22 Z9 22 U1 0 U2 1 PU ACADEMIC PRESS LTD PI LONDON PA 24-28 OVAL RD, LONDON, ENGLAND NW1 7DX SN 0047-2484 J9 J HUM EVOL JI J. Hum. Evol. PD FEB PY 1996 VL 30 IS 2 BP 139 EP 146 DI 10.1006/jhev.1996.0010 PG 8 WC Anthropology; Evolutionary Biology SC Anthropology; Evolutionary Biology GA TZ560 UT WOS:A1996TZ56000003 ER PT J AU Schaffranek, RW Lai, CT AF Schaffranek, RW Lai, CT TI Friction-term response to boundary-condition type in flow models SO JOURNAL OF HYDRAULIC ENGINEERING-ASCE LA English DT Article AB The friction-slope term in the unsteady open-channel flow equations is examined using two numerical models based on different formulations of the governing equations and employing different solution methods. The purposes of the study are to analyze, evaluate, and demonstrate the behavior of the term in a set of controlled numerical experiments using varied types and combinations of boundary conditions. Results of numerical experiments illustrate that a given model can respond inconsistently for the identical resistance-coefficient value under different types and combinations of boundary conditions. Findings also demonstrate that two models employing different dependent variables and solution methods can respond similarly for the identical resistance-coefficient value under similar types and combinations of boundary conditions. Discussion of qualitative considerations and quantitative experimental results provides insight into the proper treatment, evaluation, and significance of the friction-slope term, thereby offering practical guidelines for model implementation and calibration. C1 NATL TAIWAN UNIV,DEPT CIVIL ENGN,TAIPEI 106,TAIWAN. RP Schaffranek, RW (reprint author), US GEOL SURVEY,NATL CTR 430,12201 SUNRISE VALLEY DR,RESTON,VA 22092, USA. NR 15 TC 4 Z9 4 U1 0 U2 2 PU ASCE-AMER SOC CIVIL ENG PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2398 SN 0733-9429 J9 J HYDRAUL ENG-ASCE JI J. Hydraul. Eng.-ASCE PD FEB PY 1996 VL 122 IS 2 BP 73 EP 81 DI 10.1061/(ASCE)0733-9429(1996)122:2(73) PG 9 WC Engineering, Civil; Engineering, Mechanical; Water Resources SC Engineering; Water Resources GA TR271 UT WOS:A1996TR27100002 ER PT J AU Laughland, AS Musser, WN Shortle, JS Musser, LM AF Laughland, AS Musser, WN Shortle, JS Musser, LM TI Construct validity of averting cost measures of environmental benefits SO LAND ECONOMICS LA English DT Article ID POLLUTION; EXPENDITURES; HEALTH AB Construct validity is concerned with the consistency of empirical measures with theoretical relationships. This paper reviews and extends the theoretical relationship between averting costs and willingness to pay. Measures of these two theoretical constructs with empirical averting costs savings and contingent valuation from one population are used to establish construct validity of the averting cost technique used Empirical results indicate that the contingent valuation and averting costs measures have a low correlation. Although low correlation is consistent with the construct validity of averting costs measures, these results indicate that inferences from averting cost measures are quite limited. C1 UNIV MARYLAND,DEPT AGR & RESOURCE ECON,COLLEGE PK,MD 20742. PENN STATE UNIV,DEPT AGR ECON & RURAL SOCIOL,UNIVERSITY PK,PA 16802. AMERICAN UNIV,DEPT PSYCHOL,WASHINGTON,DC 20016. RP Laughland, AS (reprint author), US FISH & WILDLIFE SERV,DEPT INTERIOR,DIV ECON,WASHINGTON,DC 20240, USA. NR 15 TC 21 Z9 23 U1 0 U2 1 PU UNIV WISCONSIN PI MADISON PA SOCIAL SCIENCE BLDG, MADISON, WI 53706 SN 0023-7639 J9 LAND ECON JI Land Econ. PD FEB PY 1996 VL 72 IS 1 BP 100 EP 112 DI 10.2307/3147160 PG 13 WC Economics; Environmental Studies SC Business & Economics; Environmental Sciences & Ecology GA TT368 UT WOS:A1996TT36800008 ER PT J AU Spotl, C Houseknecht, DW Burns, SJ AF Spotl, C Houseknecht, DW Burns, SJ TI Diagenesis of an 'overmature' gas reservoir: The Spiro sand of the Arkoma Basin, USA SO MARINE AND PETROLEUM GEOLOGY LA English DT Article DE diagenesis; gas reservoirs; Arkoma Basin, Oklahoma ID CEMENTATION; SANDSTONES; POROSITY; BURIAL; TEXAS; REFLECTANCE; CALIFORNIA; CHLORITES; EVOLUTION; VITRINITE AB The Spiro sand is a laterally extensive thin sandstone of earliest Atokan (Pennsylvanian) age that forms a major natural gas reservoir in the western Arkoma Basin, Oklahoma. Petrographic analysis reveals a variety of diagenetic alterations, the majority of which occurred during moderate to deep burial. Early diagenetic processes include calcite cementation and the formation of Fe-clay mineral peloids and coatings around quartz framework grains. These clays, which underwent transformation to well-crystallized chamosite [polytype lb(beta = 90 degrees)] on burial, are particularly abundant in medium-grained channel sandstones, whereas illitic clays are predominant in fine-grained interchannel sandstones. Subsequent to mechanical compaction, saddle ankerite precipitated in the reservoir at temperatures in excess of 70 degrees C. Crude oil collected in favourable structural locations during and after ankeritization. Whereas hydrocarbons apparently halted inorganic diagenesis in oil-saturated zones, cementation continued in the underlying water-saturated zones. As reservoir temperatures increased further, hydrocarbons were cracked and a solid pyrobitumen residue remained in the reservoir. At temperatures exceeding similar to 140-150 degrees C, non-syntaxial quartz cement, ferroan calcite and traces of dickite(?) locally reduced the reservoir quality. Local secondary porosity was created by carbonate cement dissolution. This alteration post-dated hydrocarbon emplacement and is probably related to late-stage infiltration of freshwater along 'leaky' faults. The study shows that the Spiro sandstone locally retained excellent porosities despite deep burial and thermal conditions that correspond to the zone of incipient very low grade metamorphism. C1 US GEOL SURVEY, NATL CTR 915, RESTON, VA 22092 USA. UNIV BERN, INST GEOL, CH-3012 BERN, SWITZERLAND. RP Spotl, C (reprint author), UNIV INNSBRUCK, INST GEOL & PALAONTOL, INNRAIN 52, A-6020 INNSBRUCK, AUSTRIA. RI Burns, Stephen/H-9419-2013 NR 58 TC 5 Z9 7 U1 2 U2 6 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, OXON, ENGLAND SN 0264-8172 J9 MAR PETROL GEOL JI Mar. Pet. Geol. PD FEB PY 1996 VL 13 IS 1 BP 25 EP 40 DI 10.1016/0264-8172(95)00037-2 PG 16 WC Geosciences, Multidisciplinary SC Geology GA TL837 UT WOS:A1996TL83700002 ER PT J AU Orem, WH Neuzil, SG Lerch, HE Cecil, CB AF Orem, WH Neuzil, SG Lerch, HE Cecil, CB TI Experimental early-stage coalification of a peat sample and a peatified wood sample from Indonesia SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 11th Annual Meeting of the Society-for-Organic-Petrology CY SEP 25-30, 1994 CL JACKSON, WY SP Soc Organ Petr DE experimental coalification; NMR; FTIR; lignin phenols; Indonesian peat ID ARTIFICIAL MATURATION SERIES; NUCLEAR-MAGNETIC-RESONANCE; MAHAKAM DELTA COALS; SAPROPELIC SEDIMENTS; SUBBITUMINOUS COAL; OXIDATION-PRODUCTS; C-13 NMR; LIGNIN; PYROLYSIS; KALIMANTAN AB Experimental coalification of a peat sample and a buried wood sample from domed peat deposits in Indonesia was carried out to examine chemical structural changes in organic matter during early-stage coalification. The experiment (125 degrees C, 408 atm lithostatic pressure, and 177 arm fluid pressure for 75 days) was designed to maintain both lithostatic and fluid pressure on the sample, but allow by-products that may retard coalification to escape. We refer to this design as a geologically open system. Changes in the elemental composition, and C-13 NMR and FTIR spectra of the peat and wood after experimental coalification suggest preferential thermal decomposition of O-containing aliphatic organic compounds (probably cellulose) during early-stage coalification. The elemental compositions and C-13 NMR spectra of the experimentally coalified peat and wood were generally similar to those of Miocene coal and coalified wood samples from Indonesia. Yields of lignin phenols in the peat and wood samples decreased following experimental coalification; the wood sample exhibited a larger change. Lignin phenol yields from the experimentally coalified peat and wood were comparable to yields of lignin phenols from Miocene Indonesian lignite and coalified wood. Changes in syringyl/vanillyl and p-hydroxy/vanillyl ratios suggest direct demethoxylation as a secondary process to demethylation of methoxyl groups during early coalification, and changes in lignin phenol yields and acid/aldehyde ratios point to a coupling between demethoxylation processes and reactions in the alkyl side chain bonds of the alpha-carbon in lignin phenols. RP Orem, WH (reprint author), US GEOL SURVEY,NATL CTR 956,RESTON,VA 22092, USA. NR 50 TC 38 Z9 40 U1 1 U2 9 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD FEB PY 1996 VL 24 IS 2 BP 111 EP 125 DI 10.1016/0146-6380(96)00012-5 PG 15 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VF420 UT WOS:A1996VF42000001 ER PT J AU Peng, SP Flores, RM AF Peng, SP Flores, RM TI Modern Pearl River Delta and Permian Huainan coalfield, China: A comparative sedimentary facies study SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 11th Annual Meeting of the Society-for-Organic-Petrology CY SEP 25-30, 1994 CL JACKSON, WY SP Soc Organ Petr DE Pleistocene sedimentary facies; Huanian coalfield; China; Pleistocene peat deposits; anastomosing river systems; Pearl River ID EXAMPLES; ALBERTA AB Sedimentary facies types of the Pleistocene deposits of the Modern Pearl River Delta in Guangdong Province, China and Permian Member D deposits in Huainan coalfield in Anhui Province are exemplified by depositional facies of anastomosing fluvial systems. In both study areas, sand/sandstone and mud/mudstone-dominated facies types formed in diverging and converging, coeval fluvial channels laterally juxtaposed with floodplains containing ponds, lakes, and topogenous mires. The mires accumulated thin to thick peat/coal deposits that vary in vertical and lateral distribution between the two study areas. This difference is probably due to attendant sedimentary processes that affected the floodplain environments. The ancestral floodplains of the Modern Pearl River Delta were reworked by combined fluvial and tidal and estuarine processes. In contrast, the floodplains of the Permian Member D were mainly influenced by freshwater fluvial processes. In addition, the thick, laterally extensive coal zones of the Permian Member D may have formed in topogenous mires that developed on abandoned courses of anastomosing Fluvial systems. This is typified by Seam 13-1, which is a blanket-like body that thickens to as much as 8 m but also splits into thinner beds. This seam overlies deposits of diverging and converging, coeval fluvial channels of the Sandstone D-3 and associated overbank-floodplain deposits. The limited areal extent of lenticular Pleistocene peat deposits of the Modern Pearl River Delta is due to their primary accumulation in topogenous mires in the central floodplains that were restricted by contemporaneous anastomosing channels. Copyright (C) 1996 Elsevier Science Ltd C1 US GEOL SURVEY,DENVER,CO 80225. RP Peng, SP (reprint author), CHINA UNIV MIN & TECHNOL,BEIJING GRAD SCH,BEIJING 100083,PEOPLES R CHINA. NR 28 TC 1 Z9 1 U1 0 U2 2 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD FEB PY 1996 VL 24 IS 2 BP 159 EP 179 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VF420 UT WOS:A1996VF42000004 ER PT J AU Pierce, BS AF Pierce, BS TI Quality and petrographic characteristics of Paleocene coals from the Hanna basin, Wyoming SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 11th Annual Meeting of the Society-for-Organic-Petrology CY SEP 25-30, 1994 CL JACKSON, WY SP Soc Organ Petr DE coal geology; coal petrography; Paleocene; Wyoming; coal formation; Hanna basin AB Coal beds from the Ferris and Hanna Formations, in the Hanna basin, south-central Wyoming, exhibit distinct differences in ash yield, sulfur content, and petrographic and palynologic constituents. These differences are interpreted to be controlled by tectonic changes of the Hanna basin and adjoining uplifts during evolutionary development, which, in turn, controlled mire chemistry and sedimentation. These conditions created two very different settings under which the peats developed during deposition of the Ferris and the Hanna Formations. In addition, there appears to be a geographic (latitudinal) and/or climatic control on the coal characteristics manifested by major differences of Paleocene coals in the Hanna basin compared to those in the Raton basin in Colorado and New Mexico and the Powder River basin in Wyoming. RP Pierce, BS (reprint author), US GEOL SURVEY,NATL CTR 956,RESTON,VA 22092, USA. NR 19 TC 2 Z9 2 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD FEB PY 1996 VL 24 IS 2 BP 181 EP 187 DI 10.1016/0146-6380(96)00016-2 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VF420 UT WOS:A1996VF42000005 ER PT J AU Warwick, PD Crowley, SS Ruppert, LF Pontolillo, J AF Warwick, PD Crowley, SS Ruppert, LF Pontolillo, J TI Petrography and geochemistry of the San Miguel lignite, Jackson Group (Eocene), south Texas SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 11th Annual Meeting of the Society-for-Organic-Petrology CY SEP 25-30, 1994 CL JACKSON, WY SP Soc Organ Petr DE San Miguel lignite; Jackson Group; Texas; coal petrography; coal geochemistry; volcanic ash; trace elements; Eocene lignite ID COAL; ASH; KAOLINITE; MOBILITY AB The San Miguel lignite deposit (late Eocene, lower Jackson Group) of south Texas consists of four or more thin (generally < 1 m thick) lignite benches that are separated by claystone and mudstone partings. The partings are composed of altered volcanic air-fall ash that has been reworked by tidal or channel processes associated with a back-barrier depositional environment. The purpose of this study is to examine the relationship between the ash yield and the petrographic and geochemical characteristics of the San Miguel lignite as mined. Particular attention is given to 12 of the environmentally sensitive trace elements (As, Be, Cd, Cr, Co, Hg, Mn, Ni, Pb, Sb, Se, and U) that have been identified as possible hazardous air pollutants (HAPs) by the United States Clean Air Act Amendments of 1990. A total of 29 rock and lignite samples were collected and characterized by geochemical and petrographic methods. The major conclusions of the study are as follows: (1) The distribution of Mn is inversely related to the ash yield of the lignite samples. This indicates an organic affinity, or an association with finely disseminated minerals in the lignite that contain this element. (2) On a whole-coal basis, the concentration of the HAPs' element Pb is positively related to ash yield in lignite samples. This indicates an inorganic affinity for Pb. (3) Average whole-coal concentrations of As, Be, Sb, and U in the San Miguel samples are greater than published averages for these elements in other U.S. lignites. (4) The upper and lower lignite benches of the San Miguel deposit are both ash- and algal-rich, indicating that these intervals were probably deposited in wetter conditions than those in which the middle intervals formed. (5) The dominance of the eugelinite maceral subgroup over the huminite subgroup indicates that the San Miguel lignites were subjected to peat-forming conditions (either biogenic or chemical) that enabled degradation of wood cellular material into matrix gels, or that the plants that formed these lignite benches were less woody and more prone to formation of matrix gels. (6) An inertinite-rich layer (top of the B bed) might have formed from widespread oxidation of the San Miguel peat as a result of a volcanic ash fall which was subsequently reworked. RP Warwick, PD (reprint author), US GEOL SURVEY,MS 956,12201 SUNRISE VALLEY DR,RESTON,VA 22092, USA. OI Warwick, Peter/0000-0002-3152-7783; Pontolillo, James/0000-0002-1075-1313; Ruppert, Leslie/0000-0002-7453-1061 NR 42 TC 7 Z9 7 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD FEB PY 1996 VL 24 IS 2 BP 197 EP 217 DI 10.1016/0146-6380(96)00018-6 PG 21 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VF420 UT WOS:A1996VF42000007 ER PT J AU Keighin, CW Flores, RM Rowland, T AF Keighin, CW Flores, RM Rowland, T TI Occurrence and morphology of carbonate concretions in the Beulah-Zap coal bed, Williston Basin, North Dakota SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 11th Annual Meeting of the Society-for-Organic-Petrology CY SEP 25-30, 1994 CL JACKSON, WY SP Soc Organ Petr DE concretions; coal balls; lignite; North Dakota; Williston Basin ID BRITISH-COLUMBIA; MIDDLE EOCENE AB Carbonate concretionary bodies were encountered during mining of the Beulah-Zap lignite seam in the Coteau Properties' Freedom mine, Mercer County, North Dakota. Preliminary studies show that areal and vertical distribution of the concretions are variable. All concretions examined are composed almost entirely of calcite. They occur as thin tabular bodies, as more or less elliptical forms, or as tear shaped bodies, and may occur individually or as clusters of buff-colored, poorly consolidated to solidly crystalline material. The carbonate masses vary in size from a few millimeters to tens of centimeters. Bedding in the lignite may display some compactional folding over dense spheroidal to elliptical concretions, indicating formation of the concretions prior to compaction. Internal morphology of the concretions is complex, and includes cone-in-cone structure, cross-cutting calcite veinlets, and multiple generations of calcite. Carbon isotope values suggest the concretions are composed of biogenic carbonate, probably related to early diagenesis and decomposition of organic matter(peat); oxygen isotope values are light, and consistent with a freshwater origin. C1 COTEAU PROPERTIES CO,BEULAL,ND 58523. RP Keighin, CW (reprint author), US GEOL SURVEY,BOX 25046,MS 971,DENVER,CO 80225, USA. NR 28 TC 2 Z9 2 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD FEB PY 1996 VL 24 IS 2 BP 227 EP 232 DI 10.1016/0146-6380(96)00020-4 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VF420 UT WOS:A1996VF42000009 ER PT J AU Barker, CE AF Barker, CE TI A comparison of vitrinite reflectance measurements made on whole-rock and dispersed organic matter concentrate mounts SO ORGANIC GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 11th Annual Meeting of the Society-for-Organic-Petrology CY SEP 25-30, 1994 CL JACKSON, WY SP Soc Organ Petr DE vitrinite; identification; reflectance; whole-rock technique; dike; contact metamorphism; Walsenburg; Colorado ID COAL AB A comparison of mean-random vitrinite reflectance (R(v-r)) values calculated from measurements on polished whole-rock and on concentrates of dispersed organic matter (DOM) mounts of the same samples generally show little difference. Compared to measurements on DOM mounts, R(v-r) measurements by the same microscopist on corresponding whole-rock samples are up to a few tenths of a percent lower over the range of 0.6-3.2% R(v-r) and have a slightly higher standard deviation. Whole-rock mounts have an advantage over DOM mounts in the identification of first-cycle vitrinite and differentiation of solid bitumen from vitrinite. Published by Elsevier Science Ltd RP Barker, CE (reprint author), US GEOL SURVEY,BOX 25046,MS 971,DENVER,CO 80225, USA. NR 14 TC 15 Z9 15 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD FEB PY 1996 VL 24 IS 2 BP 251 EP 256 DI 10.1016/0146-6380(96)00022-8 PG 6 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA VF420 UT WOS:A1996VF42000012 ER PT J AU Joria, PE Jorgenson, JC AF Joria, PE Jorgenson, JC TI Comparison of three methods for mapping tundra with landsat digital data SO PHOTOGRAMMETRIC ENGINEERING AND REMOTE SENSING LA English DT Article ID THEMATIC MAPPER DATA; NORTHWEST-TERRITORIES; CLASSIFICATION; HABITAT AB Documenting the distribution of wildlife habitat on the Arctic National Wildlife Refuge (Arctic AWR) coastal plain in northeast Alaska is essential for determining potential impacts and mitigation of oil exploration and development. Landsat Thematic Mapper (TM) and ancillary data were used to map 14 cover types on a 13,000-km(2) portion of the Arctic NWR coastal plain. Three classification approaches were compared: supervised, unsupervised, and modeling. The model used ancillary layers representing elevation, slope, solar illumination, riparian zones, and terrain type in a postclassification sorting of the unsupervised spectral classes. Modeling resulted in the highest overall agreement with training areas (68 percent), but agreement with an independent data set was 48 percent, only slightly better than the other two approaches. Training data from an additional field season helped increase the overall agreement between the model and the independent data set to 52 percent. For wildlife studies, cover types from the map will be combined into fewer, more general, classes at acceptable levels of agreement. The TM map demonstrated a 27 percent improvement in agreement over a previous Landsat Multispectral Scanner (MSS) map, when a cover-type scheme of ten classes was compared for both maps. C1 US FISH & WILDLIFE SERV,ALASKA FISH & WILDLIFE RES CTR,ANCHORAGE,AK 99503. US FISH & WILDLIFE SERV,ARCTIC NATL WILDLIFE REFUGE,FAIRBANKS,AK 99701. NR 22 TC 18 Z9 18 U1 1 U2 3 PU AMER SOC PHOTOGRAMMETRY PI BETHESDA PA 5410 GROSVENOR LANE SUITE 210, BETHESDA, MD 20814-2160 SN 0099-1112 J9 PHOTOGRAMM ENG REM S JI Photogramm. Eng. Remote Sens. PD FEB PY 1996 VL 62 IS 2 BP 163 EP 169 PG 7 WC Geography, Physical; Geosciences, Multidisciplinary; Remote Sensing; Imaging Science & Photographic Technology SC Physical Geography; Geology; Remote Sensing; Imaging Science & Photographic Technology GA TT607 UT WOS:A1996TT60700039 ER PT J AU Sipkin, SA Zirbes, MD AF Sipkin, SA Zirbes, MD TI Moment-tensor solutions estimated using optimal filter theory: Global seismicity, 1994 SO PHYSICS OF THE EARTH AND PLANETARY INTERIORS LA English DT Letter ID EARTHQUAKE SOURCE PARAMETERS; WAVEFORM DATA; INVERSION AB Moment-tenser solutions, estimated using optimal filter theory, are listed for 177 moderate-to-large size earthquakes occurring during 1994. RP Sipkin, SA (reprint author), US GEOL SURVEY,DFC,MS 967,BOX 25046,DENVER,CO 80225, USA. NR 11 TC 10 Z9 10 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-9201 J9 PHYS EARTH PLANET IN JI Phys. Earth Planet. Inter. PD FEB PY 1996 VL 93 IS 3-4 BP 139 EP 146 DI 10.1016/0031-9201(95)03116-2 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UB044 UT WOS:A1996UB04400002 ER PT J AU Hampton, MA Lee, HJ Locat, J AF Hampton, MA Lee, HJ Locat, J TI Submarine landslides SO REVIEWS OF GEOPHYSICS LA English DT Review ID CONTINENTAL-SLOPE; SEDIMENT INSTABILITY; TURBIDITY CURRENTS; MISSISSIPPI DELTA; BRITISH-COLUMBIA; STOREGGA SLIDES; BAJA-CALIFORNIA; HIGH-VELOCITY; SANTA-MONICA; STEADY-STATE AB Landslides are common on inclined areas of the seafloor, particularly in environments where weak geologic materials such as rapidly deposited, fine-grained sediment or fractured rock are subjected to strong environmental stresses such as earthquakes, large storm waves, and high internal pore pressures. Submarine landslides can involve huge amounts of material and can move great distances: slide volumes as large as 20,000 km(3) and runout distances in excess of 140 km have been reported. They occur at locations where the downslope component of stress exceeds the resisting stress, causing movement along one or several concave to planar rupture surfaces. Some recent slides that originated nearshore and retrogressed back across the shoreline were conspicuous by their direct impact on human life and activities. Most known slides, however, occurred far from land in prehistoric time and were discovered by noting distinct to subtle characteristics, such as headwall scarps and displaced sediment or rock masses, on acoustic-reflection profiles and side-scan sonar images. Submarine landslides can be analyzed using the same mechanics principles as are used for occurrences on land. However, some loading mechanisms are unique, for example, storm waves, and some, such as earthquakes, can have greater impact. The potential for limited-deformation landslides to transform into sediment flows that can travel exceedingly long distances is related to the density of the slope-forming material and the amount of shear strength that is lost when the slope fails. C1 UNIV LAVAL,DEPT GEOL & GEOL ENGN,QUEBEC CITY,PQ G1K 7P4,CANADA. RP Hampton, MA (reprint author), US GEOL SURVEY,BRANCH PACIFIC MARINE GEOL,345 MIDDLEFIELD RD,MAIL STOP 99,MENLO PK,CA 94025, USA. RI Wright, Dawn/A-4518-2011 OI Wright, Dawn/0000-0002-2997-7611 NR 209 TC 515 Z9 531 U1 17 U2 133 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 8755-1209 J9 REV GEOPHYS JI Rev. Geophys. PD FEB PY 1996 VL 34 IS 1 BP 33 EP 59 DI 10.1029/95RG03287 PG 27 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TV972 UT WOS:A1996TV97200002 ER PT J AU McLaughlin, RJ Sliter, WV Sorg, DH Russell, PC SarnaWojcicki, AM AF McLaughlin, RJ Sliter, WV Sorg, DH Russell, PC SarnaWojcicki, AM TI Large-scale right-slip displacement on the East San Francisco Bay Region fault system, California: Implications for location of late Miocene to Pliocene Pacific plate boundary SO TECTONICS LA English DT Article ID NORTHWESTWARDLY YOUNGER AGE; WEST-CENTRAL CALIFORNIA; NORTHERN CALIFORNIA; VOLCANIC-ROCKS; RIDGE COLLISION; SOUTHERN CHILE; COMPLEX; ZONE; CONSTANTS; TRANSFORM AB A belt of northwardly younging Neogene and Quaternary volcanic rocks acid hydrothermal vein systems, together with a distinctive Cretaceous terrane of the Franciscan Complex (the Permanente terrane), exhibits about 160 to 170 km of cumulative dextral offset across faults of the East San Francisco Bay Region (ESFBR) fault system. The offset hydrothermal veins and volcanic rocks range in age from .01 Ma at the northwest end to about 17.6 Ma at the southeast end. In the fault block between the San Andreas and ESFBR fault systems, where volcanic rocks are scarce, hydrothermal vein system ages clearly indicate that the northward younging thermal overprint affected these rocks beginning about 18 Ma. The age progression of these volcanic rocks and hydrothermal vein systems is consistent with previously proposed models that relate northward propagation of the San Andreas transform to the opening of an asthenospheric window beneath the North American plate margin in the wake of subducting lithosphere. The similarity in the amount of offset of the Permanente terrane across the ESFBR fault system to that derived by restoring continuity in the northward younging age progression of volcanic rocks and hydrothermal veins suggests a model in which 80-110 km of offset are taken up 8 to 6 Ma on a fault aligned with the Bloomfield-Tolay-Franklin-Concord-Sunol-Calaveras faults. An additional 50-70 km of cumulative slip are taken up less than or equal to 6 Ma by the Rogers Creek-Hayward and Concord-Franklin-Sunol-Calaveras faults. An alternative model in which the Permanente terrane is offset about 80 km by pre-Miocene faults does not adequately restore the distribution of 8-12 Ma volcanic rocks and hydrothermal veins to a single nortbwardly younging age trend. If 80-110 km of slip was taken up by the ESFBR fault system between 8 and 6 Ma, dextral slip rates were 40-55 mm/yr. Such high rates might occur if the ESFBR fault system rather than the San Andreas fault acted as the transform margin at this time. Major transpression across; the boundary between the Pacific and North American plates at about 3 to 5 Ma would have resulted in the transfer of significant slip back to the San Francisco Peninsula segment of the San Andreas fault. Since that time, the ESFBR fault system has continued to slip at rates of 11-14 mm/yr. If this interpretation is valid, the ESFBR fault system was the Pacific-North American plate boundary between 8 and 6 Ma, and this boundary has migrated both eastward and westward with time, in response to changing plate margin geometry and plate motions. C1 US GEOL SURVEY,BRANCH WESTERN MINERAL RESOURCES,MENLO PK,CA 94025. US GEOL SURVEY,PALEONTOL & STRATIG BRANCH,MENLO PK,CA 94025. RP McLaughlin, RJ (reprint author), US GEOL SURVEY,BRANCH WESTERN REG GEOL,345 MIDDLEFIELD RD,MAIL STOP 975,MENLO PK,CA 94025, USA. NR 79 TC 55 Z9 55 U1 1 U2 2 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0278-7407 J9 TECTONICS JI Tectonics PD FEB PY 1996 VL 15 IS 1 BP 1 EP 18 DI 10.1029/95TC02347 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TU779 UT WOS:A1996TU77900001 ER PT J AU Sasser, CE Gosselink, JG Swenson, EM Swarzenski, CM Leibowitz, NC AF Sasser, CE Gosselink, JG Swenson, EM Swarzenski, CM Leibowitz, NC TI Vegetation, substrate and hydrology in floating marshes in the Mississippi river delta plain wetlands, USA SO VEGETATIO LA English DT Article DE Eleocharis Baldwinii; marsh buoyancy; Panicum hemitomon; Sagittaria lancifolia ID FRESH-WATER MARSH; TROPICAL SWAMP; LOUISIANA; NUTRIENTS; BUOYANCY; MATS AB In the 1940s extensive floating marshes (locally called 'flotant') were reported and mapped in coastal wetlands of the Mississippi River Delta Plain. These floating marshes included large areas of Panicum hemitomon-dominated freshwater marshes, and Spartina patens/Scirpus olneyi brackish marshes. Today these marshes appear to be quite different in extent and type. We describe five floating habitats and one non-floating, quaking habitat based on differences in buoyancy dynamics (timing and degree of floating), substrate characteristics, and dominant vegetation. All floating marshes have low bulk density, organic substrates. Nearly all are fresh marshes. Panicum hemitomon floating marshes presently occur within the general regions that were reported in the 1940's by O'Neil, but are reduced in extent. Some of the former Panicum hemitomon marshes have been replaced by seasonally or variably floating marshes dominated, or co-dominated by Sagittaria lancifolia or Eleocharis baldwinii. C1 OREGON DIV STATE LANDS,SALEM,OR. US GEOL SURVEY,BATON ROUGE,LA. RP Sasser, CE (reprint author), LOUISIANA STATE UNIV,COASTAL ECOL INST,CTR COASTAL ENERGY & ENVIRONM RESOURCES,BATON ROUGE,LA 70803, USA. NR 46 TC 35 Z9 35 U1 3 U2 16 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA SPUIBOULEVARD 50, PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS SN 0042-3106 J9 VEGETATIO JI Vegetatio PD FEB PY 1996 VL 122 IS 2 BP 129 EP 142 DI 10.1007/BF00044695 PG 14 WC Plant Sciences; Ecology; Forestry SC Plant Sciences; Environmental Sciences & Ecology; Forestry GA UE177 UT WOS:A1996UE17700002 ER PT J AU Adamski, JC Pugh, AL AF Adamski, JC Pugh, AL TI Occurrence of pesticides in ground water of the Ozark Plateaus Province SO WATER RESOURCES BULLETIN LA English DT Article DE Ozark Plateaus; water quality; hydrogeology; pesticides; agricultural land use; karst AB Pesticides were detected in ground-water samples collected from 20 springs and nine wells in the Ozark Plateaus Province of Arkansas, Kansas, Missouri, and Oklahoma. From April through September 1993, water samples were collected from 50 shallow domestic wells and 50 springs in the Springfield Plateau and Ozark aquifers and analyzed for 47 pesticides and metabolites. Pesticides were detected in 17 water samples from the Springfield Plateau aquifer and 12 water samples from the Ozark aquifer. Fourteen pesticides were detected, with a maximum of four pesticides detected in any one sample. The most commonly detected pesticides were atrazine (14 detections), prometon (11 detections), and tebuthiuron (seven detections). P,P' DDE, a metabolite of DDT, was detected in water samples from three wells and one spring. The remaining pesticides were detected in three or less samples. The occurrence and distribution of pesticides probably are related to the local land use near a sampling site. Pesticide detections were significantly related to aquifer, site type, and discharge of springs. C1 US GEOL SURVEY,WRD,LITTLE ROCK,AR 72211. NR 20 TC 15 Z9 15 U1 0 U2 0 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD FEB PY 1996 VL 32 IS 1 BP 97 EP 105 PG 9 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA TV957 UT WOS:A1996TV95700010 ER PT J AU Tasker, GD Hodge, SA Barks, CS AF Tasker, GD Hodge, SA Barks, CS TI Region of influence regression for estimating the 50-year flood at ungaged sites SO WATER RESOURCES BULLETIN LA English DT Article DE flood frequency; regional regression; surface water; statistical analysis; floods; recurrence interval; region of influence ID FREQUENCY-ANALYSIS AB Five methods of developing regional regression models to estimate flood characteristics at ungaged sites in Arkansas are examined. The methods differ in the manner in which the State is divided into subregions. Each successive method (A to E) is computationally more complex than the previous method. Method A makes no subdivision. Methods B and C define two and four geographic subregions, respectively. Method D uses cluster/discriminant analysis to define subregions on the basis of similarities in watershed characteristics. Method E, the new region of influence method, defines a unique subregion for each ungaged site. Split-sample results indicate that, in terms of root-mean-square error method E (38 percent error) is best. Methods C and D (42 and 41 percent error) were in a virtual tie for second, and methods B (44 percent error) and A (49 percent error) were fourth and fifth best. C1 US GEOL SURVEY,LITTLE ROCK,AR 72211. RP Tasker, GD (reprint author), US GEOL SURVEY,NATL CTR 430,RESTON,VA 22092, USA. NR 21 TC 28 Z9 29 U1 0 U2 0 PU AMER WATER RESOURCES ASSOC PI HERNDON PA 950 HERNDON PARKWAY SUITE 300, HERNDON, VA 22070-5528 SN 0043-1370 J9 WATER RESOUR BULL JI Water Resour. Bull. PD FEB PY 1996 VL 32 IS 1 BP 163 EP 170 PG 8 WC Engineering, Civil; Geosciences, Multidisciplinary; Water Resources SC Engineering; Geology; Water Resources GA TV957 UT WOS:A1996TV95700017 ER PT J AU Goode, DJ AF Goode, DJ TI Direct simulation of groundwater age SO WATER RESOURCES RESEARCH LA English DT Article ID RESIDENCE TIME DISTRIBUTIONS; DISPERSION-EQUATION; FLOW; RECHARGE; DIFFUSION; VELOCITY; C-14; RESERVOIRS; LANDFILL; AQUIFERS AB A new method is proposed to simulate groundwater age directly, by use of an advection-dispersion transport equation with a distributed zero-order source of unit (1) strength, corresponding to the rate of aging. The dependent variable in the governing equation is the mean age, a mass-weighted average age. The governing equation is derived from residence-time-distribution concepts for the case of steady flow. For the more general case of transient flow, a transient governing equation for age is derived from mass-conservation principles applied to conceptual ''age mass.'' The age mass is the product of the water mass and its age, and age mass is assumed to be conserved during mixing. Boundary conditions include zero age mass flux across all noflow and inflow boundaries and no age mass dispersive flux across outflow boundaries. For transient-flow conditions, the initial distribution of age must be known. The solution of the governing transport equation yields the spatial distribution of the mean groundwater age and includes diffusion, dispersion, mixing, and exchange processes that typically are considered only through tracer-specific solute transport simulation. Traditional methods have relied on advective transport to predict point values of groundwater travel time and age. The proposed method retains the simplicity and tracer-independence of advection-only models, but incorporates the effects of dispersion and mixing on volume-averaged age. Example simulations of age in two idealized regional aquifer systems, one homogeneous and the other layered, demonstrate the agreement between the proposed method and traditional particle-tracking approaches and illustrate use of the proposed method to determine the effects of diffusion, dispersion, and mixing on groundwater age. C1 PRINCETON UNIV,PRINCETON,NJ 08544. RP Goode, DJ (reprint author), US GEOL SURVEY,111 GREAT VALLEY PKWY,MALVERN,PA 19355, USA. OI Goode, Daniel/0000-0002-8527-2456 NR 42 TC 182 Z9 188 U1 3 U2 38 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD FEB PY 1996 VL 32 IS 2 BP 289 EP 296 DI 10.1029/95WR03401 PG 8 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TT025 UT WOS:A1996TT02500006 ER PT J AU Claassen, HC Halm, DR AF Claassen, HC Halm, DR TI Estimates of evapotranspiration or effective moisture in Rocky Mountain watersheds from chloride ion concentrations in stream baseflow SO WATER RESOURCES RESEARCH LA English DT Article ID COLORADO; ARIZONA; BASIN AB The principle that atmospherically derived chloride is a conservative tracer in many watersheds can be used to calculate average annual evapotranspiration or effective moisture if estimates are available for (1) the average annual chloride input to the watershed, (2) the average annual precipitation, and (3) the baseflow chloride concentration are known. The method assumes that no long-term storage of chloride occurs and there is no lithologic source of chloride, or that such source releases only insignificant amounts to groundwater compared to the atmospheric source. National Atmospheric Deposition Program estimates of chloride wet deposition, watershed precipitation records or hyetal map estimates of precipitation input to watersheds, and a single sample of chloride concentration in base flow were used to calculate evapotranspiration for diverse Rocky Mountain watersheds, This estimate was compared to evapotranspiration determined by subtracting mean discharge from precipitation. Of the 19 watersheds used to test the method, 13 agreed within 10%, 2 appear to have not met the lithology criterion, 1 appears to have not met the flow criterion, and 1 neither criterion. The method's greatest strength is the minimal data requirements and its greatest weakness is that for some watersheds it may be difficult to obtain reliable estimates of precipitation and chloride deposition. If reliable discharge data are available, the method may be used to estimate watershed-average precipitation; this is especially useful in high-altitude mountain watersheds where little or no precipitation data are available. C1 US GEOL SURVEY,DIV WATER RESOURCES,DENVER,CO 80225. NR 34 TC 14 Z9 14 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD FEB PY 1996 VL 32 IS 2 BP 363 EP 372 DI 10.1029/95WR03111 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TT025 UT WOS:A1996TT02500014 ER PT J AU Runkel, RL Bencala, KE Broshears, RE Chapra, SC AF Runkel, RL Bencala, KE Broshears, RE Chapra, SC TI Reactive solute transport in streams .1. Development of an equilibrium-based model SO WATER RESOURCES RESEARCH LA English DT Article ID ACIDIC MOUNTAIN STREAM; IRON PHOTOREDUCTION; RIFFLE STREAM; SUMMIT-COUNTY; COLORADO; STORAGE; SIMULATION; COMPONENTS; OXIDATION; SORPTION AB An equilibrium-based solute transport model is developed for the simulation of trace metal fate and transport in streams. The model is formed by coupling a solute transport model with a chemical equilibrium submodel based on MINTEQ. The solute transport model considers the physical processes of advection, dispersion, lateral inflow, and transient storage, while the equilibrium submodel considers the speciation and complexation of aqueous species, percipitation/dissolution and sorption. Within the model, reactions in the water column may result in the formation of solid phases (precipitates and sorbed species) that are subject to downstream transport and settling processes. Solid phases on the streambed may also interact with the water column through dissolution and sorption/desorption reactions. Consideration of both mobile (water-borne) and immobile (streambed) solid phases requires a unique set of governing differential equations and solution techniques that are developed herein. The partial differential equations describing physical transport and the algebraic equations describing chemical equilibria are coupled using the sequential iteration approach. C1 UNIV COLORADO,DEPT CIVIL ENGN,CTR ADV DECIS SUPPORT WATER & ENVIRONM SYST,BOULDER,CO 80309. RP Runkel, RL (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,LAKEWOOD,CO 80225, USA. RI Chapra, Steven/A-5752-2008; Bencala, Kenneth/A-6650-2010 OI Chapra, Steven/0000-0003-0238-6376; NR 35 TC 55 Z9 55 U1 2 U2 9 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD FEB PY 1996 VL 32 IS 2 BP 409 EP 418 DI 10.1029/95WR03106 PG 10 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TT025 UT WOS:A1996TT02500018 ER PT J AU Runkel, RL McKnight, DM Bencala, KE Chapra, SC AF Runkel, RL McKnight, DM Bencala, KE Chapra, SC TI Reactive solute transport in streams .2. Simulation of a pH modification experiment SO WATER RESOURCES RESEARCH LA English DT Article ID ACIDIC MOUNTAIN STREAM; IRON PHOTOREDUCTION; METAL-RICH; OXIDATION; COLORADO; CHEMISTRY; ALUMINUM; SYSTEMS; MODEL; USA AB We present an application of an equilibrium-based solute transport model to a pH-modification experiment conducted on the Snake River, an acidic, metal-rich stream located in the Rocky Mountains of Colorado. During the experiment, instream pH decreased from 4.2 to 3.2, causing a marked increase in dissolved iron concentrations. Model application requires specification of several parameters that are estimated using tracer techniques, mass balance calculations, and geochemical data. Two basic questions are addressed through model application: (1) What are the processes responsible for the observed increase in dissolved iron concentrations? (2) Can the identified processes be represented within the equilibrium-based transport model? Simulation results indicate that the increase in iron was due to the dissolution of hydrous iron oxides and the photoreduction of ferric iron. Dissolution from the streambed is represented by considering a trace compartment consisting of freshly precipitated hydrous iron oxide and an abundant compartment consisting of aged precipitates that are less soluble. Spatial variability in the solubility of hydrous iron oxide is attributed to heterogeneity in the streambed sediments, temperature effects, and/or variability in the effects of photoreduction. Solubility (pK(sp) from 40.2 to 40.8) relative to the 6 order of magnitude variation reported for laboratory experiments (pK(sp) from 37.3 to 43.3). Results also support the use of an equilibrium-based transport model as the predominate features of the iron and pH profiles are reproduced. The model provides a valuable tool for quantifying the nature and extent of pH-dependent processes within the context of hydrologic transport. C1 UNIV COLORADO,DEPT CIVIL ENGN,CTR ADV DECIS SUPPORT WATER & ENVIRONM SYST,BOULDER,CO 80309. RP Runkel, RL (reprint author), US GEOL SURVEY,DENVER FED CTR,DIV WATER RESOURCES,DENVER,CO 80225, USA. RI Chapra, Steven/A-5752-2008; Bencala, Kenneth/A-6650-2010; OI Chapra, Steven/0000-0003-0238-6376; MCKNIGHT, DIANE/0000-0002-4171-1533 NR 28 TC 43 Z9 43 U1 1 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 SN 0043-1397 J9 WATER RESOUR RES JI Water Resour. Res. PD FEB PY 1996 VL 32 IS 2 BP 419 EP 430 DI 10.1029/95WR03107 PG 12 WC Environmental Sciences; Limnology; Water Resources SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Water Resources GA TT025 UT WOS:A1996TT02500019 ER PT J AU Wernicke, B Clayton, R Ducea, M Jones, CH Park, S Ruppert, S Saleeby, J Snow, JK Squires, L Fliedner, M Jiracek, G Keller, R Klemperer, S Luetgert, J Malin, P Miller, K Mooney, W Oliver, H Phinney, R AF Wernicke, B Clayton, R Ducea, M Jones, CH Park, S Ruppert, S Saleeby, J Snow, JK Squires, L Fliedner, M Jiracek, G Keller, R Klemperer, S Luetgert, J Malin, P Miller, K Mooney, W Oliver, H Phinney, R TI Origin of high mountains in the continents: The southern Sierra Nevada SO SCIENCE LA English DT Article ID UPPER MANTLE; LITHOSPHERE; CALIFORNIA; BENEATH; XENOLITHS; EXTENSION; VALLEY; UPLIFT; FLOW AB Active and passive seismic experiments show that the southern Sierra, despite standing 1.8 to 2.8 kilometers above its surroundings, is underlain by crust of similar seismic thickness, about 30 to 40 kilometers. Thermobarometry of xenolith suites and magnetotelluric profiles indicate that the upper mantle is eclogitic to depths of 60 kilometers beneath the western and central parts of the range, but little subcrustal lithosphere is present beneath the eastern High Sierra and adjacent Basin and Range. These and other data imply the crust of both the High Sierra and Basin and Range thinned by a factor of 2 since 20 million years ago, at odds with purported late Cenozoic regional uplift of some 2 kilometers. C1 UNIV COLORADO,CIRES,BOULDER,CO 80309. UNIV CALIF RIVERSIDE,DEPT EARTH SCI,RIVERSIDE,CA 92521. LAWRENCE LIVERMORE NATL LAB,LIVERMORE,CA 94550. STANFORD UNIV,DEPT GEOPHYS,STANFORD,CA 94305. SAN DIEGO STATE UNIV,DEPT GEOL SCI,SAN DIEGO,CA 92182. UNIV TEXAS,DEPT GEOL SCI,EL PASO,TX 79968. US GEOL SURVEY,MENLO PK,CA 94025. DUKE UNIV,DEPT GEOL,DURHAM,NC 27708. PRINCETON UNIV,DEPT GEOL & GEOPHYS SCI,PRINCETON,NJ 08544. RP Wernicke, B (reprint author), CALTECH,DIV GEOL & PLANETARY SCI 170-25,PASADENA,CA 91125, USA. RI Ducea, Mihai/C-2872-2011; Klemperer, Simon/A-5919-2012; Miller, Kate/E-6800-2012; Ducea, Mihai/I-3139-2012; OI Ducea, Mihai/0000-0002-5322-0782; Jones, Craig/0000-0002-1698-0408; Klemperer, Simon/0000-0001-7050-1829 NR 51 TC 183 Z9 189 U1 3 U2 24 PU AMER ASSOC ADVANCEMENT SCIENCE PI WASHINGTON PA 1200 NEW YORK AVE, NW, WASHINGTON, DC 20005 SN 0036-8075 J9 SCIENCE JI Science PD JAN 12 PY 1996 VL 271 IS 5246 BP 190 EP 193 DI 10.1126/science.271.5246.190 PG 4 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TP364 UT WOS:A1996TP36400037 ER PT J AU Howard, KA Foster, DA AF Howard, KA Foster, DA TI Thermal and unroofing history of a thick, tilted basin-and-range crustal section in the Tortilla Mountains, Arizona SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID METAMORPHIC CORE COMPLEXES; FISSION-TRACK AGES; ANGLE NORMAL FAULTS; TRANSANTARCTIC MOUNTAINS; TECTONIC DENUDATION; CONTINENTAL EXTENSION; VICTORIA-LAND; APATITE; CONSTRAINTS; EVOLUTION AB We estimate here a geothermal gradient of only 17 +/- 5 degrees C km(-1) for the tilted Grayback fault block in southeastern Arizona when extension began similar to 25 Ma. This gradient is lower than preextension gradients estimated elsewhere in the Basin and Range, is only about 50% of typical gradients in the Basin and Range today, and needs to be accounted for in models of continental extension. The Grayback block exposes a 12-km-thick crustal section of Proterozoic and Cretaceous granitoids, which was tilted 90 degrees during extension between 25 and 15 Ma. Zircon fission-track ages decrease structurally downward (westward) across the block and were all within a zone of partial track annealing prior to tilting and quenching. The zircon age gradient suggests that the 220 degrees-240 degrees C isotherm migrated downward 5-6 km during Paleogene erosion and regional cooling. Apatite fission-track ages decrease westward from similar to 83 Ma in the structurally highest crystalline rocks to similar to 24 Ma at similar to 6-km paleodepth and then to similar to 15 Ma another 6 km farther west. Track-length analysis confirms that apatites above the break in slope in age at similar to 5.7-km paleodepth resided in a zone of partial annealing prior to tilting, and deeper apatites record rapid cooling upon tilting and unroofing beginning similar to 25 Ma. At that time the 110 +/- 10 degrees C isotherm determined by the depth at which tracks in apatite were fully erased was at a basement paleodepth of similar to 5.7 km, and the 220 +/- 30 degrees C isotherm as estimated from zircon data resided at a pretilting basement depth of similar to 12.15 km. From consistent values of paleogeothermal gradient for two depth intervals we estimate the pretilt gradient was 17 +/- 5 degrees C km(-1). From 25 to 15 Ma the rotating Grayback block cooled rapidly as higher, westward moving blocks unroofed it tectonically at a rate of similar to 1 km m.y.(-1). C1 LA TROBE UNIV, SCH EARTH SCI, VICTORIAN INST EARTH & PLANETARY SCI, BUNDOORA, VIC 3083, AUSTRALIA. RP US GEOL SURVEY, BRANCH WESTERN REG GEOL, 345 MIDDLEFIELD RD, MS 975, MENLO PK, CA 94025 USA. RI Foster, David/F-1727-2010; OI Foster, David/0000-0002-5603-9372 NR 69 TC 25 Z9 25 U1 1 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 511 EP 522 DI 10.1029/95JB02909 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600001 ER PT J AU BenAvraham, Z tenBrink, U Bell, R Reznikov, M AF BenAvraham, Z tenBrink, U Bell, R Reznikov, M TI Gravity field over the Sea of Galilee: Evidence for a composite basin along a transform fault SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID CENTRAL JORDAN VALLEY; LAKE KINNERET; PALEOMAGNETIC EVIDENCE; CONTINENTAL TRANSFORM; SEISMIC-REFLECTION; ASYMMETRIC BASINS; RIFT; ISRAEL; SYSTEM; PLATE AB The Sea of Galilee (Lake Kinneret) is located at the northern portion of the Kinneret-Bet Shean basin, in the northern Dead Sea transform. Three hundred kilometers of continuous marine gravity data were collected in the lake and integrated with land gravity data to a distance of more than 20 km around the lake. Analyses of the gravity data resulted in a free-air anomaly map, a variable density Bouguer anomaly map, and a horizontal first derivative map of the Bouguer anomaly. These maps, together with gravity models of profiles across the lake and the area south of it, were used to infer the geometry of the basins in this region and the main faults of the transform system. The Sea of Galilee can be divided into two units. The southern half is a pull-apart that extends to the Kinarot Valley, south of the lake, whereas the northern half was formed by rotational opening and transverse normal faults. The deepest part of the basinal area is located well south of the deepest bathymetric depression. This implies that the northeastern part of the lake, where the bathymetry is the deepest, is a young feature that is actively subsiding now. The pull-apart basin is almost symmetrical in the southern part of the lake and in the Kinarot Valley south of the lake. This suggests that the basin here is bounded by strike-slip faults on both sides. The eastern boundary fault extends to the northern part of the lake, while the western fault does not cross the northern part. The main factor controlling the structural complexity of this area is the interaction of the Dead Sea transform with a subperpendicular fault system and rotated blocks. C1 COLUMBIA UNIV, LAMONT DOHERTY GEOL OBSERV, PALISADES, NY 10964 USA. US GEOL SURVEY, WOODS HOLE, MA 02543 USA. RP TEL AVIV UNIV, DEPT GEOPHYS & PLANETARY SCI, IL-69978 TEL AVIV, ISRAEL. RI ten Brink, Uri/A-1258-2008 OI ten Brink, Uri/0000-0001-6858-3001 NR 35 TC 27 Z9 34 U1 0 U2 4 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 533 EP 544 DI 10.1029/95JB03043 PG 12 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600003 ER PT J AU Hagstrum, JT Murchey, BL Begar, RS AF Hagstrum, JT Murchey, BL Begar, RS TI Equatorial origin for Lower Jurassic radiolarian chert in the Franciscan Complex, San Rafael Mountains, southern California SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID COAST RANGE OPHIOLITE; MESOZOIC RED CHERT; BAJA-CALIFORNIA; NORTHWARD TRANSLATION; PALEOMAGNETIC DATA; BENITO ISLANDS; CEDROS ISLAND; MEXICO; REMAGNETIZATION; PALEOLATITUDE AB Lower Jurassic radiolarian chert sampled at two localities in the San Rafael Mountains of southern California (similar to 20 km north of Santa Barbara) contains four components of remanent magnetization. Components A, B', and B are inferred to represent uplift, Miocene volcanism, and subduction/accretion overprint magnetizations, respectively. The fourth component (C), isolated between 580 degrees and 680 degrees C, shows a magnetic polarity stratigraphy and is interpreted as a primary magnetization acquired by the chert during, or soon after, deposition. Both sequences are late Pliensbachian to middle Toarcian in age, and an average paleolatitude calculated from all tilt-corrected C components is 1 degrees +/- 3 degrees north or south. This result is consistent with deposition of the cherts beneath the equatorial zone of high biologic productivity and is similar to initial paleolatitudes determined for chert blocks in northern California and Mexico. This result supports our model in which deep-water Franciscan-type cherts were deposited on the Farallon plate as it moved eastward beneath the equatorial productivity high, were accreted to the continental margin at low paleolatitudes, and were subsequently distributed northward by strike-slip faulting associated with movements of the Kula, Farallon, and Pacific plates. Upper Cretaceous turbidites of the Cachuma Formation were sampled at Agua Caliente Canyon to determine a constraining paleolatitude for accretion of the Jurassic chert sequences. These apparently unaltered rocks, however, were found to be completely overprinted by the A component of magnetization. Similar in situ directions and demagnetization behaviors observed in samples of other Upper Cretaceous turbidite sequences in southern and Baja California imply that these rocks might also give unreliable results. RP Hagstrum, JT (reprint author), US GEOL SURVEY, 345 MIDDLEFIELD RD, MS 937, MENLO PK, CA 94025 USA. NR 43 TC 12 Z9 12 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 613 EP 626 DI 10.1029/95JB02854 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600009 ER PT J AU Crowley, JK Hook, SJ AF Crowley, JK Hook, SJ TI Mapping playa evaporite minerals and associated sediments in Death Valley, California, with multispectral thermal infrared images SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID EMISSIVITY AB Efflorescent salt crusts and associated sediments in Death Valley, California, were studied with remote-sensing data acquired by the NASA thermal infrared multispectral scanner (TIMS). Nine spectral classes that represent a variety of surface materials were distinguished, including several classes that reflect important aspects of the playa groundwater chemistry and hydrology. Evaporite crusts containing abundant thenardite (sodium sulfate) were mapped along the northern and eastern margins of the Cottonball Basin, areas where the inflow waters are rich in sodium. Gypsum (calcium sulfate) crusts were more common in the Badwater Basin, particularly near springs associated with calcic groundwaters along the western basin margin. Evaporite-rich crusts generally marked areas where groundwater is periodically near the surface and thus able to replenish the crusts though capillary evaporation. Detrital silicate minerals were prevalent in other parts of the salt pan where shallow groundwater does not affect the surface composition. The surface features in Death Valley change in response to climatic variations on several different timescales. For example, salt crusts on low-lying mudflats form and redissolve during seasonal-to-interannual cycles of wetting and desiccation. In contrast, recent flooding and erosion of rough-salt surfaces in Death Valley probably reflect increased regional precipitation spanning several decades. Remote-sensing observations of playas can provide a means for monitoring changes in evaporite facies and for better understanding the associated climatic processes. At present, such studies are limited by the availability of suitable airborne scanner data. However, with the launch of the Earth Observing System (EOS) AM-1 Platform in 1998, multispectral visible/near-infrared and thermal infrared remote-sensing data will become globally available. C1 CALTECH, JET PROP LAB, PASADENA, CA 91109 USA. RP Crowley, JK (reprint author), US GEOL SURVEY, MS 927, RESTON, VA 22092 USA. NR 42 TC 60 Z9 62 U1 4 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 643 EP 660 DI 10.1029/95JB02813 PG 18 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600011 ER PT J AU Gomberg, J Davis, S AF Gomberg, J Davis, S TI Stress strain changes and triggered seismicity at The Geysers, California SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; EARTHQUAKE SEQUENCE; LANDER EARTHQUAKE; GEOTHERMAL AREA; STATIC STRESS; AFTERSHOCKS; DEFORMATION; FRICTION; RUPTURE; MODELS AB The principal results of this study of remotely triggered seismicity in The Geysers geothermal field are the demonstration that triggering (initiation of earthquake failure) depends on a critical strain threshold and that the threshold level increases with decreasing frequency or equivalently, depends on strain rate. This threshold function derives from (1) analyses of dynamic strains associated with surface waves of the triggering earthquakes, (2) statistically measured aftershock zone dimensions, and (3) analytic functional representations of strains associated with power production and tides. The thresholds also consistent with triggering by static strain changes and implies that both static and dynamic strains may cause aftershocks. The observation that triggered seismicity probably occurs in addition to background activity also provides an important constraint on the triggering process. Assuming the physical processes underlying earthquake nucleation to be the same, Gomberg [this issue] discusses seismicity triggered by the M(w) 7.3 Landers earthquake, its constraints on the variability of triggering thresholds with site, and the implications of time delays between triggering and triggered earthquakes. Our results enable us to reject the hypothesis that dynamic strains simply nudge prestressed faults over a Coulomb failure threshold sooner than they would have otherwise. We interpret the rate-dependent triggering threshold as evidence of several competing processes with different time constants, the faster one(s) facilitating failure and the other(s) inhibiting it. Such competition is a common feature of theories of slip instability. All these results, not surprisingly, imply that to understand earthquake triggering one must consider not only simple failure criteria requiring exceedence of some constant threshold but also the requirements for generating instabilities. RP Gomberg, J (reprint author), MEMPHIS UNIV, CERI, US GEOL SURVEY, 3890 CENT AVE, MEMPHIS, TN 38152 USA. NR 69 TC 65 Z9 67 U1 1 U2 12 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 733 EP 749 DI 10.1029/95JB03250 PG 17 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600017 ER PT J AU Gomberg, J AF Gomberg, J TI Stress strain changes and triggered seismicity following the M(w)7.3 Landers, California, earthquake SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID SAN-ANDREAS FAULT; STATIC STRESS; DISPLACEMENT; THICKNESS; SEQUENCE; RUPTURE; ZONES; SLIP AB Calculations of dynamic stresses and strains, constrained by broadband seismograms, are used to investigate their role in generating the remotely triggered seismicity that followed the June 25, 1992, M(w) 7.3 Landers, California earthquake. I compare straingrams and dynamic Coulomb failure functions calculated for the Landers earthquake at sites that did experience triggered seismicity with those at sites that did not. Bounds on triggering thresholds are obtained from analysis of dynamic strain spectra calculated for the Landers and M(w) 6.1 Joshua Tree, California, earthquakes at various sites, combined with results of static strain investigations by others. I interpret three principal results of this study with those of a companion study by Gomberg and Davis [this issue]. First, the dynamic elastic stress changes themselves cannot explain the spatial distribution of triggered seismicity, particularly the lack of triggered activity along the San Andreas fault system. In addition to the requirement to exceed a Coulomb failure stress level, this result implies the need to invoke and satisfy the requirements of appropriate slip instability theory. Second, results of this study are consistent with the existence of frequency- or rate-dependent stress/strain triggering thresholds, inferred from the companion study and interpreted in terms of earthquake initiation involving a competition of processes, one promoting failure and the other inhibiting it. Such competition is also part of relevant instability theories. Third, the triggering threshold must vary from site to site, suggesting that the potential for triggering strongly depends on site characteristics and response. The lack of triggering along the San Andreas fault system may be correlated with the advanced maturity of its fault gouge zone; the strains from the Landers earthquake were either insufficient to exceed its larger critical slip distance or some other critical failure parameter; or the faults failed stably as aseismic creep events. Variations in the triggering threshold at sites of triggered seismicity may be attributed to variations in gouge zone development and properties. Finally, these interpretations provide ready explanations for the time delays between the Landers earthquake and the triggered events. RP Gomberg, J (reprint author), MEMPHIS STATE UNIV, CTR EARTHQUAKE RES & INFORMAT, US GEOL SURVEY, MEMPHIS, TN 38152 USA. NR 42 TC 66 Z9 68 U1 0 U2 3 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 751 EP 764 DI 10.1029/95JB03251 PG 14 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600018 ER PT J AU Mendoza, C Fukuyama, E AF Mendoza, C Fukuyama, E TI The July 12, 1993, Hokkaido-Nansei-Oki, Japan, earthquake: Coseismic slip pattern from strong-motion and teleseismic recordings SO JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH LA English DT Article ID RUPTURE HISTORY; INVERSION; CALIFORNIA; MICHOACAN; SEA; BOUNDARY; MODEL AB We employ a finite fault inversion scheme to infer the distribution of coseismic slip for the July 12, 1993, Hokkaido-Nansei-Oki earthquake using strong ground motions recorded by the Japan Meteorological Agency within 400 km of the epicenter and vertical P waveforms recorded by the Global Digital Seismograph Network at teleseismic distances. The assumed fault geometry is based on the location of the aftershock zone and comprises two fault segments with different orientations: a northern segment striking at N20 degrees E with a 30 degrees dip to the west and a southern segment with a N20 degrees W strike. For the southern segment we use both westerly and easterly dip directions to test thrust orientations previously proposed for this portion of the fault. The variance reduction is greater using a shallow west dipping segment, suggesting that the direction of dip did not change as the rupture propagated south from the hypocenter. This indicates that the earthquake resulted from the shallow underthrusting of Hokkaido beneath the Sea of Japan. Static vertical movements predicted by the corresponding distribution of fault slip are consistent with the general pattern of surface deformation observed following the earthquake. Fault rupture in the northern segment accounts for about 60% of the total P wave seismic moment of 3.4 x 10(20) N m and includes a large circular slip zone (4-m peak) near the earthquake hypocenter at depths between 10 and 25 km. Slip in the southern segment is also predominantly shallower than 25 km, but the maximum coseismic displacements (2.0-2.5 m) are observed at a depth of about 5 km. This significant shallow slip in the southern portion of the rupture zone may have been responsible for the large tsunami that devastated the small offshore island of Okushiri. Localized shallow faulting near the island, however, may require a steep westerly dip to reconcile the measured values of ground subsidence. C1 NATL RES INST EARTH SCI & DISASTER PREVENT, TSUKUBA, IBARAKI 305, JAPAN. RP US GEOL SURVEY, BOX 25046, MS 967, DENVER, CO 80225 USA. NR 27 TC 19 Z9 19 U1 0 U2 1 PU AMER GEOPHYSICAL UNION PI WASHINGTON PA 2000 FLORIDA AVE NW, WASHINGTON, DC 20009 USA SN 2169-9313 EI 2169-9356 J9 J GEOPHYS RES-SOL EA JI J. Geophys. Res.-Solid Earth PD JAN 10 PY 1996 VL 101 IS B1 BP 791 EP 801 DI 10.1029/95JB02805 PG 11 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ276 UT WOS:A1996TQ27600020 ER PT J AU Evans, WC AF Evans, WC TI Lake Nyos - Knowledge of the fount and the cause of disaster SO NATURE LA English DT Editorial Material ID CAMEROON RP Evans, WC (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. RI Evans, William/J-4283-2012 NR 10 TC 4 Z9 4 U1 0 U2 5 PU MACMILLAN MAGAZINES LTD PI LONDON PA 4 LITTLE ESSEX STREET, LONDON, ENGLAND WC2R 3LF SN 0028-0836 J9 NATURE JI Nature PD JAN 4 PY 1996 VL 379 IS 6560 BP 21 EP 22 DI 10.1038/379021a0 PG 2 WC Multidisciplinary Sciences SC Science & Technology - Other Topics GA TN216 UT WOS:A1996TN21600028 ER PT B AU Lawrence, GB David, MB Shortle, WC AF Lawrence, GB David, MB Shortle, WC BE Hom, J Birdsey, R OBrian, K TI Aluminum mobilization and calcium depletion in the forest floor of red spruce forests in the northeastern United States SO 1995 MEETING OF THE NORTHERN GLOBAL CHANGE PROGRAM, PROCEEDINGS SE USDA FOREST SERVICE GENERAL TECHNICAL REPORT NORTHEASTERN FOREST EXPERIMENTAL STATION LA English DT Proceedings Paper CT 1995 Meeting of the Northern-Global-Change-Program CY MAR 14-16, 1995 CL PITTSBURGH, PA SP No Global Change Program RP Lawrence, GB (reprint author), US GEOL SURVEY,425 JORDAN RD,TROY,NY 12180, USA. NR 0 TC 0 Z9 0 U1 0 U2 1 PU US DEPT AGR, FOREST SERV NE EXPTL STN PI RADNOR PA 5 RADNOR CORPORATE CTR, 100 MATSONFORD RD, STE 200, PO BOX 6775, RADNOR, PA 19087 J9 USDA NE EXP PY 1996 VL 214 BP 112 EP 117 PG 6 WC Ecology; Environmental Sciences; Forestry SC Environmental Sciences & Ecology; Forestry GA BF65J UT WOS:A1996BF65J00027 ER PT J AU Roeloffs, E AF Roeloffs, E TI Poroelastic techniques in the study of earthquake-related hydrologic phenomena SO ADVANCES IN GEOPHYSICS, VOL 37 SE ADVANCES IN GEOPHYSICS LA English DT Review ID SAN-ANDREAS FAULT; ESTIMATING AQUIFER PARAMETERS; WATER-LEVEL CHANGES; PORE PRESSURE CHANGES; FLUID-FLOW PROPERTIES; FORCED FLUCTUATIONS; GROUNDWATER-FLOW; NUBIAN FORMATION; WELL LEVEL; RUPTURE NUCLEATION RP Roeloffs, E (reprint author), US GEOL SURVEY,5400 MACARTHUR BLVD,VANCOUVER,WA 98661, USA. NR 125 TC 180 Z9 188 U1 3 U2 27 PU ACADEMIC PRESS INC PI SAN DIEGO PA 525 B STREET, SUITE 1900, SAN DIEGO, CA 92101-4495 SN 0065-2687 J9 ADV GEOPHYS PY 1996 VL 37 BP 135 EP 195 DI 10.1016/S0065-2687(08)60270-8 PG 61 WC Geosciences, Multidisciplinary SC Geology GA BH77Q UT WOS:A1996BH77Q00002 ER PT S AU Horowitz, AJ AF Horowitz, AJ BE Michaelis, W TI Spatial and temporal variations in suspended sediment and associated trace elements - Requirements for sampling, data interpretation, and the determination of annual mass transport SO ADVANCES IN LIMNOLOGY 47: SUSPENDED PARTICULATE MATTER IN RIVERS AND ESTUARIES SE ERGEBNISSE DER LIMNOLOGIE LA English DT Proceedings Paper CT International Symposium on Suspended Particulate Matter in Rivers and Estuaries CY MAR 21-25, 1994 CL REINBEK, GERMANY SP Hamburger Sparkasse, Dtsch Gesell Limnol e V, Elect Co Hamburg, GKSS Forschungszentrums Geesthacht e V, Verein Freunde & Forderer, UNESCO AB Suspended sediment plays an important role in the biological and geochemical cycling of trace elements in fluvial systems. Trace element concentrations asssociated with suspended sediments can be as much as six orders of magnitude higher than those found in the dissolved phase; thus, the sampling and analysis of suspended sediment is a requisite for any studies involving the determination of trace elements transport and fluxes. Suspended sediment and associated trace element concentrations can display marked spatial and temporal variations under conditions of both constant and changing discharge. Further, methods of sample collection also can substantively affect the determination of suspended sediment and associated trace element concentrations. As such, the collection of 'representative' suspended sediment samples is an extremely complex problem which usually requires a series of compromises based on acceptable error limits balanced against resource limitations. Attempts to quantify the annual mass transport or fluxes of suspended sediment and associated trace elements call for the collection and analysis of a large number of representative samples covering a substantial portion of the annual hydrograph. Unfortunately, this requirement is usually confounded by manpower and resource limitations. One of the few potential methods for accurately determining annual mass transport requires the use of automatic sampling equipment in conjunction with a series of site-specific regression equations designed to relate the chemical data from point (automatic sample data) samples to those that would have been obtained if a cross-sectionally representative isokinetic depth-and-width integrated sample had been collected. Experiments from two rivers in the U.S. indicate that such an approach is feasible, and permits the accurate (within +/- 20 %) determination of cross-sectional suspended sediment and associated trace element concentrations from which annual mass transport can be calculated. RP Horowitz, AJ (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,PEACHTREE BUSINESS CTR,3039 AMWILER RD,ATLANTA,GA 30360, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU E SCHWEIZERBART'SCHE VERLAGSBUCHHANDLUNG PI STUTTGART PA JOHANNESTRASSE 3, W-7000 STUTTGART, GERMANY SN 0071-1128 BN 3-510-47048-6 J9 ERGEB LIMNOL PY 1996 VL 47 BP 515 EP 536 PG 22 WC Ecology; Environmental Sciences; Limnology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA BH14Q UT WOS:A1996BH14Q00052 ER PT J AU Wittke, JH Duffield, WA Jones, C AF Wittke, JH Duffield, WA Jones, C TI Roof-rock contamination of Taylor Creek Rhyolite, New Mexico, as recorded in hornblende phenocrysts and biotite xenocrysts SO AMERICAN MINERALOGIST LA English DT Article ID EMPIRICAL IGNEOUS GEOBAROMETER; SILICIC MAGMA; EXPERIMENTAL CALIBRATION; LAVA DOMES; GRADIENTS; ALUMINUM; PRESSURE; GEOCHEMISTRY; CALIFORNIA; RESERVOIRS AB The Taylor Creek Rhyolite, a group of coeval, mid-Tertiary, silica-rich rhyolite lava domes in southwestern New Mexico, is notable for recording bulk-rock evidence of minor, yet easily measurable, contamination of its source magma reservoir resulting from assimilation of Proterozoic roof rock. Most of the evidence is recorded in trace element concentrations and Sr-87/Sr-86(i) ratios, which are far different in uncontaminated magma and roof rocks. Hornblende phenocrysts and biotite xenocrysts also record the effects of contamination. Electron microprobe analyses show that all hornblende grains are zoned to Mg-rich and Fe- and Mn-poor rims. Rim MgO content is typically about 10 wt% greater than core MgO content. Other hornblende constituents are not measurably variable. Biotite xenocrysts, trace mineral constituents, are present only in the domes that are most contaminated, as judged by bulk-rock variations in trace element concentrations and Sr-87/Sr-86(i). Biotite grains are invariably partly to almost completely altered. Microprobe analyses of the cores of the least-altered grains show that large variations in Fe and Mg and that biotite contains 2-20 times as much Mg as fresh biotite phenocrysts in other silica-rich rhyolite lavas. Fe and Mg are negatively correlated in hornblende and biotite, consistent with mixing two end-member compositions. The mass ratio of contaminant to magma was probably less than 1:100, and major constituents, including Al, were not measurably affected in hornblende. Al-in-hornblende barometry yields essentially a constant calculated pressure of about 1.5 kbar, which is consistent with the interpretation that all contamination occurred in a boundary zone about 300 m thick at the top of the magma reservoir. C1 US GEOL SURVEY, FLAGSTAFF, AZ 86001 USA. RP Wittke, JH (reprint author), NO ARIZONA UNIV, DEPT GEOL, FLAGSTAFF, AZ 86011 USA. NR 25 TC 4 Z9 4 U1 2 U2 2 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0003-004X EI 1945-3027 J9 AM MINERAL JI Am. Miner. PD JAN-FEB PY 1996 VL 81 IS 1-2 BP 135 EP 140 PG 6 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA TW233 UT WOS:A1996TW23300017 ER PT J AU Hawthorne, FC Oberti, R Ungaretti, L Ottolini, L Grice, JD Czamanske, GK AF Hawthorne, FC Oberti, R Ungaretti, L Ottolini, L Grice, JD Czamanske, GK TI Fluor-ferro-leakeite, NaNa2(Fe22+Fe23+Li)Si8O22F2, a new alkali amphibole from the Canada Pinabete pluton, Questa, New Mexico, USA SO AMERICAN MINERALOGIST LA English DT Article AB Fluor-ferro-leakeite is a new amphibole species from the Canada Pinabete pluton, Questa, New Mexico, U.S.A.; it occurs in association with quartz, alkali feldspar, acmite, ilmenite, and zircon. It forms as anhedral bluish black crystals elongated along c and up to 1 mm long. It is brittle, H = 6, D-meas = 3.37 g/cm(3), D-calc = 3.34 g/cm(3). In plane-polarized light, it is strongly pleochroic, X = very dark indigo blue, Y = gray blue, Z = yellow green; X boolean AND c = 10 degrees(in beta obtuse), Y = b, Z boolean AND a = 4 degrees (in beta obtuse), with absorption X > Y > Z. Fluor-ferro-leakeite is biaxial positive, alpha = 1.675(2), beta = 1.683(2), gamma = 1.694(1); 2V = 87(2)degrees; dispersion is not visible because of the strong absorption. Fluor-ferro-leakeite is monoclinic, space group C2/m, a = 9.792(1), b = 17.938(1), c = 5.3133(4) Angstrom, beta = 103.87(7)degrees, V = 906.0(1) Angstrom(3), Z = 2. The ten strongest X-ray diffraction lines in the powder pattern are [d(I,hkl)]: 2.710(100,151), 2.536<(92,(2)over bar 02>), 3.404(57,131), 4.481(54,040), 8.426(45,110), 2.985(<38, (2)over bar 41>), 2.585(38,061), 3.122(29,310), 2.165(26,261), and 1.586(<25,(4)over bar 03>). Analysis by a combination of electron microprobe, ion microprobe, and crystal-structure refinement (Hawthorne et al. 1993) gives SiO2 51.12, Al2O3 1.13, TiO2 0.68, Fe2O3 16.73, FeO 8.87, MgO 2.02, MnO 4.51, ZnO 0.57, CaO 0.15, Na2O 9.22, K2O 1.19, Li2O 0.99, F 2.87, H2Ocalc 0.60, sum 99.34 wt%. The formula unit, calculated on the basis of 23 O atoms, is (K0.23Na0.76)(Na1.97Ca0.03)(Mg0.46Fe1.142+Zn0.007Fe1.933+- Ti0.08Al0.02Li0.61)(Si7.81Al0.19)O-22(F1.39OH0.61). A previous crystal-structure refinement (Hawthorne et al. 1993) shows Li to be completely ordered at the M3 site. Fluor-ferro-leakeite, ideally NaNa2(Fe22+Fe22+ Li)Si8O22F2, is related to leakeite, NaNa2(Mg2Fe33+ Li)Si8O22(OH)(2),by the substitutions Fe2+ --> Mg and F --> OH. C1 CNR,CTR STUDIO CRISTALLOCHIM & CRISTALLOG,I-27100 PAVIA,ITALY. CANADIAN MUSEUM NAT,DIV RES,OTTAWA,ON K1P 6P4,CANADA. US GEOL SURVEY,MENLO PK,CA 94025. RP Hawthorne, FC (reprint author), UNIV MANITOBA,DEPT GEOL SCI,WINNIPEG,MB R3T 2N2,CANADA. RI Hawthorne, Frank/F-6864-2011; Oberti, Roberta/L-7650-2014 OI Hawthorne, Frank/0000-0001-6405-9931; Oberti, Roberta/0000-0002-2724-0042 NR 10 TC 21 Z9 23 U1 0 U2 2 PU MINERALOGICAL SOC AMER PI WASHINGTON PA 1130 17TH ST NW SUITE 330, WASHINGTON, DC 20036 SN 0003-004X J9 AM MINERAL JI Am. Miner. PD JAN-FEB PY 1996 VL 81 IS 1-2 BP 226 EP 228 PG 3 WC Geochemistry & Geophysics; Mineralogy SC Geochemistry & Geophysics; Mineralogy GA TW233 UT WOS:A1996TW23300027 ER PT B AU Feder, GL Croner, CM Pickle, LW AF Feder, GL Croner, CM Pickle, LW GP AMER STAT ASSOC TI Geologic and hydrologic data in epidemiologic analysis SO AMERICAN STATISTICAL ASSOCIATION - 1996 PROCEEDINGS OF THE EPIDEMIOLOGY SECTION LA English DT Proceedings Paper CT Symposium of the Epidemiology Section, at the Annual Meeting of the American-Statistical-Association CY AUG 04-08, 1996 CL CHICAGO, IL SP Amer Stat Assoc, Epidemiol Sect DE WATSTORE; STORET; water quality; magnesium; ecologic studies RP Feder, GL (reprint author), US GEOL SURVEY,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER STATISTICAL ASSOC PI ALEXANDRIA PA 1429 DUKE ST, ALEXANDRIA, VA 22314 BN 1-883276-43-8 PY 1996 BP 19 EP 22 PG 4 WC Public, Environmental & Occupational Health; Medical Informatics; Statistics & Probability SC Public, Environmental & Occupational Health; Medical Informatics; Mathematics GA BJ14Q UT WOS:A1996BJ14Q00004 ER PT S AU Molnia, BF Post, A Carlson, PR AF Molnia, BF Post, A Carlson, PR BE Collins, D TI 20th-century glacial-marine sedimentation in Vitus lake, Bering glacier, Alaska, USA SO ANNALS OF GLACIOLOGY, VOL. 22, 1996: PROCEEDINGS OF THE INTERNATIONAL SYMPOSIUM ON GLACIAL EROSION AND SEDIMENTATION SE ANNALS OF GLACIOLOGY LA English DT Proceedings Paper CT International Symposium on Glacial Erosion and Sedimentation CY AUG 20-25, 1995 CL REYKJAVIK, ICELAND SP Int Glaciol Soc C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 6 Z9 6 U1 0 U2 0 PU INT GLACIOLOGICAL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0260-3055 J9 ANN GLACIOL PY 1996 VL 22 BP 205 EP 210 PG 6 WC Geology SC Geology GA BG09M UT WOS:A1996BG09M00030 ER PT J AU Johnston, AC Schweig, ES AF Johnston, AC Schweig, ES TI The enigma of the New Madrid earthquakes of 1811-1812 SO ANNUAL REVIEW OF EARTH AND PLANETARY SCIENCES LA English DT Review DE continental rifts; great earthquakes; paleoseismology ID SEISMIC ZONE; UNITED-STATES; REELFOOT RIFT; MISSISSIPPI EMBAYMENT; NORTH-AMERICA; GROUND MOTION; FAULT; RECURRENCE; MAGNITUDES; TECTONICS AB Continental North America's greatest earthquake sequence struck on the western frontier of the United States. The frontier was not then California but the valley of the continent's greatest river, the Mississippi, and the sequence was the New Madrid earthquakes of the winter of 1811-1812. Their described impacts on the land and the river were so dramatic as to produce widespread modem disbelief. However, geological, geophysical, and historical research, carried out mostly in the past two decades, has verified much in the historical accounts. The sequence included at least six (possibly nine) events of estimated moment magnitude M greater than or equal to 7 and two of M similar or equal to 8. The faulting was in the intruded crust of a failed intracontinental rift, beneath the saturated alluvium of the river valley, and its violent shaking resulted in massive and extensive liquefaction. The largest earthquakes ruptured at least six (and possibly more than seven) intersecting fault segments, one of which broke the surface as a thrust fault that disrupted the bed of the Mississippi River in at least 2 (and possibly four) places. C1 US GEOL SURVEY, MEMPHIS, TN 38152 USA. RP MEMPHIS UNIV, CTR EARTHQUAKE RES & INFORMAT, MEMPHIS, TN 38152 USA. NR 121 TC 190 Z9 193 U1 1 U2 16 PU ANNUAL REVIEWS PI PALO ALTO PA 4139 EL CAMINO WAY, PO BOX 10139, PALO ALTO, CA 94303-0139 USA SN 0084-6597 J9 ANNU REV EARTH PL SC JI Annu. Rev. Earth Planet. Sci. PY 1996 VL 24 BP 339 EP 384 DI 10.1146/annurev.earth.24.1.339 PG 46 WC Astronomy & Astrophysics; Geosciences, Multidisciplinary SC Astronomy & Astrophysics; Geology GA UN640 UT WOS:A1996UN64000012 ER PT S AU Hay, L Knapp, L AF Hay, L Knapp, L BE Kovar, K Nachtnebel, HP TI Integrating a geographic information system, a scientific visualization system and an orographic precipitation model SO APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS IN HYDROLOGY AND WATER RESOURCES MANAGEMENT SE IAHS PUBLICATIONS LA English DT Proceedings Paper CT Conference on the Application of Geographic Information Systems in Hydrology and Water Resources Management (HydroGIS 96) CY APR 16-19, 1996 CL VIENNA, AUSTRIA SP Univ Bodenkultur, Inst Wasserwirtsch Hydrol & Konstruktiven, Vienna, Int Assoc Hydrol Sci, Int Commiss Groundwater, IAHS, Int Comm Remote Sensing & Data Transmiss, UNESCO, Div Water Sci, Int Assoc Hydrogeologists, Int Ground Water Modeling Ctr, Int Inst Appl Syst Anal, Austria, Amer Soc Testing & Mat, Amer Soc Photogrammetry & Remote Sensing, Austrian Hydrol Soc, Int Assoc Hydraul Res C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 0-947571-84-1 J9 IAHS-AISH P PY 1996 IS 235 BP 123 EP 131 PG 9 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BF89F UT WOS:A1996BF89F00015 ER PT S AU Battaglin, WA Goolsby, DA AF Battaglin, WA Goolsby, DA BE Kovar, K Nachtnebel, HP TI Using GIS and logistic regression to estimate agricultural chemical concentrations in rivers of the midwestern USA SO APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS IN HYDROLOGY AND WATER RESOURCES MANAGEMENT SE IAHS PUBLICATIONS LA English DT Proceedings Paper CT Conference on the Application of Geographic Information Systems in Hydrology and Water Resources Management (HydroGIS 96) CY APR 16-19, 1996 CL VIENNA, AUSTRIA SP Univ Bodenkultur, Inst Wasserwirtsch Hydrol & Konstruktiven, Vienna, Int Assoc Hydrol Sci, Int Commiss Groundwater, IAHS, Int Comm Remote Sensing & Data Transmiss, UNESCO, Div Water Sci, Int Assoc Hydrogeologists, Int Ground Water Modeling Ctr, Int Inst Appl Syst Anal, Austria, Amer Soc Testing & Mat, Amer Soc Photogrammetry & Remote Sensing, Austrian Hydrol Soc, Int Assoc Hydraul Res C1 US GEOL SURVEY,LAKEWOOD,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 0-947571-84-1 J9 IAHS-AISH P PY 1996 IS 235 BP 253 EP 260 PG 8 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BF89F UT WOS:A1996BF89F00030 ER PT S AU DAgnese, FA Faunt, CC Turner, AK AF DAgnese, FA Faunt, CC Turner, AK BE Kovar, K Nachtnebel, HP TI Using remote sensing and GIS techniques to estimate discharge and recharge fluxes for the Death Valley regional groundwater flow system, USA SO APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS IN HYDROLOGY AND WATER RESOURCES MANAGEMENT SE IAHS PUBLICATIONS LA English DT Proceedings Paper CT Conference on the Application of Geographic Information Systems in Hydrology and Water Resources Management (HydroGIS 96) CY APR 16-19, 1996 CL VIENNA, AUSTRIA SP Univ Bodenkultur, Inst Wasserwirtsch Hydrol & Konstruktiven, Vienna, Int Assoc Hydrol Sci, Int Commiss Groundwater, IAHS, Int Comm Remote Sensing & Data Transmiss, UNESCO, Div Water Sci, Int Assoc Hydrogeologists, Int Ground Water Modeling Ctr, Int Inst Appl Syst Anal, Austria, Amer Soc Testing & Mat, Amer Soc Photogrammetry & Remote Sensing, Austrian Hydrol Soc, Int Assoc Hydraul Res C1 US GEOL SURVEY,DIV WATER RESOURCES,LAKEWOOD,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 0-947571-84-1 J9 IAHS-AISH P PY 1996 IS 235 BP 503 EP 511 PG 9 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BF89F UT WOS:A1996BF89F00060 ER PT S AU Verstraeten, IM McGuire, VL Battaglin, WA AF Verstraeten, IM McGuire, VL Battaglin, WA BE Kovar, K Nachtnebel, HP TI Use of 2D and 3D GIS in well selection and interpretation of nitrate data, central Nebraska, USA SO APPLICATION OF GEOGRAPHIC INFORMATION SYSTEMS IN HYDROLOGY AND WATER RESOURCES MANAGEMENT SE IAHS PUBLICATIONS LA English DT Proceedings Paper CT Conference on the Application of Geographic Information Systems in Hydrology and Water Resources Management (HydroGIS 96) CY APR 16-19, 1996 CL VIENNA, AUSTRIA SP Univ Bodenkultur, Inst Wasserwirtsch Hydrol & Konstruktiven, Vienna, Int Assoc Hydrol Sci, Int Commiss Groundwater, IAHS, Int Comm Remote Sensing & Data Transmiss, UNESCO, Div Water Sci, Int Assoc Hydrogeologists, Int Ground Water Modeling Ctr, Int Inst Appl Syst Anal, Austria, Amer Soc Testing & Mat, Amer Soc Photogrammetry & Remote Sensing, Austrian Hydrol Soc, Int Assoc Hydraul Res C1 US GEOL SURVEY,DIV WATER RESOURCES,LINCOLN,NE 68508. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 0-947571-84-1 J9 IAHS-AISH P PY 1996 IS 235 BP 585 EP 591 PG 7 WC Geosciences, Multidisciplinary; Remote Sensing SC Geology; Remote Sensing GA BF89F UT WOS:A1996BF89F00070 ER PT J AU Lovley, DR Woodward, JC Chapelle, FH AF Lovley, DR Woodward, JC Chapelle, FH TI Rapid anaerobic benzene oxidation with a variety of chelated Fe(III) forms SO APPLIED AND ENVIRONMENTAL MICROBIOLOGY LA English DT Article ID AROMATIC-HYDROCARBONS; DENITRIFYING CONDITIONS; AQUIFER MICROORGANISMS; INSITU BIORESTORATION; BIODEGRADATION; BIOTRANSFORMATION; MINERALIZATION; DEGRADATION; COLUMNS; NITRATE AB Fe(III) chelated to such compounds as EDTA, N-methyliminodiacetic acid, ethanol diglycine, humic acids, and phosphates stimulated benzene oxidation coupled to Fe(III) reduction in anaerobic sediments from a petroleum-contaminated aquifer as effectively as or more effectively than nitrilotriacetic acid did in a previously demonstrated stimulation experiment. These results indicate that many forms of chelated Fe(III) might be applicable to aquifer remediation. C1 US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092. US GEOL SURVEY,DIV WATER RESOURCES,COLUMBIA,SC 29210. RP Lovley, DR (reprint author), UNIV MASSACHUSETTS,DEPT MICROBIOL,AMHERST,MA 01003, USA. NR 24 TC 159 Z9 168 U1 3 U2 21 PU AMER SOC MICROBIOLOGY PI WASHINGTON PA 1325 MASSACHUSETTS AVENUE, NW, WASHINGTON, DC 20005-4171 SN 0099-2240 J9 APPL ENVIRON MICROB JI Appl. Environ. Microbiol. PD JAN PY 1996 VL 62 IS 1 BP 288 EP 291 PG 4 WC Biotechnology & Applied Microbiology; Microbiology SC Biotechnology & Applied Microbiology; Microbiology GA TN226 UT WOS:A1996TN22600051 PM 16535218 ER PT J AU Hall, GEM BonhamCarter, GF Horowitz, AJ Lum, K Lemieux, C Quemerais, B Garbarino, JR AF Hall, GEM BonhamCarter, GF Horowitz, AJ Lum, K Lemieux, C Quemerais, B Garbarino, JR TI The effect of using different 0.45 mu m filter membranes on 'dissolved' element concentrations in natural waters SO APPLIED GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 3rd International Symposium on Environmental Geochemistry CY SEP 12-16, 1994 CL KRAKOW, POLAND SP Int Assoc Geochem & Cosmochem, Soc Environm Geochem & Hlth AB The effect of 4 different 0.45 mu m pore size filter membrane systems on the 'dissolved' concentration of 28 elements in 5 natural water samples of varying matrix is reported. In 3 of the 5 waters, consistently higher concentrations of most elements (minor and trace) are obtained using Nucleopore 47 mm filter and the cellulose acetate/nitrate 47 mm filter than those measured using the 142 mm cellulose nitrate MFS filter or the Gelman capsule 47 mm filter. These distinct and coherent patterns in elemental behaviour disappear for the other 2 samples, an organic-rich peat water of high suspended load and a mineralised sample high in Si and Ca. Thus the nature and degree of filtration artifacts is matrix-dependent. These trends are evident in both data sets produced by 2 independent laboratories using different instrumentation, techniques and calibrating procedures. The average relative standard deviation in elemental concentration across the 4 filter types is in the range 9-21 %. The presence of such filtration artifacts must be considered in projects where, for example, seasonal variability of water composition is under examination, data from various sources are being merged or hydrogeochemical surveys are being conducted. Copyright (C) 1996 Elsevier Science Ltd C1 US GEOL SURVEY,ATLANTA,GA 30360. ENVIRONM CANADA,CTR ST LAURENT,LONGNEUIL,PQ J4K 1A1,CANADA. US GEOL SURVEY,DENVER FED CTR,LAKEWOOD,CO 80225. RP Hall, GEM (reprint author), GEOL SURVEY CANADA,601 BOOTH ST,OTTAWA,ON K1A 0E8,CANADA. NR 6 TC 26 Z9 26 U1 1 U2 4 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD JAN-MAR PY 1996 VL 11 IS 1-2 BP 243 EP 249 DI 10.1016/0883-2927(96)00059-5 PG 7 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ481 UT WOS:A1996UQ48100038 ER PT J AU Stollenwerk, KG AF Stollenwerk, KG TI Simulation of phosphate transport in sewage-contaminated groundwater, Cape Cod, Massachusetts SO APPLIED GEOCHEMISTRY LA English DT Article; Proceedings Paper CT 3rd International Symposium on Environmental Geochemistry CY SEP 12-16, 1994 CL KRAKOW, POLAND SP Int Assoc Geochem & Cosmochem, Soc Environm Geochem & Hlth ID GRADIENT TRACER TEST; GRAVEL; SAND AB Sewage-contaminated groundwater currently discharges to Ashumet Pond, located on Cape Cod, Massachusetts. Phosphate concentrations as high as 60 mu mol l(-1) have been measured in groundwater entering Ashumet Pond, and there is concern that the rate of eutrophication could increase. Phosphate in the sewage plume is sorbed by aquifer sediment; the amount is a function of phosphate concentration and pH. A nonelectrostatic surface-complexation model coupled with a one-dimensional solute-transport code was used to simulate sorption and desorption of phosphate in laboratory column experiments. The model simulated sorption of phosphate reasonably well, although the slow rate of approach to complete breakthrough indicated a nonequilibrium process that was not accounted for in the solute-transport model. The rate of phosphate desorption in the column experiments was relatively slow. Phosphate could still be measured in effluent after 160 pore volumes of uncontaminated groundwater had been hushed through the columns. Desorption was partly a function of the slowly decreasing pH in the columns and could be modeled quantitatively. Disposal of sewage at this site is scheduled to stop in 1995; however, a large reservoir of sorbed phosphate exists on aquifer sediment upgradient from Ashumet Pond. Computer simulations predict that desorption of phosphate could result in contamination of Ashumet Pond for decades. Copyright (C) 1996 Elsevier Science Ltd RP Stollenwerk, KG (reprint author), US GEOL SURVEY, DENVER FED CTR, BOX 25046, MS 413, DENVER, CO 80225 USA. NR 18 TC 22 Z9 22 U1 2 U2 8 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD OX5 1GB, ENGLAND SN 0883-2927 J9 APPL GEOCHEM JI Appl. Geochem. PD JAN-MAR PY 1996 VL 11 IS 1-2 BP 317 EP 324 DI 10.1016/0883-2927(95)00041-0 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UQ481 UT WOS:A1996UQ48100048 ER PT J AU Redmond, MS Crocker, PA McKenna, KM Petrocelli, EA Scott, KJ Demas, CR AF Redmond, MS Crocker, PA McKenna, KM Petrocelli, EA Scott, KJ Demas, CR TI Sediment toxicity testing with the amphipod Ampelisca abdita in Calcasieu Estuary, Louisiana SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article ID CONTAMINATION; COMMUNITY AB Discharges from chemical and petrochemical manufacturing facilities have contaminated portions of Louisiana's Calcasieu River estuary with a variety of organic and inorganic contaminants. As part of a special study, sediment toxicity testing was conducted to assess potential impact to the benthic community. Ten-day flow-through sediment toxicity tests with the amphipod Ampelisca abdita revealed significant toxicity at 68% (26 of 38) of the stations tested. A. abdita mortality was highest in the effluent-dominated bayous, which are tributaries to the Calcasieu River. Mortality was correlated with total heavy metal and total organic compound concentrations in the sediments. Ancillary experiments showed that sediment interstitial water salinity as low as 2.5 o/oo did not significantly affect A. abdita's response in the flow-through system; sediment storage for 7 weeks at 4 degrees C did not significantly affect toxicity. Sediment toxicity to A. abdita was more prevalent than receiving water toxicity using three short-term chronic bioassays. Results suggest that toxicity testing using this amphipod is a valuable tool when assessing sediments containing complex contaminant mixtures and for assessing effects of pollutant loading over time. In conjunction with chemical analyses, the testing indicated that the effluent-dominated, brackish bayous (Bayou d'Inde and Bayou Verdine) were the portions of the estuary most impacted by toxicity. C1 US EPA, ECOSYST PROTECT BRANCH, DALLAS, TX 75202 USA. SCI APPLICAT INT CORP, NARRAGANSETT, RI 02882 USA. US EPA, SAIC, NARRAGANSETT, RI 02882 USA. US EPA, COMP SCI CORP, NARRAGANSETT, RI 02882 USA. US GEOL SURVEY, BATON ROUGE, LA 70816 USA. NR 30 TC 7 Z9 7 U1 0 U2 4 PU SPRINGER PI NEW YORK PA 233 SPRING ST, NEW YORK, NY 10013 USA SN 0090-4341 EI 1432-0703 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD JAN PY 1996 VL 30 IS 1 BP 53 EP 61 PG 9 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TH793 UT WOS:A1996TH79300008 ER PT J AU Tate, CM Heiny, JS AF Tate, CM Heiny, JS TI Organochlorine compounds in bed sediment and fish tissue in the South Platte River Basin, USA, 1992-1993 SO ARCHIVES OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY LA English DT Article AB Bed-sediment and fish-tissue samples were collected in the South Platte River Basin to determine the occurrence and distribution of organochlorine compounds in the basin. During August-November 1992 and August 1993, bed sediment (23 sites) and fish tissue (subset of 19 sites) were sampled and analyzed for 32 organochlorine compounds in bed sediment and 27 compounds in fish tissue. More types of organochlorine compounds were detected in fish tissue than in bed sediment. Total DDT, p,p'-DDE, o,p'-DDE, p,p'-DDD, total PCB, Dac thal(R), dieldrin, cis-chlordane, cis-nonachlor, trans-nonachlor, and p,p'-DDT were detected in fish tissue at >25% of the sites; p,p'-DDE, total DDT, cis-chlordane, and trans-chlordane were detected in bed sediment at >25% of the sites. Organochlorine concentrations in bed sediment and fish tissue were related to land-use settings. Few organochlorine compounds were detected at minimally impacted sites located in rangeland, forest, and built-up land-use settings. Chlordane-related compounds and p,p'-methoxychlor in bed sediment and fish tissue, endrin in fish tissue, and endosulfan I in bed sediment were associated with urban and mixed (urban and agricultural) sites. Dacthal(R) in bed sediment and fish tissue was associated with agricultural sites. The compounds HCB, gamma-HCH, PCA, and toxaphene were detected only at mixed land-use sites. Although DDT and DDT-metabolites, dieldrin, and total PCB were detected in urban, mixed, and agricultural land-use settings, highest mean concentrations were detected at mixed land-use sites. Mixed land-use sites had the greatest number of organochlorine compounds detected in fish tissue, whereas urban and mixed sites had the greatest number of organochlorine compounds detected in bed sediment. Measuring concentrations of organochlorine compounds in bed sediment and fish tissue at the same site offers a more complete picture of the persistence of organochlorine compounds in the environment and their relation to land-use settings. RP Tate, CM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,BOX 25046,MS 415,DENVER,CO 80225, USA. NR 29 TC 18 Z9 18 U1 0 U2 1 PU SPRINGER VERLAG PI NEW YORK PA 175 FIFTH AVE, NEW YORK, NY 10010 SN 0090-4341 J9 ARCH ENVIRON CON TOX JI Arch. Environ. Contam. Toxicol. PD JAN PY 1996 VL 30 IS 1 BP 62 EP 78 PG 17 WC Environmental Sciences; Toxicology SC Environmental Sciences & Ecology; Toxicology GA TH793 UT WOS:A1996TH79300009 ER PT J AU Anovitz, LM Hemingway, BS AF Anovitz, LM Hemingway, BS TI Thermodynamics of boron minerals: Summary of structural, volumetric and thermochemical data SO BORON SE REVIEWS IN MINERALOGY LA English DT Review ID CRYSTAL X-RAY; ZEOLITE-TYPE PENTABORATE; STANDARD FREE-ENERGIES; ALKALI-FREE TOURMALINE; ROCKS WESTERN ALPS; DARA-I-PIOZ; THERMAL-DECOMPOSITION; SILICATE MINERALS; FREE KORNERUPINE; GIBBS ENERGIES C1 US GEOL SURVEY,NATL CTR,RESTON,VA 22092. RP Anovitz, LM (reprint author), OAK RIDGE NATL LAB,DIV CHEM & ANALYT SCI,POB 2008,MS 6110,BLDG 4500-S,OAK RIDGE,TN 37831, USA. OI Anovitz, Lawrence/0000-0002-2609-8750 NR 641 TC 20 Z9 20 U1 0 U2 8 PU MINERALOGICAL SOC AMERICA PI WASHINGTON PA 1130 SEVENTEENTH ST NW, SUITE 330, WASHINGTON, DC 20036 SN 0275-0279 J9 REV MINERAL PY 1996 VL 33 BP 181 EP 261 PG 81 WC Mineralogy SC Mineralogy GA BG26A UT WOS:A1996BG26A00005 ER PT J AU Smith, GI Medrano, MD AF Smith, GI Medrano, MD TI Continental borate deposits of Cenozoic age SO BORON SE REVIEWS IN MINERALOGY LA English DT Review ID MINERALS RP Smith, GI (reprint author), US GEOL SURVEY,MS 902,MENLO PK,CA 94025, USA. NR 125 TC 18 Z9 20 U1 0 U2 0 PU MINERALOGICAL SOC AMERICA PI WASHINGTON PA 1130 SEVENTEENTH ST NW, SUITE 330, WASHINGTON, DC 20036 SN 0275-0279 J9 REV MINERAL PY 1996 VL 33 BP 263 EP 298 PG 36 WC Mineralogy SC Mineralogy GA BG26A UT WOS:A1996BG26A00006 ER PT J AU Slack, JF AF Slack, JF TI Tourmaline associations with hydrothermal ore deposits SO BORON SE REVIEWS IN MINERALOGY LA English DT Review ID MASSIVE SULFIDE DEPOSITS; ABITIBI GREENSTONE-BELT; PORPHYRY COPPER-DEPOSIT; LODE GOLD DEPOSITS; STRATABOUND TUNGSTEN MINERALIZATION; BEARING BRECCIA PIPE; AUSTROALPINE-CRYSTALLINE-COMPLEX; AU-MO MINERALIZATION; WALL-ROCK ALTERATION; SN-W MINERALIZATION RP Slack, JF (reprint author), US GEOL SURVEY,NATL CTR,MS 954,RESTON,VA 22092, USA. RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 549 TC 57 Z9 57 U1 2 U2 13 PU MINERALOGICAL SOC AMERICA PI WASHINGTON PA 1130 SEVENTEENTH ST NW, SUITE 330, WASHINGTON, DC 20036 SN 0275-0279 J9 REV MINERAL PY 1996 VL 33 BP 559 EP 643 PG 85 WC Mineralogy SC Mineralogy GA BG26A UT WOS:A1996BG26A00011 ER PT J AU McGee, JJ Anovitz, LM AF McGee, JJ Anovitz, LM TI Electron probe microanalysis of geologic materials for boron SO BORON SE REVIEWS IN MINERALOGY LA English DT Review ID X-RAY; LIGHT-ELEMENTS; MICROPROBE ANALYSIS; KORNERUPINE; MINERALS; OXYGEN; TOURMALINE; VESUVIANITE; CHEMISTRY C1 OAK RIDGE NATL LAB,OAK RIDGE,TN 37831. RP McGee, JJ (reprint author), US GEOL SURVEY,NATL CTR 953,RESTON,VA 22092, USA. RI Anovitz, Lawrence/P-3144-2016 OI Anovitz, Lawrence/0000-0002-2609-8750 NR 67 TC 27 Z9 27 U1 1 U2 2 PU MINERALOGICAL SOC AMERICA PI WASHINGTON PA 1130 SEVENTEENTH ST NW, SUITE 330, WASHINGTON, DC 20036 SN 0275-0279 J9 REV MINERAL PY 1996 VL 33 BP 771 EP 788 PG 18 WC Mineralogy SC Mineralogy GA BG26A UT WOS:A1996BG26A00015 ER PT J AU Bowers, JE AF Bowers, JE TI More flowers or new cladodes? Environmental correlates and biological consequences of sexual reproduction in a Sonoran Desert prickly pear cactus, Opuntia engelmannii SO BULLETIN OF THE TORREY BOTANICAL CLUB LA English DT Article DE flower production; fruit production; resource allocation; Sonoran Desert; Opuntia engelmannii ID FRUIT-SET; PLANTS AB Should a platyopuntia expend all aerolar meristems in flower production, no new cladodes could be produced, and further reproductive effort and vegetative growth would cease. To investigate the trade-off between flower and cladode production, the numbers of flowers, fruits, and cladodes were monitored for 4 years on 30 Opuntia engelmannii Salm-Dych. plants on Tumamoc Hill, Tucson, Arizona. Plant size controlled the number of flowers initiated each spring. The proportion of flowers that developed (i.e., did not abort) was perhaps determined by December-February rainfall in the months before bloom, with more being developed in the wettest years. Models based on different ratios of initiated cladodes to initiated flowers demonstrated that continued high investment in flowers and fruits would eventually terminate reproduction altogether; therefore periods of high sexual reproduction should alternate with periods of high vegetative growth. In the first 3 years of this study, the ratio of new cladodes to initiated flowers was low, showing a high investment in sexual reproduction. As suggested by the model, the population recouped this investment in the fourth year, when the number of new cladodes was nearly 3 times the 1992-1993 mean, and the number of initiated flowers was only 73%= of the 3-year mean. RP Bowers, JE (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 13 TC 23 Z9 25 U1 0 U2 5 PU TORREY BOTANICAL CLUB PI BRONX PA NEW YORK BOTANICAL GARDEN, BRONX, NY 10458 SN 0040-9618 J9 B TORREY BOT CLUB JI Bull. Torrey Bot. Club PD JAN-MAR PY 1996 VL 123 IS 1 BP 34 EP 40 DI 10.2307/2996304 PG 7 WC Plant Sciences SC Plant Sciences GA UE423 UT WOS:A1996UE42300005 ER PT S AU DAgnese, FA Faunt, CC Hill, MC Turner, AK AF DAgnese, FA Faunt, CC Hill, MC Turner, AK BE Kovar, K vanderHeijde, P TI Death Valley regional groundwater flow model calibration using optimal parameter estimation methods and geoscientific information systems SO CALIBRATION AND RELIABILITY IN GROUNDWATER MODELLING SE IAHS PUBLICATIONS LA English DT Proceedings Paper CT ModelCARE 96 Conference - Calibration and Reliability in Groundwater Modelling CY SEP 24-26, 1996 CL GOLDEN, CO SP Int Ground Water Modeling Ctr, Int Assoc Hydrol Sci, Int Commiss Groundwater, Int Assoc Hydrogeologists AB A three-layer Death Valley regional groundwater flow model was constructed to evaluate potential regional groundwater flow paths in the vicinity of Yucca Mountain, Nevada. Geoscientific information systems were used to characterize the complex surface and subsurface hydrogeological conditions of the area, and this characterization was used to construct likely conceptual models of the flow system. The high contrasts and abrupt contacts of the different hydrogeological units in the subsurface make zonation the logical choice for representing the hydraulic conductivity distribution. Hydraulic head and spring flow data were used to test different conceptual models by using nonlinear regression to determine parameter values that currently provide the best match between the measured and simulated heads and flows. RP DAgnese, FA (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,MS 421,BOX 25046,LAKEWOOD,CO 80225, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 0-947571-94-9 J9 IAHS-AISH P PY 1996 IS 237 BP 41 EP 52 PG 12 WC Geosciences, Multidisciplinary SC Geology GA BG73H UT WOS:A1996BG73H00005 ER PT S AU Konikow, LF Campbell, PJ Sanford, WE AF Konikow, LF Campbell, PJ Sanford, WE BE Kovar, K vanderHeijde, P TI Modelling brine transport in a porous medium: A re-evaluation of the HYDROCOIN Level 1, Case 5 problem SO CALIBRATION AND RELIABILITY IN GROUNDWATER MODELLING SE IAHS PUBLICATIONS LA English DT Proceedings Paper CT ModelCARE 96 Conference - Calibration and Reliability in Groundwater Modelling CY SEP 24-26, 1996 CL GOLDEN, CO SP Int Ground Water Modeling Ctr, Int Assoc Hydrol Sci, Int Commiss Groundwater, Int Assoc Hydrogeologists AB The HYDROCOIN project was an international cooperative study of groundwater modelling. HYDROCOIN Level 1 studies aimed to ''verify'' the accuracy of groundwater codes for various hydrogeological problems. The Case 5 problem included significant density variations related to salinity differences. Several independent teams simulated this problem using finite difference or finite element numerical models. Comparisons showed some significant differences among model results. We applied a method of characteristics model (MOCDENSE) to this same case. These results show that MOCDENSE can reliably simulate density-dependent groundwater flow and transport for the. conditions of Case 5. This analysis also revealed that the standard numerical implementation of a constant concentration boundary to represent salt release only by lateral dispersion was flawed because this boundary condition allows the release of salt into the flow field by both dispersion and advection. When the boundary is modified to truly allow salt release only by dispersion, significantly less salt is released into the flow field and the size and shape of the plume is notably different than that obtained by the HYDROCOIN participants. RP Konikow, LF (reprint author), US GEOL SURVEY,NATL CTR,MAIL STOP 431,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU INT ASSOC HYDROLOGICAL SCIENCES PI WALLINGFORD PA INST OF HYDROLOGY, WALLINGFORD, ENGLAND OX10 8BB SN 0144-7815 BN 0-947571-94-9 J9 IAHS-AISH P PY 1996 IS 237 BP 363 EP 372 PG 10 WC Geosciences, Multidisciplinary SC Geology GA BG73H UT WOS:A1996BG73H00035 ER PT J AU Kelso, JRM Wooley, C AF Kelso, JRM Wooley, C TI Introduction to the international workshop on the science and management for habitat conservation and restoration strategies (HabCARES) SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Editorial Material C1 US FISH & WILDLIFE SERV,E LANSING,MI 48823. RP Kelso, JRM (reprint author), FISHERIES & OCEANS CANADA,GREAT LAKES LAB FISHERIES & AQUAT SCI,1 CANAL DR,SAULT ST MARIE,ON P6A 6W4,CANADA. NR 6 TC 17 Z9 19 U1 0 U2 0 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1996 VL 53 SU 1 BP 1 EP 2 PG 2 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VK062 UT WOS:A1996VK06200001 ER PT J AU Young, RJ Christie, GC McDonald, RB Cuddy, DW Morse, TJ Payne, NR AF Young, RJ Christie, GC McDonald, RB Cuddy, DW Morse, TJ Payne, NR TI Effects of habitat change in the St Marys river and northern Lake Huron on sea lamprey (Petromyzon marinus) populations SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article; Proceedings Paper CT Workshop on the Science and Management for Habitat Conservation and Restoration Strategies (HabCARES) in the Great Lakes CY NOV, 1994 CL KEMPENFELT, CANADA ID GREAT-LAKES AB The abundance of parasitic and spawning-phase sea lamprey (Petromyzon marinus) in northern Lake Huron increased by more than fourfold from 1978 to 1985, remaining high through 1993. We determined whether (i) instream rehabilitation in the St. Marys River, (ii) improvements in larval habitat quality in the St. Marys River, or (iii) increased forage fish biomass and salmonid stocking in northern Lake Huron could account for this population increase. We found no significant changes in larval sea lamprey abundance in the St. Marys River from 1971 to 1992. Furthermore, habitat rehabilitation in the St. Marys River occurred 3-5 yr following the increases in adult sea lamprey. Therefore, improvements in spawning and larval habitat quality and quantity could not explain the increase in parasitic-phase sea lamprey. However, bloater chub (Coregonus hoyi), one of the initial targets for recently transformed sea lamprey, increased in biomass between 1978 and 1982. We observed significant, positive correlations between parasitic-phase sea lamprey abundance and bloater chub biomass and lake trout (Salvelinus namaycush) and chinook salmon (Oncorhynchus tshawytscha) stocking rates. We conclude that the increase in parasitic-phase sea lamprey can be attributed to improved survival of recently transformed sea lamprey resulting from greater prey availability. C1 GREAT LAKES FISHERY COMMISS,ANN ARBOR,MI 48105. US FISH & WILDLIFE SERV,MARQUETTE BIOL STN,MARQUETTE,MI 49855. ONTARIO MINIST NAT RESOURCES,LAKE HURON MANAGEMENT UNIT,OWEN SOUND,ON N4K 3E4,CANADA. RP Young, RJ (reprint author), FISHERIES & OCEANS CANADA,SEA LAMPREY CONTROL CTR,1 CANAL DR,SAULT ST MARIE,ON P6A 6W4,CANADA. NR 29 TC 18 Z9 19 U1 0 U2 5 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1996 VL 53 SU 1 BP 99 EP 104 DI 10.1139/cjfas-53-S1-99 PG 6 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VK062 UT WOS:A1996VK06200011 ER PT J AU Koonce, JF Busch, WDN Czapla, T AF Koonce, JF Busch, WDN Czapla, T TI Restoration of Lake Erie: Contribution of water quality and natural resource management SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article; Proceedings Paper CT Workshop on the Science and Management for Habitat Conservation and Restoration Strategies (HabCARES) in the Great Lakes CY NOV, 1994 CL KEMPENFELT, CANADA ID SPECIES COMPOSITION; CENTRAL BASIN; PHOSPHORUS; BIOMASS AB Since the 1960s, the open-water fish community of Lake Erie recovered dramatically, partly as a result of water-quality and natural-resource management initiatives (including reduction in loadings of phosphorus and toxic contaminants, promotion of wetland protection, restriction of commercial fishing, and implementation of quota management for walleye (Stizostedion vitreum vitreum) and yellow perch (Perca flavescens)). Reviews of historical changes reveal complex interactions of overexploitation of fishery resources, invasion of non-indigenous species, eutrophication, extensive habitat modification, and toxic contamination. Native fish species that required tributary or neashore habitat for spawning and nursery areas have declined markedly. Among surviving native species, such as walleye, stock diversity declined with the loss of tributary spawning stocks and lake spawning stocks became dominant. With the rarefaction of native species, abundance of formerly subdominant species or opportunistic, non-indigenous species increased. Species such as smelt (Osmerus mordax), gizzard shad (Dorosoma cepedianum), and white perch (Morone americana) have less dependence on critical tributary and nearshore habitat. In this paper, we evaluate whether the shifts in fish community structure in Lake Erie reflect the elimination of tributary and wetland habitat. Major unresolved issues are the extent to which habitat loss inhibits recovery of native species associations and the sufficiency of management coordination to identify and restore critical habitat. C1 US FISH & WILDLIFE SERV,AMHERST,NY 14228. RP Koonce, JF (reprint author), CASE WESTERN RESERVE UNIV,DEPT BIOL,CLEVELAND,OH 44106, USA. NR 36 TC 26 Z9 28 U1 1 U2 17 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1996 VL 53 SU 1 BP 105 EP 112 DI 10.1139/cjfas-53-S1-105 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VK062 UT WOS:A1996VK06200012 ER PT J AU Busch, WDN Lary, SJ AF Busch, WDN Lary, SJ TI Assessment of habitat impairments impacting the aquatic resources of Lake Ontario SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article; Proceedings Paper CT Workshop on the Science and Management for Habitat Conservation and Restoration Strategies (HabCARES) in the Great Lakes CY NOV, 1994 CL KEMPENFELT, CANADA ID GREAT-LAKES; ECOSYSTEM HEALTH; SIZE; MANAGEMENT; FISHERIES; BASIN AB A habitat classification system was used to describe aquatic habitat and evaluate habitat degradation in Lake Ontario. Primary consideration was given to physical loss or disruption of habitat availability; because habitat availability was treated as a functional entity, disruptions or stresses caused by chemical or biological sources were included. Data on biological, chemical, and physical anthropogenic changes were scattered, patchy, and disjointed. Therefore, the Delphi technique was used to evaluate the degree of functional habitat impairment for 29 habitats. The criteria for the impairments were the severity of the ecological impact (shift in trophic transfer efficiency) and its permanence (short > decades > permanent). The amounts of functional degradation were averaged by habitat categories (N = 88) for each habitat and multiplied by the estimated areal proportion of that habitat in the ecosystem. We estimated that during 1970-1990, Lake Ontario's ecosystem health was degraded by 58%. Impairments were caused almost equally by anthropogenic stresses from biological (loss of indigenous and introduction of exotic species), chemical (persistent toxins), and physical (dredge-fill, damming, and water-level regulations) sources. Our finding is consistent with a late 1980s study that used lake trout (Salvelinus namaycush) as an indicator of ecosystem health. RP Busch, WDN (reprint author), US FISH & WILDLIFE SERV,LOWER GREAT FISH & WILDLIFE RESOURCES,405 N FRENCH RD,AMHERST,NY 14228, USA. NR 49 TC 10 Z9 11 U1 0 U2 4 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1996 VL 53 SU 1 BP 113 EP 120 DI 10.1139/cjfas-53-S1-113 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VK062 UT WOS:A1996VK06200013 ER PT J AU Hartig, JH Kelso, JRM Wooley, C AF Hartig, JH Kelso, JRM Wooley, C TI Are habitat rehabilitation initiatives uncoupled from aquatic resource management objectives in the Great Lakes? SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article; Proceedings Paper CT Workshop on the Science and Management for Habitat Conservation and Restoration Strategies (HabCARES) in the Great Lakes CY NOV, 1994 CL KEMPENFELT, CANADA AB Surveys of the 43 Great Lakes Areas of Concern have documented an increased recognition of the need for habitat rehabilitation and conservation. Although habitat rehabilitation and conservation initiatives are underway in all Areas of Concern, there appears frequently to be a lack of connection between habitat rehabilitation initiatives and aquatic resource management objectives and the scientific method. This could be addressed by (1) placing a higher priority on establishing quantitative fish community and habitat objectives for Areas of Concern to help evaluate and select appropriate habitat rehabilitation techniques; (2) increasing research and assessment efforts to quantify habitat-related problems, establish cause-effect relationships, evaluate and select appropriate habitat rehabilitation techniques, and quantify effectiveness relative to ecosystem structure and function; and (3) pooling available data on habitat rehabilitation effectiveness to provide the basis for application of successful tools in other parts of the Great Lakes basin ecosystem. C1 FISHERIES & OCEANS CANADA,SAULT ST MARIE,ON P6A 6W4,CANADA. US FISH & WILDLIFE SERV,E LANSING,MI 48823. RP Hartig, JH (reprint author), INT JOINT COMMISS,GREAT LAKES REG OFF,100 OULLETTE AVE,WINDSOR,ON N9A 6T3,CANADA. NR 20 TC 4 Z9 5 U1 1 U2 1 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1996 VL 53 SU 1 BP 424 EP 431 DI 10.1139/cjfas-53-S1-424 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VK062 UT WOS:A1996VK06200037 ER PT J AU Koonce, JF Cairns, V Christie, A Dodge, DP Hamilton, A Lickers, H McHattie, B Roseboom, D Wooley, C AF Koonce, JF Cairns, V Christie, A Dodge, DP Hamilton, A Lickers, H McHattie, B Roseboom, D Wooley, C TI A commentary on the role of institutional arrangements in the protection and restoration of habitat in the Great Lakes SO CANADIAN JOURNAL OF FISHERIES AND AQUATIC SCIENCES LA English DT Article; Proceedings Paper CT Workshop on the Science and Management for Habitat Conservation and Restoration Strategies (HabCARES) in the Great Lakes CY NOV, 1994 CL KEMPENFELT, CANADA AB The common features of institutional arrangements associated with successful restoration and protection projects within the Great Lakes basin were extensive partnerships and involvement of local interests. We found that separation of water quality, water quantity, and resource management authority often gave rise to conflicting management actions and that the fundamental lack of coordination among national, state or provincial, and local government programs contributes to failed institutional arrangements. Even successful projects require dedicated individuals to find ways of making existing institutional arrangements work. We find that attempts to reorganize government agencies may be less effective than an approach to empowering local interests to plan and implement better habitat management projects. Our basic recommendation is to have governments empower and support communities to take responsibility for the natural environment. C1 FISHERIES & OCEANS CANADA,CANADA CTR INLAND WATERS,BURLINGTON,ON L7R 4A6,CANADA. ONTARIO MINIST NAT RESOURCES,MAPLE,ON L6A 1S9,CANADA. INT JOINT COMMISS,OTTAWA,ON K1P 5M1,CANADA. DEPT ENVIRONM,MOHAWK COUNCIL AKWESASNE,CORNWALL,ON K6H 5T3,CANADA. CANADIAN WILDLIFE SERV,CANADA CTR INLAND WATERS,BURLINGTON,ON L7R 4A6,CANADA. ILLINOIS STATE WATER SURVEY,PEORIA,IL 61652. US FISH & WILDLIFE SERV,E LANSING,MI 48823. RP Koonce, JF (reprint author), CASE WESTERN RESERVE UNIV,DEPT BIOL,CLEVELAND,OH 44106, USA. NR 18 TC 2 Z9 2 U1 0 U2 0 PU NATL RESEARCH COUNCIL CANADA PI OTTAWA PA RESEARCH JOURNALS, MONTREAL RD, OTTAWA ON K1A 0R6, CANADA SN 0706-652X J9 CAN J FISH AQUAT SCI JI Can. J. Fish. Aquat. Sci. PY 1996 VL 53 SU 1 BP 458 EP 465 DI 10.1139/cjfas-53-S1-458 PG 8 WC Fisheries; Marine & Freshwater Biology SC Fisheries; Marine & Freshwater Biology GA VK062 UT WOS:A1996VK06200041 ER PT B AU Hoxie, DT AF Hoxie, DT GP OECD, NEA TI Potentially disruptive hydrologic features, events and processes at the Yucca Mountain site, Nevada SO CHARACTERISATION OF LONG-TERM GEOLOGICAL CHANGES FOR DISPOSAL SITES LA English DT Proceedings Paper CT NEA Workshop on Characterisation of Long-Term Geological Changes for Disposal Sites CY SEP 19-21, 1994 CL PARIS, FRANCE SP OECD, NEA C1 US GEOL SURVEY,LAS VEGAS,NV 89109. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ORGANIZATION ECONOMIC COOPERATION & DEVELOPMENT PI PARIS PA 2, RUE ANDRE PASCAL, CEDEX 16, 75775 PARIS, FRANCE BN 92-64-14829-9 PY 1996 BP 11 EP 25 PG 15 WC Environmental Studies; Planning & Development SC Environmental Sciences & Ecology; Public Administration GA BG53P UT WOS:A1996BG53P00002 ER PT J AU Seto, NWH Warham, J Lisowski, NL Tanino, L AF Seto, NWH Warham, J Lisowski, NL Tanino, L TI Jouanin's Petrel Bulweria fallax observed on Sand Island, Midway Atoll SO COLONIAL WATERBIRDS LA English DT Article DE vagrants; identification; vocalizations; Bulweria fallax; Jouanin's Petrel AB A Jouanin's Petrel (Bulweria fallax) was observed on Sand Island, Midway Atoll, Northwestern Hawaiian Islands from 7-9 August 1993. This bird was heard again on 15 and 16 October of the same year. This observation complements the specimen collected on Lisianski Island in 1967 to represent a remarkable vagrancy of this species from the Indian Ocean into the Hawaiian Islands. RP Seto, NWH (reprint author), US FISH & WILDLIFE SERV,MIDWAY ATOLL NATL WILDLIFE REFUGE,POB 4,FPO,AP 96516, USA. NR 6 TC 1 Z9 3 U1 1 U2 2 PU COLONIAL WATERBIRD SOC PI WASHINGTON PA NATL MUSEUM NATURAL HISTORY SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0738-6028 J9 COLON WATERBIRD JI Colon. Waterbirds PY 1996 VL 19 IS 1 BP 132 EP 134 DI 10.2307/1521818 PG 3 WC Ecology; Ornithology SC Environmental Sciences & Ecology; Zoology GA VK496 UT WOS:A1996VK49600017 ER PT J AU Seto, NWH Conant, S AF Seto, NWH Conant, S TI The effects of rat (Rattus rattus) predation on the reproductive success of the Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll SO COLONIAL WATERBIRDS LA English DT Article DE Bonin Petrel; Pterodroma hypoleuca; black rat; Rattus rattus; rat predation; Hawaii AB The breeding population of the Bonin Petrel (Pterodroma hypoleuca) on Midway Atoll has declined dramatically since the accidental introduction of the black rat (Rattus rattus). During 1993 and 1994, we examined the effects of rat predation on Bonin Petrel reproductive success by monitoring nesting petrels in six study sites, three of which were treated dth rodenticide (treatment) and three that were not (control). Results indicate that the incubation stage of the petrels' nesting cycle is most vulnerable to rat predation. Both unattended and incubated eggs were attacked by rats. Rat predation was not observed on petrel chicks in study nests. However, incidental observations of chick remains outside of burrows suggest that rat predation on chicks may occur, but at a low frequency. Sites with low burrow density suffered more from rat predation than sites with higher burrow density. The rodenticide ''Vengeance(TM)'' appeared to successfully suppress the rat numbers in treated sites. The number of nests that failed due to rat predation was significantly lower in two of the three treatment sites when compared with their paired control sites. In addition, the indications of rat activity were lower at these two treatment sites than at the paired control sites. Therefore, this study provides some evidence that rodenticide application is success fur in reducing the number of rats, which in turn reduces the amount of rat predation and is associated with an increase in the reproductive success of Bonin Petrels. RP Seto, NWH (reprint author), US FISH & WILDLIFE SERV,MIDWAY ATOLL NATL WILDLIFE REFUGE,POB 4,FPO,AP 96516, USA. NR 37 TC 30 Z9 30 U1 1 U2 9 PU COLONIAL WATERBIRD SOC PI WASHINGTON PA NATL MUSEUM NATURAL HISTORY SMITHSONIAN INST, WASHINGTON, DC 20560 SN 0738-6028 J9 COLON WATERBIRD JI Colon. Waterbirds PY 1996 VL 19 IS 2 BP 171 EP 185 DI 10.2307/1521854 PG 15 WC Ecology; Ornithology SC Environmental Sciences & Ecology; Zoology GA WA231 UT WOS:A1996WA23100001 ER PT B AU Whitney, JC AF Whitney, JC BE Shaw, DW Finch, DM TI The Middle Rio Grande: Its ecology and management SO DESIRED FUTURE CONDITIONS FOR SOUTHWESTERN RIPARIAN ECOSYSTEMS: BRINGING INTERESTS AND CONCERNS TOGETHER SE USDA FOREST SERVICE GENERAL TECHNICAL REPORT ROCKY MOUNTAIN LA English DT Proceedings Paper CT Symposium on Desired Future Conditions for Southwestern Riparian Ecosystems - Bringing Interests and Concerns Together CY SEP 18-22, 1995 CL ALBUQUERQUE, NM SP USDA Forest Serv, Rocky Mt Forest & Range Exptl Stn C1 US FISH & WILDLIFE SERV,ALBUQUERQUE,NM. NR 0 TC 3 Z9 3 U1 0 U2 0 PU US DEPT AGR, FOREST SERV ROCKY MT FOREST & RANGE EXPTL STN PI FT COLLINS PA FT COLLINS, CO 80526 J9 USDA ROCKY PY 1996 VL 272 BP 4 EP 21 PG 18 WC Ecology; Water Resources SC Environmental Sciences & Ecology; Water Resources GA BF68T UT WOS:A1996BF68T00003 ER PT J AU Chambers, SM AF Chambers, SM BE Shaw, DW Finch, DM TI The riparian species recovery plan: A status report SO DESIRED FUTURE CONDITIONS FOR SOUTHWESTERN RIPARIAN ECOSYSTEMS: BRINGING INTERESTS AND CONCERNS TOGETHER SE USDA FOREST SERVICE GENERAL TECHNICAL REPORT ROCKY MOUNTAIN LA English DT Proceedings Paper CT Symposium on Desired Future Conditions for Southwestern Riparian Ecosystems - Bringing Interests and Concerns Together CY SEP 18-22, 1995 CL ALBUQUERQUE, NM SP USDA Forest Serv, Rocky Mt Forest & Range Exptl Stn C1 US FISH & WILDLIFE SERV,DIV ENDANGERED SPECIES,ALBUQUERQUE,NM 87103. NR 0 TC 0 Z9 0 U1 0 U2 0 PU US DEPT AGR, FOREST SERV ROCKY MT FOREST & RANGE EXPTL STN PI FT COLLINS PA FT COLLINS, CO 80526 J9 USDA ROCKY PY 1996 VL 272 BP 277 EP 280 PG 4 WC Ecology; Water Resources SC Environmental Sciences & Ecology; Water Resources GA BF68T UT WOS:A1996BF68T00040 ER PT B AU Bailey, GB Oleson, LR AF Bailey, GB Oleson, LR BE Barnes, WL TI The EDC DAAC: Serving the land processes science community SO EARTH OBSERVING SYSTEM SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Earth Observing System CY AUG 05-06, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, N Amer Remote Sensing Ind Assoc, Amer Soc Photogrammetry & Remote Sensing DE EOS; EOSDIS; EROS Data Center; DAAC; ASTER; MODIS; Landsat 7 ETM+ AB The primary objective of the Earth Resources Observation System (EROS) Data Center (EDC) Distributed Active Archive Center (DAAC) for land processes data is to promote the interdisciplinary study and understanding of the integrated Earth system by providing remotely sensed and related ancillary data for the study, characterization, and monitoring of natural and anthropogenic conditions and processes existing and operating at or near the land surface. Generating, distributing, and preserving data and products from the National Aeronautics and Space Administration's (NASA) Earth Observing System (EOS) are primary functions of the DAAC. To that end, the EDC DAAC is using existing data sets in developing capabilities to efficiently and effectively ingest, process, manage, distribute, and archive for future generations land-related data collected by EOS sensors. Capabilities also are being developed to help users search for and acquire data and products, as well as to support their scientific application of those data and products. EDC DAAC programs and capability development activities address DAAC-defined science support requirements that relate to a broad spectrum of services and capabilities needed by science users. RP Bailey, GB (reprint author), US GEOL SURVEY,EROS DATA CTR,SIOUX FALLS,SD 57198, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2208-8 J9 P SOC PHOTO-OPT INS PY 1996 VL 2820 BP 259 EP 267 DI 10.1117/12.258106 PG 3 WC Engineering, Aerospace; Remote Sensing; Optics SC Engineering; Remote Sensing; Optics GA BG81X UT WOS:A1996BG81X00024 ER PT J AU Sillitoe, RH McKee, EH AF Sillitoe, RH McKee, EH TI Age of supergene oxidation and enrichment in the Chilean porphyry copper province SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID NORTHERN CHILE; POTASSIUM-ARGON; STABLE ISOTOPE; GOLD DEPOSITS; ALUNITE; GEOCHRONOLOGY; JAROSITE; AUSTRALIA; MINERALIZATION; BRECCIAS AB Twenty-five samples of supergene alunite collected from deeply developed supergene profiles in porphyry copper deposits and prospects between latitudes 20 degrees and 27 degrees S in northern Chile yield K/Ar ages ranging from about 34 to 14 Ma. Therefore supergene oxidation and enrichment processes were active from the early Oligocene to the middle Miocene, a minimum of 20 m.y. Supergene activity at individual deposits lasted for at least 0.4 to 6.2 m.y. The early Oligocene supergene activity affected deposits in the Paleocene porphyry copper belt, whereas early and middle Miocene supergene processes are documented in the Early Cretaceous, Paleocene, and late Eocene to early Oligocene porphyry copper belts. Middle Miocene oxidation also affected the oldest epithermal gold-silver deposits in the Maricunga belt farther east. Supergene activity commenced no less than 11 m.y. after generation of each porphyry copper deposit because of the time required to unroof the copper-bearing parts of the system. Supergene activity throughout northern Chile ceased at. similar to 14 Ma. The geologic features of deposits and prospects and their morphotectonic positions, present latitudes, and present elevations display no obvious correlations with the supergene chronology. Exploration for major cumulative enrichment blankets should not be carried out either beneath thick sequences of piedmont gravels (+/- ignimbrites) of Oligocene through middle Miocene age unless their accumulation is demonstrably late in the documented history of supergene activity, or in porphyry copper provinces, such as those of central Chile and northwestern Argentina, which formed after similar to 14 Ma. The uplift responsible for efficient cumulative copper enrichment is difficult to correlate convincingly with the brief pulses of compressive tectonism postulated for northern Chile and contiguous areas unless their effects were much more prolonged. Intensifying aridity is confirmed as the likely reason for the cessation of supergene activity in northern Chile, and tectonic uplift was its most probable cause. However, more fundamental global controls producing a period of chemical weathering followed by worldwide dessication also may have played a role. C1 US GEOL SURVEY, MENLO PK, CA 94025 USA. NR 102 TC 106 Z9 115 U1 1 U2 16 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD JAN-FEB PY 1996 VL 91 IS 1 BP 164 EP 179 PG 16 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UR285 UT WOS:A1996UR28500013 ER PT J AU Ford, RC Snee, LW AF Ford, RC Snee, LW TI Ar-40/Ar-39 thermochronology of white mica from the Nome district, Alaska: The first ages of lode sources to placer gold deposits in the Seward peninsula SO ECONOMIC GEOLOGY AND THE BULLETIN OF THE SOCIETY OF ECONOMIC GEOLOGISTS LA English DT Article ID BLUESCHIST TERRANE; EVOLUTION; MINERALIZATION; METAMORPHISM C1 US GEOL SURVEY,DENVER FED CTR,BRANCH ISOTOPE GEOL,DENVER,CO 80232. RP Ford, RC (reprint author), CYPRUS CLIMAX MET CO,1501 W FOUNTAINHEAD PKWY,SUITE 290,TEMPE,AZ 85285, USA. NR 39 TC 8 Z9 9 U1 0 U2 2 PU ECONOMIC GEOLOGY PUBL CO PI EL PASO PA UNIV TEXAS AT EL PASO ROOM 202 QUINN HALL, EL PASO, TX 79968 SN 0361-0128 J9 ECON GEOL BULL SOC JI Econ. Geol. Bull. Soc. Econ. Geol. PD JAN-FEB PY 1996 VL 91 IS 1 BP 213 EP 220 PG 8 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UR285 UT WOS:A1996UR28500016 ER PT B AU Eidenshink, JC Faundeen, JL Gallo, KP AF Eidenshink, JC Faundeen, JL Gallo, KP GP AMER METEOROL SOC TI The 1-KM AVHRR global land data set: An update SO EIGHTH CONFERENCE ON SATELLITE METEOROLOGY AND OCEANOGRAPHY LA English DT Proceedings Paper CT 8th Conference on Satellite Meteorology and Oceanography CY JAN 28-FEB 02, 1996 CL ATLANTA, GA SP Amer Meteorol Soc C1 US GEOL SURVEY,EROS DATA CTR,SIOUX FALLS,SD 57198. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER METEOROLOGICAL SOC PI BOSTON PA 45 BEACON ST, BOSTON, MA 02108 PY 1996 BP 321 EP 322 PG 2 WC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing SC Meteorology & Atmospheric Sciences; Oceanography; Remote Sensing GA BF41M UT WOS:A1996BF41M00084 ER PT J AU Carr, MH AF Carr, MH TI Water erosion on Mars and its biologic implications SO ENDEAVOUR LA English DT Article ID SNC METEORITES; CLIMATE; ORIGIN; WARM; WET; ICE AB The Martian surface shows abundant evidence of water erosion. Liquid water is unstable under present climatic conditions but conditions may have been different in the past. The planet has been volcanically active throughout its history. The combination of water and volcanism must have commonly resulted in hydrothermal environments similar to those in which grow the most primitive terrestrial life-forms. RP Carr, MH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 25 TC 10 Z9 11 U1 2 U2 5 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0160-9327 J9 ENDEAVOUR JI Endeavour PY 1996 VL 20 IS 2 BP 56 EP 60 DI 10.1016/0160-9327(96)10013-2 PG 5 WC History & Philosophy Of Science; Multidisciplinary Sciences SC History & Philosophy of Science; Science & Technology - Other Topics GA UX065 UT WOS:A1996UX06500003 PM 11539854 ER PT J AU Gundersen, LCS Schumann, RR AF Gundersen, LCS Schumann, RR TI Mapping the radon potential of the United States: Examples from the Appalachians SO ENVIRONMENT INTERNATIONAL LA English DT Article; Proceedings Paper CT 6th International Symposium on The Natural Radiation Environment (NRE-VI) CY JUN 05-09, 1995 CL MONTREAL, CANADA ID RN-222; HOMES AB The geologic radon potential of the United States was recently assessed by the U.S. Geological Survey. Results indicate that approximately 33% of the U.S. population lives within geologic provinces where the average indoor radon levels have the potential to be greater than 4 pCi/L (147 Bq/m(3)). Rock types most commonly associated with high indoor radon include: 1) Uraniferous metamorphosed sediments, volcanics, and granite intrusives, especially those that are highly deformed or sheared. 2) Glacial deposits derived from uranium-bearing rocks and sediments. 3) Carboniferous, black shales. 4) Soils derived from carbonate rock, especially in karstic terrain. 5) Uraniferous fluvial, deltaic, marine, and lacustrine deposits. Different geologic terrains of the eastern United States illustrate some of the problems inherent in correlating indoor radon with geology. The Central and Southern Appalachian Highlands of the eastern United States have not been glaciated and most soils there are saprolitic, derived directly from the underlying bedrock. Regression analyses of bedrock geologic and radon parameters yield positive correlations (R > 0.5 to 0.9) and indicate that bedrock geology can account for a significant portion of the indoor radon variation. In glaciated areas of the United States such as the northern Appalachian Highlands and Appalachian Plateau, the correlation of bedrock geology to indoor radon is obscured or is positive only in certain cases. In these glaciated areas of the country, it is the type, composition, thickness, and permeability of glacial deposits, rather than the bedrock geology, that controls the radon source. Copyright (C) 1996 Elsevier Science Ltd. RP Gundersen, LCS (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 21 TC 20 Z9 20 U1 0 U2 3 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0160-4120 J9 ENVIRON INT JI Environ. Int. PY 1996 VL 22 SU 1 BP S829 EP S837 PG 9 WC Environmental Sciences SC Environmental Sciences & Ecology GA XK592 UT WOS:A1996XK59200108 ER PT J AU Schumann, RR Gundersen, LCS AF Schumann, RR Gundersen, LCS TI Geologic and climatic controls on the radon emanation coefficient SO ENVIRONMENT INTERNATIONAL LA English DT Article; Proceedings Paper CT 6th International Symposium on The Natural Radiation Environment (NRE-VI) CY JUN 05-09, 1995 CL MONTREAL, CANADA ID SOIL AB Geologic, pedologic, and climatic factors, including radium content, grain size, siting of radon parents within soil grains or on grain coatings, and soil moisture conditions, determine a soil's emanating power and radon transport characteristics. Data from field studies indicate that soils derived from similar parent rocks in different regions have significantly different emanation coefficients due to the effects of climate on these soil characteristics. An important tool for measuring radon source strength (i.e., radium content) is ground-based and aerial gamma radioactivity measurements. Regional correlations between soil radium content, determined by gamma spectrometry, and soil-gas or indoor radon concentrations can be traced to the influence of climatic and geologic factors on intrinsic permeability and radon emanation coefficients. Data on soil radium content, permeability, and moisture content, when combined with data on emanation coefficients, can form a framework for development of quantitative predictive models for radon generation in rocks and soils. Copyright (C) 1996 Elsevier Science Ltd. RP Schumann, RR (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 30 TC 14 Z9 15 U1 0 U2 1 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0160-4120 J9 ENVIRON INT JI Environ. Int. PY 1996 VL 22 SU 1 BP S439 EP S446 PG 8 WC Environmental Sciences SC Environmental Sciences & Ecology GA XK592 UT WOS:A1996XK59200062 ER PT S AU Dombrowski, TR Thurman, EM Mohrman, GB AF Dombrowski, TR Thurman, EM Mohrman, GB BE VanEmon, JM Gerlach, CL Johnson, JC TI A first application of enzyme-linked immunosorbent assay for screening cyclodiene insecticides in ground water SO ENVIRONMENTAL IMMUNOCHEMICAL METHODS: PERSPECTIVES AND APPLICATIONS SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Environmental Immunochemical Methods - Perspectives and Applications, at the National Immunochemistry Summit IV CY AUG 02-03, 1995 CL LAS VEGAS, NV SP US EPA ID IMMUNOASSAY AB A commercially available enzyme-linked immunosorbent assay (ELISA) plate kit for screening of cyclodiene insecticides (aldrin, chlordane, dieldrin, endosulfan, endrin, and heptachlor) was evaluated for sensitivity, cross reactivity, and overall performance using groundwater samples from a contaminated site. Ground-water contaminants included several pesticide compounds and their manufacturing by-products, as well as many other organic and inorganic compounds. Cross-reactivity studies were carried out for the cyclodiene compounds, and results were compared to those listed by the manufacturer. Data obtained were used to evaluate the sensitivity of the ELISA kit to the cyclodiene compounds in ground water samples with a contaminated matrix. The method quantitation limit for the ELISA kit was 15 mu g/L (as chlordane). Of the 56 ground-water samples analyzed using the ELISA plate kits, more than 85% showed cyclodiene insecticide contamination. The ELISA kit showed excellent potential as a screening tool for sites with suspected groundwater contamination by insecticides. C1 ROCKY MT ARSENAL,COMMERCE CITY,CO 80022. RP Dombrowski, TR (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. RI Thurman, Earl/B-5131-2011 NR 5 TC 4 Z9 4 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3454-X J9 ACS SYM SER PY 1996 VL 646 BP 148 EP 154 PG 7 WC Chemistry, Multidisciplinary; Chemistry, Analytical SC Chemistry GA BG68A UT WOS:A1996BG68A00013 ER PT S AU Pomes, ML Thurman, EM Goolsby, DA AF Pomes, ML Thurman, EM Goolsby, DA BE VanEmon, JM Gerlach, CL Johnson, JC TI An evaluation of a microtiter-plate enzyme-linked immunosorbent assay method for the analysis of triazine and chloroacetanilide herbicides in storm runoff samples SO ENVIRONMENTAL IMMUNOCHEMICAL METHODS: PERSPECTIVES AND APPLICATIONS SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Environmental Immunochemical Methods - Perspectives and Applications, at the National Immunochemistry Summit IV CY AUG 02-03, 1995 CL LAS VEGAS, NV SP US EPA ID CHROMATOGRAPHY MASS-SPECTROMETRY; SOLID-PHASE EXTRACTION; WATER; IMMUNOASSAY; ALACHLOR; METABOLITE; SOIL AB Nine river sites in the midwestern United States were monitored with automatic samplers to assess temporal trends of herbicide concentrations in 1990. Microtiter-plate ELISA was chosen to detect triazines and chloroacetanilides in 1,725 storm runoff samples and to select 363 samples for confirmatory analysis by GC/MS. Evaluations of cross reactivity found that the 5-isopropyl secondary amine group determined the reactivity of the triazine ELISA, and the (methoxymethyl)acetamide group determined the reactivity of the chloroacetanilide ELISA. With a slope of 1.0 determined by least squares analysis with GC/MS results, and sensitivity and yield approaching 100 percent (found by Bayes's rule), the triazine ELISA accurately predicted atrazine concentrations in storm runoff samples. The chloroacetanilide ELISA was more problematic because of the finding of slopes greater than 1.0 and a specificity approaching 0.0 percent. Both indicated false-positive detections due to cross reactivity with a similarly-structured metabolite. C1 US GEOL SURVEY,LAWRENCE,KS 66049. US GEOL SURVEY,DENVER FED CTR,LAKEWOOD,CO 80225. RI Thurman, Earl/B-5131-2011 NR 14 TC 5 Z9 5 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3454-X J9 ACS SYM SER PY 1996 VL 646 BP 170 EP 182 PG 13 WC Chemistry, Multidisciplinary; Chemistry, Analytical SC Chemistry GA BG68A UT WOS:A1996BG68A00016 ER PT J AU Tabor, CF Barber, LB AF Tabor, CF Barber, LB TI Fate of linear alkylbenzene sulfonate in the Mississippi River SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; WATER; LAS; ENVIRONMENT; SEDIMENT; DIALKYLTETRALINSULFONATES; MINERALIZATION; GROUNDWATER; SORPTION; SOILS AB The 2 800-km reach of the Mississippi River between Minneapolis, MN, and New Orleans, LA, was examined for the occurrence and fate of linear alkylbenzene sulfonate (LAS), a common anionic surfactant found in municipal sewage effluents. River water and bottom sediment were sampled in the summer and fall of 1991 and in the spring of 1992. LAS was analyzed using solid-phase extraction/derivatization/ gas chromatography/mass spectrometry. LAS was present on all bottom sediments at concentrations ranging from 0.01 to 20 mg/kg and was identified in 21% of the water samples at concentrations ranging from 0.1 to 28.2 mu g/L. The results indicate that LAS is a ubiquitous contaminant on Mississippi River bottom sediments and that dissolved LAS is present mainly downstream from the sewage outfalls of major cities. The removal of the higher LAS homologs and external isomers indicates that sorption and biodegradation are the principal processes affecting dissolved LAS. Sorbed LAS appears to degrade slowly. RP Tabor, CF (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. NR 45 TC 81 Z9 85 U1 1 U2 3 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JAN PY 1996 VL 30 IS 1 BP 161 EP 171 DI 10.1021/es950210p PG 11 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TN497 UT WOS:A1996TN49700045 ER PT J AU Tillitt, DE Gale, RW Meadows, JC Zajicek, JL Peterman, PH Heaton, SN Jones, PD Bursian, SJ Kubiak, TJ Giesy, JP Aulerich, RJ AF Tillitt, DE Gale, RW Meadows, JC Zajicek, JL Peterman, PH Heaton, SN Jones, PD Bursian, SJ Kubiak, TJ Giesy, JP Aulerich, RJ TI Dietary exposure of mink to carp from Saginaw Bay .3. Characterization of dietary exposure to planar halogenated hydrocarbons, dioxin equivalents, and biomagnification SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID POLYCHLORINATED BIPHENYL RESIDUES; DOUBLE-CRESTED CORMORANTS; DIBENZO-PARA-DIOXINS; GREAT-LAKES FISH; HERRING-GULLS; TOXIC POTENCY; GREEN BAY; 2,3,7,8-TETRACHLORODIBENZO-PARA-DIOXIN; REPRODUCTION; INDUCTION AB Mink are known to be very sensitive to the toxic effects of planar polychlorinated biphenyls (pPCBs), polychlorinated dibenzo-p-dioxins (PCDDs), and polychlorinated dibenzofurans (PCDFs), collectively known as planar halogenated hydrocarbons (PHHs). Previously, we reported the reproductive effects in mink fed a diet containing 10, 20, or 40% fish taken from Saginaw Bay, Lake Huron. The present study reports the chemical characterization of the diets and the adult mink livers, along with a comparison of an additive model of toxicity with the results of the H411E bioassay on these samples. The assessment of dietary or tissue-based exposure of the mink to 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) and related compounds revealed that TCDD equivalents of the PHH mixtures largely followed an additive model of toxicity as compared with the H411E bioassay. Consistent dietary and liver tissue-based threshold concentrations for reproductive toxicity in mink were determined regardless of whether PHHs were quantified as TEQs (additive toxicity) or TCDD-Eas (H411E bioassay). Significant reproductive effects were observed in the lowest treatment group (10% fish or 19.4 pg of H411E bioassay-derived TCDD-EQs/g). Consumption-normalized mink liver biomagnification factors (BMFs) were 6.4-74.2 for PCDDs, < 1-75.8 for PCDFs, < 1-15.9 for PCBs, and in general, increased with degree of chlorination within each class. Based on TEQs or TCDD-EQ, this study confirms that mink are among the most, if not the most, sensitive mammalian species to the reproductive toxicity of TCDD and related compounds. C1 MICHIGAN STATE UNIV,DEPT ANIM SCI,E LANSING,MI 48824. WELLINGTON SCI CTR,ESR ENVIRONM,LOWER HUTT,NEW ZEALAND. US FISH & WILDLIFE SERV,DIV ENVIRONM CONTAMINANTS,ARLINGTON,VA 22203. MICHIGAN STATE UNIV,INST ENVIRONM TOXICOL,DEPT WILDLIFE & FISHERIES,PESTICIDE RES CTR,E LANSING,MI 48824. RP Tillitt, DE (reprint author), NATL BIOL SERV,MIDW SCI CTR,4200 NEW HAVEN RD,COLUMBIA,MO 65201, USA. RI Jones, Paul/O-2046-2015 OI Jones, Paul/0000-0002-7483-5380 NR 47 TC 97 Z9 100 U1 0 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JAN PY 1996 VL 30 IS 1 BP 283 EP 291 DI 10.1021/es9503140 PG 9 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TN497 UT WOS:A1996TN49700061 ER PT J AU Kolpin, DW Thurman, EM Goolsby, DA AF Kolpin, DW Thurman, EM Goolsby, DA TI Occurrence of selected pesticides and their metabolites in near-surface aquifers of the midwestern United States SO ENVIRONMENTAL SCIENCE & TECHNOLOGY LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; ATRAZINE; HERBICIDES; WATER; SOIL; DEGRADATION; IMMUNOASSAY; POLLUTION; TRANSPORT; ALACHLOR AB The occurrence and distribution of selected pesticides and their metabolites were investigated through the collection of 837 water-quality samples from 303 wells across the Midwest. Results of this study showed that five of the six most frequently detected compounds were pesticide metabolites. Thus, it was common for a metabolite to be found more frequently in groundwater than its parent compound. The metabolite alachlor ethanesulfonic acid (alachlor-ESA; 2-[(2,6-diethylphenyl)(methoxymethyl)amino]-2-oxoethanesulfonic acid) was detected almost 10 times as frequently and at much higher concentrations than its parent compound alachlor (2-chloro-2',6'-diethyl-N-(methoxymethyl)acetamide). The median detectable atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine) concentration was almost half that of atrazine residue (atrazine plus the two atrazine metabolites analyzed). Cyanazine amide [2-chloro-4-(1-carbamoyl-1-methylethylamino)-6-ethylamino-s-triazine] was detected almost twice as frequently as cyanazine (2-chloro-4-ethylamino-6-methylpropionitrileamino-s-triazine). Results show that information on pesticide metabolites is necessary to understand the environmental fate of pesticides. Consequently, if pesticide metabolites are not quantified, the effects of chemical use on groundwater quality would be substantially underestimated. Thus, continued research is needed to identify major degradation pathways for all pesticides and to develop analytical methods to determine their concentrations in water and other environmental media. C1 US GEOL SURVEY, LAWRENCE, KS 66049 USA. US GEOL SURVEY, DENVER FED CTR, LAKEWOOD, CO 80225 USA. RP Kolpin, DW (reprint author), US GEOL SURVEY, 400 S CLINTON ST, BOX 1230, IOWA CITY, IA 52244 USA. RI Thurman, Earl/B-5131-2011 NR 57 TC 195 Z9 200 U1 0 U2 32 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 16TH ST, NW, WASHINGTON, DC 20036 USA SN 0013-936X J9 ENVIRON SCI TECHNOL JI Environ. Sci. Technol. PD JAN PY 1996 VL 30 IS 1 BP 335 EP 340 DI 10.1021/es950462q PG 6 WC Engineering, Environmental; Environmental Sciences SC Engineering; Environmental Sciences & Ecology GA TN497 UT WOS:A1996TN49700068 ER PT S AU Carr, MH AF Carr, MH BE Bock, GR Goode, JA TI Water on early Mars SO EVOLUTION OF HYDROTHERMAL ECOSYSTEMS ON EARTH (AND MARS?) SE CIBA FOUNDATION SYMPOSIA LA English DT Article; Proceedings Paper CT Symposium on Evolution of Hydrothermal Ecosystems on Earth (and Mars) CY JAN 30-FEB 01, 1996 CL CIBA FDN, LONDON, ENGLAND SP Ciba Fdn HO CIBA FDN ID THERMAL HISTORY; SNC METEORITES; NOBLE-GASES; EARTH; ORIGIN; ICE; ATMOSPHERE; EVOLUTION; ABUNDANCE; VOLATILES AB Large flood channels, valley networks and a variety of features attributed to the action of ground ice indicate that Mars emerged from heavy bombardment 3.8 Ga ago, with an inventory of water at the surface equivalent to at least a few hundred metres spread over the whole planet, as compared with 3 km for the Earth. The mantle of Mars is much drier than that of the Earth, possibly as a result of global melting at the end of accretion and the lack of plate tectonics to subsequently reintroduce water into the interior. The surface water resided primarily in a porous, kilometres-thick megaregolith created by the high impact rates. Under today's climatic conditions groundwater is trapped below a thick permafrost zone. At the end of heavy bombardment any permafrost zone would have been much thinner because of the high heat flows, but climatic conditions may have been very different then, as suggested by erosion rates 1000 times higher than subsequent rates. Water trapped below the permafrost periodically erupted onto the surface to form large flood channels and lakes. Given abundant water at the surface and sustained volcanism, hydrothermal activity must have frequently occurred but we have yet to make the appropriate observations to detect the results of such activity. RP US GEOL SURVEY, 345 MIDDLEFIELD RD, MS-975, MENLO PK, CA 94025 USA. NR 35 TC 9 Z9 10 U1 3 U2 8 PU JOHN WILEY & SONS LTD PI CHICHESTER PA THE ATRIUM, SOUTHERN GATE, CHICHESTER PO19 8SQ, WEST SUSSEX, ENGLAND SN 0300-5208 BN 0-471-96509-X J9 CIBA F SYMP PY 1996 VL 202 BP 249 EP 267 PG 19 WC Biology; Medicine, General & Internal SC Life Sciences & Biomedicine - Other Topics; General & Internal Medicine GA BG79F UT WOS:A1996BG79F00016 PM 9243020 ER PT J AU Bischoff, JL Rosenbauer, RJ Fournier, RO AF Bischoff, JL Rosenbauer, RJ Fournier, RO TI The generation of HCl in the system CaCl2-H2O: Vapor-liquid relations from 380-500 degrees C SO GEOCHIMICA ET COSMOCHIMICA ACTA LA English DT Article ID SYNTHETIC FLUID INCLUSIONS; HYDROTHERMAL SYSTEMS; PHASE-EQUILIBRIA; NACL-H2O; TEMPERATURES; 500-DEGREES-C; PRESSURES; SEAWATER; ORIGIN; BRINES AB We determined vapor-liquid relations (P-T-x) and derived critical parameters for the system CaCl2-H2O from 380-500 degrees C. Results show that the two-phase region of this system is extremely large and occupies a significant portion of the P-T space to which circulation of fluids in the Earth's crust is constrained. Results also show the system generates significant amounts of HCl (as much as 0.1 mol/kg) in the vapor phase buffered by the liquid at surprisingly high pressures(less than or equal to 230 bars at 380 degrees C, less than or equal to 580 bars at 500 degrees C), presumably by hydrolysis of CaCl2: CaCl2 + 2H(2)O = Ca(OH)(2) + 2 H overdot Cl. We interpret the abundance of HCl in the vapor as due to its preference for the vapor phase, and by the preference of Ca(OH)2 for either the liquid phase or solid. The recent recognition of the abundance of CaCl2 in deep brines of the Earth's crust and their hydrothermal mobilization makes the hydrolysis of CaCl2 geologically important. The boiling of Ca-rich brines produces abundant HCl buffered by the presence of the liquid at moderate pressures. The resultant Ca(OH)2 generated by this process reacts with silicates to form a variety of alteration products, such as epidote, whereas the vapor produces acid-alteration of rocks through which it ascends. RP Bischoff, JL (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 47 TC 51 Z9 52 U1 3 U2 15 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0016-7037 J9 GEOCHIM COSMOCHIM AC JI Geochim. Cosmochim. Acta PD JAN PY 1996 VL 60 IS 1 BP 7 EP 16 DI 10.1016/0016-7037(95)00365-7 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TQ461 UT WOS:A1996TQ46100002 ER PT J AU Hereford, R Thompson, KS Burke, KJ Fairley, HC AF Hereford, R Thompson, KS Burke, KJ Fairley, HC TI Tributary debris fans and the late Holocene alluvial chronology of the Colorado River, eastern Grand Canyon, Arizona SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Article ID DESERT PIEDMONT; MOJAVE DESERT; CALIFORNIA; RAPIDS AB Bouldery debris fans and sandy alluvial terraces of the Colorado River developed contemporaneously during the late Holocene at the mouths of nine major tributaries in eastern Grand Canyon, The age of the debris fans and alluvial terraces contributes to understanding river hydraulics and to the history of human activity along the river, which has been concentrated on these surface's for at least two to three millennia. Poorly sorted, coarse-grained debris-flow deposits of several ages are interbedded with, overlie, or are overlapped by three terrace-forming alluviums, The alluvial deposits are of three age groups: the striped alluvium, deposited from before 770 B.C. to about A.D. 300; the alluvium of Pueblo II age deposited from about A.D. 700 to 1200; and the alluvium of the upper mesquite terrace, deposited from about A.D. 1400 to 1880. Two elements define the geomorphology of a typical debris fan: the large, inactive surface of the fan and a smaller, entrenched, active debris-flow channel and fan that is about one-sixth the area of the inactive fan, The inactive fan is segmented into at least three surfaces with distinctive weathering characteristics. These surfaces are conformable with underlying debris-flow deposits that date from before 770 B.C. to around A.D. 660, A.D. 660 to before A.D. 1200, and from A.D. 1200 to slightly before 1890, respectively, based on late-19th-century photographs, radiocarbon and archaeologic dating of the three stratigraphically related alluviums, and radiocarbon dating of fine-grained debris-flow deposits, These debris flows aggraded the fans in at least three stages beginning about 2.8 ha, if not earlier in the late Holocene. Several main-stem floods eroded the margin of the segmented fans, reducing fan symmetry, The entrenched, active debris-flow channels contain deposits < 100 yr old, which form debris fans at the mouth of the channel adjacent to the river, Early anti middle Holocene debris-flow and alluvial deposits have not been recognized, as they were evidently not preserved adjacent to the river or are buried by younger deposits. C1 NATL PK SERV,GRAND CANYON,AZ 86023. RP Hereford, R (reprint author), US GEOL SURVEY,2255 N GEMINI DR,FLAGSTAFF,AZ 86001, USA. NR 48 TC 21 Z9 21 U1 0 U2 5 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JAN PY 1996 VL 108 IS 1 BP 3 EP 19 DI 10.1130/0016-7606(1996)108<0003:TDFATL>2.3.CO;2 PG 17 WC Geosciences, Multidisciplinary SC Geology GA TP031 UT WOS:A1996TP03100002 ER PT J AU Rice, CL Belkin, HE Henry, TW Kunk, MJ AF Rice, CL Belkin, HE Henry, TW Kunk, MJ TI The Pennsylvanian Fire Clay tonstein of the Appalachian basin - Its distribution, biostratigraphy, and mineralogy: Discussion and reply discussion - Reply SO GEOLOGICAL SOCIETY OF AMERICA BULLETIN LA English DT Discussion RP Rice, CL (reprint author), US GEOL SURVEY,NATL CTR,MAIL STOP 926,RESTON,VA 22092, USA. NR 14 TC 0 Z9 0 U1 0 U2 0 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0016-7606 J9 GEOL SOC AM BULL JI Geol. Soc. Am. Bull. PD JAN PY 1996 VL 108 IS 1 BP 121 EP 125 PG 5 WC Geosciences, Multidisciplinary SC Geology GA TP031 UT WOS:A1996TP03100009 ER PT J AU Amundson, R Chadwick, O Kendall, C Wang, Y DeNiro, M AF Amundson, R Chadwick, O Kendall, C Wang, Y DeNiro, M TI Isotopic evidence for shifts in atmospheric circulation patterns during the late Quaternary in mid-North America SO GEOLOGY LA English DT Article ID HOLOCENE CLIMATIC-CHANGE; UNITED-STATES; CARBONATES; CHEMISTRY; RATIOS AB Wyoming is now at the eastern margin of westerlies originating in the Pacific, but in the Pleistocene appears to have received moisture from elsewhere, possibly the Gulf of Mexico, Oxygen isotope ratios of pedogenic carbonate in postglacial terraces Correspond to ratios in equilibrium with present meteoric waters, which show a strong relation to precipitation seasonality and storm sources, In contrast, the oxygen isotope ratios of ail pre-Holocene soils are significantly more positive, even though the carbon isotope composition of coexisting organic matter suggests that the carbonate formed in temperatures cooler than today. The oxygen isotope ratios of paleowaters in mid-North America appear to be more useful for identifying past storm sources than for estimating paleotemperatures. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. UNIV CALIF BERKELEY,DEPT GEOL SCI,SANTA BARBARA,CA 94720. RP Amundson, R (reprint author), UNIV CALIF BERKELEY,DIV ECOSYST SCI,108 HILGARD,BERKELEY,CA 94720, USA. RI Amundson, Ronald /E-2654-2015 NR 42 TC 93 Z9 98 U1 0 U2 19 PU GEOLOGICAL SOC AMERICA PI BOULDER PA PO BOX 9140 3300 PENROSE PLACE, BOULDER, CO 80301 SN 0091-7613 J9 GEOLOGY JI Geology PD JAN PY 1996 VL 24 IS 1 BP 23 EP 26 DI 10.1130/0091-7613(1996)024<0023:IEFSIA>2.3.CO;2 PG 4 WC Geology SC Geology GA TP032 UT WOS:A1996TP03200006 ER PT J AU Hupp, CR Osterkamp, WR AF Hupp, CR Osterkamp, WR TI Riparian vegetation and fluvial geomorphic processes SO GEOMORPHOLOGY LA English DT Article ID PASSAGE-CREEK; FOREST; VIRGINIA; RIVER; FLOODPLAIN; PATTERNS; WASHINGTON AB Riparian vegetation and fluvial-geomorphic processes and landforms are intimately connected parts of the bottomland landscape. Relations among vegetation, processes, and landforms are described here for representative streams of four areas of the United States: high-gradient streams of the humid east, coastal-plain streams, Great Plains streams, and stream channels of the southwestern United States. Vegetation patterns suggest that species distributions in the humid east are largely controlled by frequency, duration, and intensity of floods. Along channelized streams, vegetation distribution is largely controlled by variation in fluvial geomorphic processes (cycles of degradation and aggradation) in response to increases in channel gradient associated with channelization. Similarly, riparian vegetation of Great Plains streams may be controlled by fluxes in sediment deposition and erosion along braided streams. Patterns of riparian vegetation in semi-arid regions may be most closely related to patterns of water availability, unlike most other streams in more humid environments. Channel-equilibrium conditions control stability of the coincident fluvial landform and attendant vegetation pattern throughout the continent. In most situations, riparian-vegetation patterns are indicative of specific landforms and, thus, of ambient hydrogeomorphic conditions. C1 US GEOL SURVEY,NORCROSS,GA 30092. US GEOL SURVEY,TUCSON,AZ 85745. NR 64 TC 306 Z9 314 U1 12 U2 93 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD JAN PY 1996 VL 14 IS 4 BP 277 EP 295 DI 10.1016/0169-555X(95)00042-4 PG 19 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UC058 UT WOS:A1996UC05800002 ER PT J AU Friedman, JM Osterkamp, WR Lewis, WM AF Friedman, JM Osterkamp, WR Lewis, WM TI The role of vegetation and bed-level fluctuations in the process of channel narrowing SO GEOMORPHOLOGY LA English DT Article ID RIVER FLOODPLAIN; STREAM AB A catastrophic flood in 1965 on Plum Creek, a perennial sandbed stream in the western Great Plains, removed most of the bottomland vegetation and transformed the single-thalweg stream into a wider, braided channel. Following eight years of further widening associated with minor high hows, a process of channel narrowing began in 1973; narrowing continues today. The history of channel narrowing was reconstructed by counting the annual rings of 129 trees and shrubs along a 5-km reach of Plum Creek near Louviers, Colorado. Sixty-three of these plants were excavated in order to determine the age and elevation of the germination point. The reconstructed record of channel change was verified from historical aerial photographs, and then compared to sediment stratigraphy and records of discharge and bed elevation from a streamflow gaging station in the study reach. Channel narrowing at Plum Creek occurs in two ways. First, during periods of high flow, sand and fine gravel are delivered to the channel, temporarily raising the general bed-level. Subsequently, several years of unintermpted low flows incise a narrower channel. Second, during years of low Bow, vegetation becomes established on the subaerial part of the present channel bed. In both cases, surfaces stabilize as a result of vegetation growth and vertical accretion of sediment. C1 US GEOL SURVEY,TUCSON,AZ. UNIV COLORADO,BOULDER,CO 80309. RP Friedman, JM (reprint author), NATL BIOL SERV,FT COLLINS,CO, USA. OI Friedman, Jonathan/0000-0002-1329-0663 NR 40 TC 100 Z9 102 U1 0 U2 8 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0169-555X J9 GEOMORPHOLOGY JI Geomorphology PD JAN PY 1996 VL 14 IS 4 BP 341 EP 351 DI 10.1016/0169-555X(95)00047-9 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UC058 UT WOS:A1996UC05800007 ER PT J AU Varnes, DJ Bufe, CG AF Varnes, DJ Bufe, CG TI The cyclic and fractal seismic series preceding an m(b) 4.8 earthquake on 1980 February 14 near the Virgin Islands SO GEOPHYSICAL JOURNAL INTERNATIONAL LA English DT Article DE earthquake prediction; fractals; seismicity; Virgin Islands ID DIMENSION AB Seismic activity in the 10 months preceding the 1980 February 14, m(b) 4.8 earthquake in the Virgin Islands, reported on by Frankel in 1982, consisted of four principal cycles. Each cycle began with a relatively large event or series of closely spaced events, and the duration of the cycles progressively shortened by a factor of about 3/4. Had this regular shortening of the cycles been recognized prior to the earthquake, the time of the next episode of seismicity (the main shock) might have been closely estimated 41 days in advance. That this event could be much larger than the previous events is indicated from time-to-failure analysis of the accelerating rise in released seismic energy, using a non-linear time- and slip-predictable foreshock model. Examination of the timing of all events in the sequence shows an even higher degree of order. Rates of seismicity, measured by consecutive interevent times, when plotted on an iteration diagram of a rate versus the succeeding rate, form a triangular circulating trajectory. The trajectory becomes an ascending helix if extended in a third dimension, time. This construction reveals additional and precise relations among the time intervals between times of relatively high or relatively low rates of seismic activity, including period halving and doubling. The set of 666 time intervals between all possible pairs of the 37 recorded events appears to be a fractal; the set of time points that define the intervals has a finite, non-integer correlation dimension of 0.70. In contrast, the average correlation dimension of 50 random sequences of 37 events is significantly higher, close to 1.0. In a similar analysis, the set of distances between pairs of epicentres has a fractal correlation dimension of 1.52. Well-defined cycles, numerous precise ratios among time intervals, and a non-random temporal fractal dimension suggest that the seismic series is not a random process, but rather the product of a deterministic dynamic system. RP US GEOL SURVEY, BOX 25046, MNS 966, DFC, DENVER, CO 80225 USA. NR 23 TC 30 Z9 32 U1 0 U2 3 PU OXFORD UNIV PRESS PI OXFORD PA GREAT CLARENDON ST, OXFORD OX2 6DP, ENGLAND SN 0956-540X EI 1365-246X J9 GEOPHYS J INT JI Geophys. J. Int. PD JAN PY 1996 VL 124 IS 1 BP 149 EP 158 DI 10.1111/j.1365-246X.1996.tb06359.x PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TN693 UT WOS:A1996TN69300012 ER PT J AU Pellerin, L Johnston, JM Hohmann, GW AF Pellerin, L Johnston, JM Hohmann, GW TI A numerical evaluation of electromagnetic methods in geothermal exploration SO GEOPHYSICS LA English DT Article ID INTEGRAL-EQUATIONS; INVERSION AB The size and low resistivity of the clay cap associated with a geothermal system create a target well suited for electromagnetic (EM) methods and also make electrical detection of the underlying geothermal reservoir a challenge. Using 3-D numerical models, we evaluate four EM techniques for use in geothermal exploration: magnetotellurics (MT), controlled-source audio magnetotellurics (CSAMT), long-offset time-domain EM (LOTEM), and short-offset time-domain EM (TEM). Our results show that all of these techniques can delineate the clay cap, but none can be said to unequivocally detect the reservoir. We do find, however, that the EM anomaly from a deep, conductive reservoir overlain by a larger, more conductive clay cap is caused by the presence of the electric charge at conductivity boundaries rather than electromagnetic induction. This means that, for detection of the reservoir, methods such as MT, which rely on electric field measurements, are superior to those where only the magnetic field is measured. The anomaly produced by boundary charges at the reservoir is subtle and will be evident only if high-quality data are collected at closely spaced measurement sites. LOTEM electric field measurements look promising and should be useful when efficient multidimensional tools are developed for LOTEM interpretation. Although CSAMT employs electric field measurements, this method is not recommended for reservoir detection because the anomaly caused by a deep reservoir is obscured by transmitter effects that cannot be isolated reliably. A combination of CSAMT and TEM measurements appears most appropriate for delineation of the clay cap. C1 ABNORMAL GEOPHYS,GOLDEN,CO 80401. RP Pellerin, L (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 964,DENVER,CO 80225, USA. NR 17 TC 44 Z9 46 U1 2 U2 17 PU SOC EXPLORATION GEOPHYSICISTS PI TULSA PA 8801 S YALE ST, TULSA, OK 74137 SN 0016-8033 J9 GEOPHYSICS JI Geophysics PD JAN-FEB PY 1996 VL 61 IS 1 BP 121 EP 130 DI 10.1190/1.1443931 PG 10 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA TP382 UT WOS:A1996TP38200013 ER PT J AU Kelly, D AF Kelly, D TI Disasters are a terrible thing to waste SO GEOTIMES LA English DT Editorial Material C1 US Geol Survey, Publ Affairs Off, Reston, VA 22092 USA. RP Kelly, D (reprint author), US Geol Survey, Publ Affairs Off, 119 Natl Ctr, Reston, VA 22092 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 USA SN 0016-8556 J9 GEOTIMES JI Geotimes PD JAN PY 1996 VL 41 IS 1 BP 4 EP 4 PG 1 WC Geosciences, Multidisciplinary SC Geology GA V2878 UT WOS:000168748700002 ER PT J AU Highland, LM Brown, WM AF Highland, LM Brown, WM TI Landslides - The natural hazard sleepers SO GEOTIMES LA English DT Article C1 US Geol Survey, Natl Landslide Informat Ctr, Geol Hazards Team, Denver Fed Ctr, Denver, CO 80225 USA. RP Highland, LM (reprint author), US Geol Survey, Natl Landslide Informat Ctr, Geol Hazards Team, Denver Fed Ctr, Box 25046,MS 966, Denver, CO 80225 USA. NR 15 TC 1 Z9 1 U1 0 U2 1 PU AMER GEOLOGICAL INST PI ALEXANDRIA PA 4220 KING ST, ALEXANDRIA, VA 22302-1507 USA SN 0016-8556 J9 GEOTIMES JI Geotimes PD JAN PY 1996 VL 41 IS 1 BP 16 EP 19 PG 4 WC Geosciences, Multidisciplinary SC Geology GA V2878 UT WOS:000168748700016 ER PT B AU Altheide, PS AF Altheide, PS GP ACSM TI Development of a toolkit for Spatial Data Transfer Standard applications SO GIS/LIS '96 - ANNUAL CONFERENCE AND EXPOSITION PROCEEDINGS LA English DT Proceedings Paper CT GIS/LIS 1996 Annual Conference and Exposition CY NOV 19-21, 1996 CL DENVER, CO SP Amer Congress Surveying & Mapping, Amer Soc Photogrammetry & Remote Sensing, AM FM Int, Assoc Amer Geographers, Urban & Reg Informat Syst Assoc, Amer Public Works Assoc AB The Spatial Data Transfer Standard (SDTS) enables the exchange of geospatial data between different environments without the loss of information, regardless of the types of hardware and software used. One aspect of implementing the SDTS requires data producers and geographic information system software vendors to develop SDTS import and export capabilities. The National Mapping Division of the U.S. Geological Survey is developing an object-oriented toolkit, the SDTS Common Software Platform (CSP), to aid in implementing SDTS encoders and decoders. The architecture of the class library follows the conceptual, logical, and format levels of the SDTS. The SDTS-CSP offers an application programming interface that supports interaction with SDTS modules and transfers. The development of the. SDTS-CSP is continuing, but the GIS community needs to join in the development effort to make a full suite of SDTS software available. RP Altheide, PS (reprint author), US GEOL SURVEY,1400 INDEPENDENCE RD,ROLLA,MO 65401, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC PHOTOGRAMMETRY & REMOTE SENSING PI BETHESDA PA 5410 GROSVENOR LAND, SUITE 210, BETHESDA, MD 20814-2160 BN 1-57083-042-8 PY 1996 BP 173 EP 180 PG 8 WC Food Science & Technology; Remote Sensing SC Food Science & Technology; Remote Sensing GA BG94A UT WOS:A1996BG94A00021 ER PT J AU Wood, WW AF Wood, WW TI Thank you, John - The Bredehoeft years SO GROUND WATER LA English DT Editorial Material RP Wood, WW (reprint author), US GEOL SURVEY,959 NATL CTR,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD JAN-FEB PY 1996 VL 34 IS 1 BP 1 EP 1 PG 1 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TN468 UT WOS:A1996TN46800001 ER PT J AU Hanson, RT Nishikawa, T AF Hanson, RT Nishikawa, T TI Combined use of flowmeter and time-drawdown data to estimate hydraulic conductivities in layered aquifer systems SO GROUND WATER LA English DT Article ID TESTS AB The vertical distribution of hydraulic conductivity in layered aquifer systems commonly is needed for model simulations of ground-water flow and transport. In previous studies, time-drawdown data or flowmeter data were used individually, but not in combination, to estimate hydraulic conductivity. In this study, flowmeter data and time-drawdown data collected from al long-screened production well and nearby monitoring wens are combined to estimate the vertical distribution of hydraulic conductivity in a complex multilayer coastal aquifer system. Flowmeter measurements recorded as a function of depth delineate nonuniform inflow to the wellbore, and this information is used to better discretize the vertical distribution of hydraulic conductivity using analytical and numerical methods. The tine-drawdown data complement the flowmeter data by giving insight into the hydraulic response of aquitards when now rates within the wellbore are below the detection limit of the flowmeter. The combination of these field data allows for the testing of alternative conceptual model of radial flow to the wellbore. RP Hanson, RT (reprint author), US GEOL SURVEY,5735 KEARNY VILLA RD,SUITE O,SAN DIEGO,CA 92123, USA. NR 28 TC 15 Z9 15 U1 0 U2 2 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD JAN-FEB PY 1996 VL 34 IS 1 BP 84 EP 94 DI 10.1111/j.1745-6584.1996.tb01868.x PG 11 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TN468 UT WOS:A1996TN46800012 ER PT J AU Squillace, PJ AF Squillace, PJ TI Observed and simulated movement of bank-storage water SO GROUND WATER LA English DT Article ID CHROMATOGRAPHY MASS-SPECTROMETRY; MIDWESTERN UNITED-STATES; SURFACE-WATER; GROUNDWATER; HERBICIDES; RIVER; ATRAZINE; FLOW AB Detailed hydrologic and water-chemistry data were collected that document the movement of bank-storage water during March 7-April 17, 1990, in an alluvial aquifer adjacent to the Cedar River, Iowa. Hydrologic data included 745 daily ground-water-level measurements from 27 observation wells. Water-chemistry data indicate that bank-storage water had smaller specific conductance and larger concentration of atrazine than ambient ground water, To quantify the movement of the bank-storage water, a two-dimensional ground-water flow model was constructed, and the resulting calibrated model accurately simulated observed conditions. Analysis of water chemistry and model results indicate that a 2-meter rise in the river stage caused bank-storage water to move horizontally at least 30 meters into the aquifer and vertically about 4 meters below the river bottom, whereas the remaining 30 percent moved laterally through the riverbank. The model also showed that bank storage caused the ground-water flux to the river to increase by a factor of five during the first three weeks of base flow after runoff and that it required about five weeks for bank-storage water to discharge from the alluvial aquifer after the peak river stage. These results quantitatively demonstrate the importance of bank storage as a source of recharge to the alluvial aquifer and as a source of water to the river during early base-flow conditions. RP Squillace, PJ (reprint author), DIV WATER RESOURCES,US GEOL SURVEY,1608 MT VIEW RD,RAPID CITY,SD 57702, USA. NR 32 TC 54 Z9 54 U1 2 U2 26 PU GROUND WATER PUBLISHING CO PI WESTERVILLE PA 601 DEMPSEY RD, WESTERVILLE, OH 43081 SN 0017-467X J9 GROUND WATER JI Ground Water PD JAN-FEB PY 1996 VL 34 IS 1 BP 121 EP 134 DI 10.1111/j.1745-6584.1996.tb01872.x PG 14 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA TN468 UT WOS:A1996TN46800016 ER PT B AU Chapelle, FH AF Chapelle, FH BE Kobus, H Barczewski, B Koschitzky, HP TI Quantifying rates of biodegradation in contaminated aquifers SO GROUNDWATER AND SUBSURFACE REMEDIATION: RESEARCH STRATEGIES FOR IN-SITU TECHNOLOGIES SE ENVIRONMENTAL ENGINEERING (SERIES) LA English DT Proceedings Paper CT International Symposium on Groundwater and Subsurface Remediation - Research Strategies for In-situ Technologies CY SEP 26-27, 1995 CL UNIV STUTTGART, STUTTGART, GERMANY HO UNIV STUTTGART C1 US GEOL SURVEY,COLUMBIA,SC. NR 0 TC 1 Z9 1 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN 33 PA HEIDELBERGER PLATZ 3, W-1000 BERLIN 33, GERMANY BN 3-540-60916-4 J9 ENVIRONM ENGN PY 1996 BP 67 EP 75 PG 9 WC Engineering, Environmental; Geosciences, Multidisciplinary SC Engineering; Geology GA BG45Q UT WOS:A1996BG45Q00004 ER PT S AU Thurman, EM Meyer, MT AF Thurman, EM Meyer, MT BE Meyer, MT Thurman, EM TI Herbicide metabolites in surface water and groundwater: Introduction and overview SO HERBICIDE METABOLITES IN SURFACE WATER AND GROUNDWATER SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Herbicide Metabolites in Surface Water and Groundwater at the 209th National Meeting of the American-Chemical-Society CY APR 02-07, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Agrochem, Amer Chem Soc, Div Environm Chem Inc ID MIDWESTERN UNITED-STATES; ALACHLOR; DEISOPROPYLATRAZINE; DEETHYLATRAZINE; DEGRADATION; IMMUNOASSAY; TRANSPORT; ATRAZINE; SOIL AB Several future research topics for herbicide metabolites in surface and ground water are outlined in this chapter. They are herbicide usage, chemical analysis of metabolites, and fate and transport of metabolites in surface and ground water. These three ideas follow the themes in this book, which are the summary of a symposium of the American Chemical Society on herbicide metabolites in surface and ground water. First, geographic information systems allow the spatial distribution of herbicide-use data to be combined with geochemical information on fate and transport of herbicides. Next these two types of information are useful in predicting the kinds of metabolites present and their probable distribution in surface and ground water. Finally, methods development efforts may be focused on these specific target analytes. This chapter discusses these three concepts and provides an introduction to this book on-the analysis, chemistry, and fate and transport of herbicide metabolites in surface and ground water. C1 US GEOL SURVEY,RALEIGH,NC 27607. RP Thurman, EM (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66049, USA. RI Thurman, Earl/B-5131-2011 NR 31 TC 16 Z9 16 U1 1 U2 5 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3405-1 J9 ACS SYM SER PY 1996 VL 630 BP 1 EP 15 PG 15 WC Agronomy; Chemistry, Analytical; Environmental Sciences; Water Resources SC Agriculture; Chemistry; Environmental Sciences & Ecology; Water Resources GA BF94W UT WOS:A1996BF94W00001 ER PT S AU Schroyer, BR Capel, PD AF Schroyer, BR Capel, PD BE Meyer, MT Thurman, EM TI A high-performance liquid chromatography-based screening method for the analysis of atrazine, alachlor, and ten of their transformation products SO HERBICIDE METABOLITES IN SURFACE WATER AND GROUNDWATER SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Herbicide Metabolites in Surface Water and Groundwater at the 209th National Meeting of the American-Chemical-Society CY APR 02-07, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Agrochem, Amer Chem Soc, Div Environm Chem Inc ID UNITED-STATES; WATER; RIVER; SOIL AB A high-performance liquid chromatography (HPLC) method is presented for the for the fast, quantitative analysis of the target analytes in water and in low organic-carbon, sandy soils that are known to be contaminated with the parent herbicides. Speed and ease of sample preparation was prioritized above minimizing detection limits. Soil samples were extracted using 80:20 methanol:water (volume:volume). Water samples (50 mu L) were injected directly into the HPLC without prior preparation. Method quantification limits for soil samples (10 g dry weight) and water samples ranged from 20 to 110 ng/g and from 20 to 110 mu g/L for atrazine and its transformation products and from 80 to 320 ng/g and from 80 to 320 mu g/L for alachlor and its transformation products, respectively. C1 UNIV MINNESOTA,US GEOL SURVEY,DEPT CIVIL ENGN,MINNEAPOLIS,MN 55455. NR 15 TC 3 Z9 3 U1 0 U2 2 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3405-1 J9 ACS SYM SER PY 1996 VL 630 BP 34 EP 42 PG 9 WC Agronomy; Chemistry, Analytical; Environmental Sciences; Water Resources SC Agriculture; Chemistry; Environmental Sciences & Ecology; Water Resources GA BF94W UT WOS:A1996BF94W00003 ER PT S AU Eckhardt, DAV Wagenet, RJ AF Eckhardt, DAV Wagenet, RJ BE Meyer, MT Thurman, EM TI Estimation of the potential for atrazine transport in a silt loam soil SO HERBICIDE METABOLITES IN SURFACE WATER AND GROUNDWATER SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Herbicide Metabolites in Surface Water and Groundwater at the 209th National Meeting of the American-Chemical-Society CY APR 02-07, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Agrochem, Amer Chem Soc, Div Environm Chem Inc ID SOLID-PHASE EXTRACTION; SPATIAL VARIABILITY; WATER; ZONE AB The transport potential of the herbicide atrazine (2-chloro-4-ethyl-6-isopropyl-s-triazine) through a 1-meter-thick root zone of corn (Zea mays L.) in a silty-loam soil in Kansas was estimated for a 22-year period (1972-93) using the one-dimensional water-flow and solute- transport model LEACHM. Results demonstrate that, for this soil, atrazine transport is directly related to the amount and timing of rain that follows spring applications of atrazine. Two other critical transport factors were important in wet years - [1] variability in atrazine application rate, and [2] atrazine degradation rates below the root zone. Results demonstrate that the coincidence of heavy rain soon after atrazine application can cause herbicide to move below the rooting zone into depths at which biodegradation rates are assumed to be low but are often unknown. Atrazine that reaches below the rooting zone and persists in the underlying soil can subsequently be transported into ground water as soil water drains, typically after the growing season. A frequency analysis of atrazine concentrations in subsurface drainage, combined with field data, demonstrates the relative importance of critical transport factors and confirms a need for definitive estimates of atrazine-degradation rates below the root zone. The analysis indicates that periodic leaching of atrazine can be expected for this soil when rainfall that exceeds 20 cm/mo coincides with atrazine presence in soil. C1 CORNELL UNIV,DEPT SOIL CROP & ATMOSPHER SCI,ITHACA,NY 14853. RP Eckhardt, DAV (reprint author), US GEOL SURVEY,903 HANSHAW RD,ITHACA,NY 14850, USA. NR 27 TC 1 Z9 1 U1 0 U2 0 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3405-1 J9 ACS SYM SER PY 1996 VL 630 BP 101 EP 116 PG 16 WC Agronomy; Chemistry, Analytical; Environmental Sciences; Water Resources SC Agriculture; Chemistry; Environmental Sciences & Ecology; Water Resources GA BF94W UT WOS:A1996BF94W00009 ER PT S AU Verstraeten, IM Lewis, DT McCallister, DL Parkhurst, A Thurman, EM AF Verstraeten, IM Lewis, DT McCallister, DL Parkhurst, A Thurman, EM BE Meyer, MT Thurman, EM TI Relation of landscape position and irrigation to concentrations of alachlor, atrazine, and selected degradates in regolith in northeastern Nebraska SO HERBICIDE METABOLITES IN SURFACE WATER AND GROUNDWATER SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Herbicide Metabolites in Surface Water and Groundwater at the 209th National Meeting of the American-Chemical-Society CY APR 02-07, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Agrochem, Amer Chem Soc, Div Environm Chem Inc ID SOLID-PHASE EXTRACTION; LINKED-IMMUNOSORBENT-ASSAY; TRIAZINE HERBICIDES; AQUIFER SEDIMENTS; SOIL-MOISTURE; VADOSE ZONE; WATER; METABOLITE; CHROMATOGRAPHY; BROMIDE AB Concentrations of alachlor, its ethanesulfonic acid degradate, atrazine and its degradates, deethylatrazine and deisopropylatrazine, in the upper regolith and associated shallow aquifers were determined in relation to landscape position (floodplains, terraces, and uplands) and irrigation (nonirrigated and irrigated corn cropland) in 1992. Irrigated and nonirrigated sites were located on each landscape position. Samples were collected from three depths. Canonical discriminant and multivariate analyses were used to interpret data. Herbicides and their degradation products tended to be present in soils with high percent organic matter, low pH, and low sand content. Atrazine was present more frequently on the floodplain at all depths than the other compounds. Atrazine (maximum 17.5 mu g/kg) and ethanesulfonic acid (maximum 10 mu g/kg) were associated with landscape position, but not with irrigation Alachlor (maximum 24 mu g/kg), deethylatrazine (maximum 1.5 mu g/kg), and deisopropylatrazine (maximum 3.5 mu g/kg) were not significantly associated with either landscape position or irrigation. Ground-water analytical results suggested that concentrations of these herbicides and degradates in ground water did not differ among landscape position or between irrigated and nonirrigated corn cropland. C1 UNIV NEBRASKA,DEPT AGRON,LINCOLN,NE 68588. UNIV NEBRASKA,DEPT BIOMETR,LINCOLN,NE 68588. RP Verstraeten, IM (reprint author), US GEOL SURVEY,DIV WATER RESOURCES,406 FED BLDG,100 CENTENNIAL MALL N,LINCOLN,NE 68508, USA. RI Thurman, Earl/B-5131-2011 NR 44 TC 1 Z9 1 U1 1 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3405-1 J9 ACS SYM SER PY 1996 VL 630 BP 178 EP 197 PG 20 WC Agronomy; Chemistry, Analytical; Environmental Sciences; Water Resources SC Agriculture; Chemistry; Environmental Sciences & Ecology; Water Resources GA BF94W UT WOS:A1996BF94W00015 ER PT S AU Meyer, MT Thurman, EM Goolsby, DA AF Meyer, MT Thurman, EM Goolsby, DA BE Meyer, MT Thurman, EM TI Cyanazine, atrazine, and their metabolites as geochemical indicators of contaminant transport in the Mississippi river SO HERBICIDE METABOLITES IN SURFACE WATER AND GROUNDWATER SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Herbicide Metabolites in Surface Water and Groundwater at the 209th National Meeting of the American-Chemical-Society CY APR 02-07, 1995 CL ANAHEIM, CA SP Amer Chem Soc, Div Agrochem, Amer Chem Soc, Div Environm Chem Inc ID CHROMATOGRAPHY MASS-SPECTROMETRY; MIDWESTERN UNITED-STATES; DEGRADATION PRODUCTS; TRIAZINE HERBICIDES; SURFACE-WATER; SOIL; DEETHYLATRAZINE; TRIBUTARIES; IMMUNOASSAY; ALACHLOR AB The geochemical transport of cyanazine and its metabolite cyanazine amide (CAM) was compared to atrazine and its metabolite deethylatrazine (DEA) at three sites in the Mississippi River basin during 1992 and six sites during 1993. The floods of 1993 caused an uninterrupted exponential decline in herbicide concentrations; whereas, in 1992 herbicide concentrations varied mostly in response to two discrete discharge pulses in the spring and midsummer and were stable during an extended period of summer low-flow. Concentration half-lives calculated from the 1993 data for atrazine were approximately twice those of cyanazine at all sites. The half-life for atrazine and cyanazine was shortest, 22 and 14 days, respectively at the Mississippi River at Clinton, ill. - the farthest upstream site - and longest, 42 and 22 days, respectively, at the Baton Rouge, La. site - the farthest downstream site. The concentration of CAM exceeded the concentration of DEA through September at all sites where the mean ratio of atrazine-to-cyanazine (ACR) was less than 4.0. The ratio of CAM-to-cyanazine (CAMCR) increased from 0.2 to more than 1.0 and the ratio of DEA-to-atrazine (DAR) increased from less than 0.1 to 0.3 from application in May through early to mid-July. Temporal changes in the CAMCR were used to identify pre- and post-application ''slugs'' of water transported along the reaches of the Mississippi River. C1 US GEOL SURVEY,LAWRENCE,KS 66049. US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RI Thurman, Earl/B-5131-2011; OI Meyer, Michael/0000-0001-6006-7985 NR 28 TC 2 Z9 2 U1 0 U2 1 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3405-1 J9 ACS SYM SER PY 1996 VL 630 BP 288 EP 303 PG 16 WC Agronomy; Chemistry, Analytical; Environmental Sciences; Water Resources SC Agriculture; Chemistry; Environmental Sciences & Ecology; Water Resources GA BF94W UT WOS:A1996BF94W00021 ER PT B AU Peterman, ZE Spengler, RW Singer, FR Beason, SC AF Peterman, ZE Spengler, RW Singer, FR Beason, SC GP AMER SOC CIVIL ENGINEERS TI Localized alteration of the paintbrush nonwelded hydrologic unit within the exploratory studies facility SO HIGH LEVEL RADIOACTIVE WASTE MANAGEMENT, 1996 . LA English DT Proceedings Paper CT 7th Annual International Conference on High Level Radioactive Waste Management CY APR 29-MAY 03, 1996 CL LAS VEGAS, NV SP Amer Soc Civil Engineers, Amer Nucl Soc RP Peterman, ZE (reprint author), US GEOL SURVEY,BOX 25046 DFC,MS 963,DENVER,CO 80225, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 BN 0-7844-0169-1 PY 1996 BP 46 EP 47 PG 2 WC Energy & Fuels; Engineering, Environmental; Engineering, Civil SC Energy & Fuels; Engineering GA BH12H UT WOS:A1996BH12H00016 ER PT B AU Stuckless, JS AF Stuckless, JS GP AMER SOC CIVIL ENGINEERS TI Current status of paleohydrologic studies at Yucca Mountain and vicinity, Nevada SO HIGH LEVEL RADIOACTIVE WASTE MANAGEMENT, 1996 . LA English DT Proceedings Paper CT 7th Annual International Conference on High Level Radioactive Waste Management CY APR 29-MAY 03, 1996 CL LAS VEGAS, NV SP Amer Soc Civil Engineers, Amer Nucl Soc AB Recent studies in the vicinity of Yucca Mountain have shown that a water table rise of as much as 100 m may have occurred as recently as the late Pleistocene. New studies have not confirmed the potentially favorable condition of a long-term decline in the elevation of the regional water table. Nonetheless, neither geologic evidence for these past elevations nor hydrologic flow models suggest that rises of the water table in response to climate changes similar to those of the past 2 million years would be sufficient to threaten the potential repository horizon in the future. RP Stuckless, JS (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 425,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 BN 0-7844-0169-1 PY 1996 BP 98 EP 101 PG 4 WC Energy & Fuels; Engineering, Environmental; Engineering, Civil SC Energy & Fuels; Engineering GA BH12H UT WOS:A1996BH12H00035 ER PT B AU Brocher, TM Hunter, WC AF Brocher, TM Hunter, WC GP AMER SOC CIVIL ENGINEERS TI Seismic reflection evidence against a shallow detachment beneath Yucca Mountain, Nevada SO HIGH LEVEL RADIOACTIVE WASTE MANAGEMENT, 1996 . LA English DT Proceedings Paper CT 7th Annual International Conference on High Level Radioactive Waste Management CY APR 29-MAY 03, 1996 CL LAS VEGAS, NV SP Amer Soc Civil Engineers, Amer Nucl Soc RP Brocher, TM (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 977,MENLO PK,CA 94025, USA. OI Brocher, Thomas/0000-0002-9740-839X NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER SOC CIVIL ENGINEERS PI NEW YORK PA UNITED ENGINEERING CENTER, 345 E 47TH ST, NEW YORK, NY 10017-2398 BN 0-7844-0169-1 PY 1996 BP 148 EP 150 PG 3 WC Energy & Fuels; Engineering, Environmental; Engineering, Civil SC Energy & Fuels; Engineering GA BH12H UT WOS:A1996BH12H00051 ER PT J AU Dean, WE Ahlbrandt, TS Anderson, RY Bradbury, JP AF Dean, WE Ahlbrandt, TS Anderson, RY Bradbury, JP TI Regional aridity in North America during the middle Holocene SO HOLOCENE LA English DT Review DE palaeoclimate; aridity; aeolian activity; varves; Great Plains; solar cycles; geomagnetism; North America ID CLIMATIC CHANGES; C-14 RECORD; HIGH-PLAINS; DUNES; MINNESOTA; SOLAR; LAKE; RADIOCARBON; COLORADO; FIELD AB Increased aridity throughout the Great Plains and Rocky Mountain region during the middle Holocene has been documented from pollen records, aeolian proxy variables in lake cores, and active sand dune migration. Varve calibration provided by a continuously varved record of the Holocene from a core from Elk Lake, northwestern Minnesota, shows that the influx of aeolian elastic material increased beginning about 8 ka and ended about 3.8 ka, with peak aeolian activity at about 6 ka. if aeolian influx to Elk Lake corresponds in time to aeolian influx in other lakes and to maximum dune activity in Minnesota dune fields, then the varve calibration in Elk Lake provides precise time calibration of periods of peak aeolian activity in Minnesota. Palaeowind studies from the Minnesota dune fields show that the dominant wind direction when the dunes were active was from the northwest, the same as the dominant wind direction in dune fields throughout the Great Plains and Rocky Mountains. if the mid-Holocene aeolian activity in Minnesota was driven by an increase in westerly zonal winds, then the varve calibration can be extended to more precisely determine the timing of activity of dunes over a much broader area. We suggest that an increase in the westerly zonal wind field might have a solar-geomagnetic cause. C1 UNIV NEW MEXICO,DEPT GEOL,ALBUQUERQUE,NM 87131. RP Dean, WE (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 113 TC 90 Z9 90 U1 0 U2 15 PU EDWARD ARNOLD PUBL LTD PI LONDON PA 338 EUSTON ROAD, LONDON, ENGLAND NW1 3BH SN 0959-6836 J9 HOLOCENE JI Holocene PY 1996 VL 6 IS 2 BP 145 EP 155 DI 10.1177/095968369600600202 PG 11 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UR521 UT WOS:A1996UR52100002 ER PT S AU Mills, MS Thurman, EM Ertel, J Thorn, KA AF Mills, MS Thurman, EM Ertel, J Thorn, KA BE Gaffney, JS Marley, NA Clark, SB TI Organic geochemistry and sources of natural aquatic foams SO HUMIC AND FULVIC ACIDS: ISOLATION, STRUCTURE, AND ENVIRONMENTAL ROLE SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Humic and Fulvic Acids - Isolation, Structure, and Environmental Role, at the 210th ACS National Meeting CY AUG 20-24, 1995 CL CHICAGO, IL SP Amer Chem Soc ID HUMIC SUBSTANCES; SURFACE MICROLAYER; ACID; MATTER; IRON; SEDIMENTS; COMPLEXES; METALS; STATE; SOILS AB Aquatic foams and stream-water samples were collected from two pristine sites for humic substances isolation and characterization. Biomarker compounds identified in foam and stream humic substances included phospholipid fatty acids, steroids, and lignin. Results showed that foams had a 10 to 20 fold greater DOC concentration and were enriched in humic substances (90% by weight of DOG) that showed increased hydrophobicity, aliphatic character, and compositional complexity compared to host stream humic substances (55 to 81% by weight of DOG). Foam humic substances also were enriched in humic acid (36 to 83% by weight) compared to host stream humic substances (10 to 14% by weight). Biomarkers, which contributed less than 5% by weight to the DOC pool, indicated higher plants, bacteria, algae, fungi, and diatoms as DOC sources. It is proposed that aquatic foams may be important media for the concentration and transport of organic substances in the aquatic environment. C1 US GEOL SURVEY,DIV WATER RESOURCES,LAWRENCE,KS 66049. SKIDAWAY INST OCEANOG,SAVANNAH,GA 31411. US GEOL SURVEY,ARVADA,CO 80002. RI Thurman, Earl/B-5131-2011 NR 50 TC 4 Z9 4 U1 2 U2 10 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3468-X J9 ACS SYM SER PY 1996 VL 651 BP 151 EP 192 PG 42 WC Chemistry, Multidisciplinary SC Chemistry GA BG78B UT WOS:A1996BG78B00011 ER PT S AU Thorn, KA Goldenberg, WS Younger, SJ Weber, EJ AF Thorn, KA Goldenberg, WS Younger, SJ Weber, EJ BE Gaffney, JS Marley, NA Clark, SB TI Covalent binding of aniline to humic substances - Comparison of nucleophilic addition, enzyme-, and metal-catalyzed reactions by N-15 NMR SO HUMIC AND FULVIC ACIDS: ISOLATION, STRUCTURE, AND ENVIRONMENTAL ROLE SE ACS SYMPOSIUM SERIES LA English DT Article; Proceedings Paper CT Symposium on Humic and Fulvic Acids - Isolation, Structure, and Environmental Role, at the 210th ACS National Meeting CY AUG 20-24, 1995 CL CHICAGO, IL SP Amer Chem Soc ID C-13 NMR; AROMATIC-AMINES; SOIL; 3,4-DICHLOROANILINE; OLIGOMERIZATION; 4-CHLOROANILINE; OXIDATION; MANGANESE; QUINONES; HUMUS AB The covalent binding of N-15-labelled aniline, in the presence and absence of catalysis by horseradish peroxidase and birnessite, to the fulvic and humic acids isolated from the MSS Elliot silt loam soil, has been examined by a combination of liquid and solid state N-15 NMR. In the absence of catalysts, aniline undergoes nucleophilic addition reactions with the carbonyl functionality of the fulvic and humic acids and becomes incorporated in the form of anilinohydroquinone, anilinoquinone, anilide, heterocyclic, and imine nitrogens. In the presence of peroxidase and birnessite, aniline undergoes free radical coupling reactions together with nucleophilic addition reactions with the fulvic and humic acids. Among the condensation products unique to the catalyzed reactions are azobenzene nitrogens, iminodiphenoquinone nitrogens, and nitrogens tentatively assigned as imidazole, oxazole, pyrazole, or nitrile. The incorporation of aniline into the organic matter of the whole Elliot silt loam soil and the IHSS Pahokee peat most closely resembles the noncatalyzed nucleophilic addition reactions, as determined by solid state N-15 NMR. C1 UNIV COLORADO,DEPT CHEM,BOULDER,CO 80309. US EPA,ATHENS,GA 30605. RP Thorn, KA (reprint author), US GEOL SURVEY,MAIL STOP 408,5293 WARD RD,ARVADA,CO 80002, USA. NR 47 TC 15 Z9 15 U1 1 U2 4 PU AMER CHEMICAL SOC PI WASHINGTON PA 1155 SIXTEENTH ST NW, WASHINGTON, DC 20036 SN 0097-6156 BN 0-8412-3468-X J9 ACS SYM SER PY 1996 VL 651 BP 299 EP 326 PG 28 WC Chemistry, Multidisciplinary SC Chemistry GA BG78B UT WOS:A1996BG78B00019 ER PT B AU Price, LC AF Price, LC BE Schumacher, D Abrams, MA TI Research-derived insights into surface geochemical hydrocarbon exploration SO HYDROCARBON MIGRATION AND ITS NEAR-SURFACE EXPRESSION SE AAPG MEMOIRS LA English DT Proceedings Paper CT AAPG Hedberg Research Conference on Near-Surface Expression of Hydrocarbon Migration CY APR 24-28, 1994 CL VANCOUVER, CANADA SP Amer Assoc Petr Geologists AB Research studies based on foreland basins (mainly in eastern Colorado) examined three surface geochemical exploration (SGE) methods as possible hydrocarbon (HC) exploration techniques. The first method, microbial soil surveying, has high potential as an exploration tool, especially in development and enhanced recovery operations. Integrative adsorption, the second technique, is not effective as a quantitative SGE method because water, carbon dioxide, nitrous oxide, unsaturated hydrocarbons, and organic compounds are collected by the adsorbent (activated charcoal) much more strongly than covalently bonded microseeping C-1-C-5 thermogenic HCs. Qualitative comparisons (pattern recognition) of C-8+ mass spectra cannot gauge HC gas microseepage that involves only the C-1-C-5 HCs. The third method, soil calcite surveying, also has no potential as an exploration tool. Soil calcite concentrations had patterns with pronounced areal contrasts, but these patterns had no geometric relationship to surface traces of established or potential production, that is, the patterns were random. Microscopic examination of thousands of soils revealed that soil calcite was an uncrystallized caliche coating soil particles. During its precipitation, caliche captures or occludes any gases, elements, or compounds in its immediate vicinity Thus, increased signal intensity of some SGE methods should depend on increasing soil calcite concentrations. Analyses substantiate this hypothesis. Because soil calcite has no utility as a surface exploration tool, any surface method that depends on soil calcite has a diminished utility as an SGE tool. Isotopic analyses of soil calcites revealed carbonate carbon delta(13)C values of -4.0 to +2.0 parts per thousand (indicating a strong influence of atmospheric CO2) as opposed to expected values of -45 to -30 parts per thousand if the carbonate carbon had originated from microbial oxidation of microseeping HC gases. These analyses confirm a surface origin for this soil calcite (caliche), which is not necessarily related to HC gas microseepage. This previously unappreciated pivotal role of caliche is hypothesized to contribute significantly to the poor and inconsistent results of some SGE methods. RP Price, LC (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 0 TC 1 Z9 2 U1 1 U2 1 PU AMER ASSOC PETROLEUM GEOLOGISTS PI TULSA PA PO BOX 979, TULSA, OK 74101-0949 BN 0-89181-345-4 J9 AAPG MEMOIR PY 1996 VL 66 BP 285 EP 307 PG 23 WC Engineering, Petroleum; Geology SC Engineering; Geology GA BG98E UT WOS:A1996BG98E00022 ER PT B AU Kieffer, HH AF Kieffer, HH BE Shen, SS TI Detection and correction of bad pixels in hyperspectral sensors SO HYPERSPECTRAL REMOTE SENSING AND APPLICATIONS SE PROCEEDINGS OF THE SOCIETY OF PHOTO-OPTICAL INSTRUMENTATION ENGINEERS (SPIE) LA English DT Proceedings Paper CT Conference on Hyperspectral Remote Sensing and Applications CY AUG 05-06, 1996 CL DENVER, CO SP Soc Photo Opt Instrumentat Engineers, N Amer Remote Sensing Ind Assoc, Amer Soc Photogrammetry & Remote Sensing DE remote sensing; hyperspectral; image processing; sensor calibration; sensor characterization; bad pixel processing; data analysis; anomaly correction; ground data AB Hyperspectral sensors may Use a two-dimensional array such that one direction across the army is spatial and the other direction is spectral. Any pixels therein having very poor signal-to-noise performance must have their values replaced. Because of the anisotropic nature of information at the array, common image processing techniques should not be used. A bad-pixel replacement algorithm has been developed which uses the information closest in both spectral and spatial sense to obtain a value which has both the spectral and reflectance properties of the adjacent terrain in the image. A simple and fast implementation that ''repairs'' individual bad pixels or clusters of bad pixels has three steps; the first two steps are done only once: (1) Pixels are flagged as ''bad'' if their noise level or responsivity fall outside acceptable limits for their spectral channel. (2) For each bad pixel the minimum-sized surrounding rectangle is determined that has good pixels at all 4 corners and at the 4 edge-points where the row/column of the bad pixel intersect the rectangle boundary (five cases are possible due to bad pixels near an edge or corner of the detector array); the specifications of this rectangle are saved. (3) After a detector data frame has been radiometrically corrected (dark subtraction and gain corrections), the spectral shapes represented by the rectangle edges extending in the dispersion direction are averaged; this shape is then interpolated through the two pixels in the other edges of the rectangle. This algorithm has been implemented for HYDICE. RP Kieffer, HH (reprint author), US GEOL SURVEY,BRANCH ASTROGEOL,FLAGSTAFF,AZ 86001, USA. NR 0 TC 7 Z9 7 U1 1 U2 2 PU SPIE - INT SOC OPTICAL ENGINEERING PI BELLINGHAM PA PO BOX 10, BELLINGHAM, WA 98227-0010 BN 0-8194-2209-6 J9 P SOC PHOTO-OPT INS PY 1996 VL 2821 BP 93 EP 108 DI 10.1117/12.257162 PG 16 WC Remote Sensing; Optics SC Remote Sensing; Optics GA BG73D UT WOS:A1996BG73D00010 ER PT J AU Gaddis, LR Soderblom, LA Kieffer, HH Becker, KJ Torson, J Mullins, K AF Gaddis, LR Soderblom, LA Kieffer, HH Becker, KJ Torson, J Mullins, K TI Decomposition of AVIRIS spectra: Extraction of surface-reflectance, atmospheric, and instrumental components SO IEEE TRANSACTIONS ON GEOSCIENCE AND REMOTE SENSING LA English DT Article ID IMAGING SPECTROMETER AVIRIS; SPECTROSCOPY; SCATTERING; CALIFORNIA; MINERALS; NEVADA AB We present techniques that use only information contained within a raw, high-spectral-resolution, hyperspectral Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) scene to estimate and remove additive components (atmospheric scattering and instrument dark current), These techniques allow normalization of multiplicative components (instrument gain, topography, atmospheric transmission) and enhancement, extraction, and identification of relative-reflectance information related to surface composition and mineralogy, Our derivation of additive components from raw AVIRIS data is based on an adaptation of Crippen's ''regression intersection method (RIM).'' As does RIM, we use pairs of surface units that are spectrally homogeneous, spatially extensive, and located in rugged terrain, However, our technique utilizes the long-wavelength spectral data of AVIRIS to derive and remove atmospheric scattering components for each unit. AVIRIS data from the Kelso Dunes and Granite Mountain areas of southern California served as spectrally contrasting, topographically modulated surfaces for illustration of this technique. For a given site and wavelength pair, subtraction of the wavelength-dependent additive component from individual bands will remove topographic shading in both sites in band-to-band ratio images, Normalization of all spectra in the scene to the average scene spectrum results in cancellation of multiplicative components and produces a relative reflectance scene. Absorption features due to mineral absorptions that depart from the average spectrum can be identified in the relative-reflectance AVIRIS product, The validity of these techniques is demonstrated by comparisons between relative-reflectance AVIRIS spectra derived from application of this technique and those derived by using the standard calibration techniques of JPL. Calibrated spectra were extracted from an AVIRIS scene of the Upheaval Dome area of Canyonlands National Park, UT, Results show that surface-reflectance information can be extracted and interpreted in terms of surface mineralogy after application of these techniques to AVIRIS data. RP Gaddis, LR (reprint author), US GEOL SURVEY,FLAGSTAFF,AZ 86001, USA. NR 40 TC 14 Z9 14 U1 2 U2 5 PU IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017-2394 SN 0196-2892 J9 IEEE T GEOSCI REMOTE JI IEEE Trans. Geosci. Remote Sensing PD JAN PY 1996 VL 34 IS 1 BP 163 EP 178 DI 10.1109/36.481901 PG 16 WC Geochemistry & Geophysics; Engineering, Electrical & Electronic; Remote Sensing; Imaging Science & Photographic Technology SC Geochemistry & Geophysics; Engineering; Remote Sensing; Imaging Science & Photographic Technology GA TT934 UT WOS:A1996TT93400017 ER PT B AU Boncyk, WC Markham, BL Barker, JL Helder, D AF Boncyk, WC Markham, BL Barker, JL Helder, D GP IEEE TI Artifact correction and absolute radiometric calibration techniques employed in the Landsat 7 image assessment system SO IGARSS '96 - 1996 INTERNATIONAL GEOSCIENCE AND REMOTE SENSING SYMPOSIUM: REMOTE SENSING FOR A SUSTAINABLE FUTURE, VOLS I - IV LA English DT Proceedings Paper CT 1996 International Geoscience and Remote Sensing Symposium (IGARSS 96) - Remote Sensing for a Sustainable Future CY MAY 21-31, 1996 CL LINCOLN, NE SP IEEE, Geosci & Remote Sensing Soc, Univ Nebraska, Lincoln, NASA, NOAA, USN, Off Naval Res, US Natl Comm Union Radiosci Int, Canon Modern Methods Inc, Univ Nebraska Lincoln, Ctr Adv Land Management Informat Technol, Univ Nebraska Lincoln, Ctr Commun & Informat Sci, Univ Nebraska Lincoln, Ctr Electro Opt, Univ Nebraska Lincoln, Ctr Laser Anal Studies Trace Gas Dynam, Centurion Int Inc, Univ Nebraska Lincoln, Coll Engn & Technol, Univ Nebraska Lincoln, Dept Elect Engn, ERDAS Inc, Univ Nebraska Lincoln, High Plains Climate Ctr, Li Cor Inc, US Geol Survey EROS Data Ctr C1 US GEOL SURVEY,EROS DATA CTR,SIOUX FALLS,SD 57198. RI Markham, Brian/M-4842-2013 OI Markham, Brian/0000-0002-9612-8169 NR 0 TC 1 Z9 1 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3069-2 J9 INT GEOSCI REMOTE SE PY 1996 BP 1270 EP 1272 PG 3 WC Remote Sensing SC Remote Sensing GA BF96U UT WOS:A1996BF96U00406 ER PT J AU Zodrow, EL Lyons, PC Millay, MA AF Zodrow, EL Lyons, PC Millay, MA TI Geochemistry of autochthonous and hypautochthonous siderite dolomite coal-balls (Foord Seam, Bolsovian, Upper Carboniferous), Nova Scotia, Canada SO INTERNATIONAL JOURNAL OF COAL GEOLOGY LA English DT Article AB The 11-13 m thick Foord Seam in the fault-bounded Stellarton Basin, Nova Scotia, is the thickest seam from the Euramerican floral province known to contain coal-balls. In addition to the first discovery of autochthonous coal-balls in the Foord Seam, Nova Scotia, its shale parting also contains hypautochthonous coal-balls with histologically preserved plant structures. The coal-ball discovery helps fill a stratigraphic gap in coal-ball occurrences in the upper Carboniferous (Bolsovian) of Euramerica. The autochthonous and hypautochthonous coal-balls have a similar mineralogical composition and are composed of siderite (81-100%), dolomite-ankerite (0-19%), minor quartz and illite, and trace amounts of 'calcite'. Similar is also their permineralizing mineralogy, which consists of dolomite-ankerite and siderite. Their low pyrite content and carbonate mineralogy, and nonmarine origin, differentiates the Foord Seam coal-balls from other Euramerican coal-ball occurrences. A preliminary geochemical model, which is based on oxygen and carbon isotopic data, indicates that siderite in both the autochthonous and hypautochthonous coal-balls is of very early diagenetic (nonmarine) origin from C-13-enriched bicarbonate derived from bacterial methanogenesis of organic matter. C1 US GEOL SURVEY,RESTON,VA 22092. OHIO UNIV,IRONTON,OH 45638. RP Zodrow, EL (reprint author), UNIV COLL CAPE BRETON,DEPT EARTH SCI,SYDNEY,NS B1P 6L2,CANADA. NR 28 TC 12 Z9 13 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0166-5162 J9 INT J COAL GEOL JI Int. J. Coal Geol. PD JAN PY 1996 VL 29 IS 1-3 BP 199 EP 216 DI 10.1016/0166-5162(95)00008-9 PG 18 WC Energy & Fuels; Geosciences, Multidisciplinary SC Energy & Fuels; Geology GA TP908 UT WOS:A1996TP90800009 ER PT J AU Thurman, EM Fallon, JD AF Thurman, EM Fallon, JD TI The deethylatrazine/atrazine ratio as an indicator of the onset of the spring flush of herbicides into surface water of the Midwestern United States SO INTERNATIONAL JOURNAL OF ENVIRONMENTAL ANALYTICAL CHEMISTRY LA English DT Article; Proceedings Paper CT 5th Symposium on Chemistry and Fate of Modern Pesticides CY SEP 06-08, 1995 CL PARIS, FRANCE DE atrazine; deethylatrazine; hydroxyatrazine; metabolites; surface water; and runoff ID CHROMATOGRAPHY MASS-SPECTROMETRY; NONPOINT-SOURCE CONTAMINATION; DEGRADATION PRODUCTS; ATRAZINE DEGRADATION; SOIL; TRANSPORT; DEISOPROPYLATRAZINE; HYDROXYATRAZINE; GROUNDWATER; METABOLITES AB The ratio of deethylatrazine to atrazine (DAR) may be used to record the first major runoff of herbicides from non-point-source corn fields to surface water in the Midwestern United States. The DAR dramatically decreases from similar to 0.5 to < 0.1 upon application of herbicide and the first major runoff event of a basin. The DAR then gradually increases to values of approximately 0.4-0.6 during the harvest season. Furthermore, the DAR may be used in studies of surface water movement to give a temporal indicator of water moving into reservoirs for possible storage of herbicides. It is hypothesized that deethylatrazine, which accounts for only 6% of the degradation of atrazine, becomes a significant metabolite in surface water (similar to 50% of parent compound) because of its selective removal from soil. This removal process may be an important concept for consideration in studies of herbicide contamination of rivers and reservoirs. C1 US GEOL SURVEY,ST PAUL,MN 55112. RP Thurman, EM (reprint author), US GEOL SURVEY,4821 QUAIL CREST PL,LAWRENCE,KS 66044, USA. RI Thurman, Earl/B-5131-2011 NR 33 TC 30 Z9 30 U1 0 U2 5 PU GORDON BREACH SCI PUBL LTD PI READING PA C/O STBS LTD, PO BOX 90, READING, BERKS, ENGLAND RG1 8JL SN 0306-7319 J9 INT J ENVIRON AN CH JI Int. J. Environ. Anal. Chem. PY 1996 VL 65 IS 1-4 BP 203 EP 214 DI 10.1080/03067319608045555 PG 12 WC Chemistry, Analytical; Environmental Sciences SC Chemistry; Environmental Sciences & Ecology GA WD253 UT WOS:A1996WD25300018 ER PT S AU Stuckless, JS Peterman, ZE AF Stuckless, JS Peterman, ZE GP INT ATOM ENERGY AGCY TI Application of lead isotopes in the study of brines found in the vicinity of proposed nuclear waste sites SO ISOTOPES IN WATER RESOURCES MANAGEMENT, VOL 1 SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT Symposium on Isotopes in Water Resources Management CY MAR 20-24, 1995 CL VIENNA, AUSTRIA SP Int Atom Energy Agcy, UNESCO C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-105595-1 J9 P S IAEA PY 1996 BP 108 EP 110 PG 3 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BF67P UT WOS:A1996BF67P00013 ER PT S AU Kendall, C Silva, SR Chang, CCY Burns, DA Campbell, DH Shanley, JB AF Kendall, C Silva, SR Chang, CCY Burns, DA Campbell, DH Shanley, JB GP INT ATOM ENERGY AGCY TI Use of the delta O-18 and delta N-15 of nitrate to determine sources of nitrate in early spring runoff in forested catchments SO ISOTOPES IN WATER RESOURCES MANAGEMENT, VOL 1 SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT Symposium on Isotopes in Water Resources Management CY MAR 20-24, 1995 CL VIENNA, AUSTRIA SP Int Atom Energy Agcy, UNESCO C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 10 Z9 10 U1 0 U2 3 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-105595-1 J9 P S IAEA PY 1996 BP 167 EP 176 PG 10 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BF67P UT WOS:A1996BF67P00020 ER PT S AU Michel, RL Turk, JT AF Michel, RL Turk, JT GP INT ATOM ENERGY AGCY TI Use of S-35 to study rates of sulphur migration in the Flat Tops Wilderness area, Colorado SO ISOTOPES IN WATER RESOURCES MANAGEMENT, VOL 1 SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT Symposium on Isotopes in Water Resources Management CY MAR 20-24, 1995 CL VIENNA, AUSTRIA SP Int Atom Energy Agcy, UNESCO C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 2 Z9 2 U1 0 U2 0 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-105595-1 J9 P S IAEA PY 1996 BP 293 EP 301 PG 9 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BF67P UT WOS:A1996BF67P00049 ER PT S AU Revesz, K Coplen, T Baedecker, MJ Glynn, PD Hult, M AF Revesz, K Coplen, T Baedecker, MJ Glynn, PD Hult, M GP INT ATOM ENERGY AGCY TI Investigation of methane production and consumption by use of stable isotopes SO ISOTOPES IN WATER RESOURCES MANAGEMENT, VOL 1 SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT Symposium on Isotopes in Water Resources Management CY MAR 20-24, 1995 CL VIENNA, AUSTRIA SP Int Atom Energy Agcy, UNESCO C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-105595-1 J9 P S IAEA PY 1996 BP 381 EP 387 PG 7 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BF67P UT WOS:A1996BF67P00064 ER PT S AU Sanford, WE Buapeng, S AF Sanford, WE Buapeng, S GP INT ATOM ENERGY AGCY TI A comparison of groundwater ages based on C-14 data and three dimensional advective transport modelling of the lower Chao Phraya basin - Palaeohydrology and implications for water resources development in Thailand SO ISOTOPES IN WATER RESOURCES MANAGEMENT, VOL 2 SE PROCEEDING SERIES OF THE INTERNATIONAL ATOMIC ENERGY AGENCY LA English DT Proceedings Paper CT Symposium on Isotopes in Water Resources Management CY MAR 20-24, 1995 CL VIENNA, AUSTRIA SP Int Atom Energy Agcy, UNESCO C1 US GEOL SURVEY,DIV WATER RESOURCES,RESTON,VA 22092. NR 0 TC 1 Z9 1 U1 0 U2 2 PU INT ATOMIC ENERGY AGENCY PI VIENNA PA WAGRAMERSTRASSE 5, PO BOX 100, A-1400 VIENNA, AUSTRIA SN 0074-1884 BN 92-0-100796-5 J9 P S IAEA PY 1996 BP 383 EP 394 PG 12 WC Geosciences, Multidisciplinary; Water Resources SC Geology; Water Resources GA BF67Q UT WOS:A1996BF67Q00046 ER PT J AU Heinrichs, TA Mayo, LR Echelmeyer, KA Harrison, WD AF Heinrichs, TA Mayo, LR Echelmeyer, KA Harrison, WD TI Quiescent-phase evolution of a surge-type glacier: Black Rapids Glacier, Alaska, USA SO JOURNAL OF GLACIOLOGY LA English DT Article ID VARIEGATED GLACIER; POTHOLES AB Black Rapids Glacier, a surge-type glacier in the Alaska Range, most recently surged in 1936-37 and is currently in its quiescent phase. Mass balance, ice velocity and thickness change have been measured at three to ten sites from 1972 to 1994. The annual speed has undergone cyclical fluctuations of as much as 45% about the mean speed. Ice thickness and surface slope did nor change enough to cause the speed fluctuations through changes in ice deformation, which indicates that they are being driven by changes in basal motion. The behavior of Black Rapids Glacier during this quiescent phase is significantly different from that of Variegated Glacier. another well-studied surge-type glacier in Alaska. The present medial-moraine configuration of Black Rapids Glacier indicates that a surge could occur al any time. However, ice velocity data indicate that the next surge may not be imminent. We believe that there is little chance that the next surge will cross and dam the Delta River. C1 UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775. RP Heinrichs, TA (reprint author), US GEOL SURVEY,800 YUKON DR,FAIRBANKS,AK 99775, USA. NR 28 TC 30 Z9 30 U1 0 U2 2 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1996 VL 42 IS 140 BP 110 EP 122 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UF208 UT WOS:A1996UF20800011 ER PT J AU Nolan, M Motyka, RJ Echelmeyer, K Trabant, DC AF Nolan, M Motyka, RJ Echelmeyer, K Trabant, DC TI Ice-thickness measurements of Taku Glacier, Alaska, USA, and their relevance to its recent behavior (vol 41, pg 541, 1995) SO JOURNAL OF GLACIOLOGY LA English DT Correction, Addition C1 DEPT NAT RESOURCES,DIV GEOL GEOPHYS SURVEYS,FAIRBANKS,AK 99709. US GEOL SURVEY,DIV WATER RESOURCES,FAIRBANKS,AK 99708. RP Nolan, M (reprint author), UNIV ALASKA,INST GEOPHYS,FAIRBANKS,AK 99775, USA. NR 1 TC 2 Z9 2 U1 0 U2 1 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1996 VL 42 IS 141 BP 400 EP 400 PG 1 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA VQ974 UT WOS:A1996VQ97400021 ER PT J AU Clow, GD Saltus, RW Waddington, ED AF Clow, GD Saltus, RW Waddington, ED TI A new high-precision borehole-temperature logging system used at GISP2, Greenland, and Taylor Dome, Antarctica SO JOURNAL OF GLACIOLOGY LA English DT Article AB We describe a high-precision (0.1-1.0 mK) borehole-temperature (BT) logging system developed at the United States Geological Survey (USGS) for use in remote polar regions. We discuss calibration, operational and data-processing procedures, and present an analysis of the measurement errors. The system is modular to facilitate calibration procedures and field repairs. By interchanging logging cables and temperature sensors, measurements can be made in either shallow air-filled boreholes or liquid-filled holes up to 7 km deep. Data can be acquired in either incremental or continuous-logging modes. The precision of data collected by the new logging system is high enough to detect and quantify various thermal effects at the milli-Kelvin level. To illustrate this capability, we present sample data from the 3 km deep borehole at GISP2, Greenland, and from a 130 m deep air-filled hole at Taylor Dome, Antarctica. The precision of the processed GISP2 continuous temperature logs is 0.25-0.34 mK. while the accuracy is estimated to be 1.5 mK. The effects of fluid convection and the dissipation of the thermal disturbance caused by drilling the borehoIe are clearly visible in the data. The precision of the incremental Taylor Dome measurements varies from 0.11 to 0.32 mK depending on the wind strength during the esperiments. With this precision, we found that temperature fluctuations and multi-hour trends in the BT measurements correlate well with atmospheric-pressure changes. C1 US GEOL SURVEY,DENVER,CO 80225. UNIV WASHINGTON,SEATTLE,WA 98195. RP Clow, GD (reprint author), US GEOL SURVEY,MENLO PK,CA 94025, USA. NR 18 TC 16 Z9 17 U1 0 U2 3 PU INT GLACIOL SOC PI CAMBRIDGE PA LENSFIELD RD, CAMBRIDGE, ENGLAND CB2 1ER SN 0022-1430 J9 J GLACIOL JI J. Glaciol. PY 1996 VL 42 IS 142 BP 576 EP 584 PG 9 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA WE624 UT WOS:A1996WE62400018 ER PT J AU Custer, CM Custer, TW Sparks, DW Hines, RK Kochanny, CO AF Custer, CM Custer, TW Sparks, DW Hines, RK Kochanny, CO TI Movement patterns of wintering Lesser scaup in Grand Calumet River Indiana Harbor Canal, Indiana SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE Lesser scaup; Aythya affinis; Lake Michigan ID CANVASBACKS AB Lesser scaup (Aythya affinis) winter in the Grand Calumet River-Indiana Harbor Canal (GCR-IHC) drainage into southern Lake Michigan, a polluted oasis in the highly urban and industrial corridor of northern Illinois and Indiana. The GCR-IHC is an important wintering area for lesser scaup in northwestern Indiana, especially after Lake Michigan freezes, because of the lack of other wildlife habitat in the area. We investigated the feeding and movement patterns of these wintering lesser scaup to better understand the ecological significance of this area to wintering waterfowl and to interpret contaminant levels in these lesser scaup. We implanted radio transmitters in 20 individuals in January 1994 and tracked them until early March 1994. Four lesser scaup disappeared and four died within the first 2 weeks after implantation; 12 lesser scaup remained in the GCR-IHC for the next 6-7 weeks. Individual radio-marked scaup (n = 12) were located in the GCR-IHC on an average of 62.2% (extreme values = 25-87%) of the searches. No radio-marked lesser scaup were located outside the GCR-IHC. Lesser scaup were feeding during 23% of the radio fixes. C1 US FISH & WILDLIFE SERV,BLOOMINGTON,IN 47403. RP Custer, CM (reprint author), NATL BIOL SERV,UPPER MISSISSIPPI SCI CTR,POB 818,LA CROSSE,WI 54602, USA. RI Custer, Christine/H-4871-2014; OI Custer, Thomas/0000-0003-3170-6519 NR 17 TC 6 Z9 6 U1 0 U2 1 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1996 VL 22 IS 1 BP 95 EP 99 PG 5 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA UE692 UT WOS:A1996UE69200012 ER PT J AU Elder, JF James, RV Steuer, JJ AF Elder, JF James, RV Steuer, JJ TI Mobility of 2,2',5,5'-tetrachlorobiphenyl in model systems containing bottom sediments and water from the lower Fox River, Wisconsin SO JOURNAL OF GREAT LAKES RESEARCH LA English DT Article DE PCBs; sediment-water interface; sorption; desorption; Fox River; Lake Michigan ID POLYCHLORINATED BIPHENYL CONGENERS; PARTITION-COEFFICIENTS; LAKE-MICHIGAN; ORGANIC-MATTER; GREEN BAY; NATURAL SEDIMENTS; TRANSPORT; SORPTION; PCBS; POLLUTANTS AB Sediment-water partitioning and diffusive transport of 2,2'5,5'-tetrachlorobiphenyl, PCB congener IUPAC #52 (TCB52) were examined in laboratory experiments with sediments from two sites in the lower Fox River, Wisconsin. Native water was pumped at controlled flow rates through cells containing sediments amended with a known activity of carbon-14-labeled TCB52. Concentrations of TCB52 in water and sediments were determined by liquid scintillation measurements of carbon-14 activity. Sediment-wafer partitioning was independent of flow rate for rates up to 8 m/d. Distribution coefficients (K-d) and soil-sorption coefficients (K-oc) were found to be at maximum levels 5-10 cm below the surface, despite an absence of significant variation in the fraction of organic carbon (f(oc)) through the same profile. Other factors, such as the effects of colloids and microbial activity in the sediments, are likely to be important in controlling the PCB distribution. Log K-d and log K-oc ranges were 4.1-4.9 and 5.3-6.1, respectively, and calculated effective diffusivities at the sediment-water interface ranged from 3 to 8 x 10(-10) cm(2)/s. Gradual increases with time in TCB52 concentrations in the water phase, possibly due to effects of microbial activity, were observed. Diffusion experiments and models showed that the TCB52 migration rate within, the sediment column is 8-9 mm/yr. C1 US GEOL SURVEY,MENLO PK,CA 94025. RP Elder, JF (reprint author), US GEOL SURVEY,6417 NORMANDY LANE,MADISON,WI 53719, USA. NR 40 TC 5 Z9 5 U1 2 U2 6 PU INT ASSOC GREAT LAKES RES PI ANN ARBOR PA 2200 BONISTEEL BLVD, ANN ARBOR, MI 48109-2099 SN 0380-1330 J9 J GREAT LAKES RES JI J. Gt. Lakes Res. PY 1996 VL 22 IS 3 BP 697 EP 706 PG 10 WC Environmental Sciences; Limnology; Marine & Freshwater Biology SC Environmental Sciences & Ecology; Marine & Freshwater Biology GA VQ491 UT WOS:A1996VQ49100017 ER PT J AU Culver, SJ Repetski, JE Pojeta, J Hunt, D AF Culver, SJ Repetski, JE Pojeta, J Hunt, D TI Early and middle(?) Cambrian metazoan and protistan fossils from West Africa SO JOURNAL OF PALEONTOLOGY LA English DT Article ID FORAMINIFERA; EVOLUTION; SENEGAL; RECORD AB Supposed Upper Proterozoic strata in the southwest Taoudeni Basin, Guinea and Senegal, and from the Mauritanide fold belt, Mauritania, have yielded mostly poorly preserved small skeletal fossils of metazoan and protistan origin. Problematic, but possible echinoderm material and spicules of the heteractinid sponge Eiffelia dominate the Taoudeni Basin assemblage. The age of the material is not certain but the paleontologic data suggest an Early Cambrian age for the stratigraphically lowest faunas, and a Middle Cambrian age is possible for the stratigraphically highest collections. C1 US GEOL SURVEY,RESTON,VA 22092. UNIV MANCHESTER,DEPT GEOL,MANCHESTER M13 9PL,LANCS,ENGLAND. RP Culver, SJ (reprint author), NAT HIST MUSEUM,DEPT PALAEONTOL,CROMWELL RD,LONDON SW7 5BD,ENGLAND. NR 31 TC 13 Z9 14 U1 0 U2 0 PU PALEONTOLOGICAL SOC INC PI ITHACA PA 1259 TRUMANSBURG ROAD, ITHACA, NY 14850 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD JAN PY 1996 VL 70 IS 1 BP 1 EP 4 PG 4 WC Paleontology SC Paleontology GA TQ976 UT WOS:A1996TQ97600001 ER PT J AU Oliver, WA Sorauf, JE Brett, CE AF Oliver, WA Sorauf, JE Brett, CE TI A unique occurrence of Endophyllum (Rugose coral; Devonian) in Eastern North America: An ecological and biogeographical puzzle SO JOURNAL OF PALEONTOLOGY LA English DT Article ID NEW-YORK AB Endophyllum is described for the first time from North America. The occurrence of a single, large colony in Middle Devonian strata in New York is both biogeographically and environmentally anomalous: it belongs to an Old World Realm genus but was found in the Eastern Americas Realm, and it occurred in a gray, ambocoeliid-bearing mudstone, a facies in which morphologically complex corals are otherwise unknown. Available evidence suggests that the coral lived not far from where it was found, possibly on a hardground or bank a few km north of the outcrop. Endophyllum ciurcai new species is described. C1 SUNY BINGHAMTON,DEPT GEOL SCI,BINGHAMTON,NY 13902. UNIV ROCHESTER,DEPT EARTH & ENVIRONM SCI,ROCHESTER,NY 14627. RP Oliver, WA (reprint author), SMITHSONIAN INST,US GEOL SURVEY,MUSEUM NAT HIST E 305,WASHINGTON,DC 20560, USA. NR 39 TC 1 Z9 1 U1 0 U2 1 PU PALEONTOLOGICAL SOC INC PI ITHACA PA 1259 TRUMANSBURG ROAD, ITHACA, NY 14850 SN 0022-3360 J9 J PALEONTOL JI J. Paleontol. PD JAN PY 1996 VL 70 IS 1 BP 44 EP 54 PG 11 WC Paleontology SC Paleontology GA TQ976 UT WOS:A1996TQ97600005 ER PT J AU Wald, DJ AF Wald, DJ TI Slip history of the 1995 Kobe, Japan, earthquake determined from strong motion, teleseismic, and geodetic data SO JOURNAL OF PHYSICS OF THE EARTH LA English DT Article ID CALIFORNIA AB Near-source ground motions, teleseismic body waveforms, and geodetic displacements produced by the 1995 Kobe, Japan, earthquake have been used to determine the spatial and temporal dislocation pattern on the faulting surfaces. A linear, least-squares approach was used to invert the data sets both independently and in unison in order to investigate the resolving power of each data set and to determine a model most consistent with all the available data. A two-fault model was used, with a single rupture plane representing faulting beneath Kobe and a second plane representing slip underneath Awaji Island. The total seismic moment is estimated to be 2.4 x 10(19) N m (M-w 6.9), with rupture partitioned such that about 40% of the slip was relatively deep (5-20 km) and northeast of the epicenter toward Kobe, and about 60% was toward the southwest and shallower (mostly 0-10 km) beneath Awaji Island. Analysis of the slip model indicates that the ground motions recorded within the severely damaged region of Kobe originated From the region of relatively low slip (about 1 m) deep beneath Kobe and not from the shallow, higher slip regions (about 3 m) beneath Awaji Island. Although the slip was relatively low beneath Kobe, the combined effects of source rupture directivity, a short slip duration, and site amplification conspired to generate very damaging ground motions within the city. RP Wald, DJ (reprint author), US GEOL SURVEY, 525 S WILSON AVE, PASADENA, CA 91106 USA. OI Wald, David/0000-0002-1454-4514 NR 20 TC 95 Z9 99 U1 0 U2 2 PU CENTER ACADEMIC PUBL JAPAN PI TOKYO PA 2-4-16 YAYOI, BUNKYO-KU, TOKYO, 113-0032, JAPAN SN 0022-3743 J9 J PHYS EARTH JI J. Phys. Earth PY 1996 VL 44 IS 5 BP 489 EP 503 PG 15 WC Geosciences, Multidisciplinary SC Geology GA WY106 UT WOS:A1996WY10600005 ER PT J AU Spotl, C Kralik, M Kunk, MJ AF Spotl, C Kralik, M Kunk, MJ TI Authigenic feldspar as an indicator of paleo-rock water interactions in Permian carbonates of the northern Calcareous Alps, Austria SO JOURNAL OF SEDIMENTARY RESEARCH LA English DT Article ID K-FELDSPAR; PRECAMBRIAN BASEMENT; POTASSIUM-FELDSPAR; EASTERN ALPS; AGE; ALBITIZATION; DIAGENESIS; EVAPORITES; MIGRATION; CHAIN AB Dolostones interbedded with Upper Permian evaporites at the base of the Northern Calcareous Alps contain abundant authigenic K-feldspar. Two petrographically, structurally, and isotopically distinct generations of K-feldspar can be distinguished: crystals composed of an inclusion-rich core and a clear rim, and optically unzoned, transparent crystals. Both feldspar types have essentially identical K-feldspar end-member compositions with greater than or equal to 99.5 mole % Or component. Low oxygen isotope ratios (+16.1 parts per thousand to +18.1 parts per thousand SMOW) suggest precipitation from O-18-enriched, saline fluids at temperatures in excess of similar to 140 degrees C. Ar-40/Ar-39 plateau-age spectra of five samples range from 145 +/- 1 to 144 +/- 1 Ma (Early Berriasian) and suggest that both types of feldspar were formed within an interval that did not exceed similar to 2 m.y. Rb/Sr model ages range from 152 to 140 Ma, assuming that the burial diagenetic regime was buffered with respect to strontium by the associated marine Permian evaporites. Authigenic K-feldspar records two distinct events of hot brine flow, most likely triggered by tectonic movements (detachment) and by an increase in the subsurface temperature in response to thrust loading. C1 BUNDESFORSCH & PRUFZENTRUM ARSENAL, INST GEOTECH, A-1030 VIENNA, AUSTRIA. US GEOL SURVEY, RESTON, VA 22092 USA. RP UNIV INNSBRUCK, INST GEOL & PALAONTOL, INNRAIN 52, A-6020 INNSBRUCK, AUSTRIA. NR 57 TC 22 Z9 22 U1 0 U2 5 PU SEPM-SOC SEDIMENTARY GEOLOGY PI TULSA PA 6128 EAST 38TH ST, STE 308, TULSA, OK 74135-5814 USA SN 1527-1404 EI 1938-3681 J9 J SEDIMENT RES JI J. Sediment. Res. PD JAN PY 1996 VL 66 IS 1 BP 139 EP 146 PN A PG 8 WC Geology SC Geology GA TT541 UT WOS:A1996TT54100016 ER PT J AU Augspurger, T Smith, MR Meteyer, CU Converse, KA AF Augspurger, T Smith, MR Meteyer, CU Converse, KA TI Mortality of passerines adjacent to a North Carolina corn field treated with granular carbofuran SO JOURNAL OF WILDLIFE DISEASES LA English DT Article DE Carbofuran; Furadan(R); anticholinesterase poisoning; North Carolina; passerines; red-winged blackbirds; Agelaius phoeniceus ID REACTIVATION TECHNIQUES; ORGANO-PHOSPHORUS; BIRDS AB Red-winged blackbirds (Agelaius phoeniceus) were collected during an epizootic in southeastern North Carolina (USA). Activity of brain cholinesterase (ChE) was inhibited by 14 to 48% in three of five specimens, and returned to normal levels after incubation. Gastrointestinal tracts were analyzed for 30 anti-ChE agents. Carbofuran, the only compound detected, was present in all specimens at levels from 5.44 to 72.7 mu g/g wet weight. Application of granular carbofuran in an adjacent corn field, results of necropsy examinations, and chemical analyses are consistent with a diagnosis of carbofuran poisoning in these specimens. C1 US FISH & WILDLIFE SERV,NATL WILDLIFE HLTH CTR,MADISON,WI 53711. RP Augspurger, T (reprint author), US FISH & WILDLIFE SERV,ECOL SERV,POB 33726,RALEIGH,NC 27636, USA. NR 13 TC 23 Z9 24 U1 0 U2 0 PU WILDLIFE DISEASE ASSN, INC PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0090-3558 J9 J WILDLIFE DIS JI J. Wildl. Dis. PD JAN PY 1996 VL 32 IS 1 BP 113 EP 116 PG 4 WC Veterinary Sciences SC Veterinary Sciences GA TP805 UT WOS:A1996TP80500018 PM 8627921 ER PT J AU McAuley, DG Longcore, JR Sepik, GF Pendleton, GW AF McAuley, DG Longcore, JR Sepik, GF Pendleton, GW TI Habitat characteristics of American woodcock nest sites on a managed area in Maine SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE American woodcock; habitat; Maine; nest; Scolopax minor AB We measured characteristics of habitat near 89 nests of American woodcock (Scolopax minor) and 100 randomly selected points on Moosehorn National Wildlife Refuge, Calais, Maine, an area managed for woodcock. At nest sites, basal area was lower (P < 0.001), densities of deciduous saplings were greater (P < 0.001), densities of coniferous saplings were lower (P = 0.001), densities of shrub stems were greater (P = 0.002), and height of trees was shorter (P = 0.001) than at random sites. Nest sites were closer to openings (P < 0.001) than were random sites. Nests were in 15 cover types. The aspen (Populus spp.), tamarack (Larix laricina), and alder (Alnus rugosa) types were used as nest sites more often than expected in relation to habitat types available at random sites (P < 0.001). Fifty-eight percent (n = 89) of nests were in stands of aspen, 11% in alder or tamarack, and 10% in mature second-growth gray birch (Betula populifolia) and red maple (Acer rubrum). Forty-four percent (n = 89) of the nests were in clearcuts less than or equal to 10 years old. Habitat characteristics around sites of first nests were not different among years (P, 0.05) or between sites of successful nests and nests destroyed by predators, although the large variances of the variables reduced our power to detect differences. Habitat around sites of renests differed from sites of first nests. Sites around first nests had lower basal area of dead trees (P = 0.05) and higher stem densities of aspen (P = 0.03) and cherry saplings (Prunus spp.) (P = 0.001), and viburnum (Viburnum spp.) (P = 0.05), while renest sites had taller trees (P = 0.02). The change from nest sites in areas dominated by alders and tree-size gray birch used in 1977-80 to sites dominated by sapling trees, especially aspen, used during 1987-90 suggests that woodcock in the expanding population at the refuge are selecting nest sites created by habitat management since 1979. C1 US FISH & WILDLIFE SERV,MOOSEHORN NATL WILDLIFE REFUGE,CALAIS,ME 04619. PATUXENT ENVIRONM SCI CTR,NATL BIOL SERV,LAUREL,MD 20708. RP McAuley, DG (reprint author), NE RES GRP,PATUXENT ENVIRONM SCI CTR,NATL BIOL SERV,5768 S ANNEX A,ORONO,ME 04469, USA. NR 29 TC 7 Z9 9 U1 7 U2 18 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JAN PY 1996 VL 60 IS 1 BP 138 EP 148 DI 10.2307/3802048 PG 11 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA TU165 UT WOS:A1996TU16500016 ER PT J AU Wood, PB White, JH Steffer, A Wood, JM Facemire, CF Percival, HF AF Wood, PB White, JH Steffer, A Wood, JM Facemire, CF Percival, HF TI Mercury concentrations in tissues of Florida bald eagles SO JOURNAL OF WILDLIFE MANAGEMENT LA English DT Article DE bald eagle; Florida; Haliaeetus leucocephalus; mercury; toxicology ID ENVIRONMENTAL CONTAMINANTS; BIRD FEATHERS; METHYLMERCURY; PRODUCTIVITY; RESIDUES; WATER; LAKES; EGGS AB We collected 48 blood and 61 feather samples from nestling bald eagles (Haliaeetus leucocephalus) at 42 nests and adult feather samples from 20 nests in north and central Florida during 1991-93. We obtained 32 liver, 10 feather, and 5 blood samples from 33 eagle carcasses recovered in Florida during 1987-93. For nestlings, mercury concentrations in blood (GM = 0.16 ppm wet wt) and feather (GM = 3.23 ppm) samples were correlated (r = 0.69, P = 0.0001). Although nestlings had lower mercury concentrations in feathers than did adults (GM = 6.03 ppm), the feather mercury levels in nestlings and adults from the same nest were correlated (r = 0.63, P < 0.02). Mercury concentration in blood of captive adult eagles (GM = 0.23 ppm) was similar to Florida nestlings but some Florida nestlings had blood mercury concentrations up to 0.61 ppm, more than twice as high as captive adults. Feather mercury concentrations in both nestlings and adults exceeded those in captive eagles, but concentrations in all tissues were similar to, or lower than, those in bald eagles from other wild populations. Although mercury concentrations in Florida eagles are below those that cause mortality, they are in the range of concentrations that can cause behavioral changes or reduce reproduction. We recommend periodic monitoring of mercury in Florida bald eagles for early detection of mercury increases before negative effects on reproduction occur. C1 FLORIDA GAME & FRESH WATER FISH COMMISS,EUSTIS,FL 32727. BIOL RES ASSOCIATES,TAMPA,FL 33619. W VIRGINIA UNIV,DIV FORESTRY,MORGANTOWN,WV 26506. US FISH & WILDLIFE SERV,ATLANTA,GA 30303. UNIV FLORIDA,DEPT WILDLIFE ENERGY & CONSERVAT,FLORIDA COOPERAT FISH & WILDLIFE RES UNIT,GAINESVILLE,FL 32611. RP Wood, PB (reprint author), W VIRGINIA UNIV,DIV FORESTRY,W VIRGINIA COOPERAT FISH & WILDLIFE RES UNIT,NATL BIOL SERV,MORGANTOWN,WV 26506, USA. NR 31 TC 28 Z9 30 U1 0 U2 2 PU WILDLIFE SOC PI BETHESDA PA 5410 GROSVENOR LANE, BETHESDA, MD 20814-2197 SN 0022-541X J9 J WILDLIFE MANAGE JI J. Wildl. Manage. PD JAN PY 1996 VL 60 IS 1 BP 178 EP 185 DI 10.2307/3802053 PG 8 WC Ecology; Zoology SC Environmental Sciences & Ecology; Zoology GA TU165 UT WOS:A1996TU16500021 ER PT B AU Wieczorek, GF Gori, PL Jager, S Kappel, WM Negussey, D AF Wieczorek, GF Gori, PL Jager, S Kappel, WM Negussey, D BE Senneset, K TI Assessment and management of landslide hazards near the Tully Valley landslide, Syracuse, New York, USA SO LANDSLIDES LA English DT Proceedings Paper CT 7th International Symposium on Landslides CY JUN 17-21, 1996 CL TRONDHEIM, NORWAY SP Norwegian Geotech Soc, Norwegian Univ Sci & Technol, Dept Geotech Engn, Int Soc Soil Mech & Fdn Engn, Tech Comm Landslides, Int Assoc Engn Geol, Commiss Landslides C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 1 Z9 1 U1 0 U2 0 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-818-5 PY 1996 BP 411 EP 416 PG 6 WC Engineering, Civil; Geography; Geology; Geosciences, Multidisciplinary SC Engineering; Geography; Geology GA BF88Y UT WOS:A1996BF88Y00054 ER PT B AU Savage, WZ Varnes, DJ Schuster, RL Highland, LM AF Savage, WZ Varnes, DJ Schuster, RL Highland, LM BE Senneset, K TI The Slumgullion earth flow, southwestern Colorado SO LANDSLIDES LA English DT Proceedings Paper CT 7th International Symposium on Landslides CY JUN 17-21, 1996 CL TRONDHEIM, NORWAY SP Norwegian Geotech Soc, Norwegian Univ Sci & Technol, Dept Geotech Engn, Int Soc Soil Mech & Fdn Engn, Tech Comm Landslides, Int Assoc Engn Geol, Commiss Landslides C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 1 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-818-5 PY 1996 BP 883 EP 888 PG 6 WC Engineering, Civil; Geography; Geology; Geosciences, Multidisciplinary SC Engineering; Geography; Geology GA BF88Y UT WOS:A1996BF88Y00131 ER PT B AU Schuster, RL AF Schuster, RL BE Chacon, J Irigaray, C Fernandez, T TI The 25 most catastrophic landslides of the 20th century SO LANDSLIDES - PROCEEDINGS OF THE EIGHTH INTERNATIONAL CONFERENCE AND FIELD TRIP ON LANDSLIDES LA English DT Proceedings Paper CT 8th International Conference and Field Trip on Landslides CY SEP 27-28, 1996 CL GRANADA, SPAIN SP Univ Granada, Int Landslide Res Grp, Polytech Univ Catalunya, Polytech Univ Valencia, IAEG, Spanish Branch, Andalusian Grp Environm & Nat Hazards C1 US GEOL SURVEY,DENVER,CO. RI Irigaray, Clemente/F-7345-2016 OI Irigaray, Clemente/0000-0002-7942-0926 NR 0 TC 0 Z9 0 U1 0 U2 2 PU A A BALKEMA PI ROTTERDAM PA PO BOX 1675, 3000 BR ROTTERDAM, NETHERLANDS BN 90-5410-832-0 PY 1996 BP 53 EP 62 PG 10 WC Geochemistry & Geophysics; Geography; Geology SC Geochemistry & Geophysics; Geography; Geology GA BG41F UT WOS:A1996BG41F00006 ER PT S AU Cronin, TM Dwyer, GS Baker, PA RodriguezLazaro, J Briggs, WM AF Cronin, TM Dwyer, GS Baker, PA RodriguezLazaro, J Briggs, WM BE Andrews, JT Austin, WEN Bergsten, H Jennings, AE TI Deep-sea ostracode shell chemistry (Mg:Ca ratios) and late Quaternary Arctic Ocean history SO LATE QUATERNARY PALAEOCEANOGRAPHY OF THE NORTH ATLANTIC MARGINS SE GEOLOGICAL SOCIETY SPECIAL PUBLICATION LA English DT Proceedings Paper CT Workshop on Late Quaternary Palaeoceanography of the North Atlantic Margins CY JAN 05-07, 1995 CL EDINBURGH, SCOTLAND C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 11 Z9 12 U1 0 U2 1 PU GEOLOGICAL SOC PUBLISHING HOUSE PI BATH PA UNIT 7, BRASSMILL ENTERPRISE CTR, BRASSMILL LANE, BATH, AVON, ENGLAND BA1 3JN SN 0305-8719 BN 1-897799-61-6 J9 GEOL SOC SP PY 1996 IS 111 BP 117 EP 134 DI 10.1144/GSL.SP.1996.111.01.08 PG 18 WC Geology SC Geology GA BG08T UT WOS:A1996BG08T00008 ER PT J AU Wang, WX Reinfelder, JR Lee, BG Fisher, NS AF Wang, WX Reinfelder, JR Lee, BG Fisher, NS TI Assimilation and regeneration of trace elements by marine copepods SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Article ID DECOMPOSING PLANKTONIC DEBRIS; RELEASE RATES; TRANSURANIC ELEMENTS; PHYTOPLANKTON DEBRIS; FEEDING RATES; ACARTIA-TONSA; ZOOPLANKTON; CALANUS; BIOKINETICS; METABOLISM AB Assimilation efficiencies (AE) of five trace elements (Am, Cd, Co, Se, and Zn) and carbon by neritic copepods (Acartia tonsa and Temora longicornis) feeding at different food concentrations and on different food types (diatoms, green algae, flagellates, dinoflagellates, and Fe oxides) were measured with radiotracer techniques. Food concentration had little influence on AEs of C, Cd, Co, and Se within a range of 16-800 mu g C liter(-1). AEs of Am and Zn were highest at low food concentrations (16-56 mu g C liter(-1)) but remained relatively constant when food levels exceeded 160 mu g C liter(-1). Different algal diets had no major influence on AEs, which generally were in the order Cd > Se > Zn > Co > Am. Metals (Cd, Co, and Zn) were assimilated from Fe oxides with 50% less efficiency than from algal cells. Element regeneration into the dissolved phase was a significant route for the release of ingested elements by copepods and increased with increased food concentration. Element regeneration rates for Cd, Se, and Zn were comparable to the regeneration rates of major nutrients such as P (30-70% daily). Retention half-times of elements in decomposing fecal pellets ranged from <1 d (Cd) to >10 d (Am). The efficient assimilation and regeneration of Cd, Se, and Zn can significantly lengthen the residence time of these elements in ocean surface waters. C1 SUNY STONY BROOK,MARINE SCI RES CTR,STONY BROOK,NY 11794. PRINCETON UNIV,DEPT GEOL & GEOPHYS SCI,PRINCETON,NJ 08544. US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. RI Wang, Wen-Xiong/E-7254-2011; Reinfelder, John/C-7214-2016; OI Reinfelder, John/0000-0002-3737-604X; Wang, Wenxiong/0000-0001-9033-0158 NR 49 TC 62 Z9 65 U1 0 U2 10 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JAN PY 1996 VL 41 IS 1 BP 70 EP 81 PG 12 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UC907 UT WOS:A1996UC90700007 ER PT J AU Tate, CM McKnight, DM Broshears, RE AF Tate, CM McKnight, DM Broshears, RE TI Using lithium (Li+) as a conservative tracer does not prevent algal uptake of phosphate in an acid mine drainage stream (Reply to the comment by Stewart and Kszos) SO LIMNOLOGY AND OCEANOGRAPHY LA English DT Letter RP Tate, CM (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 415,LAKEWOOD,CO 80225, USA. OI MCKNIGHT, DIANE/0000-0002-4171-1533 NR 4 TC 4 Z9 4 U1 0 U2 0 PU AMER SOC LIMNOLOGY OCEANOGRAPH PI LAWRENCE PA 810 EAST 10TH ST, LAWRENCE, KS 66044-8897 SN 0024-3590 J9 LIMNOL OCEANOGR JI Limnol. Oceanogr. PD JAN PY 1996 VL 41 IS 1 BP 191 EP 192 PG 2 WC Limnology; Oceanography SC Marine & Freshwater Biology; Oceanography GA UC907 UT WOS:A1996UC90700020 ER PT J AU Pereira, WE Hostettler, FD Rapp, JB AF Pereira, WE Hostettler, FD Rapp, JB TI Distributions and fate of chlorinated pesticides, biomarkers and polycyclic aromatic hydrocarbons in sediments along a contamination gradient from a point-source in San Francisco Bay, California SO MARINE ENVIRONMENTAL RESEARCH LA English DT Article ID RESIDUES AB The distribution and fate of chlorinated pesticides, biomarkers, and polycyclic aromatic hydrocarbons (PAHs) in surficial sediments along a contamination gradient in the Lauritzen Canal and Richmond Harbor in San Francisco Bay was investigated. Compounds were identified and quantified using gas chromatography-ion trap mass spectrometry. Biomarkers and PAHs were derived primarily from weathered petroleum. DDT was reductively dechlorinated under anoxic conditions to DDD and several minor degradation products, DDMU, DDMS, and DDNU. Under aerobic conditions, DDT was dehydrochlorinated to DDE and DBP. Aerobic degradation of DDT was diminished or inhibited in zones of high concentration, and increased significantly in zones of lower concentration. Other chlorinated pesticides identified in sediment included dieldrin and chlordane isomers. Multivariate analysis of the distributions of the DDTs suggested that there ave probably two sources of DDD. In addition, DDE and DDMU ave probably formed by similar mechanisms, i.e. dehydrochlorination. A steep concentration gradient existed from the Canal to the Outer Richmond Harbor, but higher levels of DDD than those found in the remainder of the Bay indicated that these contaminants are transported on particulates and colloidal organic matter from this source into San Francisco Bay. Chlorinated pesticides and PAHs may pose a potential problem to biota in San Francisco Bay. RP Pereira, WE (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MENLO PK,CA 94025, USA. NR 35 TC 112 Z9 146 U1 4 U2 22 PU ELSEVIER SCI LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, OXON, ENGLAND OX5 1GB SN 0141-1136 J9 MAR ENVIRON RES JI Mar. Environ. Res. PY 1996 VL 41 IS 3 BP 299 EP 314 DI 10.1016/0141-1136(95)00021-6 PG 16 WC Environmental Sciences; Marine & Freshwater Biology; Toxicology SC Environmental Sciences & Ecology; Marine & Freshwater Biology; Toxicology GA TY274 UT WOS:A1996TY27400005 ER PT J AU Marmontel, M OShea, TJ Kochman, HI Humphrey, SR AF Marmontel, M OShea, TJ Kochman, HI Humphrey, SR TI Age determination in manatees using growth-layer-group counts in bone SO MARINE MAMMAL SCIENCE LA English DT Article DE age determination; Florida; growth layers; manatee; Sirenia; Trichechus manatus; bone ID EASTERN TROPICAL PACIFIC; FLORIDA; REPRODUCTION; PREGNANCY; DOLPHINS; PATTERNS; TEETH AB Growth layers were observed in histological preparations of bones of known-age, known minimum-age, and tetracycline-marked free-ranging and captive Florida manatees (Trichechus manatus latirostris), substantiating earlier preliminary findings of other studies. Detailed analysis of 17 new case histories showed that growth-layer group (GLG) counts in the periotic bone were consistent with known age, or time since tetracycline administration, but were less reliable in other bones. GLG counts were also made in periotic bones of 1,196 Florida manatees of unknown age found dead from 1974 through 1991. These counts were conducted in order to assess variability and to determine relationships among estimated age, size, sex, and degree of bone resorption. Resorption can interfere with accuracy of GLG counts. This effect does not occur until ages greater than about 15 yr and body lengths greater than 300 cm are attained. GLGs were also observed in periotic bones of Antillean manatees (Trichechus manatus manatus) but were not validated against known-age specimens. Use of GLG counts in the periotic bone is suitable for application to studies of population dynamics and other age-related aspects of manatee biology. C1 UNIV FLORIDA, DEPT WILDLIFE & RANGE SCI, GAINESVILLE, FL 32611 USA. US FISH & WILDLIFE SERV, NATL ECOL RES CTR, SIRENIA PROJECT, GAINESVILLE, FL 32601 USA. UNIV FLORIDA, FLORIDA MUSEUM NAT HIST, GAINESVILLE, FL 32611 USA. NR 70 TC 19 Z9 22 U1 2 U2 11 PU WILEY-BLACKWELL PI HOBOKEN PA 111 RIVER ST, HOBOKEN 07030-5774, NJ USA SN 0824-0469 EI 1748-7692 J9 MAR MAMMAL SCI JI Mar. Mamm. Sci. PD JAN PY 1996 VL 12 IS 1 BP 54 EP 88 DI 10.1111/j.1748-7692.1996.tb00305.x PG 35 WC Marine & Freshwater Biology; Zoology SC Marine & Freshwater Biology; Zoology GA TQ361 UT WOS:A1996TQ36100005 ER PT B AU Oremland, RS AF Oremland, RS BE Lidstrom, ME Tabita, FR TI Microbial cycling of methyl bromide SO MICROBIAL GROWTH ON C(1) COMPOUNDS LA English DT Proceedings Paper CT 8th International Symposium on Microbial Growth on C(1) Compounds CY AUG 27-SEP 01, 1995 CL SAN DIEGO, CA SP Bayer Corp, Environm Now, Pharmacia Corp, US DOE, NASA, Natl Sci Fdn C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 0 U2 0 PU KLUWER ACADEMIC PUBL PI DORDRECHT PA PO BOX 17, 3300 AA DORDRECHT, NETHERLANDS BN 0-7923-3938-X PY 1996 BP 310 EP 317 PG 8 WC Biochemistry & Molecular Biology; Microbiology SC Biochemistry & Molecular Biology; Microbiology GA BF34V UT WOS:A1996BF34V00041 ER PT B AU Oremland, RS AF Oremland, RS BE Murrell, CJ Kelly, DP TI Microbial degradation of atmospheric halocarbons SO MICROBIOLOGY OF ATMOSPHERIC TRACE GASES: SOURCES, SINKS AND GLOBAL CHANGE PROCESSES SE NATO ADVANCED SCIENCE INSTITUTE SERIES, SERIES I, GLOBAL ENVIRONMENT CHANGE LA English DT Proceedings Paper CT NATO Advanced Research Workshop on the Microbiology of Atmospheric Trace Gases - Sources, Sinks and Global Change Processes CY MAY 13-18, 1995 CL IL CIOCCO, ITALY SP NATO C1 US GEOL SURVEY,MENLO PK,CA 94025. RI Murrell, John/B-1443-2012 NR 0 TC 2 Z9 2 U1 0 U2 0 PU SPRINGER-VERLAG BERLIN PI BERLIN 33 PA HEIDELBERGER PLATZ 3, W-1000 BERLIN 33, GERMANY BN 3-540-60612-2 J9 NATO ASI SER SER I PY 1996 VL 39 BP 85 EP 101 PG 17 WC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Microbiology SC Geochemistry & Geophysics; Meteorology & Atmospheric Sciences; Microbiology GA BF72V UT WOS:A1996BF72V00006 ER PT S AU Keenlyne, KD AF Keenlyne, KD BE Miranda, LE DeVries, DR TI Multiple resource management on an interjurisdictional river SO MULTIDIMENSIONAL APPROACHES TO RESERVOIR FISHERIES MANAGEMENT SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Proceedings Paper CT 3rd National Reservoir Fisheries Symposium on Multidimensional Approaches to Reservoir Fisheries Management CY JUN 12-14, 1995 CL CHATTANOOGA, TN SP Amer Fisheries Soc, So Div, Reservoir Comm, US Dept Interior, Fish & Wildlife Serv, Div Fed Aid, Tennessee Valley Authority, US Army Corps Engineers AB A historical review of attempts to develop interjurisdictional resource management on the 3,768-km-long Missouri River is presented. Resource concerns are multijurisdictional and involve a broad spectrum of issues, including such things as water rights, habitat needs for rare and endangered species, and management of sport fisheries in a changing environment. These concerns are superimposed on a mixture of state and federal laws that presuppose removal of water from the river under rules of western water law. This paper describes formation of an intejurisdictional committee to consider fish and wildlife resource issues, including discussion of the committee's operation, results to date, and reflection on the significance of such a group in future deliberations on the river. RP Keenlyne, KD (reprint author), US FISH & WILDLIFE SERV,420 S GARFIELD AVE,PIERRE,SD 57501, USA. NR 0 TC 1 Z9 1 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-92-X J9 AM FISH S S PY 1996 VL 16 BP 47 EP 53 PG 7 WC Fisheries SC Fisheries GA BG96R UT WOS:A1996BG96R00007 ER PT J AU Ziegler, W Sandberg, CA AF Ziegler, W Sandberg, CA TI Reflexions on Frasnian and Famennian stage boundary decisions as a guide to future deliberations SO NEWSLETTERS ON STRATIGRAPHY LA English DT Article AB The pros and cons of the three conodont-based boundaries of the Frasnian and Famennian Stages and their corresponding GSSPs (Global Stratotype Section and Point) are evaluated in terms of current taxonomic, biostratigraphic, and sedimentologic knowledge. Two Of these boundaries are based on easily identified pelagic species, which provide excellent bases for global correlation. The third, for the base of the Frasnian, is based on a neritic species, whose taxonomy has been heatedly debated. The GSSPs for these three levels are all located in the Montagne Noire of southern France, partly because of political motivation to balance GSSPs selected in other regions. All three GSSPs are at levels from which global correlations cannot be effectively accomplished without aid from other, more complete sections or without making correlations strictly on the basis of taxonomic concepts - i.e., the entry of the definitive conodont species. Future deliberating bodies may want to reconsider the species chosen to delimit the base of the Frasnian and to select better GSSPs for all three boundaries. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Ziegler, W (reprint author), FORSCHUNGSINST SENCKENBERG,D-60325 FRANKFURT,GERMANY. NR 33 TC 21 Z9 23 U1 1 U2 1 PU GEBRUDER BORNTRAEGER PI STUTTGART PA JOHANNESSTR 3A, D-70176 STUTTGART, GERMANY SN 0078-0421 J9 NEWSL STRATIGR JI Newsl. Stratigr. PY 1996 VL 33 IS 3 BP 157 EP 169 PG 13 WC Geology SC Geology GA UN459 UT WOS:A1996UN45900004 ER PT B AU Collett, T AF Collett, T GP PROGEP NGH 96 TI Geologic assessment of the natural gas hydrate resources in the onshore and offshore regions of the United States SO NGH '96 - 2ND INTERNATIONAL CONFERENCE ON NATURAL GAS HYDRATES, PROCEEDINGS LA English DT Proceedings Paper CT 2nd International Conference on Natural Gas Hydrates (NGH 96) CY JUN 02-06, 1996 CL TOULOUSE, FRANCE SP Elf Aquitaine, Gasunie, Gaz France, Inst Francais Petr, Statoil, Total, Minist Educ Natl, Minist Affaires Etrangeres, Conseil Reg Midi Pyrenees C1 US GEOL SURVEY,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 1 PU INSTITUT NATIONAL POLYTECHNIQUE PI TOULOUSE PA ECOLE NATIONALE SUPERIEURE INGENIEURS GENIE CHIMIQUE 18 CHEMIN DE LA LOGE, TOULOUSE, FRANCE PY 1996 BP 499 EP 506 PG 8 WC Engineering, Petroleum SC Engineering GA BF98M UT WOS:A1996BF98M00069 ER PT J AU Ling, CH Josberger, EG Thorndike, AS AF Ling, CH Josberger, EG Thorndike, AS TI Mesoscale variability of the upper Colorado river snowpack SO NORDIC HYDROLOGY LA English DT Article ID PASSIVE MICROWAVE AB In the mountainous regions of the Upper Colorado River Basin, snow course observations give local measurements of snow water equivalent, which can be used to estimate regional averages of snow conditions. We develop a statistical technique to estimate the mesoscale average snow accumulation, using 8 years of snow course observations. For each of three major snow accumulation regions in the Upper Colorado River Basin - the Colorado Rocky Mountains, Colo orado, the Uinta Mountains, Utah, and the Wind River Range, Wyoming snow course observations yield a correlation length scale of 38 km, 46 km, and 116 km respectively. This is the scale for which the snow course data at different sites are correlated with 70 per cent correlation. This correlation of snow accumulation over large distances allows for the estimation of the snow water equivalent on a mesoscale basis. With the snow course data binned into 1/4 degrees latitude by 1/4 degrees longitude pixels, an error analysis shows the following: for no snow course data in a given pixel, the uncertainty in the water equivalent estimate reaches 50 cm; that is, the climatological variability. However, as the number of snow courses in a pixel increases the uncertainty decreases, and approaches 5-10 cm when there are five snow courses in a pixel. C1 UNIV PUGET SOUND,DEPT PHYS,TACOMA,WA 98416. US GEOL SURVEY,ICE & CLIMATE PROJECT,TACOMA,WA 98416. RP Ling, CH (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 439,MENLO PK,CA 94025, USA. NR 4 TC 2 Z9 2 U1 0 U2 0 PU NORDISK ASSN HYDROLOGY PI DK LYNGBY PA TECHNICAL UNIV DENMARK BUILDING 115, 2800 DK LYNGBY, DENMARK SN 0029-1277 J9 NORD HYDROL JI Nord. Hydrol. PY 1996 VL 27 IS 5 BP 313 EP 322 PG 10 WC Water Resources SC Water Resources GA WF265 UT WOS:A1996WF26500002 ER PT J AU Larson, GL AF Larson, GL TI Overview of the limnology of Crater Lake SO NORTHWEST SCIENCE LA English DT Article AB Crater Lake occupies the collapsed caldera of volcanic Mount Mazama in Crater Lake National Park, Oregon. It is the deepest lake (589 m) in the United States and the 7th deepest lake in the world. The water column mixes to a depth of about 200 m in winter and spring from wind energy and cooling. The deep lake is mixed in winter and early spring each year when relatively cold water near the surface sinks and exchanges positions with water in the deep basins of the lake. The lake becomes thermally stratified in summer and early fall. The metalimnion extends to a depth of about 100 m; thus most of the water column is a cold hypolimnion. Secchi disk clarity measurements typically are in the upper-20-m range to the low-30-m range in summer and early fall. Concentrations of nutrients are low, although conductivity is relatively high owing to the inflow of hydrothermal fluids. Total chlorophyll is low in concentration, but typically maximal at a depth of 120 m during periods of thermal stratification. Primary production also is low, with the maximum levels occurring between the depth of 40 and 80 m. Phytoplankton taxa are spatially segregated from each other within the water column to a depth of 200 m in summer and early fall. The same generalization applies to the zooplankton taxa. Water level, clarity, concentrations of total chlorophyll, primary production, and abundances of zooplankton and introduced kokanee salmon exhibit long-term fluctuations. Based primarily on a recent 10-year study of the lake, the lake is considered to be pristine, except for the consequences of fish introductions. RP Larson, GL (reprint author), US GEOL SURVEY,FOREST & RANGELAND ECOSYST SCI CTR,3200 SW JEFFERSON WAY,CORVALLIS,OR 97331, USA. NR 14 TC 1 Z9 1 U1 1 U2 11 PU WASHINGTON STATE UNIV PI PULLMAN PA PO BOX 645910, PULLMAN, WA 99164-5910 SN 0029-344X J9 NORTHWEST SCI JI Northwest Sci. PY 1996 VL 70 SI 2 BP 39 EP 47 PG 9 WC Ecology SC Environmental Sciences & Ecology GA VY396 UT WOS:A1996VY39600005 ER PT B AU Gartner, JW Cheng, RT AF Gartner, JW Cheng, RT GP MARINE TECHNOL SOC TI Near bottom velocity measurements in San Francisco Bay, California SO OCEANS '96 MTS/IEEE, CONFERENCE PROCEEDINGS, VOLS 1-3 / SUPPLEMENTARY PROCEEDINGS: COASTAL OCEAN - PROSPECTS FOR THE 21ST CENTURY LA English DT Proceedings Paper CT Conference on Prospects for the 21st-Century (OCEANS 96 MTS/IEEE) CY SEP 23-26, 1996 CL FT LAUDERDALE, FL SP Marine Technol Soc, OES, IEEE AB The ability to accurately measure long-term time-series of tidal currents in bays and estuaries is critical in estuarine hydrodynamic studies. Accurate measurements of tidal currents near the air-water interface and in the bottom boundary layer remain difficult in spite of the significant advances in technology for measuring tidal currents which have been achieved in recent years. One of the objectives of this study is to demonstrate that turbulent mean velocity distribution within the bottom boundary layer can be determined accurately by using a broad-band acoustic Doppler current profiler (BB-ADCP). A suite of instruments, including two BB-ADCPs and four electromagnetic (EM) current meters was deployed in San Francisco Bay, California in an investigation of resuspension and transport of sediment during March 1995. The velocity measurements obtained in the bottom boundary layer by BB-ADCP were highly coherent (r(2) > 0.94) with the velocity measurements obtained by EM current meters. During early March 1995, both BB-ADCPs and EM current meters recorded a very unusual flow event. Agreement among independent measurements by these instruments in describing such an atypical hydrodynamic occurrence further validates the velocity measurements obtained by BB-ADCP in the bottom boundary layer. RP Gartner, JW (reprint author), US GEOL SURVEY,345 MIDDLEFIELD RD,MS 496,MENLO PK,CA 94025, USA. NR 0 TC 2 Z9 2 U1 0 U2 0 PU I E E E PI NEW YORK PA 345 E 47TH ST, NEW YORK, NY 10017 BN 0-7803-3520-1 PY 1996 BP 457 EP 462 PG 6 WC Engineering, Marine; Engineering, Civil SC Engineering GA BG80E UT WOS:A1996BG80E00072 ER PT J AU Bence, AE Kvenvolden, KA Kennicutt, MC AF Bence, AE Kvenvolden, KA Kennicutt, MC TI Organic geochemistry applied to environmental assessments of Prince William Sound, Alaska, after the Exxon Valdez oil spill - A review SO ORGANIC GEOCHEMISTRY LA English DT Review ID POLYCYCLIC AROMATIC-HYDROCARBONS; CRUDE-OIL; SEDIMENTS; PETROLEUM; GULF; IDENTIFICATION; CALIFORNIA; ISLANDS; MARKER; IMPACT AB Organic geochemistry played a major role in the environmental assessments conducted following the Exxon Valdez oil spill, which occurred on March 24, 1989, and released about 258,000 bbls (41 million liters) of Alaska North Slope crude oil into Prince William Sound. Geochemical analyses of more than 15,000 sediment, tar, and biological samples and about 5000 water samples provide the largest database yet collected on oil-spill chemistry, and we review the results here. The marine environment of the Sound has a complex background of petrogenic, pyrogenic, and biogenic hydrocarbons from natural and anthropogenic sources. Geochemical evaluation of the fate and effects of the spilled oil required that this oil and its residues be distinguished from the background. A variety of molecular and isotopic techniques were employed to identify various hydrocarbon sources and to distinguish quantitatively among mixed sources in the samples. Although the specific criteria used to distinguish multiple sources in the region affected by the Exxon Valdez spill are not necessarily applicable to all spill situations, the principles that governed their selection are. Distributions of polycyclic aromatic hydrocarbons (PAH) and dibenzothiophenes distinguish Exxon Valdez oil and its weathered residues from background hydrocarbons in benthic sediments. Ratios of C-2-dibenzothiophene/C-2-phenanthrene and C-3-dibenzothiophene/C-3-phenanthrene were particularly useful. Carbon isotopes and terpane distributions distinguished Exxon Valdez residues found on shorelines from tars from other sources. Diesel and diesel soot were identified by the absence of alkylated chrysenes and a narrow distribution of n-alkanes, whereas pyrogenic products were distinguished by the dominance of 4- to 6-ring PAH over 2- to 3-ring PAH acid by the dominance of non-alkylated over alkylated homologues of each PAH series. The presence of 18 alpha(H)-oleanane in benthic sediments, coupled with its absence in Exxon Valdez oil and its residues, confirm another petrogenic source. Results of geochemical studies suggest that the petrogenic component in the background of benthic sediments is derived from oil seeps in the eastern Gulf of Alaska. In 1990 and 1991, Exxon Valdez residues, generally forming a small increment to the pre-spill background, were found to be only sporadically distributed in some shallow, near shore sediments adjacent to shorelines that had been heavily oiled in 1989. In 1994, occurrences of Exxon Valdez tars on shoreline surfaces were rare, although residues could be found buried in shoreline sediments at some isolated locations along the spill path where they were protected from wave action. Spilled oil residues collected 16 months after the spill were degraded, on average, by nearly 50%. Shoreline residues from sources other than the spill were also identified and are widespread throughout the Sound. These residues include (1) geochemically distinct tars and oils imported from California oil fields to Alaska for fuel and construction purposes prior to the discovery of the Cook Inlet and North Slope oil fields, (2) diesel and diesel soot, and (3) more highly refined products. Of the more than 2700 chemical analyses of biological samples of higher life forms (fish, birds, and mammals) about 150 (6%) indicate recognizable residues of Exxon Valdez oil, which were identified by their distribution of polycyclic aromatic hydrocarbons (PAH). Most of these samples (138) were collected in 1989 and most were associated with external surfaces or the gastrointestinal tract. Rarely do internal tissues or fluids contain recognizable fingerprints of spilled oil. This observation includes samples from marine mammals that were visibly oiled externally. Other hydrocarbon sources, including diesel and a non-petroleum artifact that occurs when concentrations of individual PAH are at or near their method detection limit, are also identified in biological samples. Copyright (C) 1996 Elsevier Science Ltd C1 US GEOL SURVEY,MENLO PK,CA 94025. TEXAS A&M UNIV,GEOCHEM & ENVIRONM RES GRP,COLLEGE STN,TX 77845. RP Bence, AE (reprint author), EXXON PROD RES CO,POB 2189,HOUSTON,TX 77252, USA. NR 122 TC 184 Z9 190 U1 10 U2 70 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0146-6380 J9 ORG GEOCHEM JI Org. Geochem. PD JAN PY 1996 VL 24 IS 1 BP 7 EP 42 DI 10.1016/0146-6380(96)00010-1 PG 36 WC Geochemistry & Geophysics SC Geochemistry & Geophysics GA UZ805 UT WOS:A1996UZ80500004 ER PT J AU Benson, L Peterman, Z AF Benson, L Peterman, Z TI Carbonate deposition, Pyramid Lake subbasin, Nevada .3. The use of Sr-87 values in carbonate deposits (tufas) to determine the hydrologic state of paleolake systems SO PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY LA English DT Article AB Sierran rivers that discharge to the Lahontan basin have much lower (similar to 4.5%) delta(87)Sr values than the Humboldt River which drains northeastern Nevada. The delta(87)Sr values of tufas deposited during the last lake cycle were used to determine when Humboldt derived Sr entered the Pyramid Lake subbasin. Prior to similar to 15,000 yr B.P., the Humboldt River flowed to the Smoke Creek-Black Rock Desert subbasin. During the recession of Lake Lahontan, the Humboldt River diverted to the Carson Desert subbasin. This study has demonstrated that Sr-87 can be used to determine drainage histories of multi-basin lake systems if the delta(87)Sr values of rivers that discharge to the basins are sufficiently different. C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. RP Benson, L (reprint author), US GEOL SURVEY,3215 MARINE ST,BOULDER,CO 80303, USA. NR 15 TC 5 Z9 6 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0031-0182 J9 PALAEOGEOGR PALAEOCL JI Paleogeogr. Paleoclimatol. Paleoecol. PD JAN PY 1996 VL 119 IS 3-4 BP 201 EP 213 DI 10.1016/0031-0182(95)00010-0 PG 13 WC Geography, Physical; Geosciences, Multidisciplinary; Paleontology SC Physical Geography; Geology; Paleontology GA TW857 UT WOS:A1996TW85700001 ER PT J AU Eliason, EM LaVoie, SK Soderblom, LA AF Eliason, EM LaVoie, SK Soderblom, LA TI The Imaging Node for the Planetary Data System SO PLANETARY AND SPACE SCIENCE LA English DT Article ID GALILEO AB The Planetary Data System Imaging Node maintains and distributes the archives of planetary image data acquired from NASA's flight projects with the primary goal of enabling the science community to perform image processing and analysis on the data. The Node provides direct and easy access to the digital image archives through wide distribution of the data on CD-ROM media and on-line remote-access tools by way of Internet services. The Node provides digital image processing tools and the expertise and guidance necessary to understand the image collections. The data collections, now approaching one terabyte in volume, provide a foundation for remote sensing studies for virtually all the planetary systems in our solar system (except for Pluto). The Node is responsible for restoring data sets from past missions in danger of being lost. The Node works with active flight projects to assist in the creation of their archive products and to ensure that their products and data catalogs become an integral part of the Node's data collections. C1 CALTECH,JET PROP LAB,PASADENA,CA 91109. RP Eliason, EM (reprint author), US GEOL SURVEY,FLAGSTAFF,AZ 86001, USA. NR 24 TC 1 Z9 1 U1 0 U2 0 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0032-0633 J9 PLANET SPACE SCI JI Planet Space Sci. PD JAN PY 1996 VL 44 IS 1 BP 23 EP 32 DI 10.1016/0032-0633(95)00103-4 PG 10 WC Astronomy & Astrophysics SC Astronomy & Astrophysics GA TT758 UT WOS:A1996TT75800004 ER PT S AU Rowan, LC Clark, RN Green, RO AF Rowan, LC Clark, RN Green, RO GP ENVIRONM RES INST MICHIGAN TI Mapping minerals in the mountain pass, California area using the airborne visible/infrared imaging spectrometer (AVIRIS) SO PROCEEDINGS OF THE ELEVENTH THEMATIC CONFERENCE: GEOLOGIC REMOTE SENSING - PRACTICAL SOLUTIONS FOR REAL WORLD PROBLEMS, VOL I SE PROCEEDINGS OF THE THEMATIC CONFERENCE ON GEOLOGIC REMOTE SENSING LA English DT Meeting Abstract CT 11th Thematic Conference on Applied Geologic Remote Sensing CY FEB 27-29, 1996 CL LAS VEGAS, NV SP Environm Res Inst Michigan, Geophys & Environm Res Corp, NASA, RadarSat Int, US DOE, Nevada Operat Off, US DOE, Remote Sensing Lab, US Geol Survey C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 1 Z9 1 U1 0 U2 2 PU ENVIRONMENTAL RESEARCH INST MICHIGAN PI ANN ARBOR PA PO BOX 134001, ANN ARBOR, MI 48113-4001 SN 1067-0106 J9 PR THEMAT CONF GEOL PY 1996 BP 175 EP 176 PG 2 WC Engineering, Petroleum; Geology; Geosciences, Multidisciplinary; Remote Sensing; Mining & Mineral Processing SC Engineering; Geology; Remote Sensing; Mining & Mineral Processing GA BF12D UT WOS:A1996BF12D00017 ER PT S AU Crowley, JK Zimbelman, DR AF Crowley, JK Zimbelman, DR GP ENVIRONM RES INST MICHIGAN TI Mapping hydrothermally altered rock on Mount Rainier, Washington: Application of airborne imaging spectrometry to volcanic hazards assessment SO PROCEEDINGS OF THE ELEVENTH THEMATIC CONFERENCE - GEOLOGIC REMOTE SENSING: PRACTICAL SOLUTIONS FOR REAL WORLD PROBLEMS, VOL II SE PROCEEDINGS OF THE THEMATIC CONFERENCE ON GEOLOGIC REMOTE SENSING LA English DT Meeting Abstract CT 11th Thematic Conference on Applied Geologic Remote Sensing CY FEB 27-29, 1996 CL LAS VEGAS, NV SP Environm Res Inst Michigan, Geophys & Environm Res Corp, NASA, RadarSat Int, US DOE, Nevada Operat Off, US DOE, Remote Sensing Lab, US Geol Survey C1 US GEOL SURVEY,RESTON,VA 22092. NR 0 TC 0 Z9 0 U1 0 U2 2 PU ENVIRONMENTAL RESEARCH INST MICHIGAN PI ANN ARBOR PA PO BOX 134001, ANN ARBOR, MI 48113-4001 SN 1067-0106 J9 PR THEMAT CONF GEOL PY 1996 BP 460 EP 461 PG 2 WC Engineering, Petroleum; Geology; Geosciences, Multidisciplinary; Remote Sensing; Mining & Mineral Processing SC Engineering; Geology; Remote Sensing; Mining & Mineral Processing GA BF12E UT WOS:A1996BF12E00057 ER PT S AU Carlson, PR Kvenvolden, KA AF Carlson, PR Kvenvolden, KA BE Rice, SD Spies, RB Wolfe, DA Wright, BA TI Tracking Exxon Valdez oil from beach to deepwater sediments of Prince William Sound, Alaska SO PROCEEDINGS OF THE EXXON VALDEZ OIL SPILL SYMPOSIUM SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Proceedings Paper CT Exxon Valdez Oil Spill Symposium CY FEB 02-05, 1993 CL ANCHORAGE, AK SP Exxon Valdez Oil Spill Trustee Council, Amer Fisheries Soc, Alaska Chapter, Alaska Sea Grant Program C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 2 Z9 2 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-95-4 J9 AM FISH S S PY 1996 VL 18 BP 109 EP 120 PG 12 WC Ecology; Environmental Sciences; Fisheries; Zoology SC Environmental Sciences & Ecology; Fisheries; Zoology GA BG35Z UT WOS:A1996BG35Z00007 ER PT S AU Irons, DB AF Irons, DB BE Rice, SD Spies, RB Wolfe, DA Wright, BA TI Size and productivity of black-legged kittiwake colonies in Prince William Sound before and after the Exxon Valdez oil spill SO PROCEEDINGS OF THE EXXON VALDEZ OIL SPILL SYMPOSIUM SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Proceedings Paper CT Exxon Valdez Oil Spill Symposium CY FEB 02-05, 1993 CL ANCHORAGE, AK SP Exxon Valdez Oil Spill Trustee Council, Amer Fisheries Soc, Alaska Chapter, Alaska Sea Grant Program C1 US FISH & WILDLIFE SERV,MIGRATORY BIRD MANAGEMENT,ANCHORAGE,AK 99503. NR 0 TC 15 Z9 17 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-95-4 J9 AM FISH S S PY 1996 VL 18 BP 738 EP 747 PG 10 WC Ecology; Environmental Sciences; Fisheries; Zoology SC Environmental Sciences & Ecology; Fisheries; Zoology GA BG35Z UT WOS:A1996BG35Z00049 ER PT S AU Oakley, KL Kuletz, KJ AF Oakley, KL Kuletz, KJ BE Rice, SD Spies, RB Wolfe, DA Wright, BA TI Population, reproduction, and foraging of pigeon guillemots at Naked Island, Alaska, before and after the Exxon Valdez oil spill SO PROCEEDINGS OF THE EXXON VALDEZ OIL SPILL SYMPOSIUM SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Proceedings Paper CT Exxon Valdez Oil Spill Symposium CY FEB 02-05, 1993 CL ANCHORAGE, AK SP Exxon Valdez Oil Spill Trustee Council, Amer Fisheries Soc, Alaska Chapter, Alaska Sea Grant Program C1 US FISH & WILDLIFE SERV,MIGRATORY BIRD MANAGEMENT,ANCHORAGE,AK 99503. NR 0 TC 19 Z9 20 U1 0 U2 2 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-95-4 J9 AM FISH S S PY 1996 VL 18 BP 759 EP 769 PG 11 WC Ecology; Environmental Sciences; Fisheries; Zoology SC Environmental Sciences & Ecology; Fisheries; Zoology GA BG35Z UT WOS:A1996BG35Z00051 ER PT S AU Kuletz, KJ AF Kuletz, KJ BE Rice, SD Spies, RB Wolfe, DA Wright, BA TI Marbled murrelet abundance and breeding activity at Naked Island, Prince William Sound, and Kachemak Bay, Alaska, before and after the Exxon Valdez oil spill SO PROCEEDINGS OF THE EXXON VALDEZ OIL SPILL SYMPOSIUM SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Proceedings Paper CT Exxon Valdez Oil Spill Symposium CY FEB 02-05, 1993 CL ANCHORAGE, AK SP Exxon Valdez Oil Spill Trustee Council, Amer Fisheries Soc, Alaska Chapter, Alaska Sea Grant Program C1 US FISH & WILDLIFE SERV,MIGRATORY BIRD MANAGEMENT,ANCHORAGE,AK 99503. NR 0 TC 11 Z9 14 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-95-4 J9 AM FISH S S PY 1996 VL 18 BP 770 EP 784 PG 15 WC Ecology; Environmental Sciences; Fisheries; Zoology SC Environmental Sciences & Ecology; Fisheries; Zoology GA BG35Z UT WOS:A1996BG35Z00052 ER PT S AU Bernatowicz, JA Schempf, PF Bowman, TD AF Bernatowicz, JA Schempf, PF Bowman, TD BE Rice, SD Spies, RB Wolfe, DA Wright, BA TI Bald eagle productivity in south-central Alaska in 1989 and 1990 after the Exxon Valdez oil spill SO PROCEEDINGS OF THE EXXON VALDEZ OIL SPILL SYMPOSIUM SE AMERICAN FISHERIES SOCIETY SYMPOSIUM SERIES LA English DT Proceedings Paper CT Exxon Valdez Oil Spill Symposium CY FEB 02-05, 1993 CL ANCHORAGE, AK SP Exxon Valdez Oil Spill Trustee Council, Amer Fisheries Soc, Alaska Chapter, Alaska Sea Grant Program C1 US FISH & WILDLIFE SERV,JUNEAU,AK 99801. NR 0 TC 8 Z9 8 U1 0 U2 0 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE, STE 110, BETHESDA, MD 20814-2199 SN 0892-2284 BN 0-913235-95-4 J9 AM FISH S S PY 1996 VL 18 BP 785 EP 797 PG 13 WC Ecology; Environmental Sciences; Fisheries; Zoology SC Environmental Sciences & Ecology; Fisheries; Zoology GA BG35Z UT WOS:A1996BG35Z00053 ER PT B AU Bowen, ZH Freeman, MC Watson, DL AF Bowen, ZH Freeman, MC Watson, DL BE Eversole, AG TI Index of biotic integrity applied to a flow-regulated river system SO PROCEEDINGS OF THE FIFTIETH ANNUAL CONFERENCE - SOUTHEASTERN ASSOCIATION OF FISH AND WILDLIFE AGENCIES LA English DT Proceedings Paper CT 50th Annual Conference of the Southeastern-Association-of-Fish-and-Wildlife-Agencies CY OCT 05-09, 1996 CL HOT SPRINGS, AR SP SE Assoc Fish & Wildlife Agencies AB We developed a modified index of biotic integrity (IBI) for the Tallapoosa River system based on small-bodied fishes. The modified IBI comprised 9 metrics in 4 categories: (1) species richness and composition, (2) indicator species, (3) trophic function, and (4) abundance. We used distribution records and collection data from 1990-1995 to derive expected values for metrics. The IBI was most sensitive to changes in percentage of insectivorous cyprinids, percentage of intolerant species, fish abundance, and number of darter species, and least sensitive to total species richness. IBI scores generally were lower at sites experiencing more severe flow fluctuations as a result of hydropeaking dam operation. We recommend that the IBI be further tested, refined, and used as part of long-term monitoring programs in regulated southeastern river systems. C1 US Geol Survey, Midcontinent Ecol Sci Ctr, Ft Collins, CO 80525 USA. RP Bowen, ZH (reprint author), US Geol Survey, Midcontinent Ecol Sci Ctr, 4512 McMurry Ave, Ft Collins, CO 80525 USA. NR 0 TC 4 Z9 6 U1 1 U2 3 PU SOUTHEASTERN ASSOCIATION FISH & WILDLIFE AGENCIES (SEAFWA) PI TALLAHASSEE PA 8005 FRESHWATER FARMS RD, TALLAHASSEE, FL 32308 USA PY 1996 BP 26 EP 37 PG 2 WC Fisheries; Forestry; Zoology SC Fisheries; Forestry; Zoology GA BK97A UT WOS:000073965500003 ER PT B AU Johnson, JE Pardew, MG Bowman, DW AF Johnson, JE Pardew, MG Bowman, DW BE Eversole, AG TI Use of a nursery pond to establish smallmouth bass in Beaver Reservoir, Arkansas SO PROCEEDINGS OF THE FIFTIETH ANNUAL CONFERENCE - SOUTHEASTERN ASSOCIATION OF FISH AND WILDLIFE AGENCIES LA English DT Proceedings Paper CT 50th Annual Conference of the Southeastern-Association-of-Fish-and-Wildlife-Agencies CY OCT 05-09, 1996 CL HOT SPRINGS, AR SP SE Assoc Fish & Wildlife Agencies AB Production of smallmouth bass (Micropterus dolomieu) in 11-ha Beaver Nursery Pond was estimated from 1990 to 1994 to determine numbers of fish stocked in Beaver Reservoir. In 1990, 2 rapid population sampling methods, seining a known area and SCUBA transects. were tested against a Petersen mark-and-recapture estimate. Both sampling methods provided population estimates that did not differ significantly from mark-and-recapture values, but both generated greater confidence intervals. Annual production in the nursery pond by late June varied between 57,000 and 164,733 fish/year, with a mean of about 97,500 +/- 59,750 (confidence interval, CI); mean total length of the smallmouth bass produced was 50 mm. Smallmouth bass were usually released into the reservoir in late June to reduce cannibalism, but during 1993 and 1994 fish were retained in order to assess growth and population changes. Post-June mean growth rate of young bass was as high as 0.46 mm/day and population declines were not statistically significant, indicating cannibalism was minor. Once in Beaver Reservoir, young smallmouth bass dispersed up to 5.2 km during the first 48 hours and up to 9 km after 24 days. Dispersal was principally directed down-lake. In 1992, wild-spawned smallmouth bass were discovered in Beaver Reservoir, the first time the species had spawned in that reservoir since the dam was closed in 1963. Subsequent year classes have been produced and the species has extended down-lake >36 km to the dam area. C1 Univ Arkansas, Dept Biol Sci, Arkansas Cooperat Fish & Wildlife Res Unit, US Geol Survey, Fayetteville, AR 72701 USA. RP Johnson, JE (reprint author), Univ Arkansas, Dept Biol Sci, Arkansas Cooperat Fish & Wildlife Res Unit, US Geol Survey, Fayetteville, AR 72701 USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU SOUTHEASTERN ASSOCIATION FISH & WILDLIFE AGENCIES (SEAFWA) PI TALLAHASSEE PA 8005 FRESHWATER FARMS RD, TALLAHASSEE, FL 32308 USA PY 1996 BP 122 EP 130 PG 3 WC Fisheries; Forestry; Zoology SC Fisheries; Forestry; Zoology GA BK97A UT WOS:000073965500012 ER PT B AU Coon, RA Simonton, C Bowers, EF Trapp, JL AF Coon, RA Simonton, C Bowers, EF Trapp, JL BE Eversole, AG TI Migratory bird depredation permits issued to southeast aquaculture facilities SO PROCEEDINGS OF THE FIFTIETH ANNUAL CONFERENCE - SOUTHEASTERN ASSOCIATION OF FISH AND WILDLIFE AGENCIES LA English DT Proceedings Paper CT 50th Annual Conference of the Southeastern-Association-of-Fish-and-Wildlife-Agencies CY OCT 05-09, 1996 CL HOT SPRINGS, AR SP SE Assoc Fish & Wildlife Agencies AB This paper summarizes the issuance of federal depredation permits to commercial aquaculture facilities in the Southeast Region by the U.S. Fish and Wildlife Service from 1989 to 1996. Data were evaluated from 1,103 depredation permits issued to individual aquaculture facilities allowing lethal take of fish-eating birds. The take of 21 species of birds comprised of waders, fliers, and swimmers was permitted. In the 9 states where permits were authorized, the number of facilities receiving permits increased from 54 in 1989 to 228 in 1996. The number of birds allowed in the take increased from 7,401 in 1989 to 28,991 in 1996. Sixty percent of the birds permitted for take at aquaculture facilities were reported taken. The double-crested cormorant (Phalacrocorax auritus) was the species most often requested for taking (N = 70,888). Most depredation permits were issued to aquaculture sites in Mississippi (N = 459) and Arkansas (N = 448). We conclude that the trend in permit issuance reflects the increased number of commercial aquaculture facilities in the Southeast, increased awareness of the problem and increases in some fish-eating bird populations such as the double-crested cormorant. C1 US Fish & Wildlife Serv, Atlanta, GA 30345 USA. RP Coon, RA (reprint author), US Fish & Wildlife Serv, 1875 Century Blvd, Atlanta, GA 30345 USA. NR 0 TC 0 Z9 0 U1 1 U2 2 PU SOUTHEASTERN ASSOCIATION FISH & WILDLIFE AGENCIES (SEAFWA) PI TALLAHASSEE PA 8005 FRESHWATER FARMS RD, TALLAHASSEE, FL 32308 USA PY 1996 BP 287 EP 293 PG 3 WC Fisheries; Forestry; Zoology SC Fisheries; Forestry; Zoology GA BK97A UT WOS:000073965500031 ER PT B AU Wright, DL Grover, TP Labson, VF Pellerin, L AF Wright, DL Grover, TP Labson, VF Pellerin, L BE Bell, RS Cramer, MH TI The very early time electromagnetic (VETEM) system: First field test results SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB The very early time electromagnetic (VETEM) system is a time-domain, surface-deployed system that has potential applications to direct detection of non-aqueous phase liquids as well as to the detection of buried objects. It is designed to operate in environments that are too conductive for ground penetrating radar (GPR) to be effective, and too shallow for standard electromagnetic systems. The VETEM system is a faster profiling complement to the frequency-domain high frequency sounder (HFS). First field tests of the VETEM were made at the Geophysics Performance Evaluation Range at Rabbit Valley west of Grand Junction, Colorado in June and July, 1995. A number of well defined targets of various types are buried there (Alien, 1995). The VETEM system was next used as part of the Electromagnetics Integrated Demonstation (EMID) at the Cold Test Pit at the Idaho National Engineering Laboratory (INEL) in November, 1995. The Cold Test Pit has a number of subareas with buried objects of various types. For the EMID tests, VETEM was run over three gridded areas: the Primary Grid (PG), the Large Object Pit (LOP), and the Calibration Cell (CC). In this paper we display recorded lines from the LOP that show VETEM is responding to electrical properties of the near surface and to buried objects. RP Wright, DL (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 964,DENVER,CO 80225, USA. NR 0 TC 5 Z9 5 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 81 EP 90 PG 10 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00008 ER PT B AU Plumlee, GS Smith, KS Miller, WR Wallace, AR Streufert, RK Bove, DJ Lee, GK Smith, SM AF Plumlee, GS Smith, KS Miller, WR Wallace, AR Streufert, RK Bove, DJ Lee, GK Smith, SM BE Bell, RS Cramer, MH TI GIS-based geoenvironmental assessments of watersheds affected by metal-mining activity SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc RP Plumlee, GS (reprint author), US GEOL SURVEY,DENVER FED CTR,MS 973,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 233 EP 239 PG 7 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00024 ER PT B AU Church, SE AF Church, SE BE Bell, RS Cramer, MH TI Indicators and discriminators used to separate metal sources from contrasting upstream mining districts SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc RP Church, SE (reprint author), US GEOL SURVEY,POB 25046,MS973,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 261 EP 268 PG 8 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00027 ER PT B AU King, TVV Clark, RN Swayze, GA AF King, TVV Clark, RN Swayze, GA BE Bell, RS Cramer, MH TI Geologic and vegetation mapping using Aviris data at Summitville, Colorado and in the adjacent San Juan Mountains and San Luis Valley SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc RP King, TVV (reprint author), US GEOL SURVEY,POB 25046,MS 964,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 285 EP 301 PG 17 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00029 ER PT B AU Lane, JW Haeni, FP Soloyanis, S Placzek, G Williams, JH Johnson, CD Buursink, ML Joesten, PK Knutson, KD AF Lane, JW Haeni, FP Soloyanis, S Placzek, G Williams, JH Johnson, CD Buursink, ML Joesten, PK Knutson, KD BE Bell, RS Cramer, MH TI Geophysical characterization of a fractured-bedrock aquifer and blast-fractured contaminant-recovery trench SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB Borehole- and surface-geophysical methods were used to characterize the hydrogeology and the effects of blast fracturing an in-situ recovery trench in a contaminated fractured-bedrock aquifer. The recovery trench is located at the former fire-training area of Loring Air Force Base in Aroostook County, Maine. Borehole-geophysical methods, used in six wells at the site, included video, acoustic televiewer, heat-pulse flowmeter under nonpumping and low-rate pumping conditions, natural gamma, electromagnetic induction, fluid temperature and conductivity, caliper, deviation, and borehole radar. Borehole radar was used in a single-hole reflection configuration with directional and non-directional 60-MHz (megahertz) antennas and in a cross-hole tomography configuration with 22-MHz antennas. One surface-geophysical method, azimuthal square-array direct-current resistivity, also was used. Geophysical surveys were conducted before and after blast fracturing the recovery trench. Integrated interpretation of the geophysical data collected before blasting indicates that most transmissive fractures are steeply dipping and are oriented northeast and southwest. Analysis of azimuthal square-array-resistivity data indicates that the secondary porosity of the fractured-bedrock aquifer is about 1 percent. The borehole-geophysical data and cross-hole radar tomography data indicate that more fractures are present in the upper 20 to 25 m (meters) of bedrock than in bedrock below this depth. Interpretation of the geophysical data collected after blast fracturing the recovery trench indicates that the blast created an intensely fractured zone about 3 m wide, 26 m deep, along the 50-m length of the recovery trench. Blast-induced porosity in the recovery trench is estimated from the borehole-radar data to be 13.5 +/- 5 percent at the midpoint of the trench, decreasing to 7.3 +/- 6 percent at the northwestern end. Post-blast effects on the hydrology of the area adjacent to the recovery trench include (1) a decline in static water levels, (2) order-of-magnitude increases in upward flow in two wells, (3) reversal of flow directions in two wells, (4) order-of-magnitude increases in the estimated transmissivity of three wells, and (5) an estimated increase in aquifer secondary porosity to 2 percent near the trench. The increase in secondary porosity is estimated on the basis of azimuthal square-array resistivity data collected over the recovery trench and cross-hole tomography collected parallel to but outside the trench. These effects are consistent with increased porosity and permeability in the blast-fractured recovery trench and with increased fracture transmissivity near the recovery trench. The increased fracture transmissivity resulted from an apparent hydraulic cleaning that occurred when water was ejected out of wells neat. the trench during the blast. RP Lane, JW (reprint author), US GEOL SURVEY,WASHINGTON,DC 20242, USA. NR 0 TC 1 Z9 1 U1 1 U2 1 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 429 EP 441 PG 13 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00044 ER PT B AU Campbell, DL Lucius, JE Ellefsen, KJ DeszczPan, M AF Campbell, DL Lucius, JE Ellefsen, KJ DeszczPan, M BE Bell, RS Cramer, MH TI Monitoring of a controlled LNAPL spill using ground-penetrating radar SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB Using ground penetrating radar (GPR), we monitored a controlled low-density non-aqueous phase liquid (LNAPL) gasoline spill at a test facility at Oregon Graduate Institute, near Portland OR. The results were different from some reported for uncontrolled gasoline spills, in which the gasoline apparently blurs the contrast in dielectric permittivity that usually exists at the top of the saturated zone (SZ), so that GPR reflections from the SZ are subdued. Instead, at OGI we saw a SZ reflection almost everywhere, but this reflection was brighter (higher amplitude) under the spill. The bright spots grew and spread as the spill progressed. We explain this effect by noting that sand grains above the SZ were quite moist, so that values of relative dielectric permittivity (RDP) were relatively high there. As the spilled gasoline displaced this interstitial moisture, RDP values dropped, leading to a GPR high velocity layer and concomitant bright spots. RP Campbell, DL (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 0 TC 17 Z9 17 U1 0 U2 1 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 511 EP 517 PG 7 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00056 ER PT B AU Wright, DL Grover, TP Ellefsen, KJ Lane, JW Kase, PG AF Wright, DL Grover, TP Ellefsen, KJ Lane, JW Kase, PG BE Bell, RS Cramer, MH TI Radar tomograms at Mirror Lake, New Hampshire: 3-D visualization and a brine tracer experiment SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB In this paper we examine radar tomograms produced from data acquired in the FSE well field at the fractured rock hydrology site at Mirror Lake, Grafton County, New Hampshire. We first show an example of 3-dimensional tomogram visualization with superimposed projections of hydraulically significant fractures. We find a generally good, but not one-to-one, correlation between electromagnetic velocity tomograms and fracture projections from individual wells. One reason why the velocity tomograms do not always provide unambiguous indications of flow paths is that the tomograms reflect rock electrical properties which vary because of lithologic heterogeneity at the site. Another is that hydraulic permeability in fractured media may be controlled by small-aperture ''choke points'' that are probably not well imaged by the tomograms. In addition, hydraulic flow may be through a network of interconnected fractures, many of which may be oriented differently from any particular fracture observed at a borehole. We then show a difference attenuation tomogram produced from a brine tracer experiment carried out at the Mirror Lake site in 1995. An objective of this experiment was to distinguish between the mere presence of water and hydraulic permeability. When interpreting tomograms between two hydraulically connected wells, an unrecognized assumption is often made that hydraulic flow paths are in the plane of the wells. This assumption may be invalid, especially in crystalline rock where flow is dominantly through fractures, rather than through the rock matrix. Our difference attenuation tomogram shows that the primary flow path left the plane of the injection and pumped wells. RP Wright, DL (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MS 964,DENVER,CO 80225, USA. NR 0 TC 4 Z9 4 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 565 EP 575 PG 11 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00062 ER PT B AU Williams, JH AF Williams, JH BE Bell, RS Cramer, MH TI Application of borehole geophysics at the Retsof salt-mine collapse site, western New York SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB Borehole-geophysical methods were used in the hydrogeologic characterization of the valley fill and bedrock at the site of the 1994 Retsof salt-mine collapse in western New York. Collapse of the mine roof and fracturing of the overlying bedrock in the southern downdip section of the 10-square-mile salt mine resulted in flow of ground water into the historically dry mine at a rate of more than 15,000 gallons per minute. A suite of borehole-geophysical logs, including caliper, gamma, electromagnetic induction, specific conductance, temperature, acoustic televiewer, video camera, and impeller flowmeter, was collected from 17 test wells. Most of the logged test wells were 700 to 850 feet deep and were completed with steel casing through the valley fill and finished as open hole in the bedrock. The valley-fill sequence at the mine-collapse site was about 500 feet thick and the bedrock sequence, from top of bedrock to the salt mine, was about 600 feet thick. Analysis of the borehole-geophysical logs and correlation with reported drilling logs delineated (1) glaciolacustrine fine-grained sediments that restricted downward flow of surface water and ground water from the overlying alluvium; and (2) ground-water flow zones in glaciofluvial sand and gravel in the mixed deposits of the lower valley fill, near the top of bedrock, and in fracture zones at the limestone-dolomite contact and in the lower part of the dolomite. Fractures that provided the vertical hydraulic connection between the ground-water flow system and the mine were penetrated by several test wells drilled within the collapse. Borehole geophysics proved to be a highly efficient method for obtaining information on the hydrogeology of the valley fill and bedrock at the Retsof salt-mine collapse site. This information was critical in evaluating potential remedial actions at the site and developing a plan of study to assess the effects of the mine collapse on the water resources of the area. RP Williams, JH (reprint author), US GEOL SURVEY,425 JORDAN RD,TROY,NY 12180, USA. NR 0 TC 0 Z9 0 U1 1 U2 1 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 813 EP 821 PG 9 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00087 ER PT B AU Paillet, F Barton, C AF Paillet, F Barton, C BE Bell, RS Cramer, MH TI The synthetic roadcut - A numerical technique for the multiple-scale integration of surface and borehole data SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB Integration of geophysical soundings or tomograms with geophysical logs and hydraulic test data from boreholes is complicated by the very different scales of investigation of each of these techniques. We present a numerical approach designed to optimize the comparison of large-scale geophysical measurements with data from borehole arrays. This technique addresses four important requirements: 1) borehole data are projected into a single vertical plane or ''synthetic roadcut''; 2) projections between boreholes are adjusted in the representation plane within specified limits to improve spatial correlations between boreholes; 3) borehole data are subjected to a range of spatial averaging and smoothing techniques; and 4) soundings or tomograms and borehole data sets are kept rigorously separate until the processed data are formally compared. The technique is illustrated using data from the FSE borehole array at the Mirror Lake, New Hampshire fractured rock hydrology research site. The Mirror Lake data show that comparisons of borehole logs and borehole packer test data with tomograms can indicate how discontinuous fractures are organized into larger scale conductive zones, and how the distribution of those zones may be related to the lithologic fabric of the bedrock. RP Paillet, F (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 823 EP 832 PG 10 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00088 ER PT B AU McCafferty, AE Knepper, DH Alminas, HV AF McCafferty, AE Knepper, DH Alminas, HV BE Bell, RS Cramer, MH TI Integration of geochemical and geophysical data for the Montana mineral-environmental study SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB Aeromagnetic, Landsat multispectral scanner (MSS), radiometric, and geochemical data covering the state of Montana were digitally integrated to identify areas that may be negatively affected from surface-water contamination by metals and acid run-off due to mining activity and natural processes. Two mineral-environmental models were constructed using a variety of statistical, image processing, and frequency filtering techniques. The first model is a combination of relative magnetizations (calculated from the aeromagnetic data) and two suites of geochemical elements. The geochemical distributions include one based on a lanthanide association, which characterizes intermediate and alkalic intrusives; another association characterizes sulfide mineralization. The second model is a mathematical combination of relative magnetizations, iron oxide data (calculated from MSS data), and apparent potassium concentrations (derived from airborne gamma-ray data). This model is useful for locating areas of possible potassic alteration and leaching or weathering of exposed and shallowly buried iron-rich igneous rocks. Magnetization domains associated with iron oxide and relatively high potassium concentrations can be indicative of hydrothermal alteration environments that host metal sulfides. Despite sedimentary cover in eastern Montana, both models reveal areas where magnetization sources are at depths shallow enough to permit leaching, possible alteration, and the presence of heavy metals at the surface. Follow-up studies and integration of these results with geologic and hydrologic information will provide a clearer understanding of the possible environmental effects within the identified areas. RP McCafferty, AE (reprint author), US GEOL SURVEY,DENVER FED CTR,BOX 25046,MAIL STOP 964,DENVER,CO 80225, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 877 EP 886 PG 10 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00093 ER PT B AU Hansen, BP Lane, JW AF Hansen, BP Lane, JW BE Bell, RS Cramer, MH TI Orientation and characteristics of fractures in crystalline bedrock determined by surface and borehole geophysical surveys, Millville and Uxbridge, Massachusetts SO PROCEEDINGS OF THE SYMPOSIUM ON THE APPLICATION OF GEOPHYSICS TO ENGINEERING AND ENVIRONMENTAL PROBLEMS LA English DT Proceedings Paper CT Symposium on the Application of Geophysics to Engineering and Environmental Problems (SAGEEP 96) CY APR 28-MAY 02, 1996 CL KEYSTONE, CO SP Environm & Engn Geophys Soc AB Four geophysical techniques were used to determine bedrock fracture orientation and other site characteristics that can be used to determine ground-water flow and contaminant transport at a study area underlain by fractured crystalline bedrock in Millville and Uxbridge, Massachusetts. In the study area, azimuthal seismic-refraction and azimuthal square-array direct-current resistivity surveys were conducted at three sites, borehole-radar surveys were conducted in a cluster of three wells, and ground-penetrating radar surveys were conducted along roads. Azimuthal seismic-refraction data indicated a primary fracture strike ranging from 56 to 101 degrees at the three sites. Graphical and analytical analysis of azimuthal square-array resistivity data indicated a primary fracture strike ranging from 45 to 90 degrees at the same three sites. Directional borehole-radar data from three wells indicated 46 fractures or fracture zones located as far as 147 feet from the surveyed wells. Patterns of low radar-wave velocity and high radar-wave attenuation from cross-hole radar surveys of two well pairs were interpreted as a planar fracture zone that strikes 297 degrees and dips 55 degrees south. Ground-penetrating radar surveys with 100-MHz antennas penetrated 5 to 50 feet of unconsolidated overburden and as much as 60 feet of bedrock where the bedrock surface was at or near land surface. Horizontal and subhorizontal fractures were observed on the ground-penetrating radar records at numerous locations. Comparison of results from the various geophysical techniques indicates good agreement and indicates primary high-angle fracturing striking east-northeast. Square-array resistivity data yielded an average secondary bedrock porosity of 0.0044 and an average aperture of 0.0071 foot for high-angle fractures. RP Hansen, BP (reprint author), US GEOL SURVEY,WASHINGTON,DC 20242, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ENVIRONMENTAL & ENGINEERING GEOPHYSICAL SOCIETY PI WHEAT RIDGE PA 10200 W 44TH AVE #304, WHEAT RIDGE, CO 80033 PY 1996 BP 927 EP 940 PG 14 WC Geochemistry & Geophysics; Engineering, Environmental; Environmental Sciences SC Geochemistry & Geophysics; Engineering; Environmental Sciences & Ecology GA BJ30J UT WOS:A1996BJ30J00099 ER PT S AU Starret, SW Lecompte, JR AF Starret, SW Lecompte, JR BE Blair, NL TI Geonames and GNULEX - Databases of the stratigraphic nomenclature of the United States SO PROCEEDINGS OF THE THIRTIETH MEETING OF THE GEOSCIENCE INFORMATION SOCIETY: CROSSING THE BRIDGE TO THE FUTURE: MANAGING GEOSCIENCE INFORMATION IN THE NEXT DECADE SE PROCEEDINGS OF THE GEOSCIENCE INFORMATION SOCIETY LA English DT Meeting Abstract CT 30th Meeting of the Geoscience-Information-Society on Crossing the Bridge to the Future - Managing Geoscience Information in the Next Decade CY NOV 05-08, 1995 CL NEW ORLEANS, LA SP Geosci Informat Soc C1 US GEOL SURVEY,MENLO PK,CA 94025. NR 0 TC 0 Z9 0 U1 0 U2 0 PU GEOSCIENCE INFORMATION SOC PI ALEXANDRIA PA AMERICAN GEOLOGICAL INSTITUTE, 4220 KING ST, ALEXANDRIA, VA 22302 SN 0072-1409 BN 0-934485-26-7 J9 P GEOS INF PY 1996 VL 26 BP 63 EP 63 PG 1 WC Geosciences, Multidisciplinary SC Geology GA BJ75Q UT WOS:A1996BJ75Q00013 ER PT B AU Ingersoll, GP Campbell, DH Spahr, NE AF Ingersoll, GP Campbell, DH Spahr, NE BE Troendle, C TI Snow depth variability in a small Alpine watershed SO PROCEEDINGS OF THE WESTERN SNOW CONFERENCE, SIXTY FOURTH ANNUAL MEETING LA English DT Proceedings Paper CT 64th Annual Meeting of the Western-Snow-Conference CY APR 15-18, 1996 CL BEND, OR SP W Snow Conf C1 US GEOL SURVEY,DENVER FED CTR,DENVER,CO 80225. NR 0 TC 0 Z9 0 U1 0 U2 1 PU 64TH WESTERN SNOW CONFERENCE PI PORTLAND PA C/O JAMES K MARRON PO BOX 2646, PORTLAND, OR 97208-2646 PY 1996 BP 159 EP 162 PG 4 WC Environmental Sciences SC Environmental Sciences & Ecology GA BG57R UT WOS:A1996BG57R00019 ER PT B AU Betancourt, JL AF Betancourt, JL BE Barrow, JR McArthur, ED Sosebee, RE Tausch, RJ TI Long- and short-term climate influences on southwestern shrublands SO PROCEEDINGS: SHRUBLAND ECOSYSTEM DYNAMICS IN A CHANGING ENVIRONMENT SE USDA FOREST SERVICE GENERAL TECHNICAL REPORT INTERMOUNTAIN LA English DT Proceedings Paper CT Symposium on Shrubland Ecosystem Dynamics in a Changing Environment CY MAY 23-25, 1995 CL LAS CRUCES, NM SP Shrub Res Consortium, Intermountain Res Stn, New Mexico State Univ, USDA Agr Res Serv, Natl Sci Fdn AB New findings raise questions about long and short-term climatic effects on Southwestern shrublands. Millennial-scale climate variability during the last glacial may have quickened the pace of evolution for genetically variable shrub species. During the last deglaciation, greater plant water use efficiency due to 30 percent CO2 enrichment was not enough to offset Holocene aridity, and desertscrub replaced woodlands over much of the Southwestern United States. Likewise, the degree to which present CO2 enrichment is driving C-3 shrubs into C-4 grasslands is probably a function of interdecadal climate variability. Shrub encroachment accelerated during the 1950's drought, when both winters and summers went dry, and continues under the wet winter-summer dry regime since 1976. Climate is also modulating the spread of exotic annual grasses and introduction of a vigorous fire regime in native shrublands, where none existed before. A combination of biogeographic, historical, experimental, modeling, and monitoring approaches is proposed to predict the ecological outcomes of climate change and direct human impacts. RP Betancourt, JL (reprint author), US GEOL SURVEY,1675 W ANKLAM RD,TUCSON,AZ 85745, USA. NR 0 TC 8 Z9 8 U1 0 U2 3 PU US DEPT AGR, FOREST SERV INTERMOUNTARIN RESEARCH STN PI OGDEN PA FEDERAL BLDG, 324 25TH ST, OGDEN, UT 84401 J9 USDA INTERM PY 1996 VL 338 BP 5 EP 9 PG 5 WC Agronomy; Plant Sciences; Ecology; Forestry SC Agriculture; Plant Sciences; Environmental Sciences & Ecology; Forestry GA BG78V UT WOS:A1996BG78V00002 ER PT J AU Sloan, KN AF Sloan, KN TI Alternative to expensive, commercially produced egg-hatching jars for salmonids SO PROGRESSIVE FISH-CULTURIST LA English DT Article AB The design and construction of an inexpensive egg-hatching jar is described. The jar provides the fish culturist with an alternative to hatching jars of similar design offered by various vendors at higher prices. This design has been used successfully at Hotchkiss National Fish Hatchery to hatch eyed eggs of rainbow trout Oncorhynchus mykiss at an average survival rate of approximately 90%, without the use of chemical fungicides. C1 US FISH & WILDLIFE SERV,HOTCHKISS NATL FISH HATCHERY,HOTCHKISS,CO 81419. RI Perez , Claudio Alejandro/F-8310-2010 OI Perez , Claudio Alejandro/0000-0001-9688-184X NR 1 TC 6 Z9 6 U1 0 U2 1 PU AMER FISHERIES SOC PI BETHESDA PA 5410 GROSVENOR LANE SUITE 110, BETHESDA, MD 20814-2199 SN 0033-0779 J9 PROG FISH CULT JI Progress. Fish-Cult. PD JAN PY 1996 VL 58 IS 1 BP 52 EP 54 DI 10.1577/1548-8640(1996)058<0052:ATECPE>2.3.CO;2 PG 3 WC Fisheries SC Fisheries GA TP195 UT WOS:A1996TP19500009 ER PT J AU Winograd, IJ Ludwig, KR AF Winograd, IJ Ludwig, KR TI High resolution paleotemperature proxy record for the last interglaciation based on Norwegian speleothems - Comment SO QUATERNARY RESEARCH LA English DT Letter C1 BERKELEY GEOCHRONOL CTR,BERKELEY,CA 94709. RP Winograd, IJ (reprint author), US GEOL SURVEY,432 NATL CTR,RESTON,VA 22092, USA. NR 1 TC 0 Z9 0 U1 1 U2 2 PU ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS PI SAN DIEGO PA 525 B ST, STE 1900, SAN DIEGO, CA 92101-4495 SN 0033-5894 J9 QUATERNARY RES JI Quat. Res. PD JAN PY 1996 VL 45 IS 1 BP 102 EP 102 DI 10.1006/qres.1996.0010 PG 1 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA UF728 UT WOS:A1996UF72800010 ER PT J AU Colman, SM Jones, GA Rubin, M King, JW Peck, JA Orem, WH AF Colman, SM Jones, GA Rubin, M King, JW Peck, JA Orem, WH TI AMS radiocarbon analyses from Lake Baikal, Siberia: Challenges of dating sediments from a large, oligotrophic lake SO QUATERNARY SCIENCE REVIEWS LA English DT Article ID BIOGENIC SILICA AB A suite of 146 new accelerator-mass spectrometer (AMS) radiocarbon ages provides the first reliable chronology for late Quaternary sediments in Lake Baikal. In this large, highly oligotrophic lake, biogenic and authigenic carbonate are absent, and plant macrofossils are extremely rare. Total organic carbon is therefore the primary material available for dating. Several problems are associated with the TOC ages. One is the mixture of carbon sources in TOC, not all of which are syndepositional in age. This problem manifests itself in apparent ages for the sediment surface that are greater than zero. However, because most of the organic carbon in Lake Baikal sediments is algal (autochthonous) in origin, this effect is limited to about 1000+/-500 years, which can be corrected, at least for young deposits. The other major problem with dating Lake Baikal sediments is the very low carbon contents of glacial-age deposits, which makes them extremely susceptible to contamination with modern carbon. This problem can be minimized by careful sampling and handling procedures. The ages show almost an order of magnitude difference in sediment-accumulation rates among different sedimentary environments in Lake Baikal, from about 0.04 mm/year on isolated banks such as Academician Ridge, to nearly 0.3 mm/year in the turbidite depositional areas beneath the deep basin floors, such as the Central Basin. The new AMS ages clearly indicate that the dramatic increase in diatom productivity in the lake, as evidenced by increases in biogenic silica and organic carbon, began about 13 ka, in contrast to previous estimates of 7 ka for the age of this transition. Holocene net sedimentation rates may be less than, equal to, or greater than those in the late Pleistocene, depending on the site. This variability reflects the balance between variable terrigenous sedimentation and increased biogenic sedimentation during interglaciations. The ages reported here, and the temporal and spatial variation in sedimentation rates that they imply, provide opportunities for paleoenvironmental reconstructions at different time scales and resolutions. Published by Elsevier Science Ltd C1 WOODS HOLE OCEANOG INST,WOODS HOLE,MA 02543. US GEOL SURVEY,RESTON,VA 22092. UNIV RHODE ISL,GRAD SCH OCEANOG,NARRAGANSETT,RI 02882. RP Colman, SM (reprint author), US GEOL SURVEY,WOODS HOLE,MA 02543, USA. NR 29 TC 112 Z9 122 U1 3 U2 11 PU PERGAMON-ELSEVIER SCIENCE LTD PI OXFORD PA THE BOULEVARD, LANGFORD LANE, KIDLINGTON, OXFORD, ENGLAND OX5 1GB SN 0277-3791 J9 QUATERNARY SCI REV JI Quat. Sci. Rev. PY 1996 VL 15 IS 7 BP 669 EP 684 DI 10.1016/0277-3791(96)00027-3 PG 16 WC Geography, Physical; Geosciences, Multidisciplinary SC Physical Geography; Geology GA VP609 UT WOS:A1996VP60900003 ER PT J AU Payne, TE Davis, JA Waite, TD AF Payne, TE Davis, JA Waite, TD TI Uranium adsorption on ferrihydrite - Effects of phosphate and humic acid SO RADIOCHIMICA ACTA LA English DT Article DE uranium; sorption; ferrihydrite; phosphate; humic acid ID WATERS AB Uranium adsorption on ferrihydrite was studied as a function of pH in systems equilibrated with air, in the presence and absence of added phosphate and humic acid (HA). The objective was to determine the influence of PO43- and HA on uranium uptake. Below pH 7, the sorption of UO22+ typically increases with increasing pH (the 'low pH sorption edge'), with a sharp decrease in sorption above this pH value (the 'high pH edge'). The presence of Sigma PO43- of 10(-4) mol/L moved the low pH edge to the left by approximately 0.8 pH units. The PO43- was strongly bound by the ferrihydrite surface, and the increased uptake of U was attributed to the formation of ternary surface complexes involving both UO22+ and PO43-. The addition of HA (9 mg/L) increased U uptake at pH values below 7, with little effect at higher pH values. The positions of the pH edges were also affected by the ionic strength and total U content. These experiments show that sorption interactions involving PO43- and HA must be considered in order to model the behavior of U in natural systems, in which these components are often present. C1 US GEOL SURVEY,DIV WATER RESOURCES,MENLO PK,CA 94025. UNIV NEW S WALES,DEPT WATER ENGN,KENSINGTON,NSW 2033,AUSTRALIA. RP Payne, TE (reprint author), AUSTRALIAN NUCL SCI & TECHNOL ORG,PRIVATE MAIL BAG 1,MENAI,NSW 2234,AUSTRALIA. RI Payne, Timothy/F-2545-2010; Waite, T. David/A-1400-2008 OI Payne, Timothy/0000-0002-3502-7567; Waite, T. David/0000-0002-5411-3233 NR 18 TC 96 Z9 96 U1 3 U2 42 PU R OLDENBOURG VERLAG PI MUNICH 80 PA ROSENHEIMER STR 145 POSTFACH 801360, W-8000 MUNICH 80, GERMANY SN 0033-8230 J9 RADIOCHIM ACTA JI Radiochim. Acta PY 1996 VL 74 BP 239 EP 243 PG 5 WC Chemistry, Inorganic & Nuclear; Nuclear Science & Technology SC Chemistry; Nuclear Science & Technology GA VP904 UT WOS:A1996VP90400041 ER PT S AU Glynn, P Brown, J AF Glynn, P Brown, J BE Lichtner, PC Steefel, CI Oelkers, EH TI Reactive transport modeling of acidic metal-contaminated ground water at a site with sparse spatial information SO REACTIVE TRANSPORT IN POROUS MEDIA SE REVIEWS IN MINERALOGY LA English DT Review CT Short Course on Reactive Transport in Porous Media CY OCT 25-27, 1996 CL GOLDEN, CO SP Mineral Soc Amer ID MASS-TRANSPORT; MOVEMENT; SYSTEMS; AQUIFER C1 US GEOL SURVEY, TUCSON, AZ 85719 USA. RP Glynn, P (reprint author), US GEOL SURVEY, 432 NATL CTR, RESTON, VA 22091 USA. NR 40 TC 31 Z9 31 U1 1 U2 3 PU MINERALOGICAL SOC AMER PI CHANTILLY PA 3635 CONCORDE PKWY STE 500, CHANTILLY, VA 20151-1125 USA SN 0275-0279 BN 0-939950-42-1 J9 REV MINERAL JI Rev. Mineral. PY 1996 VL 34 BP 377 EP 438 PG 62 WC Mineralogy SC Mineralogy GA BG55B UT WOS:A1996BG55B00009 ER PT J AU Wnuk, C Pfefferkorn, HW AF Wnuk, C Pfefferkorn, HW TI The value of paleophytogeography - Foreword SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Editorial Material C1 UNIV PENN,PHILADELPHIA,PA 19104. RP Wnuk, C (reprint author), US GEOL SURVEY,NATL CTR 956,RESTON,VA 22092, USA. NR 0 TC 0 Z9 0 U1 0 U2 0 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0034-6667 J9 REV PALAEOBOT PALYNO JI Rev. Palaeobot. Palynology PD JAN PY 1996 VL 90 IS 1-2 BP 1 EP 3 DI 10.1016/0034-6667(95)00021-6 PG 3 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA TQ172 UT WOS:A1996TQ17200001 ER PT J AU Wnuk, C AF Wnuk, C TI The development of floristic provinciality during the Middle and Late Paleozoic SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Article ID EARLY LAND PLANTS; SILURIAN CRYPTOSPORES; NEW-MEXICO; TEXAS; PHYTOGEOGRAPHY; PALEOECOLOGY; ENVIRONMENT; ASSEMBLAGES; MIOSPORES; PANGAEA AB Phytogeographic reconstructions have been published for most Paleozoic series since the Pridoli, but there have been few attempts to synthesize this data into a comprehensive review of the characteristics and causes of the changing phytogeographic patterns for the whole Paleozoic history of the vascular flora. Existing floristic analyses have been compiled in this manuscript and the resulting data are used to reconstruct the evolution of floristic provinces since the Silurian. The earliest plant fossil records indicate that provinciality was characteristic of terrestrial vascular plant distributions right from the beginning of terrestrial colonization by vascular plants. This interpretation differs markedly from the views of many workers who still maintain that pre-Upper Carboniferous floras were uniform and cosmopolitan in distribution. Three of the four major phytogeographic units, i.e. Angara, Euramerica, and Gondwana, can be recognized in the earliest fossil floras. The fourth unit, Cathaysia, differentiated from Euramerica during the late Upper Carboniferous. Phytogeographic differentiation occurs in direct response to climatic gradients and physiographic barriers. As these gradients and barriers change, provincial boundaries expand and contract, fragment, reassemble and reassert. Phytogeographic units are dynamic through time. RP Wnuk, C (reprint author), US GEOL SURVEY,NATL CTR 956,RESTON,VA 22092, USA. NR 165 TC 30 Z9 36 U1 0 U2 5 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0034-6667 J9 REV PALAEOBOT PALYNO JI Rev. Palaeobot. Palynology PD JAN PY 1996 VL 90 IS 1-2 BP 5 EP 40 DI 10.1016/0034-6667(95)00022-4 PG 36 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA TQ172 UT WOS:A1996TQ17200002 ER PT J AU Kosanke, RM Cecil, CB AF Kosanke, RM Cecil, CB TI Late Pennsylvanian climate changes and palynomorph extinctions SO REVIEW OF PALAEOBOTANY AND PALYNOLOGY LA English DT Article ID COAL-SWAMP VEGETATION; USA AB A major floral change occurs in the Upper Pennsylvanian strata in the Midcontinent, Illinois basin, and in the northern Appalachian basin of eastern United States. Lycospora spp. (derived from arborescent lycopsids) became extinct along with some other palynomorph taxa. This investigation is concerned with the importance of this major floral change. Samples were studied from western Pennsylvania, eastern Ohio, and West Virginia (from a previous study) cover the stratigraphic interval from the Upper Freeport coal bed, uppermost part of the Allegheny Formation, to the Mahoning, Mason, Brush Creek, Wilgus, and Anderson coal beds in the lower part of the Conemaugh Formation. The floral change occurs either at or below the accepted Desmoinesian-Missourian boundary in the Midcontinent and Illinois basin, whereas in the northern Appalachians this change occurs in the lower part of the Conemaugh Formation, between the Mahoning and Brush Creek coal beds, or when the Mason is present, between the Mahoning and Mason coal beds. With the advent of late Middle Pennsylvanian time, the climate began to change from wet tropical to seasonal tropical. The Middle-Upper Pennsylvanian boundary is the culmination of this drying trend, which was marked by reduction of available water. The peat swamps are interpreted as having changed from the domed type of bog to the planar type under these circumstances. Thus, in general, the coals of the Conemaugh Formation are characteristically much thinner than those of the Allegheny Formation. This was caused by a number of factors including reduced or more seasonal rainfall, decline of arborescent lycopsids, and the increased dominance of herbaceous and fern plants. As a result, there are fewer minable coal beds in the Conemaugh Formation. The first coal bed above the extinction of Lycospora spp. is dominated by the palynomorph taxon Endosporites globiformis which is derived from a heterosporous, herbaceous lycopsid. However, Sigillaria, another arborescent lycopsid, did not become extinct at this time as evidenced by the presence of the palynomorph genus Crassispora which is derived from Sigillaria. The reason for the survival of Sigillaria is not known, but it may have been able to adapt, in a limited fashion, to some sort of specialized microenvironment. The ferns, based on palynomorph occurrence, become numerically more important throughout the balance of the Conemaugh Formation, and dominate the Pittsburgh No. 8 and Pomeroy coal beds in the overlying Monogahela Formation. C1 US GEOL SURVEY,RESTON,VA 22092. RP Kosanke, RM (reprint author), US GEOL SURVEY,BOX 25046,DENVER,CO 80225, USA. NR 21 TC 17 Z9 19 U1 0 U2 1 PU ELSEVIER SCIENCE BV PI AMSTERDAM PA PO BOX 211, 1000 AE AMSTERDAM, NETHERLANDS SN 0034-6667 J9 REV PALAEOBOT PALYNO JI Rev. Palaeobot. Palynology PD JAN PY 1996 VL 90 IS 1-2 BP 113 EP 140 DI 10.1016/0034-6667(95)00027-5 PG 28 WC Plant Sciences; Paleontology SC Plant Sciences; Paleontology GA TQ172 UT WOS:A1996TQ17200007 ER EF