UDATE1: A computer program for the calculation of uranium-series isotopic ages
R.J. Rosenbauer
1991, Computers & Geosciences (17) 45-75
UDATE1 is a FORTRAN-77 program with an interface for an Apple Macintosh computer that calculates isotope activities from measured count rates to date geologic materials by uranium-series disequilibria. Dates on pure samples can be determined directly by the accumulation of 230Th from 234U and of 231Pa from 235U. Dates for...
Use of the Priestley-Taylor evaporation equation for soil water limited conditions in a small forest clearcut
Alan L. Flint, S.W. Childs
1991, Agricultural and Forest Meteorology (56) 247-260
The Priestley-Taylor equation, a simplification of the Penman equation, was used to allow calculations of evapotranspiration under conditions where soil water supply limits evapotranspiration. The Priestley-Taylor coefficient, α, was calculated to incorporate an exponential decrease in evapotranspiration as soil water content decreases. The method is appropriate for use when detailed...
Statistical analyses of soil properties on a quaternary terrace sequence in the upper sava river valley, Slovenia, Yugoslavia
N. Vidic, M. Pavich, F. Lobnik
1991, Geoderma (51) 189-211
Alpine glaciations, climatic changes and tectonic movements have created a Quaternary sequence of gravely carbonate sediments in the upper Sava River Valley, Slovenia, Yugoslavia. The names for terraces, assigned in this model, Günz, Mindel, Riss and Würm in order of decreasing age, are used as morphostratigraphic terms. Soil chronosequence on...
Preliminary palynological zonation of the Chinle formation, southwestern U.S.A., and its correlation to the Newark supergroup (eastern U.S.A.)
R. J. Litwin, A. Traverse, S.R. Ash
1991, Review of Palaeobotany and Palynology (68) 269-287
Three informal palynological assemblage zones can be distinguished in samples from Chinle Formation outcrops in Utah, Arizona and New Mexico. The oldest zone (zone I) is in the Temple Mountain Member in southeastern Utah; the middle zone (zone II) is in the Shinarump, Moss Back, Monitor Butte and (lower part...
Seismicity and detection/location threshold in the southern Great Basin seismic network
J. Gomberg
1991, Journal of Geophysical Research (96) 16401-16414
A spatially varying model of the detection/location capabilities of the Southern Great Basin seismic network (SGBSN) has been derived that is based on simple empirical relations and statistics. This permits use of almost all the catalog data gathered; instead of ignoring data that are below...
In situ measurement of methane oxidation in groundwater by using natural-gradient tracer tests
R. L. Smith, B.L. Howes, S. P. Garabedian
1991, Applied and Environmental Microbiology (57) 1997-2004
Methane oxidation was measured in an unconfined sand and gravel aquifer (Cape Cod, Mass.) by using in situ natural-gradient tracer tests at both a pristine, oxygenated site and an anoxic, sewage-contaminated site. The tracer sites were equipped with multilevel sampling devices to create target grids of sampling points; the injectate...
Origin of xenoliths in the trachyte at Puu Waawaa, Hualalai Volcano, Hawaii
David A. Clague, Wendy A. Bohrson
1991, Contributions to Mineralogy and Petrology (108) 439-452
Rare dunite and 2-pyroxene gabbro xenoliths occur in banded trachyte at Puu Waawaa on Hualalai Volcano, Hawaii. Mineral compositions suggest that these xenoliths formed as cumulates of tholeiitic basalt at shallow depth in a subcaldera magma reservoir. Subsequently, the minerals in the xenoliths underwent subsolidus reequilibration that particularly affected chromite...
Gravitational circulation in a tidal strait
P. E. Smith, R. T. Cheng, J.R. Burau, M.R. Simpson
Shane Richard M., editor(s)
1991, Conference Paper, Proceedings - National Conference on Hydraulic Engineering
Eight months of continuous measurements of tidal current profiles with an acoustic Doppler current profiler (ADCP) were made in Carquinez Strait, California, during 1988 for the purpose of estimating long-term variations in vertical profiles of Eulerian residual currents. Salinity stratification near the ADCP deployment site also was analyzed. The strength...
A microcomputer program for energy assessment and aggregation using the triangular probability distribution
R. A. Crovelli, R.H. Balay
1991, Computers & Geosciences (17) 197-225
A general risk-analysis method was developed for petroleum-resource assessment and other applications. The triangular probability distribution is used as a model with an analytic aggregation methodology based on probability theory rather than Monte-Carlo simulation. Among the advantages of the analytic method are its computational speed and flexibility, and the saving...
Some Nd and Sr isotopic systematics for the REE-enriched deposit at Bayan Obo, China
J. Philpotts, M. Tatsumoto, X. Li, K. Wang
1991, Chemical Geology (90) 177-188
Sm/1bNd and Rb/1bSr isotopic systematics have been determined for rare-earth element (REE) rich samples of carbonate, iron ore, and silicate types from the world's largest known REE deposit at Bayan Obo, China. The results yielded neither Rb/1bSr nor Sm/1bNd isochrons within analytical error. Isochronous relationships may have been disturbed in...
Pleistocene slope instability of gas hydrate-laden sediment on the Beaufort Sea margin
R. E. Kayen, H.J. Lee
1991, Marine Geotechnology (10) 125-141
In oceanic areas underlain by sediment with gas hydrate, reduction of sea level initiates disassociation along the base of the gas hydrate, which, in turn, causes the release of large volumes of gas into the sediment and creates excess pore-fluid pressures and reduced slope stability. Fluid diffusion properties dominate the...
Gaylussite formation at Mono Lake, California
J. L. Bischoff, D.B. Herbst, R.J. Rosenbauer
1991, Geochimica et Cosmochimica Acta (55) 1743-1747
The salinity of Mono Lake has steadily increased since 1941 from 50%. to about 90%. due to diversion of tributary streams. This increase has resulted in the newly discovered precipitation of gaylussite (Na2Ca(CO3)2 · 5H2O). Chemical modeling of the lake water using Pitzer equations suggests that gaylussite has been forming year...
A review of the hydrogeologic-geochemical model for Cerro Prieto
M.J. Lippmann, A.H. Truesdell, S. E. Halfman-Dooley, A. Manonm
1991, Geothermics (20) 39-52
With continued exploitation of the Cerro Prieto, Mexico, geothermal field, there is increasing evidence that the hydrogeologic model developed by Halfman and co-workers presents the basic features controlling the movement of geothermal fluids in the system. In mid–1987 the total installed capacity at Cerro Prieto reached 620 MWc, requiring a...
A giant submarine slope failure on the northern insular slope of Puerto Rico
W. C. Schwab, W. W. Danforth, Kathryn M. Scanlon, D.G. Masson
1991, Marine Geology (96) 237-246
A large amphitheater-shaped scarp, approximately 55 km across, was imaged on the northern insular slope of Puerto Rico using long-range sidescan sonar and bathymetric data. This scarp results from the removal of more than 1500 km3 of Tertiary strata. A review of seismic-reflection profiles, stratigraphic data, and subsidence models of the...
A geochemical model of the Platanares geothermal system, Honduras
C. J. Janik, A.H. Truesdell, F. Goff, L. Shevenell, M.L. Stallard, P.E. Trujillo Jr., D. Counce
1991, Journal of Volcanology and Geothermal Research (45) 125-146
Results of exploration drilling combined with results of geologic, geophysical, and hydrogeochemical investigations have been used to construct a geochemical model of the Platanares geothermal system, Honduras. Three coreholes were drilled, two of which produced fluids from fractured Miocene andesite and altered Cretaceous to Eocene conglomerate at 450 to 680...
Evaluation of evidence pertaining to the origin of vein deposits exposed in trench 14, Nevada Test Site, Nevada
J. S. Stuckless
Anon, editor(s)
1991, Conference Paper, High Level Radioactive Waste Management
Large vein-like deposits of calcite and opaline silica that infill the Bow Ridge fault are exposed by Trench 14 at the Nevada Test Site. The origin of the deposits has been the center of considerable controversy because the deposits occur on the edge of Yucca Mountain, which is being characterized...
Distribution of rubidium, strontium, and zirconium in tuff from two deep coreholes at Yucca Mountain, Nevada
Richard W. Spengler, Zell E. Peterman
Anon, editor(s)
1991, Conference Paper, High Level Radioactive Waste Management
Variations in concentrations of trace elements Rb, Sr, and Zr within the sequence of high-silica tuff and dacitic lava beneath Yucca Mountain reflect both primary composition and secondary alteration. Rb and K concentrations have parallel trends. Rb concentrations are significantly lower within intervals containing zeolitic nonwelded to partially welded and...
Satellite telemetry: performance of animal-tracking systems
Kim A. Keating, Wayne G. Brewster, Carl H. Key
1991, Journal of Wildlife Management (55) 160-171
t: We used 10 Telonics ST-3 platform transmitter terminals (PTT's) configured for wolves and ungulates to examine the performance of the Argos satellite telemetry system. Under near-optimal conditions, 68 percentile errors for location qualities (NQ) 1, 2, and 3 were 1,188, 903, and 361 m, respectively. Errors (rE) exceeded expected...
Sudden, probably coseismic submergence of Holocene trees and grass in coastal Washington State
B.F. Atwater, D.K. Yamaguchi
1991, Geology (19) 706-709
Growth-position plant fossils in coastal Washington State imply a suddenness of Holocene submergence that is better explained by coseismic lowering of the land than by decade- or century-long rise of the sea. These fossils include western red cedar and Sitka spruce whose death...
Circum-Pacific seismic potential: 1989-1999
S.P. Nishenko
1991, Pure and Applied Geophysics PAGEOPH (135) 169-259
The seismic potential for 96 segments of simple plate boundaries around the circum-Pacific region is presented in terms of the conditional probability for the occurrence of either large or great interplate earthquakes during the next 5, 10, and 20 years (i.e., 1989-1994, 1989-1999 and 1989-2009). This study represents the first...
Effects of uranium mining, Puerco River, New Mexico
Thomas J. Lopes
1991, Conference Paper
Effluent from uranium-mine dewatering and acidic water released by a tailings-pond dike failure increased radionuclide activities in streamflow in the Puerco River in New Mexico and Arizona. Median dissolved gross-alpha activity in the streamflow was 1,130 picocuries per liter from 1975 to 1986 when mine discharges ceased and 6.2 picocuries...
Processes controlling the retreat of the Isles Dernieres, a Louisiana barrier-island chain
John R. Dingler, Thomas E. Reiss
1991, Conference Paper, Coastal Sediments '91
The Isles Dernieres is a low-lying, transgressive barrier-island chain situated about 150 km west of the modern Mississippi delta. Much of the Isles Dernieres consists of highly dissected salt-marsh muds that lie at or slightly above sea level and are covered by a veneer of sand along the shoreline facing...
Fluid inclusion gas chemistry as a potential minerals exploration tool: Case studies from Creede, CO, Jerritt Canyon, NV, Coeur d'Alene district, ID and MT, southern Alaska mesothermal veins, and mid-continent MVT's
G. P. Landis, A. H. Hofstra
1991, Journal of Geochemical Exploration (42) 25-59
Recent advances in instrumentation now permit quantitative analysis of gas species from individual fluid inclusions. Fluid inclusion gas data can be applied to minerals exploration empirically to establish chemical (gas composition) signatures of the ore fluids, and conceptually through the development...
Wind generated wave resuspension of sediment in Old Tampa Bay, Florida
David H. Schoellhamer, Victor A. Levesque
Shane Richard M., editor(s)
1991, Conference Paper, Proceedings - National Conference on Hydraulic Engineering
Vertical profiles of velocity and suspended-solids concentration were measured at a scientific instrumentation platform in Old Tampa Bay during the passage of a cold front in March 1990. Strong sustained winds behind the front increased wave activity in the bay, which resulted in resuspension of bottom sediments. The concentration of...
Modern sedimentary environments in Boston Harbor, Massachusetts
H.J. Knebel, R.R. Rendigs, Michael H. Bothner
1991, Journal of Sedimentary Petrology (61) 791-804
Analyses of sidescan-sonar records supplemented by available bathymetric, sedimentary, subbottom, and bottom-current data reveal the distributions of the following three categories of sedimentary environments within the glaciated, topographically complex Boston Harbor estuary in Massachusetts. 1) Environments of erosion appear on the sonographs either as patterns with isolated strong reflections or...
