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...
An AEM-TEM study of weathering and diagenesis, Abert Lake, Oregon: II. Diagenetic modification of the sedimentary assemblage
J.F. Banfield, B.F. Jones, D.R. Veblen
1991, Geochimica et Cosmochimica Acta (55) 2795-2810
This paper compares the mineralogy and chemistry of clay minerals in sediments from various depths and positions in Abert Lake and surrounding playa with those of the weathered materials entering the lake in order to reveal the nature and extent of post-depositional mineralogical modification.Analytical electron microscope (AEM) data from individual...
On plate tectonics and the geologic evolution of southwestern North America
P.L. Ward
1991, Journal of Geophysical Research (96) 12479-12496
Very rapid subduction of the Farallon plate under southwestern North America between 60 and 40 Ma was accompanied by a relatively low volume of magmatism throughout the southwestern United States and northern Mexico. Between 40 and 20 Ma, when subduction slowed significantly and in one...
Vertical structure of cross-shore currents from wind-induced setup
Guy Gelfenbaum
1991, Conference Paper, Coastal Sediments '91
Most of the storm surge models presented in the literature are vertically averaged and calculate only the sea-surface elevation and mean flow. Whereas these models may be adequate for predicting storm surge heights for flooding purposes, they neglect the vertical structure of the flow and the boundary shear stress, which...
Identification of dissolved-constituent sources in mine-site ground water using batch mixing
Gregory M. Clark, Robert S. Williams Jr.
1991, Water Resources Bulletin (27) 93-100
Batch-mixing experiments were used to help identify lithologic and mineralogic sources of increased concentrations of dissolved solids in water affected by surface coal mining in northwestern Colorado. Ten overburden core samples were analyzed for mineral composition and mixed with distilled water for 90 days until mineral-water equilibrium was reached. Between...
Evaluation of geographic information systems for three-dimensional ground-water modeling, Yucca Mountain, Nevada
A. Keith Turner, Elisabeth M. Ervin, Joe S. Downey
Anon, editor(s)
1991, Conference Paper, High Level Radioactive Waste Management
Fully three-dimensional representations of the geologic system at Yucca Mountain have been developed using a Geoscientific Information System, which is an expansion of a traditional Geographic Information Systems. These advanced, three dimensional, representations of Yucca Mountain are required to adequately evaluate the complex geologic and hydrologic conditions surrounding the site....
Genesis of sediment-hosted disseminated-gold deposits by fluid mixing and sulfidization: chemical-reaction-path modeling of ore- depositional processes documented in the Jerritt Canyon district, Nevada
A. H. Hofstra
1991, Geology (19) 36-40
Integrated geologic, geochemical, fluid-inclusion, and stableisotope studies of the gold deposits in the Jerritt Canyon district, Nevada, provide evidence that gold deposition was a consequence of both fluid mixing and sulfidization of host-rock iron. Chemical-reaction-path models of these ore-depositional processes confirm that the...
A comparison of Sr-Nd-Pb isotopes in young and old continental lithospheric mantle: Patagonia and eastern China
R. E. Zartman, K. Futa, Z. C. Peng
1991, Australian Journal of Earth Sciences (38) 545-557
It is commonly accepted that beneath the continental crust lies a keel of lithospheric mantle, which extends 50–200 kilometres downward to a transition zone into the asthenosphere. The chemical and physical properties of this reservoir are best known through studies of the basalts and xenoliths that provide samples of the...
Large-scale distribution of metal contamination in the fine-grained sediments of the Clark Fork River, Montana, U.S.A.
E.V. Axtmann, S. N. Luoma
1991, Applied Geochemistry (6) 75-88
Historic discharges from the mining and smelting complex at the head-waters of the Clark Fork River have resulted in elevated Ag, Cd, Cu, Pb and Zn concentrations in the <60 μm fraction of both bed and flood-plain sediments of the river. Processes affecting the trends in longitudinal distributions of these...
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...
ReOs isotope systematics of NiCu sulfide ores, Sudbury Igneous Complex, Ontario: Evidence for a major crustal component
R.J. Walker, J. W. Morgan, A.J. Naldrett, C. Li, J.D. Fassett
1991, Earth and Planetary Science Letters (105) 416-429
Sudbury Igneous Complex sublayer ores from the Levack West, Falconbridge and Strathcona mines were analyzed for their Re and Os concentrations and Os isotopic compositions. The Re-Os isotope systematics of three ores from the different mines give isochron ages of1 840...
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...
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...
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...
Late Quaternary faulting along the Death Valley-Furnace Creek fault system, California and Nevada
George E. Brogan, Karl S. Kellogg, D. Burton Slemmons, Christina L. Terhune
1991, Bulletin 1991
The Death Valley-Furnace Creek fault system, in California and Nevada, has a variety of impressive late Quaternary neotectonic features that record a long history of recurrent earthquake-induced faulting. Although no neotectonic features of unequivocal historical age are known, paleoseismic features from multiple late Quaternary events of surface faulting are well...
Proposed U.S. Geological Survey standard for digital orthophotos
David Hooper, Vincent Caruso
1991, Conference Paper, GIS/LIS 1991 ACSM-ASPRS Fall Convention
The U.S. Geological Survey has added the new category of digital orthophotos to the National Digital Cartographic Data Base. This differentially rectified digital image product enables users to take advantage of the properties of current photoimagery as a source of geographic information. The product and accompanying standard were implemented in...
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...
Metasomatic oxidation of upper mantle periodotite
A. V. McGuire, M.D. Dyar, J. E. Nielson
1991, Contributions to Mineralogy and Petrology (109) 252-264
Examination of Fe3+ in metasomatized spinel peridotite xenoliths reveals new information about metasomatic redox processes. Composite xenoliths from Dish Hill, California possess remnants of magmatic dikes which were the sources of the silicate fluids responsible for metasomatism of the peridotite part of the same xenoliths. Mo??ssbauer spectra of mineral separates...
Uranium and minor-element partitioning in Fe-Ti oxides and zircon from partially melted granodiorite, Crater Lake, Oregon
T.Z.L. Tourrette, D.S. Burnett, C. R. Bacon
1991, Geochimica et Cosmochimica Acta (55) 457-469
Crystal-liquid partitioning in Fe-Ti oxides and zircon was studied in partially melted granodiorite blocks ejected during the climactic eruption of Mt. Mazama (Crater Lake), Oregon. The blocks, which contain up to 33% rhyolite glass (75 wt% SiO2), are interpreted to be portions of the magma chamber walls that were torn...
Some current themes in physical hydrology of the land-atmosphere interface
P. C. D. Milly
1991, Conference Paper, IAHS Publication (International Association of Hydrological Sciences)
Certain themes arise repeatedly in current literature dealing with the physical hydrology of the interface between the atmosphere and the continents. Papers contributed to the 1991 International Association of Hydrological Sciences Symposium on Hydrological Interactions between Atmosphere, Soil and Vegetation echo these themes, which are discussed in this paper. The...
Re - Os isotopic constraints on the origin of volcanic rocks, Gorgona Island, Colombia: Os isotopic evidence for ancient heterogeneities in the mantle
R.J. Walker, L.M. Echeverria, S.B. Shirey, M.F. Horan
1991, Contributions to Mineralogy and Petrology (107) 150-162
The Re - Os isotopic systematics of komatiites and spatially associated basalts from Gorgona Island, Colombia, indicate that they were produced at 155??43 Ma. Subsequent episodes of volcanism produced basalts at 88.1??3.8 Ma and picritic and basaltic lavas at ca. 58 Ma. The age for the ultramafic rocks is important...
Calibration of a texture-based model of a ground-water flow system, western San Joaquin Valley, California
Steven P. Phillips, Kenneth Belitz
1991, Ground Water (29) 702-715
The occurrence of selenium in agricultural drain water from the western San Joaquin Valley, California, has focused concern on the semiconfined ground-water flow system, which is underlain by the Corcoran Clay Member of the Tulare Formation. A two-step procedure is used to calibrate a preliminary model of the system for...
Importance of hydrologic data for interpreting wetland maps and assessing wetland loss and mitigation
V. Carter
1991, Biological Report - US Fish & Wildlife Service (90) 79-85
The US Geological Survey collects and disseminates, in written and digital formats, groundwater and surface-water information related to the tidal and nontidal wetlands of the United States. This information includes quantity, quality, and availability of groundwater and surface water; groundwater and surface-water interactions (recharge-discharge); groundwater flow; and the basic surface-water...
Oil-generating coals of the San Juan Basin, New Mexico and Colorado, U.S.A.
J.L. Clayton, D. D. Rice, G.E. Michael
1991, Organic Geochemistry (17) 735-742
Coal beds of the Upper Cretaceous Fruitland Formation in the San Juan Basin of northwestern New Mexico and southwestern Colorado have significant liquid hydrocarbon generation potential as indicated by typical Rock-Eval Hydrogen Indexes in the range of 200–400 mg hydrocarbon/g organic carbon (type II and III organic matter). Small, non-commercial...
