Cretaceous-Eocene (Laramide) landscape development and Oligocene- Pliocene drainage reorganization of transition zone and Colorado Plateau, Arizona
D. P. Elston, R.A. Young
1991, Journal of Geophysical Research (96) 12389-12406
Landscape development of central and northern Arizona can no longer be ascribed mainly to events of Miocene and Pliocene age. New information on the age and distribution of older Cenozoic deposits has led to the recognition of a regional Cretaceous-Paleocene(?) surface of erosion that conforms...
Oligocene basaltic volcanism of the northern Rio Grande Rift: San Luis Hills, Colorado
R. A. Thompson, C.M. Johnson, H. H. Mehnert
1991, Journal of Geophysical Research (96) 13577-13592
The inception of the Rio Grande rift in northern New Mexico and southern Colorado was accompanied by voluminous mafic volcanism preserved in part as erosional remnants on an intrarift horst within the current axial rift graben of the San Luis Valley. Oligocene (∼26 Ma) volcanic...
Geochemistry of dissolved inorganic carbon in a Coastal Plain aquifer. 1. Sulfate from confining beds as an oxidant in microbial CO2 production
F. H. Chapelle, P.B. McMahon
1991, Journal of Hydrology (127) 85-108
A primary source of dissolved inorganic carbon (DIC) in the Black Creek aquifer of South Carolina is carbon dioxide produced by microbially mediated oxidation of sedimentary organic matter. Groundwater chemistry data indicate, however, that the available mass of inorganic electron acceptors (oxygen, Fe(III),...
Implications for organic maturation studies of evidence of a geologically rapid increase and stabilization of vitrinite reflectance at peak temperature: Cerro Prieto geothermal system, Mexico
C.E. Barker
1991, American Association of Petroleum Geologists Bulletin (75) 1852-1863
A short-term rapid heating and cooling of the rock in well M-94 below 1300 m was caused by a pulse of hot water passing through the edge of the Cerro Prieto, Mexico, geothermal system. Below 1300 m, the peak paleotemperatures were about 225-250 degrees C, but equilibrium well log temperatures...
Late Cretaceous paleomagnetism of the Tucson Mountains: Implications for vertical axis rotations in south central Arizona
J.T. Hagstrum, P. W. Lipman
1991, Journal of Geophysical Research (96) 16069-16081
The Tucson Mountains of southern Arizona are the site of an Upper Cretaceous caldera from which the rhyolitic Cat Mountain Tuff was erupted at about 72 Ma. Two magnetic units within the Cat Mountain Tuff are distinguished by paleomagnetic data in both the northern and...
A northern Cordilleran ocean-continent transect: Sitka Sound, Alaska, to Atlin Lake, British Columbia
D. A. Brew, Susan M. Karl, D.F. Barnes, R.C. Jachens, A. B. Ford, R. Horner
1991, Canadian Journal of Earth Sciences (28) 840-853
The 155 km wide, 310 km long Sitka Sound – Atlin Lake continent–ocean transect includes almost all the geologic, geophysical, and geotectonic elements of the Canadian Cordillera. It crosses the Chugach, Wrangellia, Alexander, Stikine, and Cache Creek terranes, the Gravina and Laberge overlap assemblages, intrusive and metamorphic belts, and neotectonic faults that...
MBSSAS: A code for the computation of margules parameters and equilibrium relations in binary solid-solution aqueous-solution systems
P. D. Glynn
1991, Computers & Geosciences (17) 907-966
The computer code MBSSAS uses two-parameter Margules-type excess-free-energy of mixing equations to calculate thermodynamic equilibrium, pure-phase saturation, and stoichiometric saturation states in binary solid-solution aqueous-solution (SSAS) systems. Lippmann phase diagrams, Roozeboom diagrams, and distribution-coefficient diagrams can be constructed from the output data files,...
Proposed method of hydrogeochemical exploration for salt deposits using ClBr ratios, Eastern Province, Kingdom of Saudi Arabia
C. L. Smith
1991, Applied Geochemistry (6) 249-255
Despite the value of the salt (NaCl) and brine used by the chemical industry, geochemical prospecting techniques are not customarily employed in the search for these raw materials. In this study, Br geochemistry is used as the basis for a proposed hydrogeochemical prospecting technique that was designed to search for...
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...
Large landslides from oceanic volcanoes
R. T. Holcomb, R. C. Searle
1991, Marine Geotechnology (10) 19-32
Large landslides are ubiquitous around the submarine flanks of Hawaiian volcanoes, and GLORIA has also revealed large landslides offshore from Tristan da Cunha and El Hierro. On both of the latter islands, steep flanks formerly attributed to tilting or marine erosion have been reinterpreted as landslide headwalls mantled by younger...
Soil chronosequence studies in temperate to subtropical, low-latitude, low-relief terrain with data from the eastern United States
H. W. Markewich, M.J. Pavich
1991, Geoderma (51) 213-239
The Coastal Plain of the eastern United States is a low-latitude, low-altitude, low-relief terrain composed primarily of gently dipping marine and marginal-marine sediments that range in age from Cretaceous to Quaternary. Population density of the area is moderate, and most of the population is concentrated along the coast. Inland of...
Comment on "Aluminum hydroxide solubility in aqueous solutions containing fluoride ions at 50°C" by B. Sanjuan and G. Michard
Bruch S. Hemingway
1991, Geochimica et Cosmochimica Acta (55) 3873-3874
[No abstract available]...
U.S. Geological Survey: earth science in the public service
Water Resources Division, U.S. Geological Survey
1991, Report
No abstract available....
Revised age of deglaciation of Lake Emma based on new radiocarbon and macrofossil analyses
S. A. Elias, P. E. Carrara, L.J. Toolin, A.J.T. Jull
1991, Quaternary Research (36) 307-321
Previous radiocarbon ages of detrital moss fragments in basal organic sediments of Lake Emma indicated that extensive deglaciation of the San Juan Mountains occurred prior to 14,900 yr B.P. (Carrara et al., 1984). Paleoecological analyses of insect and plant macrofossils from these basal sediments cast doubt on the reliability of...
A statistical approach to the interpretation of aliphatic hydrocarbon distributions in marine sediments
J. B. Rapp
1991, Chemical Geology (93) 163-177
Q-mode factor analysis was used to quantitate the distribution of the major aliphatic hydrocarbon (n-alkanes, pristane, phytane) systems in sediments from a variety of marine environments. The compositions of the pure end members of the systems were obtained from factor scores and the distribution of the systems within each sample...
Porosity trends of the Lower Cretaceous J Sandstone, Denver Basin, Colorado
J. W. Schmoker, D.K. Higley
1991, Journal of Sedimentary Petrology (61) 909-920
This study examines relationships between porosity and time-temperature history, and the influence of rock properties upon porosity, for the Lower Cretaceous J Sandstone in the Colorado portion of the Denver basin. The J Sandstone is classified as a quartzarenite to litharenite and was...
Field-scale investigation of infiltration into a compacted soil liner
Samuel V. Panno, Beverly L. Herzog, Keros Cartwright, Kenneth R. Rehfeldt, Ivan G. Krapac, Bruce R. Hensel
1991, Groundwater (29) 914-921
Little field-scale research has been done to evaluate the effectiveness of compacted soil barriers in retarding the movement of water and leachates. In response to this need, the Illinois State Geological Survey constructed and instrumented an experimental compacted soil liner. Infiltration of water into...
Chemical equilibrium and mass balance relationships associated with the Long Valley hydrothermal system, California, U.S.A.
A. F. White, M. L. Peterson
1991, Journal of Volcanology and Geothermal Research (48) 283-302
Recent drilling and sampling of hydrothermal fluids from Long Valley permit an accurate characterization of chemical concentrations and equilibrium conditions in the hydrothermal reservoir. Hydrothermal fluids are thermodynamically saturated with secondary quartz, calcite, and pyrite but are in disequilibrium with respect to aqueous sulfide-sulfate speciation. Hydrothermal fluids are enriched in...
Origins of acid fluids in geothermal reservoirs
Alfred Truesdell
1991, Conference Paper, Transactions - Geothermal Resources Council
Acid fluids in geothermal reservoirs are rare. Their occurrence in geothermal systems associated with recent volcanism (Tatun, Sumikawa, Miravalles) probably indicates that the geothermal reservoir fluid was derived from volcanic fluid incompletely neutralized by reaction with feldspars and micas. Superheated steam containing HCl (Larderello, The Geysers) forms acid where it...
Reconciliation of stress and structural histories of the Tharsis region of Mars
K. L. Tanaka, M.P. Golombek, W.B. Banerdt
1991, Journal of Geophysical Research (96) 15617-15633
We present a new compilation of the structural and stratigraphic evolution of the Tharsis region of Mars that incorporates recent advances in understanding its stratigraphy, and we introduce a lithospheric deformation model that can account for the observations. The first period in the formation of...
Effects of advanced wastewater treatment on the quality of White River, Indiana
Charles G. Crawford, David J. Wangsness
1991, Water Resources Bulletin (27) 769-779
In 1983, the City of Indianapolis, Indiana, completed construction of advanced wastewater treatment (AWT) systems to enlarge and upgrade its existing Belmont Road and Southport Road secondary treatment plants. A nonparametric statistical procedure, a modified form of the Wilcoxon-Mann-Whitney rank-sum test, was used to test for trends in water quality...
Release of 226Ra from uranium mill tailings by microbial Fe(III) reduction
E. R. Landa, Elizabeth J.P. Phillips, Derek R. Lovley
1991, Applied Geochemistry (6) 647-652
Uranium mill tailings were anaerobically incubated in the presence of H2 with Alteromonas putrefaciens, a bacterium known to couple the oxidation of H2 and organic compounds to the reduction of Fe(III) oxides. There was a direct correlation between the extent of Fe(III) reduction and...
Examination of micrinite concentrates from the Cannel City coal bed of eastern Kentucky: Proposed mechanism of formation
D.N. Taulbee, J.C. Hower, S.F. Greb
1991, Organic Geochemistry (17) 557-565
A high volatile B, micrinite-rich bituminous coal from Morgan County, Kentucky, was crushed and screened to −100 mesh, demineralized and subjected to density gradient centrifugation (DGC). In an initial density separation, micrinite concentration was increased from 52 vol% in the demineralized coal to a maximum of 67% in the 1.25–1.26...
White-fronts...on the way back!
G.R. Mensik, John Y. Takekawa
1991, California Waterfowl (17) 36-38
No abstract available at this time...
Imaging the Juan de Fuca plate beneath southern Oregon using teleseismic P wave residuals
R.A. Harris, H. M. Iyer, P.B. Dawson
1991, Journal of Geophysical Research (96) 19879-19889
The Juan de Fuca plate subducts under the western margin of the North American plate in southern British Columbia, Washington, Oregon, and northern California. Benioff zone seismicity delineates shallow parts of the plate in Washington and northern California, whereas in Oregon there is a lack of...
