Drought description
N.C. Matalas
1991, Stochastic Hydrology and Hydraulics (5) 255-260
What constitutes a comprehensive description of drought, a description forming a basis for answering why a drought occurred is outlined. The description entails two aspects that are "naturally" coupled, named physical and economic, and treats the set of hydrologic measures of droughts in terms of their multivariate distribution, rather than...
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...
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]...
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...
Chaparral & fire ecology: role of fire in seed germination
N.L.C. Steele, Jon E. Keeley
1991, American Biology Teacher (53) 432-435
No abstract available at this time...
Genesis and continuity of quaternary sand and gravel in glacigenic sediment at a proposed low-level radioactive waste disposal site in east-central Illinois
K. G. Troost, B. Brandon Curry
1991, Environmental Geology and Water Sciences (18) 159-170
The Illinois Department of Nuclear Safety has characterized the Martinsville Alternative Site (MAS) for a proposed low-level radioactive waste disposal facility. The MAS is located in east-central Illinois approximately 1.6 km (1 mi) north of the city of Martinsville. Geologic investigation of the 5.5-km2 (1380-acre) site revealed a sequence of...
Lg and Rg waves on the California regional networks from the December 23, 1985 Nahanni earthquake
L. A. Wald, T. H. Heaton
1991, Journal of Geophysical Research (96) 12099-12125
We investigate Lg and Rg propagation in California using the central and southern California regional networks. Approximately 550 stations constitute these two short-period networks providing a dense coverage of almost the entire state. The waveforms recorded from the December 23, 1985, Nahanni, Canada, earthquake are used to construct three...
Low intensity of the geomagnetic field in early Jurassic time
M. Perrin, M. Prevot, E. A. Mankinen
1991, Journal of Geophysical Research (96) 14197-14210
From a large collection of Jurassic continental tholeiites cropping out in Europe and Africa, we selected 90 samples for paleointensity determinations. The samples were carefully selected to avoid any secondary magnetizations, especially viscous magnetization. Use of the Thellier method reveals that magnetic property changes due to...
Feeding ecology of waterfowl wintering on evaporation ponds in California
N.H. Euliss Jr., R. L. Jarvis, D.S. Gilmer
1991, Condor (93) 582-590
We examined the feeding ecology of Northern Pintails (Anas acuta), Northern Shovelers (A. clypeata), and Ruddy Ducks (Oxyura jamaicensis) wintering on drainwater evaporation ponds in California from 1982 through 1984. Pintails primarily consumed midges (Chironomidae) (39.3%) and widegeongrass (Ruppia maritima) nutlets (34.6%). Shovelers and Ruddy Ducks consumed 92.5% and 90.1%...
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...
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...
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...
Analysis of borehole expansion and gallery tests in anisotropic rock masses
B. Amadei, W. Z. Savage
1991, International Journal of Rock Mechanics and Mining Sciences & Geomechanics Abstracts (28) 383-396
Closed-form solutions are used to show how rock anisotropy affects the variation of the modulus of deformation around the walls of a hole in which expansion tests are conducted. These tests include dilatometer and NX-jack tests in boreholes and gallery tests in tunnels. The effects of rock anisotropy on the...
Habitat use and movements of canvasback broods in southwestern Manitoba
J. E. Austin, J.R. Serie
1991, Prairie Naturalist (23) 223-228
Canvasback (Aythya valisineria) broods (n = 69) accompanying marked females were observed during five summers in southwestern Manitoba. We evaluated movements of broods of different age classes ( 14 days old, 15-28 days old, and >28 days old) among ponds of different size and wetland class. Of 202 brood sightings,...
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...
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,...
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...
Coprecipitation mechanisms and products in manganese oxidation in the presence of cadmium
J.D. Hem, Carol J. Lind
1991, Geochimica et Cosmochimica Acta (55) 2435-2451
Manganese oxidation products were precipitated in an aerated open-aqueous system where a continuous influx of mixed Mn2+ and Cd2+ solution was supplied and pH was maintained with an automated pH-stat adding dilute NaOH. X-ray diffraction and electron diffraction identified the solids produced as mixtures of Cd2Mn34+O8, Mn2+2Mn4+3O8, MnO2 (ramsdellite), and CdCO3. Mean oxidation...
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...
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),...
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...
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...
Habitat use, survival, and causes of mortality among mallard broods hatched near the James River in North Dakota
Gary L. Krapu, C.R. Luna
1991, Prairie Naturalist (23) 213-222
Habitat use and survival by nine mallard (Anas platyrhynchos) broods from nests on the James River floodplain and adjacent drift plain were monitored during summer 1987. Radio-marked broods were relocated an average of 22% of the time in the river channel, 22% in oxbow ponds, 43% in a large sewage...
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...
