Evaluation of proposed precipitation mechanisms for Mississippi Valley-type deposits
Charles S. Spirakis, A. V. Heyl
1995, Ore Geology Reviews (10) 1-17
The mechanism of precipitation is an important aspect of any genetic model for Mississippi Valley-type deposits. Yet most of the precipitation mechanisms for minerals in the Mississippi Valley-type association have serious flaws. Solution mixing would require an unlikely series of solutions to account for the various minerals in the ores,...
Evidence of hydrous differentiation and crystal accumulation in the low-MgO, high-Al2O3 Lake Basalt from Medicine Lake volcano, California
T.P. Wagner, Julie M. Donnelly-Nolan, T.L. Grove
1995, Contributions to Mineralogy and Petrology (121) 201-216
The late Pleistocene Lake Basalt of Medicine Lake volcano, California is comprised of variably porphyritic basalt and basaltic andesite flows and scoria. These eruptives are similar in composition and phenocryst abundance to the low-MgO, high-Al2O3 mafic magmas common in convergent margin settings. The petrogenesis of the magmas that produced the Lake...
Chemical reaction path modeling of ore deposition in Mississippi Valley-type Pb-Zn deposits of the Ozark region, U.S. Midcontinent: A reply
Geoffrey S. Plumlee, David L. Leach, Albert H. Hofstra, Gary P. Landis, Elisabeth L. Rowan, John G. Viets
1995, Economic Geology (90) 1346-1349
No abstract available....
Simulation of ground-water flow in the Albuquerque Basin, central New Mexico, 1901-1994, with projections to 2020
J. M. Kernodle, D. P. McAda, C. R. Thorn
1995, Water-Resources Investigations Report 94-4251
This report describes a three-dimensional finite-difference ground-water-flow model of the Santa Fe Group aquifer system in the Albuquerque Basin, which comprises the Santa Fe Group (late Oligocene to middle Pleistocene age) and overlying valley and basin-fill deposits (Pleistocene to Holocene age). The model is designed to...
South Florida Ecosystem Program of the U.S. Geological Survey
Benjamin F. McPherson, Aaron L. Higer, Sarah Gerould, Irwin H. Kantrowitz
1995, Fact Sheet 134-95
IntroductionThe South Florida Ecosystem Program is one of several study areas within the USGS Ecosystem Program. The Ecosystem Program was established to enable the USGS to enhance its scientific assistance to resource managers who require an improved scientific information base to resolve or prevent complex resource conflicts or environmental problems...
Stratigraphy, sedimentology, paleontology, and paleomagnetism of Pliocene-early Pleistocene lacustrine deposits in two cores from western Utah
R.S. Thompson, Charles G. Oviatt, A.P. Roberts, J. Buchner, R. Kelsey, C.J. Bracht, R. M. Forester, J.P. Bradbury
1995, Open-File Report 95-1
The paleoclimatic history of western Utah is being investigated as part of the USGS Global Change and Climate History Program studies of long-term climatic changes in the western United States. The initial objective of the study is to document the environmental conditions during the mid-Pliocene period of warmer-than-modern global climates...
Hydrogeology and simulation of flow between the alluvial and bedrock aquifers in the upper Black Squirrel Creek basin, El Paso County, Colorado
Kenneth R. Watts
1995, Water-Resources Investigations Report 94-4238
Anticipated increases in pumping from the bedrock aquifers in El Paso County potentially could affect the direction and rate of flow between the alluvial and bedrock aquifers and lower water levels in the overlying alluvial aquifer. The alluvial aquifer underlies about 90 square miles in the upper Black Squirrel Creek...
An update on USGS studies of the Summitville Mine and its downstream environmental effects
Geoffrey S. Plumlee, Patrick R. Edelmann
1995, Open-File Report 95-23
The Summitville gold mine, located at ~3800 meters (11,500 ft) elevation in the San Juan Mountains of southwestern Colorado, was the focus of extensive public attention in 1992 and 1993 for environmental problems stemming from recent open-pit mining activities. Summitville catalyzed national debates about the environmental effects of modern mining...
Optimizing sampling effort for sampling warmwater stream fish communities
J.T. Peterson, C.F. Rabeni
1995, North American Journal of Fisheries Management (15) 528-541
We measured the variation of some commonly used fish community attributes for two warmwater stream reaches during June–October 1992 and 1993. Habitat‐specific variation among samples, expressed as coefficients of variation (SD/mean) collected throughout the study ranged from 0.13 to 1.58 and were lower for community‐level attributes such as species richness...
Verification and adjustment of regional regression models for urban storm-runoff quality using data collected in Little Rock, Arkansas
C. S. Barks
1995, Water-Resources Investigations Report 94-4216
Storm-runoff water-quality data were used to verify and, when appropriate, adjust regional regression models previously developed to estimate urban storm- runoff loads and mean concentrations in Little Rock, Arkansas. Data collected at 5 representative sites during 22 storms from June 1992 through January 1994 compose the Little Rock data base....
Simulated monthly hydrologic data and estimated flood characteristics for Cherry Creek at a proposed reservoir site near Terry, Montana
Charles Parrett, D.R. Johnson
1995, Water-Resources Investigations Report 94-4230
Methods used to simulate a monthly hydrologic budget for water years 1937-92 for the proposed Cherry Creek Reservoir (maximum volume about 14,100 acre-feet) are described and monthly results of the simulation are presented. The budget is based on recorded and estimated streamflow, precipitation, evaporation, and estimated reservoir seepage. The budget...
Pathological and behavioral manifestations of the “Cayuga syndrome,” a thiamine deficiency in larval landlocked Atlantic salmon
Jeffrey P. Fisher, Jan M. Spitsbergen, Tina Iamonte, Edward E. Little, Aaron DeLonay
1995, Journal of Aquatic Animal Health (7) 269-283
The “Cayuga syndrome” is a maternally transmitted, naturally occurring thiamine deficiency that causes 100% mortality of larval landlocked Atlantic salmon Salmo salar in several of New York's Finger Lakes, Results of multiyear studies to qualify and quantify the neurobehavioral and gross pathological signs of this condition are described, Affected sac fry became...
Surface electromagnetic geophysical exploration of the ground-water resources of Isla de Mona, Puerto Rico, a caribbean carbonate island
M.I. Martinez, Joseph W. Troester, Ronald T. Richards
1995, Carbonates and Evaporites (10) 184-192
Two electromagnetic surface geophysical techniques were used to explore the ground-water resources of Isla de Mona, Puerto Rico—a 55-square-kilometer island located between Puerto Rico and Hispañiola, Isla de Mona is a tectonically uplifted carbonate plateau of Neogene age that has an average elevation of about 50 meters above mean...
Surface seismic and electrical methods to detect fluids related to faulting
Donna Eberhart-Phillips, William D. Stanley, Brian D. Rodriguez, William J. Lutter
1995, Journal of Geophysical Research Solid Earth (100) 12919-12936
In the absence of drilling, surface-based geophysical methods are necessary to observe fault zones and fault zone physical properties at seismogenic depths. These in situ physical properties can then be used to infer the presence and distribution of fluids along faults, although such observations are by nature indirect and become...
Use of solicited bands and separation of hunting and natural mortality: a comment
Michael J. Conroy, James E. Hines, B. Kenneth Williams
1995, Journal of Wildlife Management (59) 619-621
We previously presented (Conroy 1985, Conroy et al. 1989) models for analysis of band recovery data stratified into those voluntarily reported and those obtained by solicitation, similar to models described by Pollock et al. (1994). We discuss differences between the 2 modeling approaches and suggest designs and analyses involving...
The relationship of habitat characteristics to the distribution of chironomidae (Diptera) as measured by pupal exuviae collections in a large river system
Steven V. Fend, James L. Carter
1995, Journal of Freshwater Ecology (10) 343-359
Floating chironomid pupal exuviae were collected throughout the Yakima River (Washington, USA) and tributaries in 1989 and 1990. All samples were taken during the October-November low-flow season and most sites were visited once with a sampling effort of approximately 10 minutes. Sampled stream segments ranged from 3rd to 7th order...
Mechanical modeling of circumferential and radial dike intrusion on Galapagos volcanoes
W.W. Chadwick Jr., James H. Dieterich
1995, Journal of Volcanology and Geothermal Research (66) 37-52
A distinctive and unusual pattern of eruptive fissures is observed on the active volcanoes of the Galapagos islands, reflecting circumferential dike intrusion near the calderas and radial dike intrusion on the volcano flanks. Elastic finite-element models were used to investigate how a stress field could be produced and maintained to...
Roberts rift, Canyonlands, Utah, a natural hydraulic fracture caused by comet or asteroid impact
Peter W. Huntoon, Eugene Merle Shoemaker
1995, Ground Water (33) 561-569
The impact that created Upheaval crater in Canyonlands National Park, Utah, is invoked here as the source for energy that simultaneously caused Roberts rift. However, no temporal linkage has been proven between the impact and rifting events.Roberts rift lies between 22 and 32 km northeast of the Upheaval impact crater...
Preliminary Geologic Map of the Thousand Oaks 7.5' Quadrangle, Southern California: A Digital Database
R.F. Yerkes, Russell H. Campbell
1995, Open-File Report 95-88
Thousand Oaks is located in Arroyo Conejo, a region spanning both southeastern Ventura County and extreme northwest Los Angeles County in southern California. It was discovered in 1542 by Spanish explorer Juan Rodriquez Cabrillo and eventually became part of the Spanish Rancho El Conejo land grant (conejo means 'rabbit' in...
Geohydrology, water quality, and nitrogen geochemistry in the saturated and unsaturated zones beneath various land uses, Riverside and San Bernardino counties, California, 1991-93
Terry F. Rees, Daniel J. Bright, Ronald G. Fay, Allen H. Christensen, Robert Anders, Brian S. Baharie, Michael T. Land
1995, Water-Resources Investigations Report 94-4127
The U.S. Geological Survey, in cooperation with the Eastern Municipal Water District, the Metropolitan Water District of Southern California, and the Orange County Water District, has completed a detailed study of the Hemet groundwater basin. The quantity of ground water stored in the basin in August 1992 is estimated to...
Preliminary geologic map of the Oat Mountain 7.5' quadrangle, southern California: A digital database
R.F. Yerkes, Russell H. Campbell
1995, Open-File Report 95-89
This database, identified as "Preliminary Geologic Map of the Oat Mountain 7.5' Quadrangle, southern California: A Digital Database," has been approved for release and publication by the Director of the USGS. Although this database has been reviewed and is substantially complete, the USGS reserves the right to revise the data...
Gravity of the New Madrid seismic zone; a preliminary study
V.E. Langenheim
1995, Professional Paper 1538-L
In the winter of 1811-12, three of the largest historic earthquakes in the United States occurred near New Madrid, Mo. Seismicity continues to the present day throughout a tightly clustered pattern of epicenters centered on the bootheel of Missouri, including parts of northeastern Arkansas, northwestern Tennessee, western Kentucky, and southern...
Surface-water-quality assessment of the upper Illinois River Basin in Illinois, Indiana, and Wisconsin: Analysis of relations between fish-community structure and environmental conditions in the Fox, Des Plaines, and Du Page River basins in Illinois, 1982-84
P. M. Ruhl
1995, Water-Resources Investigations Report 94-4094
Multivariate analyses of fish-community, water- quality, streambed-sediment-quality, and habitat data collected from 1982 through 1984 in the Fox, Des Plaines, and Du Page River Basins in northeastern Illinois indicate that fish-community structure was strongly related to water-quality gradients commonly associated with differences between agricultural and urban land uses. Detrended correspondence...
Dog "bites" earthquake; a handout for the valley/mountain shaking model
John R. Evans, J.M. Coakley
1995, Open-File Report 95-22
Maps showing modern fissures and Quaternary faults in the Dry Lake Valley area, Lincoln County Nevada
W. C. Swadley
1995, IMAP 2501
No abstract available....
