Conference Papers
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The USGS provides unbiased, objective, and impartial scientific information upon which our audiences, including resource managers, planners, and other entities, rely.
Browse almost 5,000 conference papers authored by our scientists and refine search by topic, location, year, and advanced search.
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Identifying the appropriate porphyry-copper deposit grade and tonnage model for a large-scale mineral resource assessment in southeast Asia Identifying the appropriate porphyry-copper deposit grade and tonnage model for a large-scale mineral resource assessment in southeast Asia
No abstract available.
Authors
Lawrence J. Drew, Donald A. Singer
Remote sensing sensitivity to fire severity and fire recovery Remote sensing sensitivity to fire severity and fire recovery
The paper examines fundamental ways that geospatial data on fire severity and recovery are influenced by conditions of the remote sensing. Remote sensing sensitivities are spatial, temporal and radiometric in origin. Those discussed include spatial resolution, the sampling time of year, and time since fire. For standard reference, sensitivities are demonstrated with examples drawn from...
Authors
C.H. Key
Comparison of mine waste assessment methods at the Rattler mine site, Virginia Canyon, Colorado Comparison of mine waste assessment methods at the Rattler mine site, Virginia Canyon, Colorado
In a joint project, the mine waste-piles at the Rattler Mine near Idaho Springs, Colorado, were sampled and analyzed by scientists from the U.S. Geological Survey (USGS) and the Colorado School of Mines (CSM). Separate sample collection, sample leaching, and leachate analyses were performed by both groups and the results were compared. For the study, both groups used the USGS sampling...
Authors
Phil L. Hageman, Kathleen S. Smith, Thomas R. Wildeman, James F. Ranville
Use of the Biotic Ligand Model to predict metal toxicity to aquatic biota in areas of differing geology Use of the Biotic Ligand Model to predict metal toxicity to aquatic biota in areas of differing geology
This work evaluates the use of the biotic ligand model (BLM), an aquatic toxicity model, to predict toxic effects of metals on aquatic biota in areas underlain by different rock types. The chemical composition of water, soil, and sediment is largely derived from the composition of the underlying rock. Geologic source materials control key attributes of water chemistry that affect metal...
Authors
Kathleen S. Smith
Sources of acid and metals from the weathering of the Dinero waste pile, Lake Fork watershed, Leadville, Colorado Sources of acid and metals from the weathering of the Dinero waste pile, Lake Fork watershed, Leadville, Colorado
Two trenches were dug into the south Dinero mine-waste pile near Leadville, Colorado, to study the weathering of rock fragments and the mineralogic sources of metal contaminants in the surrounding wetland and Lake Fork Watershed. Water seeping from the base of the south Dinero waste-rock pile was pH 2.9, whereas leachate from a composite sample of the rock waste was pH 3.3. The waste...
Authors
S. F. Diehl, Phil L. Hageman, Kathleen S. Smith, J.T. Herron, G. A. Desborough
Using enzyme bioassays as a rapid screen for metal toxicity Using enzyme bioassays as a rapid screen for metal toxicity
Mine tailings piles and abandoned mine soils are often contaminated by a suite of toxic metals, which were released in the mining process. Traditionally, toxicity of such areas has been determined by numerous chemical methods including the Toxicity Characteristic Leachate Procedure (TCLP) and traditional toxicity tests using organisms such as the cladoceran Ceriodaphnia dubia. Such tests...
Authors
LaDonna M. Choate, P.E. Ross, E. P. Blumenstein, James F. Ranville
Pulsing and circulation in rip current system Pulsing and circulation in rip current system
Current pulsations from a longshore bar and trough rip system located on the eastern coast of Moreton Island, Australia are presented. These pulsations occur over 10-20minute intervals through the rip system and are correlated to both water level gradients and wave energy variations. The field measurements suggest that rip current pulsations can be driven by fluctuating mass transport...
Authors
D. P. Callaghan, T. E. Baldock, P. Nielsen, D.M. Hanes, K. Haas, J. MacMahan
Recent changes toward earlier springs---early signs of climate warming in western North America Recent changes toward earlier springs---early signs of climate warming in western North America
No abstract available.
Authors
D. Cayan, M. Dettinger, I. Stewart, N. Knowles
A fresh look at the taxonomy of midcontinental sandhill cranes A fresh look at the taxonomy of midcontinental sandhill cranes
The midcontinental population of sandhill crane (Grus canadensis) includes about 500,000 birds and provides valuable recreational crane-watching and hunting opportunities in Canada and the United States. It comprises three subspecies, one of which (G. c. rowani) was of uncertain taxonomic status and another of which (G. c. tabida) merited protection from excessive harvest due to its...
Authors
Douglas H. Johnson, Jane E. Austin, Jill A. Shaffer
Wildlife disease in a changing world Wildlife disease in a changing world
No abstract available.
Authors
Milton Friend
Integrated surface and borehole strong-motion, soil-response arrays in San Francisco, California: Empirical measurements of low-strain site coefficients at site class E and D soil sites Integrated surface and borehole strong-motion, soil-response arrays in San Francisco, California: Empirical measurements of low-strain site coefficients at site class E and D soil sites
An integrated set of four borehole arrays and ten surface installations is installed in the city of San Francisco, California to measure the response of soft-soil deposits to strong earthquake ground motions. The borehole arrays extend through thick layers of soft water-saturated soils of Holocene age and older more consolidated soils of Pleistocene age into bedrock at depths up to 90 m...
Authors
Roger D. Borcherdt, G. Glassmoyer, Christopher M. Dietel, R.E. Westerlund