Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2350
Holocene dune formation at Ash Meadows National Wildlife Area, Nevada, USA
Small isolated dune fields in the northern Mojave Desert are important centers of biodiversity and archaeological occupation sites. Currently dunes at Ash Meadows, Nevada, are stabilized by vegetation and are experiencing erosion of their upwind margins, indicating a negative sediment budget. New OSL ages from dunes at Ash Meadows indicate continuous eolian accumulation from 1.5 to 0.8 ka, with fu
Authors
Nicholas Lancaster, Shannon Mahan
Monitoring subsurface hydrologic response for precipitation-induced shallow landsliding in the San Francisco Bay area, California, USA
Intense winter storms in the San Francisco Bay area (SFBA) of California, USA often trigger shallow landslides. Some of these landslides mobilize into potentially hazardous debris flows. A growing body of research indicates that rainfall intensity-duration thresholds are insufficient for accurate prediction of landslide occurrence. In response, we have begun long-term monitoring of the hydrologic
Authors
Brian D. Collins, Jonathan D. Stock, Lisa C. Weber, K. Whitman, N. Knepprath
Geologic processes influence the effects of mining on aquatic ecosystems
Geologic processes strongly influence water and sediment quality in aquatic ecosystems but rarely are geologic principles incorporated into routine biomonitoring studies. We test if elevated concentrations of metals in water and sediment are restricted to streams downstream of mines or areas that may discharge mine wastes. We surveyed 198 catchments classified as “historically mined” or “unmined,”
Authors
Travis S. Schmidt, William H. Clements, Richard B. Wanty, Philip L. Verplanck, Stan E. Church, Carma A. San Juan, David L. Fey, Barnaby W. Rockwell, Ed H. DeWitt, Terry L. Klein
Fingerprinting of glacial silt in lake sediments yields continuous records of alpine glaciation (35–15 ka), western USA
Fingerprinting glacial silt in last glacial-age sediments from Upper Klamath Lake (UKL) and Bear Lake (BL) provides continuous radiocarbon-dated records of glaciation for the southeastern Cascade Range and northwestern Uinta Mountains, respectively. Comparing of these records to cosmogenic exposure ages from moraines suggests that variations in glacial flour largely reflect glacial extent. The two
Authors
Joseph G. Rosenbaum, Richard L. Reynolds, Steven M. Colman
A half-million-year record of paleoclimate from the Lake Manix Core, Mojave Desert, California
Pluvial lakes in the southwestern U.S. responded sensitively to past climate through effects on rainfall, runoff, and evaporation. Although most studies agree that pluvial lakes in the southwestern U.S. reached their highest levels coeval with glacial stages, the specific timing of increased effective moisture and lake-level rise is debated, particularly for the southwesternmost lakes. We obtained
Authors
Marith C. Reheis, Jordon Bright, Steve P. Lund, David M. Miller, Gary Skipp, Robert J. Fleck
Strontium isotope systematics of mixing groundwater and oil-field brine at Goose Lake in northeastern Montana, USA
Groundwater, surface water, and soil in the Goose Lake oil field in northeastern Montana have been affected by Cl−-rich oil-field brines during long-term petroleum production. Ongoing multidisciplinary geochemical and geophysical studies have identified the degree and local extent of interaction between brine and groundwater. Fourteen samples representing groundwater, surface water, and brine were
Authors
Zell E. Peterman, Joanna N. Thamke, Kiyoto Futa, Todd Preston
Using cluster analysis to organize and explore regional GPS velocities
Cluster analysis offers a simple visual exploratory tool for the initial investigation of regional Global Positioning System (GPS) velocity observations, which are providing increasingly precise mappings of actively deforming continental lithosphere. The deformation fields from dense regional GPS networks can often be concisely described in terms of relatively coherent blocks bounded by active fau
Authors
Robert W. Simpson, Wayne Thatcher, James C. Savage
By
Natural Hazards Mission Area, Energy and Minerals Mission Area, Earthquake Hazards Program, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Earthquake Science Center, Geology, Minerals, Energy, and Geophysics Science Center
Shipboard surveys track magnetic sources in marine sediments--geophysical studies of the Stono and North Edisto Inlets near Charleston, South Carolina
Magnetic field data are traditionally used to analyze igneous and metamorphic rocks, but recent efforts have shown that magnetic sources within sediments may be detectable, suggesting new applications for high-resolution magnetic field surveys. Candidates for sedimentary sources include heavy mineral sand concentrations rich in magnetite or hematite, alteration-induced glauconite, or biogenic magn
Authors
Anjana K. Shah, M. Scott Harris
Groundwater status and trends for the Columbia Plateau Regional Aquifer System, Washington, Oregon, and Idaho
Well information and groundwater-level measurements for the Columbia Plateau Regional Aquifer System in Washington, Oregon, and Idaho, were compiled from data provided by the U.S. Geological Survey and seven other organizations. From the full set of about 60,000 wells and 450,000 water-level measurements a subset of 761 wells within the aquifers of the Columbia River Basalt Group (CRBG) then was u
Authors
Erick R. Burns, Daniel T. Snyder, Jonathan V. Haynes, Michael S. Waibel
Building on previous OSL dating techniques for gypsum: a case study from Salt Basin playa, New Mexico and Texas
The long term stability and reliability of the luminescence signal for gypsum has not been well documented or systematically measured until just recently. A review of the current literature for luminescence dating of gypsum is compiled here along with original efforts at dating an intact and in-situ bed of selenite gypsum at Salt Basin Playa, New Mexico and Texas. This effort differs from other do
Authors
Shannon Mahan, John Kay
Geophysical expression of elements of the Rio Grande rift in the northeast Tusas Mountains - Preliminary interpretations
New interpretations of the nature of the Rio Grande rift and pre-existing rocks in the northeast Tusas Mountains region are derived from new and existing gravity and aeromagnetic data. 12-15 mGal amplitude gravity lows are interpreted to mainly reflect large thicknesses of the upper Oligocene to upper Miocene, syn-rift Los Pinos Formation and possibly significant amounts of the Eocene El Rito Form
Authors
Benjamin J. Drenth, Kenzie J. Turner, Ren A. Thompson, V. J. Grauch, Michael A. Cosca, John Lee
Geochemical data from waters in Prospect Gulch, San Juan County, Colorado, that span pre- and post-Lark Mine remediation
In San Juan County, Colorado, the effects of historical mining continue to contribute dissolved metals to groundwater and surface water. Water samples in Prospect Gulch near Silverton, Colorado, were collected at selected locations that span pre- and post-reclamation activities at the Lark Mine, located in the Prospect Gulch watershed. Geochemical results from those water samples are presented in
Authors
Raymond H. Johnson, Douglas B. Yager, Hugh D. Johnson