Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
Conceptualizing ecological responses to dam removal: If you remove it, what's to come?
One of the desired outcomes of dam decommissioning and removal is the recovery of aquatic and riparian ecosystems. To investigate this common objective, we synthesized information from empirical studies and ecological theory into conceptual models that depict key physical and biological links driving ecological responses to removing dams. We define models for three distinct spatial domains: upstre
Authors
J. Ryan Bellmore, George R. Pess, Jeffrey J. Duda, Jim E. O'Connor, Amy E. East, Melissa M. Foley, Andrew C. Wilcox, Jon J. Major, Patrick B. Shafroth, Sarah A. Morley, Christopher S. Magirl, Chauncey W. Anderson, James E. Evans, Christian E. Torgersen, Laura S. Craig
By
Ecosystems Mission Area, Coastal and Marine Hazards and Resources Program, Species Management Research Program, Arizona Water Science Center, Forest and Rangeland Ecosystem Science Center, Fort Collins Science Center, Geology, Minerals, Energy, and Geophysics Science Center, John Wesley Powell Center for Analysis and Synthesis, Oregon Water Science Center, Pacific Coastal and Marine Science Center, Western Fisheries Research Center
Assessment of undiscovered copper resources of the world, 2015
The U.S. Geological Survey completed the first-ever global assessment of undiscovered copper resources for the two most significant sources of global copper supply: porphyry copper deposits and sediment-hosted stratabound copper deposits. The geology-based study identified 236 areas for undiscovered copper in 11 regions of the world. Estimated amounts of undiscovered copper resources are reported
Authors
Jane M. Hammarstrom, Michael L. Zientek, Heather L. Parks, Connie L. Dicken
Shear-wave seismic reflection studies of unconsolidated sediments in the near surface
We have successfully applied of SH-wave seismic reflection methods to two different near-surface problems targeting unconsolidated sediments. At the former Fort Ord, where the water table is approximately 30m deep, we imaged aeolian and marine aquifer and aquitard stratigraphy to a depth of approximately 80m. We identified reflections from sand/clay and sand/silt interfaces and we mapped these int
Authors
Karl J. Ellefsen, Seth S. Haines
Probabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report
The U.S. Geological Survey is partnering with the IberoAmerican Association of Geological and Mining Surveys (ASGMI) to conduct an assessment of undiscovered metallic and non-metallic resources in the Greater Antilles region. The assessment plans to provide science-based information on the geologic availability of these resources for development, land-use planning, and decision making. The USGS an
Authors
Lukas Zürcher, Floyd Gray, Stephen Ludington, Frederic H. Wilson, Greta J. Orris, Mark D. Cocker, Mark E. Gettings, Timothy Hayes
Extreme‐value geoelectric amplitude and polarization across the northeast United States
Maps are presented of extreme‐value geoelectric field amplitude and horizontal polarization for the Northeast United States. These maps are derived from geoelectric time series calculated for sites across the Northeast by frequency‐domain multiplication (time‐domain convolution) of 172 magnetotelluric impedance tensors, acquired during a survey, with decades‐long, 1‐min resolution time series of g
Authors
Jeffrey J. Love, Greg M. Lucas, Paul A. Bedrosian, Anna Kelbert
Geologic map and database of the Chocolate Mountain Aerial Gunnery Range, Riverside and Imperial Counties, California
The northwest-trending Chocolate Mountains are situated along the northeastern margin of the southern Salton Trough. The Chocolate Mountain Aerial Gunnery Range occupies most of the 75-km-long part of the Chocolate Mountains that lies between Salt Creek to the north and California State Highway 78 to the south. Mapping studies in the Chocolate Mountains within the gunnery range are few and this st
Authors
Robert E. Powell, Robert J. Fleck, Pamela M. Cossette
Lithostratigraphic framework in boreholes from Goldstone Lake and Nelson Lake Basins, Fort Irwin, California
In 2011 and 2012, the sedimentary basins in the Fort Irwin National Training Center, California, were evaluated for groundwater resources using a variety of techniques, including drilling of boreholes. This study summarizes lithostratigraphic features and deposits in 8 of 10 boreholes drilled in 2 basins located in the western part of Fort Irwin. The western part of Fort Irwin straddles the easter
Authors
David C. Buesch
Cenozoic geology of Fort Irwin and vicinity, California
The geology of the Fort Irwin National Training Center in the north-central Mojave Desert, California, provides insights into the hydrology and water resources of the area. The Fort Irwin area is underlain by rocks ranging in age from Proterozoic to Quaternary that have been deformed by faults as young as Quaternary. Pre-Tertiary sedimentary, igneous, and metamorphic bedrock and Miocene volcanic a
Authors
David C. Buesch, David M. Miller, Christopher M. Menges
Which geologic factors control permeability development in geothermal systems? The geologic structure of Dixie Valley
Geothermal systems occur where subsurface permeability and temperature are sufficiently high to drive fluid circulation. In the Great Basin region of the United States, which hosts ~20% of domestic geothermal electricity generation capacity and much of the projected undeveloped and undiscovered resource, crustal heat flow is relatively high, so permeability is the dominant factor controlling the o
Authors
Drew L. Siler, Jonathan M. G. Glen
New data yield new geologic insights at the Fallon FORGE site, Carson Sink Region, Nevada
The geologic structure beneath the Fallon Frontier Observatory for Research in Geothermal Energy (FORGE) site represents a record of the Mesozoic through Cenozoic tectonism, volcanism, and sedimentation that has affected the Carson Sink local to Fallon, NV. A robust dataset confirms that the lithologic sequence consists of Quaternary through Miocene sedimentary and volcanic rocks resting non-confo
Authors
Drew L. Siler, James E. Faulds, Jonathan M. G. Glen, Jeffrey B. Witter
2D and 3D potential field mapping and modelling at the Fallon FORGE site, Nevada, USA
Accurate geological characterization of Fallon FORGE is important for preparing the site as an EGS laboratory. As part of this effort, a 3D geologic map was constructed previously from well logs, surface geologic mapping, 2D seismic profiles, interpreted gravity & magnetic maps, and a gravity-inferred basement surface. In this study, we have conducted both 2D and 3D modelling of high-resolution gr
Authors
Jeffrey B. Witter, Jonathan M. G. Glen, Drew L. Siler, Dominique Fournier
Discovery of a blind geothermal system in Southern Gabbs Valley, western Nevada, through application of the play fairway analysis at multiple scales
The Great Basin region is capable of generating much greater amounts of geothermal energy than currently produced. Most geothermal resources in this region are blind, and thus favorable characteristics for geothermal activity must be synthesized and methodologies developed to discover new commercial-grade systems. The geothermal play fairway concept involves integration of multiple parameters indi
Authors
James Faulds, Jason W. Craig, Nicholas H. Hinz, Mark F. Coolbaugh, Jonathan M. Glen, Tait E. Earney, William D. Schermerhorn, Jared R. Peacock, Stephen B. Deoreo, Drew L. Siler