Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
Overview: The Chemehuevi Formation along the lower Colorado River
A distinctive set of fine-grained deposits occurs throughout the lower Colorado River Valley, extending from just below the mouth of Grand Canyon to well into the river delta below Yuma, AZ (Figure 1), an along-channel distance of over 700 km. Upstream of Parker, Arizona, the deposits consist of scattered erosional remnants up to 150 m above the modern floodplain. Below Parker, they occur in isola
Authors
Daniel V. Malmon, Keith A. Howard
Stratigraphy of Colorado River deposits in lower Mohave Valley, Arizona and California
Deposits in lower Mohave Valley and upper Topock Gorge near Topock, Arizona and Park Moabi, California record a succession of depositional and erosional events since late Miocene time that relate to the development of the Colorado River. Upper Miocene alluvial fans were deposited toward a depocenter east of the present valley bottom, indicating there was no valley outlet then through the area of T
Authors
Keith A. Howard, D.V. Malmon
The geology and tectonic history of Santa Clara County
No abstract available.
Authors
M. Clark Blake, C. M. Wentworth
Integrated geoscience studies in the Greater Yellowstone Area - Volcanic, tectonic, and hydrothermal processes in the Yellowstone geoecosystem
Yellowstone National Park, rimmed by a crescent of older mountainous terrain, has at its core the Quaternary Yellowstone Plateau, an undulating landscape shaped by forces of volcanism, tectonism, and later glaciation. Its spectacular hydrothermal systems cap this landscape. From 1997 through 2003, the United States Geological Survey Mineral Resources Program conducted a multidisciplinary project o
Preliminary non-fuel mineral resource assessment of Afghanistan 2007
The U.S. Geological Survey (USGS) cooperated with the Afghanistan Geological Survey (AGS) of the Afghanistan Ministry of Mines to assess the undiscovered non-fuel mineral resources of Afghanistan between 2006 and 2007. This report presents the results of this work and contains chapters describing and assessing the mineral resources of Afghanistan. An accompanying Geographical Information System (G
Authors
Stephen G. Peters, Stephen Ludington, Greta J. Orris, David M. Sutphin, James D. Bliss, James J. Rytuba
Gravity Data from Newark Valley, White Pine County, Nevada
The Newark Valley area, eastern Nevada is one of thirteen major ground-water basins investigated by the BARCAS (Basin and Range Carbonate Aquifer Study) Project. Gravity data are being used to help characterize the geophysical framework of the region. Although gravity coverage was extensive over parts of the BARCAS study area, data were sparse for a number of the valleys, including the northern pa
Authors
Edward A. Mankinen, Edwin H. McKee
Understanding Metal Pathways in Mineralized Ecosystems
Successful management of ecosystems containing historical mine wastes requires understanding of processes that are responsible for the distribution, concentration, and bioavailability of potentially toxic elements. U.S. Geological Survey (USGS) scientists recently completed several investigations at historical mine sites in the western United States. These investigations have improved our understa
Authors
Laurie S. Balistrieri, Andrea L. Foster, Larry P. Gough, Floyd Gray, James J. Rytuba, Lisa L. Stillings
Preliminary Isostatic Gravity Map of Joshua Tree National Park and Vicinity, Southern California
This isostatic residual gravity map is part of an effort to map the three-dimensional distribution of rocks in Joshua Tree National Park, southern California.
This map will serve as a basis for modeling the shape of basins beneath the Park and in adjacent valleys and also for determining the location and geometry of faults within the area. Local spatial variations in the Earth's gravity field,
Authors
V. E. Langenheim, Shawn Biehler, D.K. McPhee, C.A. McCabe, J. T. Watt, M.L. Anderson, B. A. Chuchel, P. Stoffer
Geophysical framework investigations influencing ground-water resources in east-central Nevada and west-central Utah, with a section on geologic and geophysical basin by basin descriptions
A geophysical investigation was undertaken as part of an effort to characterize the geologic framework influencing ground-water resources in east-central Nevada and west-central Utah. New gravity data were combined with existing aeromagnetic, drill-hole, and geologic data to help determine basin geometry, infer structural features, estimate depth to pre-Cenozoic basement rocks, and further constra
Authors
Janet T. Watt, David A. Ponce, Alan R. Wallace
Age, stratigraphy, and correlations of the late Neogene Purisima Formation, central California coast ranges
The Purisima Formation is an important upper Miocene and Pliocene stratigraphic unit in central California, cropping out from the coast at Point Reyes north of San Francisco to more extensive exposures in the Santa Cruz Mountains to the south. The fine-grained rocks in the lower parts of the Purisima Formation record a latest Miocene transgressive event, whereas the middle and upper parts of the f
Authors
Charles L. Powell, John A. Barron, Andrei M. Sarna-Wojcicki, Joseph C. Clark, Frank A. Perry, Earl E. Brabb, Robert J. Fleck
Marl Prairie Vegetation Response to 20th Century Hydrologic Change
We conducted geochronologic and pollen analyses from sediment cores collected in solution holes within marl prairies of Big Cypress National Preserve to reconstruct vegetation patterns of the last few centuries and evaluate the stability and longevity of marl prairies within the greater Everglades ecosystem. Based on radiocarbon dating and pollen biostratigraphy, these cores contain sediments depo
Authors
Christopher E. Bernhardt, Debra A. Willard
Minerales en nuestro ambiente
No abstract available.
Authors
Dave G. Frank, John P. Galloway, Susan Garcia, Judy Weathers