Publications
Products (journal articles, reports, fact sheets) authored by current and past scientists are listed below. Please check the USGS Pubs Warehouse for other USGS publications.
Filter Total Items: 1829
Mauritania – A greenfields exploration opportunity in northwestern Africa
No abstract available.
Authors
Cliff D. Taylor, E. D. Anderson, D. C. Bradley, G. Beaudoin, Michael A. Cosca, Robert G. Eppinger, Gregory L. Fernette, Carol A. Finn, Michael J. Friedel, Stuart A. Giles, Richard J. Goldfarb, John D. Horton, Gregory K. Lee, Erin E. Marsh, Jeffrey L. Mauk, Holly A. Motts, M. Y. Ould El Joud, S. Ould Soueidatt, A. Ould Taleb Mohamed, Barnaby W. Rockwell
Laboratory investigations of the effects of nitrification-induced acidification on Cr cycling in vadose zone material partially derived from ultramafic rocks
Sacramento Valley (California, USA) soils and sediments have high concentrations of Cr(III) because they are partially derived from ultramafic material. Some Cr(III) is oxidized to more toxic and mobile Cr(VI) by soil Mn oxides. Valley soils typically have neutral to alkaline pH at which Cr(III) is highly immobile. Much of the valley is under cultivation and is both fertilized and irrigated. A ser
Authors
Christopher T. Mills, Martin B. Goldhaber
Conditions and processes affecting radionuclide transport
Characteristics of host rocks, secondary minerals, and fluids would affect the transport of radionuclides from a previously proposed repository at Yucca Mountain, Nevada. Minerals in the Yucca Mountain tuffs that are important for retarding radionuclides include clinoptilolite and mordenite (zeolites), clay minerals, and iron and manganese oxides and hydroxides. Water compositions along flow paths
Authors
Ardyth M. Simmons, Leonid A. Neymark
Ore genesis constraints on the Idaho Cobalt Belt from fluid inclusion gas, noble gas isotope, and ion ratio analyses
The Idaho cobalt belt is a 60-km-long alignment of deposits composed of cobaltite, Co pyrite, chalcopyrite, and gold with anomalous Nb, Y, Be, and rare-earth elements (REEs) in a quartz-biotite-tourmaline gangue hosted in Mesoproterozoic metasedimentary rocks of the Lemhi Group. It is the largest cobalt resource in the United States with historic production from the Blackbird Mine. All of the depo
Authors
Albert H. Hofstra, Gary P. Landis
SHRIMP U-Pb ages of xenotime and monazite from the Spar Lake red bed-associated Cu-Ag deposit, western Montana: Implications for ore genesis
Xenotime occurs as epitaxial overgrowths on detrital zircons in the Mesoproterozoic Revett Formation (Belt Supergroup) at the Spar Lake red bed-associated Cu-Ag deposit, western Montana. The deposit formed during diagenesis of Revett strata, where oxidizing metal-bearing hydrothermal fluids encountered a reducing zone. Samples for geochronology were collected from several mineral zones. Xenotime o
Authors
John N. Aleinikoff, Timothy S. Hayes, Karl V. Evans, Frank K. Mazdab, Renee M. Pillers, C. Mark Fanning
Airborne electromagnetic imaging of discontinuous permafrost
The evolution of permafrost in cold regions is inextricably connected to hydrogeologic processes, climate, and ecosystems. Permafrost thawing has been linked to changes in wetland and lake areas, alteration of the groundwater contribution to streamflow, carbon release, and increased fire frequency. But detailed knowledge about the dynamic state of permafrost in relation to surface and groundwater
Authors
B. J. Minsley, J.D. Abraham, B. D. Smith, J. C. Cannia, C.I. Voss, M.T. Jorgenson, Michelle Ann Walvoord, B.K. Wylie, L. Anderson, L.B. Ball, M. Deszcz-Pan, T.P. Wellman, T. A. Ager
Field experiment provides ground truth for surface nuclear magnetic resonance measurement
The need for sustainable management of fresh water resources is one of the great challenges of the 21st century. Since most of the planet's liquid fresh water exists as groundwater, it is essential to develop non-invasive geophysical techniques to characterize groundwater aquifers. A field experiment was conducted in the High Plains Aquifer, central United States, to explore the mechanisms governi
Authors
R. Knight, E. Grunewald, T. Irons, K. Dlubac, Y. Song, H.N. Bachman, B. Grau, D. Walsh, J.D. Abraham, J. Cannia
Titan's fluvial valleys: Morphology, distribution, and spectral properties
Titan's fluvial channels have been investigated based on data obtained by the Synthetic Aperture Radar (SAR) instrument and the Visible and Infrared Mapping Spectrometer (VIMS) onboard the Cassini spacecraft. In this paper, a database of fluvial features is created based on radar-SAR data aiming to unveil the distribution and the morphologic and spectral characteristics of valleys on Titan on a gl
Authors
M.H. Langhans, R. Jaumann, K. Stephan, R. H. Brown, B. J. Buratti, Roger N. Clark, K. H. Baines, P. D. Nicholson, R. D. Lorenz, Laurence A. Soderblom, J.M. Soderblom, Christophe Sotin, J. W. Barnes, R. Nelson
Landscape controls on the timing of spring, autumn, and growing season length in mid-Atlantic forests
The timing of spring leaf development, trajectories of summer leaf area, and the timing of autumn senescence have profound impacts to the water, carbon, and energy balance of ecosystems, and are likely influenced by global climate change. Limited field-based and remote-sensing observations have suggested complex spatial patterns related to geographic features that influence climate. However, much
Authors
A.J. Elmore, S.M. Guinn, B. J. Minsley, A.D. Richardson
Origins of mineral deposits, Belt-Purcell Basin, United States and Canada: An introduction
The fill of the Mesoproterozoic Belt-Purcell Basin, which straddles the United States-Canada border within the Rocky Mountains of western North America (Fig. 1), consists of marine and nonmarine clastic and carbonate strata 15 to 20 km thick. Three giant metal-producing ore deposits or districts account for the bulk of the known metal endowment within the bounds of the Belt-Purcell Basin: (1) the
Authors
Stephen E. Box, Arthur A. Bookstrom, Robert G. Anderson
The principal rare earth elements deposits of the United States: A summary of domestic deposits and a global perspective
Demand for the rare earth elements (REE, lanthanide elements) is estimated to be increasing at a rate of about 8% per year due to increasing applications in consumer products, computers, automobiles, aircraft, and other advanced technology products. Much of this demand growth is driven by new technologies that increase energy efficiency and substitute away from fossil fuels. Production of these el
Authors
Keith R. Long, Bradley S. Van Gosen, Nora K. Foley, Daniel Cordier
Climate-change-driven deterioration of water quality in a mineralized watershed
A unique 30-year streamwater chemistry data set from a mineralized alpine watershed with naturally acidic, metal-rich water displays dissolved concentrations of Zn and other metals of ecological concern increasing by 100–400% (400–2000 μg/L) during low-flow months, when metal concentrations are highest. SO4 and other major ions show similar increases. A lack of natural or anthropogenic land distur
Authors
Andrew Todd, Andrew H. Manning, Philip L. Verplanck, Caitlin Crouch, Diane M. McKnight, Ryan Dunham