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: 2021
Ross Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry Ross Ice Shelf response to climate driven by the tectonic imprint on seafloor bathymetry
Ocean melting has thinned Antarctica's ice shelves at an increasing rate over the past two decades, leading to loss of grounded ice. The Ross Ice Shelf is currently close to steady state but geological records indicate that it can disintegrate rapidly, which would accelerate grounded ice loss from catchments equivalent to 11.6 m of global sea level rise. Here, we use data from the...
Authors
K J Tinto, L Padman, C S Siddoway, M.R. Springer, H.A. Fricker, I. Das, F. Caratori Tontini, D.F. Porter, N.P. Frearson, S. J. Howard, M.R. Siegfried, C. Mosbeux, M.K. Becker, C. Bertinato, A. Boghosian, N. Brady, Bethany L. Burton, W. Chu, S.I. Cordero, T. Dhakal, L. Dong, C.D. Gustafson, S. Keeshin, C. Locke, A. Lockett, G. O'Brien, J.J. Spergel, S.E. Starke, M. Tankersley, M. Wearing, R. E. Bell
Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
The purpose of this report is to summarize geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada (fig. 1). Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during...
Authors
Edward A. du Bray, David A. John, Peter G. Vikre, Joseph P. Colgan, Michael A. Cosca, Leah E. Morgan, Robert J. Fleck, Wayne R. Premo, Christopher S. Holm-Denoma
Inversion of airborne EM data with an explicit choice of prior model Inversion of airborne EM data with an explicit choice of prior model
Inversion of airborne electromagnetic (AEM) data is an under-determined inverse problem, in that infinitely many resistivity models exist that will be able to explain the observed data, within measurement errors. Therefore, additional information or constraints must be taken into account to solve the inverse problem. In deterministic approaches, the goal is to locate one optimal model...
Authors
Thomas Mejer Hansen, Burke J. Minsley
Revisiting Herto: New evidence of Homo sapiens from Ethiopia Revisiting Herto: New evidence of Homo sapiens from Ethiopia
Localities in the radiometrically dated Upper Herto Member of Ethiopia’s Bouri Formation continue to produce new data that complement and extend initial reports of fossils and artifacts published in 2003. Results of these revisits are reported here and include the in situ recovery of artifacts from the same sediments containing hominid fossils. We evaluate the absolute and relative...
Authors
Yonatan Sahle, Yonas Beyene, Alban Defleur, Berhane Asfaw, Giday WoldeGabriel, William K Hart, Leah E. Morgan, Paul R. Renne, Joshua Carlson, Tim D White
Distributed fault slip in the eastern California shear zone: Adding pieces to the puzzle near Barstow, California Distributed fault slip in the eastern California shear zone: Adding pieces to the puzzle near Barstow, California
We investigate the dextral Lockhart and Mt. General faults, which are among four active structures in the northwestern portion of the eastern California shear zone (ECSZ). Early mapping depicts the Lockhart and Mt. General faults as discontinuous fault traces that continue northwest of the Lenwood Fault. Recent work indicates that the Lenwood Fault slips at ~0.2-1.0 mm/yr over the past...
Authors
Elizabeth K. Haddon, David M. Miller, Victoria Langenheim, Shannon A. Mahan
Geochemical and mineralogical maps, with interpretation, for soils of the conterminous United States Geochemical and mineralogical maps, with interpretation, for soils of the conterminous United States
Between 2007 and 2013, the U.S. Geological Survey conducted a low-density (1 site per 1,600 square kilometers, 4,857 sites) geochemical and mineralogical survey of soils in the conterminous United States. The sampling protocol for the national-scale survey included, at each site, a sample from a depth of 0 to 5 centimeters, a composite of the soil A horizon, and a deeper sample from the...
Authors
David B. Smith, Federico Solano, Laurel G. Woodruff, William F. Cannon, Karl J. Ellefsen
Comment on “Particle fluxes in groundwater change subsurface rock chemistry over geologic time” Comment on “Particle fluxes in groundwater change subsurface rock chemistry over geologic time”
Over the last decade, studies at the Shale Hills Critical Zone Observatory (Shale Hills) have greatly expanded knowledge of weathering in previously understudied, shale-mantled terrains, as well as Earth's Critical Zone as a whole. Among the many discoveries made was the importance of redistribution and losses of micron-sized particles during development of shale-derived soils. A...
Authors
Carleton R. Bern, Tiffany Yesavage
Calcrete uranium deposits in the Southern High Plains, USA Calcrete uranium deposits in the Southern High Plains, USA
The Southern High Plains (SHP) is a new and emerging U.S. uranium province. Here, uranyl vanadates form deposits in Pliocene to Pleistocene sandstone, dolomite, and limestone. Fifteen calcrete uranium occurrences are identified; two of these, the Buzzard Draw and Sulfur Springs Draw deposits, have combined in-place resources estimated at about 4 million pounds of U3O8. Ore minerals...
Authors
Susan Hall, Bradley S. Van Gosen, James B. Paces, Robert A. Zielinski
U-Pb geochronology of tin deposits associated with the Cornubian Batholith of southwest England: Direct dating of cassiterite by in situ LA-ICPMS U-Pb geochronology of tin deposits associated with the Cornubian Batholith of southwest England: Direct dating of cassiterite by in situ LA-ICPMS
The Cornwall and Devon vein- and greisen-type copper and tin deposits of southwest England are spatially and genetically related to shallow-seated granitic intrusions. These late Variscan intrusions, collectively known as the Cornubian Batholith, extend over 200 km and form a continuous granitic spine from the Isles of Scilly Granite in the west to the Dartmoor Granite in the east. The...
Authors
Richard J. Moscati, Leonid A. Neymark
Aluminum mobility in mildly acidic mine drainage: Interactions between hydrobasaluminite, silica and trace metals from the nano to the meso-scale Aluminum mobility in mildly acidic mine drainage: Interactions between hydrobasaluminite, silica and trace metals from the nano to the meso-scale
Aluminum precipitates control the hydrochemistry and mineralogy of a broad variety of environments on Earth (e.g., acid mine drainage, AMD, coastal wetlands, boreal and alpine streams, tropical acid sulfate soils, laterites and bauxites, …). However, the geochemical and mineralogical processes controlling Al (and other associated metals and metalloids) transport and removal in those...
Authors
Manuel A. Caraballo, Richard B. Wanty, Philip Verplanck, Leonardo Navarro-Valdivia, Carlos Ayora, Michael Hochella
Rare earth element mineral deposits in the United States Rare earth element mineral deposits in the United States
Because of their unique special chemical properties, many of the metals in the group of rare earth elements (REEs) have essential applications in 21st century technologies. Examples of products that use REEs are cell phones, computers, fluorescent and light-emitting-diode lights, flat-screen television and computer monitors, and in high-strength magnets used by clean energy technologies...
Authors
Bradley S. Van Gosen, Philip L. Verplanck, Poul Emsbo
A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system
Establishing temporal constrains on major volcanic eruptions is limited by the precision of existing geochronometers. Prior work on the La Garita caldera, created by the eruption of the Fish Canyon Tuff, failed to resolve temporal differences between pre-, syn-, and post-collapse eruptive units. Here, we report 40Ar/39Ar geochronologic data supporting a ca. 100 ka eruptive history of the...
Authors
Leah E. Morgan, Samuel Johnstone, Amy K. Gilmer, Michael A. Cosca, Ren A. Thompson