Geology, Geophysics, and Geochemistry Science Center

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.

USGS Publications Warehouse

Filter Total Items: 1,647
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Year Published: 2019

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,...

Hansen, Thomas Mejer; Minsley, Burke J.

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Year Published: 2019

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...

Sahle, Yonatan; Beyene, Yonas; Defleur, Alban; Asfaw, Berhane; WoldeGabriel, Giday; Hart, William K; Morgan, Leah E.; Renne, Paul R.; Carlson, Joshua; White, Tim D

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Year Published: 2019

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...

Haddon, Elizabeth K.; Miller, David M.; Langenheim, Victoria; Mahan, Shannon A.

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Year Published: 2019

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...

Smith, David B.; Solano, Federico; Woodruff, Laurel G.; Cannon, William F.; Ellefsen, Karl J.
Smith, D.B., Solano, Federico, Woodruff, L.G., Cannon, W.F., and Ellefsen, K.J., 2019, Geochemical and mineralogical maps, with interpretation, for soils of the conterminous United States: U.S. Geological Survey Scientific Investigations Report 2017-5118, https://doi.org/10.3133/sir20175118. [Available as HTML.]

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Year Published: 2019

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...

Bern, Carleton R.; Tiffany Yesavage

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Year Published: 2019

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...

Hall, Susan; Van Gosen, Bradley S.; Paces, James B.; Zielinski, Robert A.

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Year Published: 2019

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...

Moscati, Richard J.; Neymark, Leonid A.

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Year Published: 2019

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...

Caraballo, Manuel A.; Wanty, Richard; Verplanck, Philip; Navarro-Valdivia, Leonardo; Ayora, Carlos; Hochella, Michael

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Year Published: 2019

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...

Van Gosen, Bradley S.; Verplanck, Philip L.; Emsbo, Poul
Van Gosen, B.S., Verplanck, P.L., and Emsbo, Poul, 2019, Rare earth element mineral deposits in the United States (ver 1.1, April 15, 2019): U.S. Geological Survey Circular 1454, 16 p., https://doi.org/10.3133/cir1454.

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Year Published: 2019

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...

Morgan, Leah E.; Johnstone, Samuel A.; Gilmer, Amy K.; Cosca, Michael A.; Thompson, Ren A.
Morgan, L. E., Johnstone, S. A., Gilmer, A. K., Cosca, M. A., & Thompson, R. A. (2019). A supervolcano and its sidekicks: A 100 ka eruptive chronology of the Fish Canyon Tuff and associated units of the La Garita magmatic system, Colorado, USA. Geology, 47(5), 453-456.

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Year Published: 2019

Imaging spectroscopy for the detection, assessment and monitoring of natural and anthropogenic hazards

Natural and anthropogenic hazards have the potential to impact all aspects of society including its economy and the environment. Diagnostic data to inform decision-making are critical for hazard management whether for emergency response, routine monitoring or assessments of potential risks. Imaging spectroscopy (IS) has unique contributions to...

Ong, Cindy; Carrere, Véronique; Chabrillat, Sabine; Clark, Roger N.; Hoefen, Todd M.; Kokaly, Raymond; Marion, Rodolphe; Souza Filho, Carlos Roberto de; Swayze, Gregg A.; Thompson, David R.

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Year Published: 2019

Effect of size-biased sampling on resource predictions from the three-part method for quantitative mineral resource assessment—A case study of the gold mines in the Timmins-Kirkland Lake area of the Abitibi greenstone belt, Canada:

The three-part method for quantitative mineral resource assessment is used by the U.S. Geological Survey to predict, within a specified assessment area, the number of undiscovered mineral deposits and the quantity of mineral resources in those undiscovered deposits. The effects of size-biased sampling on such predictions are evaluated in a case...

Ellefsen, Karl J.
Ellefsen, K.J., 2019, Effect of size-biased sampling on resource predictions from the three-part method for quantita-tive mineral resource assessment—A case study of the gold mines in the Timmins-Kirkland Lake area of the Abitibi greenstone belt, Canada: U.S. Geological Scientific Investigations Report 2018–5149, 15 p., https://doi.org/10.3133/sir20185149.