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: 2014
Niobium-bearing minerals from the Sheep Creek carbonatite-related deposits of southwest Montana, USA Niobium-bearing minerals from the Sheep Creek carbonatite-related deposits of southwest Montana, USA
The Sheep Creek area in southwest Montana contains a number of small, tabular, carbonatite-related deposits that are rich in Nb and REE minerals. Nb-rich minerals from Sheep Creek and nearby Woods Creek are herein described in detail. The carbonatite veins contain a mix of calcite and Fe-bearing dolomite, with locally abundant apatite, baryte, celsian, actinolite, phlogopite, monazite-...
Authors
Christopher H. Gammons, Heather A. Lowers, Jay M. Thompson, Gary F. Wyss
Evidence for a polar ethane cloud on Titan Evidence for a polar ethane cloud on Titan
Spectra from Cassini's Visual and Infrared Mapping Spectrometer reveal the presence of a vast tropospheric cloud on Titan at latitudes 51° to 68° north and all longitudes observed (10° to 190° west). The derived characteristics indicate that this cloud is composed of ethane and forms as a result of stratospheric subsidence and the particularly cool conditions near the moon's north pole
Authors
C.A. Griffith, P. Penteado, P. Rannou, R. Brown, V. Boudon, K.H. Baines, Roger N. Clark, P. Drossart, B. Buratti, P. Nicholson, C.P. McKay, A. Coustenis, A. Negrao, R. Jaumann
Trace element heterogeneity and crystallization history of the Plesovice zircon: Implications for its use as a U–Pb LA-ICP-MS reference material Trace element heterogeneity and crystallization history of the Plesovice zircon: Implications for its use as a U–Pb LA-ICP-MS reference material
Zircon crystals from Plešovice hyperpotassic granulite (HPG) have been widely used as a reference material for LA-ICP-MS dating. Detailed cathodoluminescence (CL) imaging and trace element analysis reveal a complex internal structure of Plešovice zircon linked to extreme chemical heterogeneity, which allows us to distinguish different zircon domains formed during its crystallization: (i)...
Authors
Jana Kotková, Urs Schaltegger, Alexey Ulianov, Sean Patrick Gaynor, Dan Parvaz, Jiří Sláma
A methods framework for evaluating measurement consistency across spectrometers for multispectral uncrewed aerial system vegetation mapping applications A methods framework for evaluating measurement consistency across spectrometers for multispectral uncrewed aerial system vegetation mapping applications
The U.S. Geological Survey collects remote sensing data to support national scientific assessments of natural resources, hazards, and landscape change. Spectrometers and spectroradiometers are essential for gathering point-based spectral measurements used in applications such as uncrewed aerial systems (UAS) multispectral image calibration, validation, and analysis. Evaluating how...
Authors
Victoria Mary Scholl, Jennifer Marie Cramer, Alexandra Danielle Evans, Evan Cox, Raymond F. Kokaly
Effect of mineral deposit data on predictions from the three-part approach to quantitative mineral resource assessment—A study of 16 previous U.S. Geological Survey assessments Effect of mineral deposit data on predictions from the three-part approach to quantitative mineral resource assessment—A study of 16 previous U.S. Geological Survey assessments
The three-part approach to quantitative mineral resource assessment requires information about the properties of undiscovered mineral deposits in an assessment area. These properties are unknown, so the properties of discovered mineral deposits of the same mineral deposit type are used instead. In the three-part approach, these discovered mineral deposits come from around the world, and...
Authors
Karl J. Ellefsen
Re-Os dating of paleozoic organic-rich black shales by LA-ICP-MS/MS Re-Os dating of paleozoic organic-rich black shales by LA-ICP-MS/MS
We present a new in-situ method for Re-Os geochronology of black shales using LA-ICP-MS/MS that is rapid, cost-effective, and sufficiently accurate and precise to address many geological questions. The method is tested on Paleozoic organic-rich black shales with independently constrained stratigraphic or radiometric ages. Results demonstrate that LA-ICP-MS/MS analysis yields Re-Os dates...
Authors
Jay M. Thompson, Stijn Glorie, Amanda Kate Souders, Sarah E. Gilbert, Timothy Paton, Poul Emsbo
Exhumation history of the Sangre de Cristo Range, Colorado, from mid- to low-temperature thermochronology: New insights into Laramide contraction and Oligocene–Miocene extension in the northern Rio Grande rift, USA Exhumation history of the Sangre de Cristo Range, Colorado, from mid- to low-temperature thermochronology: New insights into Laramide contraction and Oligocene–Miocene extension in the northern Rio Grande rift, USA
The Sangre de Cristo Range in southern Colorado records a complex tectonic history that includes Late Cretaceous–Eocene Laramide contraction and Oligocene–Quaternary Rio Grande rift extension. We present new thermochronologic data (40Ar/39Ar, fission-track, (U-Th)/He) and thermal history models that provide insight into this polyphase history and spatiotemporal patterns of extensional...
Authors
John S. Singleton, Samantha Malavarca, Alexis K. Ault, Omar Ghamedi, M. Cole Sitar, Paul O’Sullivan, Martin Wong, Jonathan Saul Caine, James R. Metcalf, Dylan Frawley, Jeffrey M. Rahl
Subsurface vertical connectivity shapes solute transport to montane streams: Insights from watershed-scale geophysics-informed modeling Subsurface vertical connectivity shapes solute transport to montane streams: Insights from watershed-scale geophysics-informed modeling
Headwater catchments provide essential water and nutrients to downstream ecosystems. The timing and evolution of their transport is shaped in part by the “invisible” subsurface structure but have been largely unexplored at the watershed scale. This raises a fundamental question: how and to what extent does subsurface structure influence streamflow and solute transport in montane...
Authors
Xueyuan Kang, Pamela L. Sullivan, Burke J. Minsley, Li Li, Marc Dumont, Kamini Singha
USGS Geochron Database USGS Geochron Database
Authors
Leah E. Morgan, Kelly D. Thomson, Ian W. Hillenbrand, Amy K. Gilmer
The saline groundwater legacy of a large buried coastal paleo-estuary The saline groundwater legacy of a large buried coastal paleo-estuary
Elevated groundwater salinity in coastal regions threatens the beneficial use of fresh groundwater. Coastal groundwater management typically focuses on preventing intrusion from modern sources of seawater; however, past geological processes can also leave a legacy of saline groundwater now hidden in the subsurface. Here, multiple extensive airborne electromagnetic surveys provide...
Authors
Burke J. Minsley, Holly A. Michael, Maxwell A. Lindaman, Lyndsay B. Ball, Stephanie R. James, James R. Rigby, Wade H. Kress, Frank T.C. Tsai, Bennett Eugene Hoogenboom
Mid-Cretaceous porphyritic magmatism in the Beartooth Mountains of the northern Laramide foreland and its connection to Frontier Formation sediment dispersal in Bighorn basin, Montana-Wyoming (USA), and Cordilleran tectonism Mid-Cretaceous porphyritic magmatism in the Beartooth Mountains of the northern Laramide foreland and its connection to Frontier Formation sediment dispersal in Bighorn basin, Montana-Wyoming (USA), and Cordilleran tectonism
Porphyritic intrusions in the southeast Beartooth Mountains and porphyritic cobbles from the Torchlight conglomerate of the Cenomanian Frontier Formation in Bighorn basin (Montana-Wyoming, USA) bear striking resemblance. We utilize geologic mapping, petrography, geochemistry, and geochronology to characterize rocks from both locations and test whether the Beartooth Mountains area was the
Authors
Jacob O. Thacker, Nicholas A. Brailer, Gary S. Michelfelder, Barry Shaulis, Rebecca A. VanderLeest, Snir Attia, Eddy Cunningham
Tetraphenylborate-assisted extraction of K and Ar from micaceous clay minerals: A promising method for the geochronology of diagenetic illite Tetraphenylborate-assisted extraction of K and Ar from micaceous clay minerals: A promising method for the geochronology of diagenetic illite
Tetraphenylborate (TPB)-assisted exchange of Na+ for structural K was explored to establish the extent to which K and radiogenic Ar were removed from mixed-layer illite-smectite (Ilt-Sme) and detrital muscovite in various clay fractions (
Authors
Arya Shahbazi-Asl, J. Marion Wampler, W. Crawford Elliott, Julia A. McIntosh