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: 1954
Thermomagmatic evolution of Mesoproterozoic crust in the Blue Ridge of SW Virginia and NW North Carolina: Evidence from U-Pb geochronology and zircon geothermometry Thermomagmatic evolution of Mesoproterozoic crust in the Blue Ridge of SW Virginia and NW North Carolina: Evidence from U-Pb geochronology and zircon geothermometry
New geologic mapping, petrology, and U-Pb geochronology indicate that Mesoproterozoic crust near Mount Rogers consists of felsic to mafic meta-igneous rocks emplaced over 260 m.y. The oldest rocks are compositionally diverse and migmatitic, whereas younger granitoids are porphyritic to porphyroclastic. Cathodoluminescence imaging indicates that zircon from four representative units...
Authors
Richard P. Tollo, John N. Aleinikoff, Joseph L. Wooden, Frank K. Mazdab, Scott Southworth, Mark C. Fanning
A review of silver-rich mineral deposits and their metallogeny A review of silver-rich mineral deposits and their metallogeny
Mineral deposits with large inventories or high grades of silver are found in four genetic groups: (1) volcanogenic massive sulfide (VMS), (2) sedimentary exhalative (SEDEX), (3) lithogene, and, (4) magmatichydrothermal. Principal differences between the four groups relate to source rocks and regions, metal associations, process and timing of mineralization, and tectonic setting. These...
Authors
Frederick Graybeal, Peter G. Vikre
Mapping the last frontier in Yellowstone National Park: Yellowstone Lake Mapping the last frontier in Yellowstone National Park: Yellowstone Lake
No abstract available.
Authors
Lisa A. Morgan, Wayne (Pat) Shanks
J is for jack J is for jack
The early days of drilling created a test of strength and endurance for miners.
Authors
W. H. Langer
The tectono-stratigraphic framework and evolution of southwestern Maine and southeastern New Hampshire The tectono-stratigraphic framework and evolution of southwestern Maine and southeastern New Hampshire
Five belts of metamorphosed sedimentary and volcanic rocks underlie southwestern Maine and southeastern New Hampshire: Middle Ordovician Falmouth-Brunswick sequence; Middle and Late Ordovician Casco Bay Group, and Late Ordovician to Early Silurian rocks of the Merribuckfred Basin; Late Ordovician to Early Silurian rocks of the East Harpswell Group; Silurian to Early Devonian rocks of the...
Authors
Arthur M. Hussey, Wallace A. Bothner, John N. Alienikoff
Latitudinal variations in Titan's methane and haze from Cassini VIMS observations Latitudinal variations in Titan's methane and haze from Cassini VIMS observations
We analyze observations taken with Cassini's Visual and Infrared Mapping Spectrometer (VIMS), to determine the current methane and haze latitudinal distribution between 60??S and 40??N. The methane variation was measured primarily from its absorption band at 0.61 ??m, which is optically thin enough to be sensitive to the methane abundance at 20-50 km altitude. Haze characteristics were...
Authors
P.F. Penteado, C.A. Griffith, M.G. Tomasko, S. Engel, C. See, L. Doose, K. H. Baines, R. H. Brown, B. J. Buratti, R. Clark, P. Nicholson, Christophe Sotin
Cassini spectra and photometry 0.25–5.1 μm of the small inner satellites of Saturn Cassini spectra and photometry 0.25–5.1 μm of the small inner satellites of Saturn
The nominal tour of the Cassini mission enabled the first spectra and solar phase curves of the small inner satellites of Saturn. We present spectra from the Visual Infrared Mapping Spectrometer (VIMS) and the Imaging Science Subsystem (ISS) that span the 0.25-5.1 ??m spectral range. The composition of Atlas, Pandora, Janus, Epimetheus, Calypso, and Telesto is primarily water ice, with a...
Authors
B. J. Buratti, J.M. Bauer, M.D. Hicks, J. A. Mosher, G. Filacchione, T. Momary, K. H. Baines, R. H. Brown, R. N. Clark, P. D. Nicholson
Estimating natural background groundwater chemistry, Questa molybdenum mine, New Mexico Estimating natural background groundwater chemistry, Questa molybdenum mine, New Mexico
This 2 1/2 day field trip will present an overview of a U.S. Geological Survey (USGS) project whose objective was to estimate pre-mining groundwater chemistry at the Questa molybdenum mine, New Mexico. Because of intense debate among stakeholders regarding pre-mining groundwater chemistry standards, the New Mexico Environment Department and Chevron Mining Inc. (formerly Molycorp) agreed...
Authors
Phillip L. Verplanck, D. Kirk Nordstrom, Geoffrey S. Plumlee, Bruce M. Walker
Tectonic, magmatic, and metamorphic history of the New Jersey Highlands: New insights from SHRIMP U-Pb geochronology Tectonic, magmatic, and metamorphic history of the New Jersey Highlands: New insights from SHRIMP U-Pb geochronology
No abstract available.
Authors
Richard A. Volkert, John N. Aleinikoff, C. Mark Fanning
Are modern geothermal waters in northwest Nevada forming epithermal gold deposits? Are modern geothermal waters in northwest Nevada forming epithermal gold deposits?
Hydrothermal systems currently are active near some gold deposits in northwestern Nevada. Possible links of these modern systems to gold mineralization were evaluated by chemically and isotopically analyzing water samples from the Brady, Dixie Valley, Humboldt House, San Emidio-Empire, Soda Lake, and Wabuska geothermal areas. In addition, quartz veins from Humboldt House and the adjacent...
Authors
George N. Breit, Andrew G. Hunt, Ruth E. Wolf, Alan E. Koenig, Richard Fifarek, Mark F. Coolbaugh
D is for diamond D is for diamond
Real diamonds are a girl's best friend, but synthetic ones opened up a whole new world for granite.
Authors
W. H. Langer