Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2481
Loess records: North America Loess records: North America
No abstract available.
Authors
H.M. Roberts, D.R. Muhs, E. Arthur Bettis
Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA Assessing the concentration, speciation, and toxicity of dissolved metals during mixing of acid-mine drainage and ambient river water downstream of the Elizabeth Copper Mine, Vermont, USA
The authors determine the composition of a river that is impacted by acid-mine drainage, evaluate dominant physical and geochemical processes controlling the composition, and assess dissolved metal speciation and toxicity using a combination of laboratory, field and modeling studies. Values of pH increase from 3.3 to 7.6 and the sum of dissolved base metal (Cd + Co + Cu + Ni + Pb + Zn)
Authors
Laurie S. Balistrieri, R.R. Seal, N.M. Piatak, B. Paul
Environmental geochemistry at Red Mountain, an unmined volcanogenic massive sulphide deposit in the Bonnifield district, Alaska Range, east-central Alaska Environmental geochemistry at Red Mountain, an unmined volcanogenic massive sulphide deposit in the Bonnifield district, Alaska Range, east-central Alaska
The unmined, pyrite-rich Red Mountain (Dry Creek) deposit displays a remarkable environmental footprint of natural acid generation, high metal and exceedingly high rare earth element (REE) concentrations in surface waters. The volcanogenic massive sulphide deposit exhibits well-constrained examples of acid-generating, metal-leaching, metal-precipitation and self-mitigation (via co...
Authors
Robert G. Eppinger, Paul H. Briggs, Cynthia Dusel-Bacon, Stuart A. Giles, Larry P. Gough, Jane M. Hammarstrom, Bernard E. Hubbard
Fault locking, block rotation and crustal deformation in the Pacific Northwest Fault locking, block rotation and crustal deformation in the Pacific Northwest
We interpret Global Positioning System (GPS) measurements in the northwestern United States and adjacent parts of western Canada to describe relative motions of crustal blocks, locking on faults and permanent deformation associated with convergence between the Juan de Fuca and North American plates. To estimate angular velocities of the oceanic Juan de Fuca and Explorer plates and...
Authors
Robert McCaffrey, Anthony I. Qamar, Robert W. King, Ray E. Wells, G. Khazaradze, C.A. Williams, C.W. Stevens, J.J. Vollick, P.C. Zwick
Dune fields: mid-latitudes Dune fields: mid-latitudes
No abstract available.
Authors
Jielun Sun, D.R. Muhs
Three-dimensional P wave velocity model for the San Francisco Bay region, California Three-dimensional P wave velocity model for the San Francisco Bay region, California
[1] A new three-dimensional P wave velocity model for the greater San Francisco Bay region has been derived using the double-difference seismic tomography method, using data from about 5,500 chemical explosions or air gun blasts and approximately 6,000 earthquakes. The model region covers 140 km NE-SW by 240 km NW-SE, extending from 20 km south of Monterey to Santa Rosa and reaching from...
Authors
C.H. Thurber, T.M. Brocher, H. Zhang, V.E. Langenheim
Preliminary Gravity and Magnetic Data of the Lake Pillsbury Region, Northern Coast Ranges, California Preliminary Gravity and Magnetic Data of the Lake Pillsbury Region, Northern Coast Ranges, California
The Lake Pillsbury region is transected by the Bartlett Springs Fault zone, one of the main strike-slip faults of the San Andreas system north of San Francisco Bay, California. Gravity and magnetic data were collected to help characterize the geometry and offset of the fault zone as well as determine the geometry of the Gravelly Valley pull-apart basin and Potter Valley, an alluvial...
Authors
Victoria E. Langenheim, Robert C. Jachens, Robert L. Morin, Craig A. McCabe
Gravity and magnetic studies to characterize the geologic framework of the Spring Valley region Gravity and magnetic studies to characterize the geologic framework of the Spring Valley region
No abstract available.
Authors
Edward A. Mankinen
Formation of tectonic peperites from alkaline magmas intruded into wet sediments in the Beiya area, western Yunnan, China Formation of tectonic peperites from alkaline magmas intruded into wet sediments in the Beiya area, western Yunnan, China
Tertiary (3.78 Ma to 3.65 Ma) biotite-K-feldspar porphyritic bodies intrude Tertiary, poorly consolidated lacustrine sedimentary rocks in the Beiya mineral district in southwestern China. The intrusives are characterized by a microcrystalline and vitreous-cryptocrystalline groundmass, by replacement of some tabular K-feldspar phenocrysts with microcrystalline chlorite and calcite, and by...
Authors
Xing-Wang Xu, Xin-Ping Cai, Jia-You Zhong, Bao-Chang Song, Stephen G. Peters
Loess deposits, origins and properties Loess deposits, origins and properties
No abstract available.
Authors
D.R. Muhs
Ages of Quaternary Rio Grande terrace-fill deposits, Albuquerque area, New Mexico Ages of Quaternary Rio Grande terrace-fill deposits, Albuquerque area, New Mexico
Results from luminescence dating on 13 samples from the Albuquerque area show that major-drainage fluvial deposits represent significant periods of aggradation that formed paired, correlatable terraces on the east and west margins of the Rio Grande valley . The youngest terrace fills (Primero Alto) formed during late Pleistocene as a result of streamflow variations with climate cooling...
Authors
Shannon Mahan, Byron D. Stone, Ralph R. Shroba