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Publications

Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center

Filter Total Items: 2354

Reevaluation of the Crooked Ridge River- Early Pleistocene (ca. 2 Ma) age and origin of the White Mesa Alluvium, northeastern Arizona

Essential features of the previously named and described Miocene Crooked Ridge River in northeastern Arizona (USA) are reexamined using new geologic and geochronologic data. Previously it was proposed that Cenozoic alluvium at Crooked Ridge and southern White Mesa was pre–early Miocene, the product of a large, vigorous late Paleogene river draining the 35–23 Ma San Juan Mountains volcanic field of
Authors
Richard Hereford, Sue Beard, William R. Dickinson, Karl E. Karlstrom, Matthew T. Heizler, Laura J. Crossey, Lee Amoroso, Kyle House, Mark Pecha

Seasonal changes in atmospheric noise levels and the annual variation in pigeon homing performance

Repeated releases of experienced homing pigeons from single sites were conducted between 1972 and 1974 near Cornell University in upstate New York and between 1982 and 1983 near the University of Pittsburgh in western Pennsylvania, USA. No annual variation in homing performance was observed at these sites in eastern North America, in contrast to results from a number of similar experiments in Euro
Authors
Jonathan T. Hagstrum, Hugh P. McIsaac, Douglas P. Drob

Making it and breaking it in the Midwest: Continental assembly and rifting from modeling of EarthScope magnetotelluric data

A three-dimensional lithospheric-scale resistivity model of the North American mid-continent has been estimated based upon EarthScope magnetotelluric data. Details of the resistivity model are discussed in relation to lithospheric sutures, defined primarily from aeromagnetic and geochronologic data, which record the southward growth of the Laurentian margin in the Proterozoic. The resistivity sign
Authors
Paul A. Bedrosian

Geologic map of the Morena Reservoir 7.5-minute quadrangle, San Diego County, California

IntroductionMapping in the Morena Reservoir 7.5-minute quadrangle began in 1980, when the Hauser Wilderness Area, which straddles the Morena Reservoir and Barrett Lake quadrangles, was mapped for the U.S. Forest Service. Mapping was completed in 1993–1994. The Morena Reservoir quadrangle contains part of a regional-scale Late Jurassic(?) to Early Cretaceous tectonic suture that coincides with the
Authors
Victoria R. Todd

Latest Miocene-earliest Pliocene evolution of the ancestral Rio Grande at the Española-San Luis Basin boundary, northern New Mexico

We use stratigraphic relations, paleoflow data, and 40Ar/39Ar dating to interpret net aggradation, punctuated by at least two minor incisional events, along part of the upper ancestral Rio Grande fluvial system between 5.5 and 4.5 Ma (in northern New Mexico). The studied fluvial deposits, which we informally call the Sandlin unit of the Santa Fe Group, overlie a structural high between the San Lui
Authors
Daniel J. Koning, Scott B. Aby, V. J. Grauch, Matthew J. Zimmerer

Geologic history of the Blackbird Co-Cu district in the Lemhi subbasin of the Belt-Purcell Basin

The Blackbird cobalt-copper (Co-Cu) district in the Salmon River Mountains of east-central Idaho occupies the central part of the Idaho cobalt belt—a northwest-elongate, 55-km-long belt of Co-Cu occurrences, hosted in grayish siliciclastic metasedimentary strata of the Lemhi subbasin (of the Mesoproterozoic Belt-Purcell Basin). The Blackbird district contains at least eight stratabound ore zones a
Authors
Arthur A. Bookstrom, Stephen E. Box, Pamela M. Cossette, Thomas P. Frost, Virginia Gillerman, George King, N. Alex Zirakparvar

Geology of the Greenwater Range, and the dawn of Death Valley, California—Field guide for the Death Valley Natural History Conference, 2013

Much has been written about the age and formation of Death Valley, but that is one—if not the last—chapter in the fascinating geologic history of this area. Igneous and sedimentary rocks in the Greenwater Range, one mountain range east of Death Valley, tell an earlier story that overlaps with the formation of Death Valley proper. This early story has been told by scientists who have studied these
Authors
J. P. Calzia, O.T. Rämö, Robert Jachens, Eugene Smith, Jeffrey Knott

Magnetotelluric investigation of the Vestfold Hills and Rauer Group, East Antarctica

The Vestfold Hills and Rauer Group in East Antarctica have contrasting Archean to Neoproterozoic geological histories and are believed to be juxtaposed along a suture zone that now lies beneath the Sørsdal Glacier. Exact location and age of this suture zone are unknown, as is its relationship to regional deformation associated with the amalgamation of East Gondwana. To image the suture zone, magne
Authors
Jared R. Peacock, Katherine Selway

User’s guide for GcClust—An R package for clustering of regional geochemical data

GcClust is a software package developed by the U.S. Geological Survey for statistical clustering of regional geochemical data, and similar data such as regional mineralogical data. Functions within the software package are written in the R statistical programming language. These functions, their documentation, and a copy of the user’s guide are bundled together in R’s unit of sharable code, which
Authors
Karl J. Ellefsen, David B. Smith

Simulation of groundwater storage changes in the eastern Pasco Basin, Washington

The Miocene Columbia River Basalt Group and younger sedimentary deposits of lacustrine, fluvial, eolian, and cataclysmic-flood origins compose the aquifer system of the Pasco Basin in eastern Washington. Irrigation return flow and canal leakage from the Columbia Basin Project have caused groundwater levels to rise substantially in some areas, contributing to landslides along the Columbia River. Wa
Authors
Charles E. Heywood, Sue C. Kahle, Theresa D. Olsen, James D. Patterson, Erick Burns

Improving the ecological relevance of toxicity tests on scleractinian corals: Influence of season, life stage, and seawater temperature

Metal pollutants in marine systems are broadly acknowledged as deleterious: however, very little data exist for tropical scleractinian corals. We address this gap by investigating how life-history stage, season and thermal stress influence the toxicity of copper (Cu) and lead (Pb) in the coral Pocillopora damicornis. Our results show that under ambient temperature, adults and larvae appear to tole
Authors
Laetitia Hedouin, Ruth E. Wolf, Jeff Phillips, Ruth D. Gates