Publications
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Architecture, geochemistry, and paleomagnetic directions of the 5.42 Ma Broadwell Mesa basalt volcanic field, Bristol Mountains, California
No abstract available.
Authors
David C. Buesch, Geoffrey Phelps
Accretionary lapilli: what’s holding them together?
Accretionary lapilli from Tagus cone, Isla Isabela, Galápagos were analyzed using scanning electron microscope (SEM) and energy-dispersive X-ray spectroscopy (EDS) techniques. Our main findings are (1) the lapilli formed and hardened in a few minutes while still aloft in the dispersing eruption column. (2) Palagonite rinds developed first on the basaltic glass clasts, and subsequently crystallized
Authors
Paul M. Adams, David K. Lynch, David C. Buesch
Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada
Zircon geochronology is a critical tool for establishing geologic ages and time scales of processes in the Earth's crust. However, for zircons compromised by open system behavior, achieving robust dates can be difficult. Chemical abrasion (CA) is a routine step prior to thermal ionization mass spectrometry (TIMS) dating of zircon to remove radiation-damaged parts of grains that may have experience
Authors
Kathryn E. Watts, Matthew A. Coble, Jorge A. Vazquez, Christopher D. Henry, Joseph Colgan, David John
By
Energy and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center
Geology and geologic history of the Moscow-Pullman basin, Idaho and Washington, from late Grande Ronde to late Saddle Mountains time
The Moscow-Pullman basin, located on the eastern margin of the Columbia River flood basalt province, consists of a subsurface mosaic of interlayered Miocene sediments and lava flows of the Imnaha, Grande Ronde, Wanapum, and Saddle Mountains Basalts of the Columbia River Basalt Group. This sequence is ~1800 ft (550 m) thick in the east around Moscow, Idaho, and exceeds 2300 ft (700 m) in the west a
Authors
John H Bush, Dean L Garwood, Pamela Dunlap
Gravity and magnetic studies of the eastern Mojave Desert, California and Nevada
IntroductionFrom May 2011 to August 2014, the U.S. Geological Survey (USGS) collected gravity data at more than 2,300 stations and physical property measurements on more than 640 rock samples from outcrops in the eastern Mojave Desert, California and Nevada. Gravity, magnetic, and physical-property data are used to study and locate regional crustal structures as an aid to understanding the geologi
Authors
Kevin M. Denton, David A. Ponce
Historical files from Federal Government mineral exploration-assistance programs, 1950 to 1974
The Defense Minerals Administration (DMA), Defense Minerals Exploration Administration (DMEA), and Office of Minerals Exploration (OME) mineral exploration programs were active over the period 1950–1974. Under these programs, the Federal Government contributed financial assistance in the exploration for certain strategic and critical minerals. The information about a mining property that was colle
Authors
David G. Frank
Surface slip during large Owens Valley earthquakes
The 1872 Owens Valley earthquake is the third largest known historical earthquake in California. Relatively sparse field data and a complex rupture trace, however, inhibited attempts to fully resolve the slip distribution and reconcile the total moment release. We present a new, comprehensive record of surface slip based on lidar and field investigation, documenting 162 new measurements of lateral
Authors
E.K. Haddon, C.B. Amos, O. Zielke, Angela S. Jayko, R. Burgmann
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
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
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