Publications
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Grand challenges for integrated USGS science — A workshop report
Executive SummaryThe U.S. Geological Survey (USGS) has a long history of advancing the traditional Earth science disciplines and identifying opportunities to integrate USGS science across disciplines to address complex societal problems. The USGS science strategy for 2007–2017 laid out key challenges in disciplinary and interdisciplinary arenas, culminating in a call for increased focus on a numbe
Authors
Karen E. Jenni, Martin B. Goldhaber, Julio L. Betancourt, Jill S. Baron, Sky Bristol, Mary Cantrill, Paul E. Exter, Michael J. Focazio, John W. Haines, Lauren E. Hay, Leslie Hsu, Victor F. Labson, Kevin D. Lafferty, K. A. Ludwig, Paul C. D. Milly, Toni L. Morelli, Suzette A. Morman, Nedal T. Nassar, Timothy R. Newman, Andrea C. Ostroff, Jordan S. Read, Sasha C. Reed, Carl D. Shapiro, Richard A. Smith, Ward E. Sanford, Terry L. Sohl, Edward G. Stets, Adam J. Terando, Donald E. Tillitt, Michael A. Tischler, Patricia L. Toccalino, David J. Wald, Mark P. Waldrop, Anne Wein, Jake F. Weltzin, Christian E. Zimmerman
The Neogene genus Streptochilus (Brönnimann and Resig, 1971) from the Gulf of California
Four species of the planktonic foraminiferal genus Streptochilus from key Neogene marine localities are documented in relation to the evolution of the Gulf of California: S. globigerus, S. latus, S. macdougallae sp. nov., and S. inglei sp. nov. Planktonic foraminiferal bioevents and strontium isotopes in the Bouse, Tirabuzón, Carmen and Ojo de Buey lithostratigraphic units constrain the local dist
Authors
A.Y. Miranda Martínez, A.L. Carreño, Kristin McDougall
Regional and temporal variability of melts during a Cordilleran magma pulse: Age and chemical evolution of the jurassic arc, eastern mojave desert, California
Intrusive rock sequences in the central and eastern Mojave Desert segment of the Jurassic Cordilleran arc of the western United States record regional and temporal variations in magmas generated during the second prominent pulse of Mesozoic continental arc magmatism. U/Pb zircon ages provide temporal control for describing variations in rock and zircon geochemistry that reflect differences in magm
Authors
A.P. Barth, J.L. Wooden, David M. Miller, Keith A. Howard, Lydia Fox, Elizabeth R. Schermer, C.E. Jacobson
Re-Os systematics and geochemistry of cobaltite (CoAsS) in the Idaho cobalt belt, Belt-Purcell Basin, USA: Evidence for middle Mesoproterozoic sediment-hosted Co-Cu sulfide mineralization with Grenvillian and Cretaceous remobilization
We report the first study of the Re-Os systematics of cobaltite (CoAsS) using disseminated grains and massive sulfides from samples of two breccia-type and two stratabound deposits in the Co-Cu-Au Idaho cobalt belt (ICB), Lemhi subbasin to the Belt-Purcell Basin, Idaho, USA. Using a 185Re + 190Os spike solution, magnetic and non-magnetic fractions of cobaltite mineral separates give reproducible R
Authors
N.J. Saintilan, R.A. Creaser, Arthur A. Bookstrom
Assessing changes in the physico-chemical properties and fluoride adsorption capacity of activated alumina under varied conditions
Adsorption using activated alumina is a simple method for removing fluoride from drinking water, but to be cost effective the adsorption capacity must be high and effective long-term. The intent of this study was to assess changes in its adsorption capacity under varied conditions. This was determined by evaluating the physico-chemical properties, surface charge, and fluoride (F−) adsorption capac
Authors
Laura Craig, Lisa L. Stillings, David L. Decker
Impacts to ecosystem services from aquatic acidification: Using FEGS-CS to understand the impacts of air pollution
Increases in anthropogenic emissions of sulfur (S) and nitrogen (N) have resulted in increases in the associated atmospheric deposition of acidic compounds. In sensitive watersheds, this deposition has initiated a cascade of negative environmental effects on aquatic ecosystems, resulting in a degradation or loss of valuable ecosystem goods and services. Here, we report the activities of an expert
Authors
Claire O'Dea, Sarah M. Anderson, Timothy Sullivan, Dixon H. Landers, C. Frank Casey
Cascadia subduction tremor muted by crustal faults
Deep, episodic slow slip on the Cascadia subduction megathrust of western North America is accompanied by low-frequency tremor in a zone of high fluid pressure between 30 and 40 km depth. Tremor density (tremor epicenters per square kilometer) varies along strike, and lower tremor density statistically correlates with upper plate faults that accommodate northward motion and rotation of forearc blo
Authors
Ray Wells, Richard J. Blakely, Aaron G. Wech, Patricia A. McCrory, Andrew Michael
By
Energy and Minerals Mission Area, Natural Hazards Mission Area, Earthquake Hazards Program, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Earthquake Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Subduction Zone Science
The Evergreen basin and the role of the Silver Creek fault in the San Andreas fault system, San Francisco Bay region, California
The Evergreen basin is a 40-km-long, 8-km-wide Cenozoic sedimentary basin that lies mostly concealed beneath the northeastern margin of the Santa Clara Valley near the south end of San Francisco Bay (California, USA). The basin is bounded on the northeast by the strike-slip Hayward fault and an approximately parallel subsurface fault that is structurally overlain by a set of west-verging reverse-o
Authors
Robert C. Jachens, Carl M. Wentworth, Russell W. Graymer, Robert Williams, David A. Ponce, Edward A. Mankinen, William J. Stephenson, Victoria E. Langenheim
Reconnaissance sedimentology of selected tertiary exposures in the upland region bordering the Yukon Flats basin, east-central Alaska
This report summarizes reconnaissance sedimentologic and stratigraphic observations made during six days of helicopter-supported fieldwork in 2002 on Tertiary sedimentary rocks exposed in the upland region around the flanks of the Yukon Flats basin in east-central Alaska (fig. 1). This project was a cooperative effort between the Alaska Division of Geological & Geophysical Surveys (DGGS) and the U
Authors
David L. LePain, Richard G. Stanley
Paleomagnetism and 40Ar/39Ar geochronology of the Plio-Pleistocene Boring Volcanic Field: Implications for the geomagnetic polarity time scale and paleosecular variation
Paleomagnetic directions and 40Ar/39Ar ages have been determined for samples of lava flows from the same outcrops, where possible, for 84 eruptive units ranging in age from 3200 ka to 60 ka within the Boring Volcanic Field (BVF) of the Pacific Northwest, USA. This study expands upon our previous results for the BVF, and compares the combined results with the current geomagnetic polarity time scale
Authors
Jonathan T. Hagstrum, Robert J. Fleck, Russell C. Evarts, Andrew T. Calvert
By
Energy and Minerals Mission Area, Natural Hazards Mission Area, Energy Resources Program, Geomagnetism Program, Mineral Resources Program, National Cooperative Geologic Mapping Program, National Laboratories Program, Science and Decisions Center, Volcano Hazards Program, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center
Geology of Seattle, a field trip
Seattle’s geologic record begins with Eocene deposition of fluvial arkosic sandstone and associated volcanic rocks of the Puget Group, perhaps during a time of regional strike-slip faulting, followed by late Eocene and Oligocene marine deposition of the Blakeley Formation in the Cascadia forearc. Older Quaternary deposits are locally exposed.Most of the city is underlain by up to 100 m of glacial
Authors
Ralph A. Haugerud, Kathy Goetz Troost, William T. Laprade
Lidar-Based Rock-Fall Hazard Characterization of Cliffs
Rock falls from cliffs and other steep slopes present numerous challenges for detailed geological characterization. In steep terrain, rock-fall source areas are both dangerous and difficult to access, severely limiting the ability to make detailed structural and volumetric measurements necessary for hazard assessment. Airborne and terrestrial lidar survey methods can provide high-resolution data n
Authors
Brian D. Collins, Greg M.Stock