Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
Geology and geophysics applied to groundwater hydrology at Fort Irwin, California
Geologic and geophysical investigations in the vicinity of Fort Irwin National Training Center, California, have been completed in support of groundwater investigations, and are presented in eight chapters of this report. A generalized surficial geologic map along with field and borehole investigations conducted during 2010–11 provide a lithostratigraphic and structural framework for the area duri
Time-domain electromagnetic surveys at Fort Irwin, San Bernardino County, California, 2010–12
Between 2010 and 2012, a total of 79 time-domain electromagnetic (TEM) soundings were collected in 12 groundwater basins in the U.S. Army Fort Irwin National Training Center (NTC) study area to help improve the understanding of the hydrogeology of the NTC. The TEM data are discussed in this chapter in the context of geologic observations of the study area, the details of which are provided in the
Authors
Matthew K. Burgess, Paul A. Bedrosian
Hydrogeochemistry of prairie pothole region wetlands: Role of long-term critical zone processes
This study addresses the geologic and hydrogeochemical processes operating at a range of scales within the prairie pothole region (PPR). The PPR is a 750,000 km2portion of north central North America that hosts millions of small wetlands known to be critical habitat for waterfowl and other wildlife. At a local scale, we characterized the geochemical evolution of the 92-ha Cottonwood Lake study are
Authors
Martin B. Goldhaber, Christopher T. Mills, Jean Morrison, Craig A. Stricker, David M. Mushet, James W. LaBaugh
Airborne electromagnetic data and processing within Leach Lake Basin, Fort Irwin, California
From December 2010 to January 2011, the U.S. Geological Survey conducted airborne electromagnetic and magnetic surveys of Leach Lake Basin within the National Training Center, Fort Irwin, California. These data were collected to characterize the subsurface and provide information needed to understand and manage groundwater resources within Fort Irwin. A resistivity stratigraphy was developed using
Authors
Paul A. Bedrosian, Lyndsay B. Ball, Benjamin R. Bloss
Tectonic evolution of the Tualatin basin, northwest Oregon, as revealed by inversion of gravity data
The Tualatin basin, west of Portland (Oregon, USA), coincides with a 110 mGal gravity low along the Puget-Willamette lowland. New gravity measurements (n = 3000) reveal a three-dimensional (3-D) subsurface geometry suggesting early development as a fault-bounded pull-apart basin. A strong northwest-trending gravity gradient coincides with the Gales Creek fault, which forms the southwestern boundar
Authors
Darcy McPhee, Victoria E. Langenheim, Ray Wells, Richard J. Blakely
Geomorphic evidence for enhanced Pliocene-Quaternary faulting in the northwestern Basin and Range
Mountains in the U.S. Basin and Range Province are similar in form, yet they have different histories of deformation and uplift. Unfortunately, chronicling fault slip with techniques like thermochronology and geodetics can still leave sizable, yet potentially important gaps at Pliocene–Quaternary (∼105–106 yr) time scales. Here, we combine existing geochronology with new geomorphic observations an
Authors
Magdalena A Ellis, Barnes Jason B, Joseph Colgan
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
40Ar/39Ar geochronology, paleomagnetism, and evolution of the Boring volcanic field, Oregon and Washington, USA
The 40Ar/39Ar investigations of a large suite of fine-grained basaltic rocks of the Boring volcanic field (BVF), Oregon and Washington (USA), yielded two primary results. (1) Using age control from paleomagnetic polarity, stratigraphy, and available plateau ages, 40Ar/39Ar recoil model ages are defined that provide reliable age results in the absence of an age plateau, even in cases of significant
Authors
Robert J. Fleck, Jonathan T. Hagstrum, Andrew T. Calvert, Russell C. Evarts, Richard M. Conrey
By
Energy and Minerals Mission Area, Natural Hazards Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Volcano Hazards Program, Volcano Science Center, Geology, Minerals, Energy, and Geophysics Science Center
Geophysical framework of the Peninsular Ranges batholith—Implications for tectonic evolution and neotectonics
The crustal structure of the Peninsular Ranges batholith can be divided geophysically into two parts: (1) a western mafic part that is dense, magnetic, and characterized by relatively high seismic velocities (>6.25 km/s), low heat flow (<60 mW/m2), and relatively sparse seismicity, and (2) an eastern, more felsic part that is less dense, weakly magnetic, and characterized by lower seismic velociti
Authors
Victoria E. Langenheim, Robert C. Jachens, Carlos Aiken
Magmatism, ash-flow tuffs, and calderas of the ignimbrite flareup in the western Nevada volcanic field, Great Basin, USA
The western Nevada volcanic field is the western third of a belt of calderas through Nevada and western Utah. Twenty-three calderas and their caldera-forming tuffs are reasonably well identified in the western Nevada volcanic field, and the presence of at least another 14 areally extensive, apparently voluminous ash-flow tuffs whose sources are unknown suggests a similar number of undiscovered cal
Authors
Christopher D. Henry, David John
Trace metals in Saharan dust: The use of in vitro bioaccessibility extractions to assess potential health risks in a dustier world
Exposure to fine particulate matter (PM) is acknowledged as a risk factor for human morbidity and mortality. Epidemiology and toxicology studies have focused on anthropogenic sources of PM and few consider contributions produced by natural processes (geogenic), or PM produced from natural sources as a result of human activities (geoanthropogenic PM). The focus of this study was to elucidate relati
Authors
Suzette A. Morman, Virginia H. Garrison, Geoffrey S. Plumlee
Formation of a low-crystalline Zn-silicate in a stream in SW Sardinia, Italy
n southwestern Sardinia, Italy, the Rio Naracauli drains a catchment that includes several abandoned mines. The drainage from the mines and associated waste rocks has led to extreme concentrations of dissolved Zn, but because of the near-neutral pH, concentrations of other metals remain low. In the reach from approximately 2300 to 3000 m downstream from the headwaters area, an amorphous Zn-silicat
Authors
Richard B. Wanty, G. De Giudici, P. Onnis, D. Rutherford, B. A. Kimball, F. Podda, R. Cidu, P. Lattanzi, D. Medas
Contaminants from Cretaceous black shale: II. Effect of geology, weathering, climate, and land use on salinity and selenium cycling, Mancos Shale landscapes, southwestern United States
The Cretaceous Mancos Shale (MS) is a known nonpoint source for a significant portion of the salinity and selenium (Se) loads in the Colorado River in the southwestern United States and northwestern corner of Mexico. These two contaminants pose a serious threat to rivers in these arid regions where water supplies are especially critical. Tuttle et al. (companion paper) investigates the cycling of
Authors
Michele L. Tuttle, Juli W. Fahy, John G. Elliott, Richard I. Grauch, Lisa L. Stillings