Publications
Products (journal articles, reports, fact sheets) authored by current and past scientists are listed below. Please check the USGS Pubs Warehouse for other USGS publications.
Filter Total Items: 1826
Hells Canyon to the Bitterroot front: A transect from the accretionary margin eastward across the Idaho batholith
This field guide covers geology across north-central Idaho from the Snake River in the west across the Bitterroot Mountains to the east to near Missoula, Montana. The regional geology includes a much-modified Mesozoic accretionary boundary along the western side of Idaho across which allochthonous Permian to Cretaceous arc complexes of the Blue Mountains province to the west are juxtaposed against
Authors
Reed S. Lewis, Keegan L. Smith, Richard M. Gaschnig, Todd A. LaMaskin, Karen Lund, Keith D. Gray, Basil Tikoff, Tor Stetson-Lee, Nicholas Moore
Geochemistry of a marine phosphate deposit: A signpost to phosphogenesis
The Permian age Phosphoria Formation in southeastern Idaho and adjoining states represents possibly the largest marine phosphate deposit in the world. The Meade Peak Member, which contains the highest concentrations and amount of carbonate fluorapatite in the formation, was not significantly altered by mechanical reworking during deposition or subsequently by chemical weathering. Thus, its present
Authors
David Z. Piper, R.B. Perkins
Segmentation of plate coupling, fate of subduction fluids, and modes of arc magmatism in Cascadia, inferred from magnetotelluric resistivity
Five magnetotelluric (MT) profiles have been acquired across the Cascadia subduction system and transformed using 2-D and 3-D nonlinear inversion to yield electrical resistivity cross sections to depths of ∼200 km. Distinct changes in plate coupling, subduction fluid evolution, and modes of arc magmatism along the length of Cascadia are clearly expressed in the resistivity structure. Relatively hi
Authors
Philip E. Wannamaker, Rob L. Evans, Paul A. Bedrosian, Martyn J. Unsworth, Virginie Maris, R. Shane McGary
Multielevation calibration of frequency-domain electromagnetic data
Systematic calibration errors must be taken into account because they can substantially impact the accuracy of inverted subsurface resistivity models derived from frequency-domain electromagnetic data, resulting in potentially misleading interpretations. We have developed an approach that uses data acquired at multiple elevations over the same location to assess calibration errors. A significant a
Authors
Burke J. Minsley, M. Andy Kass, Greg Hodges, Bruce D. Smith
Science applications of a multispectral microscopic imager for the astrobiological exploration of Mars
Future astrobiological missions to Mars are likely to emphasize the use of rovers with in situ petrologic capabilities for selecting the best samples at a site for in situ analysis with onboard lab instruments or for caching for potential return to Earth. Such observations are central to an understanding of the potential for past habitable conditions at a site and for identifying samples most like
Authors
Jorge Nunez, Jack Farmer, R. Glenn Sellar, Gregg A. Swayze, Diana L. Blaney
Spectroscopy from Space
This chapter reviews detection of materials on solid and liquid (lakes and ocean) surfaces in the solar system using ultraviolet to infrared spectroscopy from space, or near space (high altitude aircraft on the Earth), or in the case of remote objects, earth-based and earth-orbiting telescopes. Point spectrometers and imaging spectrometers have been probing the surfaces of our solar system for dec
Authors
Roger N. Clark, Gregg A. Swayze, Robert R. Carlson, Will Grundy, Keith Noll
Mapping saltwater intrusion in the Biscayne Aquifer, Miami-Dade County, Florida using transient electromagnetic sounding
Saltwater intrusion in southern Florida poses a potential threat to the public drinking-water supply that is typically monitored using water samples and electromagnetic induction logs collected from a network of wells. Transient electromagnetic (TEM) soundings are a complementary addition to the monitoring program because of their ease of use, low cost, and ability to fill in data gaps between wel
Authors
David V. Fitterman
Petrology and chemistry of the Green Acres gabbro complex near Winchester, Riverside County, California
The Cretaceous Green Acres layered igneous complex, northeast of Winchester, California, is composed of a suite of olivine- and hornblende-bearing gabbros in the Peninsular Ranges batholith within the Perris tectonic block. A consistent mineral assemblage is observed throughout the complex, but there is considerable textural and modal heterogeneity. Both preclude a consistent set of principles bas
Authors
Byron R. Berger
13.3 – Stable Isotope Geochemistry of Mineral Deposits
In this chapter, the intent is to summarize the results of traditional stable isotope studies (mainly H, B, O, C, and S) that have greatly contributed to the understanding of ore-forming processes over the last 60 years and to provide an up-to-date assessment of the application of new nontraditional isotope systems (Fe, Cu, Zn, Se, Mo, Hg, and Tl).
Authors
W.C. Pat Shanks
Modeling the hydrogeophysical response of lake talik evolution
Geophysical methods provide valuable information about subsurface permafrost and its relation to dynamic hydrologic systems. Airborne electromagnetic data from interior Alaska are used to map the distribution of permafrost, geological features, surface water, and groundwater. To validate and gain further insight into these field datasets, we also explore the geophysical response to hydrologic simu
Authors
Burke J. Minsley, Tristan Wellman, Michelle Ann Walvoord, Andre Revil
The planning process
No abstract available.
Authors
Carol C. Russell, Kathleen S. Smith, Virginia T. McLemore