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: 1913
IMWA 2013 mid-conference tour to Leadville, Colorado, August 7th, 2013 IMWA 2013 mid-conference tour to Leadville, Colorado, August 7th, 2013
An itinerary, maps, and details about the IMWA 2013 mid-conference tour from Golden, Colorado to Leadville, Colorado on August 7, 2013, are provided.
Authors
Raymond H. Johnson
Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium Low salinity hydrocarbon water disposal through deep subsurface drip irrigation: leaching of native selenium
A subsurface drip irrigation system is being used in Wyoming’s Powder River Basin that treats high sodium, low salinity, coal bed methane (CBM) produced water with sulfuric acid and injects it into cropped fields at a depth of 0.92 m. Dissolution of native gypsum releases calcium that combats soil degradation that would otherwise result from high sodium water. Native selenium is leached...
Authors
Carleton R. Bern, Mark A. Engle, Adam R. Boehlke, John W. Zupancic
Integrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska Integrated geophysical imaging of a concealed mineral deposit: a case study of the world-class Pebble porphyry deposit in southwestern Alaska
We combined aeromagnetic, induced polarization, magnetotelluric, and gravity surveys as well as drillhole geologic, alteration, magnetic susceptibility, and density data for exploration and characterization of the Cu-Au-Mo Pebble porphyry deposit. This undeveloped deposit is almost completely concealed by postmineralization sedimentary and volcanic rocks, presenting an exploration...
Authors
Anjana K. Shah, Paul A. Bedrosian, Eric D. Anderson, Karen D. Kelley, James Lang
U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada U–Pb, Rb–Sr, and U-series isotope geochemistry of rocks and fracture minerals from the Chalk River Laboratories site, Grenville Province, Ontario, Canada
As part of the Geologic Waste Management Facility feasibility study, Atomic Energy of Canada Ltd. (AECL) is evaluating the suitability of the Chalk River Laboratories (CRL) site in Ontario, situated in crystalline rock of the southwestern Grenville Province, for the possible development of an underground repository for low- and intermediate-level nuclear waste. This paper presents...
Authors
Leonid A. Neymark, Zell E. Peterman, Richard J. Moscati, R. H. Thivierge
Epidote from the Zard Mountains, Kharan, Balochistan, Pakistan Epidote from the Zard Mountains, Kharan, Balochistan, Pakistan
The authors received two unusual crystals of epidote from Rock Currier, Jewel Tunnel Imports, in 2012. The mineral specimens were collected at Zard Mountain (Zard Koh), in the central part of the Ruskoh Mountains (Rusk Koh), west of Kharan, Balochistan, Pakistan (written communication, Rock Currier, 2013). The epidote locality was most likely discovered in 2010. These epidote crystals...
Authors
Michael E. Brownfield, Heather Lowers, William K. Betterton
A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites A deposit model for magmatic iron-titanium-oxide deposits related to Proterozoic massif anorthosite plutonic suites
This descriptive model for magmatic iron-titanium-oxide (Fe-Ti-oxide) deposits hosted by Proterozoic age massif-type anorthosite and related rock types presents their geological, mineralogical, geochemical, and geoenvironmental attributes. Although these Proterozoic rocks are found worldwide, the majority of known deposits are found within exposed rocks of the Grenville Province...
Authors
Laurel G. Woodruff, Suzanne W. Nicholson, David L. Fey
Hybrid modeling of spatial continuity for application to numerical inverse problems Hybrid modeling of spatial continuity for application to numerical inverse problems
A novel two-step modeling approach is presented to obtain optimal starting values and geostatistical constraints for numerical inverse problems otherwise characterized by spatially-limited field data. First, a type of unsupervised neural network, called the self-organizing map (SOM), is trained to recognize nonlinear relations among environmental variables (covariates) occurring at...
Authors
Michael J. Friedel, Fabio Iwashita
Quantifying mineral abundances of complex mixtures by coupling spectral deconvolution of SWIR spectra (2.1-2.4 μm) and regression tree analysis Quantifying mineral abundances of complex mixtures by coupling spectral deconvolution of SWIR spectra (2.1-2.4 μm) and regression tree analysis
This paper presents a methodology for assessing mineral abundances of mixtures having more than two constituents using absorption features in the 2.1-2.4 μm wavelength region. In the first step, the absorption behaviour of mineral mixtures is parameterised by exponential Gaussian optimisation. Next, mineral abundances are predicted by regression tree analysis using these parameters as...
Authors
V.L. Mulder, Michael Plotze, Sytze de Bruin, Michael E. Schaepman, C. Mavris, Raymond F. Kokaly, Markus Egli
Advancements in understanding the aeromagnetic expressions of basin-margin faults—An example from San Luis Basin, Colorado Advancements in understanding the aeromagnetic expressions of basin-margin faults—An example from San Luis Basin, Colorado
Advancements in aeromagnetic acquisition technology over the past few decades have led to greater resolution of shallow geologic sources with low magnetization, such as intrasedimentary faults and paleochannels. Detection and mapping of intrasedimentary faults in particular can be important for understanding the overall structural setting of an area, even if exploration targets are much...
Authors
V. J. Grauch, Paul A. Bedrosian, Benjamin J. Drenth
Geologic occurrences of erionite in the United States: an emerging national public health concern for respiratory disease Geologic occurrences of erionite in the United States: an emerging national public health concern for respiratory disease
Erionite, a mineral series within the zeolite group, is classified as a Group 1 known respiratory carcinogen. This designation resulted from extremely high incidences of mesothelioma discovered in three small villages from the Cappadocia region of Turkey, where the disease was linked to environmental exposures to fibrous forms of erionite. Natural deposits of erionite, including fibrous...
Authors
Bradley S. Van Gosen, Thomas A. Blitz, Geoffrey S. Plumlee, Gregory P. Meeker, M. Patrick Pierson
Consequences of flight height and line spacing on airborne (helicopter) gravity gradient resolution in the Great Sand Dunes National Park and Preserve, Colorado Consequences of flight height and line spacing on airborne (helicopter) gravity gradient resolution in the Great Sand Dunes National Park and Preserve, Colorado
Line spacing and flight height are critical parameters in airborne gravity gradient surveys; the optimal trade-off between survey costs and desired resolution, however, is different for every situation. This article investigates the additional benefit of reducing the flight height and line spacing though a study of a survey conducted over the Great Sand Dunes National Park and Preserve...
Authors
M. Andy Kass
Implications for late Grenvillian (Rigolet phase) construction of Rodinia using new U-Pb data from the Mars Hill terrane, Tennessee and North Carolina, United States Implications for late Grenvillian (Rigolet phase) construction of Rodinia using new U-Pb data from the Mars Hill terrane, Tennessee and North Carolina, United States
New data for zircon (external morphology, cathodoluminescence zoning, and sensitive high resolution ion microprobe [SHRIMP] U-Pb ages) from the Carvers Gap granulite gneiss of the Mars Hill terrane (Tennessee and North Carolina, United States) require reevaluation of interpretations of the age and origin of this rock. The new results indicate that the zircon is detrital and that the...
Authors
John N. Aleinikoff, Scott Southworth, Arthur J. Merschat