Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2494
A prominent geophysical feature along the northern Nevada rift and its geologic implications, north-central Nevada A prominent geophysical feature along the northern Nevada rift and its geologic implications, north-central Nevada
We consider the origin and character of a prominent large-scale geophysical feature in north-central Nevada that is coincident with the western margin of the northern Nevada rift—a mid-Miocene rift that includes mafic dike swarms and associated volcanic rocks expressed by a NNW-striking magnetic anomaly. The geophysical feature also correlates with mid-Miocene epithermal gold deposits...
Authors
David A. Ponce, Jonathan M.G. Glen
Large-magnitude Miocene extension of the Eocene Caetano caldera, Shoshone and Toiyabe Ranges, Nevada Large-magnitude Miocene extension of the Eocene Caetano caldera, Shoshone and Toiyabe Ranges, Nevada
Because major mineral deposits in north-central Nevada predate significant Basin and Range extension, a detailed understanding of the timing and kinematics of extensional faulting is necessary to place these deposits in their original structural context. The complexity of pre-Cenozoic deformation in northern Nevada makes restoring Basin and Range faulting difficult without locating well...
Authors
Joseph P. Colgan, David A. John, Christopher D. Henry, Robert J. Fleck
Analysis of a spatial point pattern: Examining the damage to pavement and pipes in Santa Clara Valley resulting from the Loma Prieta earthquake Analysis of a spatial point pattern: Examining the damage to pavement and pipes in Santa Clara Valley resulting from the Loma Prieta earthquake
This report describes some simple spatial statistical methods to explore the relationships of scattered points to geologic or other features, represented by points, lines, or areas. It also describes statistical methods to search for linear trends and clustered patterns within the scattered point data. Scattered points are often contained within irregularly shaped study areas...
Authors
G. A. Phelps
Geology: Chapter 2 Geology: Chapter 2
No abstract available.
Authors
Richard G. Stanley, G. E. Weber
Cyanide speciation at four gold leach operations undergoing remediation Cyanide speciation at four gold leach operations undergoing remediation
Analyses have been made of 81 effluents from four gold leach operations in various stages of remediation to identify the most-persistent cyanide species. Total cyanide and weak acid-dissociable (WAD) cyanide were measured using improved methods, and metals known to form stable cyanocomplexes were also measured. Typically, total cyanide greatly exceeded WAD indicating that cyanide was...
Authors
Craig A. Johnson, David J. Grimes, Reinhard W. Leinz, Robert O. Rye
Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d'Alene River, Idaho: Comparisons among chemical equilibrium models and implications for biotic ligand models Dissolved and labile concentrations of Cd, Cu, Pb, and Zn in the South Fork Coeur d'Alene River, Idaho: Comparisons among chemical equilibrium models and implications for biotic ligand models
In order to evaluate thermodynamic speciation calculations inherent in biotic ligand models, the speciation of dissolved Cd, Cu, Pb, and Zn in aquatic systems influenced by historical mining activities is examined using equilibrium computer models and the diffusive gradients in thin films (DGT) technique. Several metal/organic-matter complexation models, including WHAM VI, NICA-Donnan...
Authors
Laurie S. Balistrieri, R.G. Blank
Environmental factors affecting mercury in Camp Far West Reservoir, California, 2001-03 Environmental factors affecting mercury in Camp Far West Reservoir, California, 2001-03
This report documents water quality in Camp Far West Reservoir from October 2001 through August 2003. The reservoir, located at approximately 300 feet above sea level in the foothills of the northwestern Sierra Nevada, California, is a monomictic lake characterized by extreme drawdown in the late summer and fall. Thermal stratification in summer and fall is coupled with anoxic conditions...
Authors
Charles N. Alpers, A. Robin Stewart, Michael K. Saiki, Mark C. Marvin-DiPasquale, Brent R. Topping, Kelly M. Rider, Steven K. Gallanthine, Cynthia A. Kester, Robert O. Rye, Ronald C. Antweiler, John F. De Wild
Structures controlling geothermal circulation identified through gravity and magnetic transects, Surprise Valley, California, northwestern Great Basin Structures controlling geothermal circulation identified through gravity and magnetic transects, Surprise Valley, California, northwestern Great Basin
No abstract available.
Authors
Jonathan M.G. Glen, Anne E. Egger, David A. Ponce
Axial high topography and partial melt in the crust and mantle beneath the western Galápagos Spreading Center Axial high topography and partial melt in the crust and mantle beneath the western Galápagos Spreading Center
The hot spot-influenced western Galápagos Spreading Center (GSC) has an axial topographic high that reaches heights of ∼700 m relative to seafloor depth ∼25 km from the axis. We investigate the cause of the unusual size of the axial high using a model that determines the flexural response to loads resulting from the thermal and magmatic structure of the lithosphere. The thermal structure...
Authors
Tanya M. Blacic, Garrett Ito, Anjana K. Shah, Juan Pablo Canales, Jian Lin
Origin and paleoclimatic significance of late Quaternary loess in Nebraska: Evidence from stratigraphy, chronology, sedimentology, and geochemistry Origin and paleoclimatic significance of late Quaternary loess in Nebraska: Evidence from stratigraphy, chronology, sedimentology, and geochemistry
Loess is one of the most extensive surficial geologic deposits in midcontinental North America, particularly in the central Great Plains region of Nebraska. Last-glacial-age loess (Peoria Loess) reaches its greatest known thickness in the world in this area. New stratigraphic, geochronologic, mineralogic, and geochemical data yield information about the age and provenance of Peoria Loess...
Authors
Daniel R. Muhs, E. Arthur Bettis, John N. Aleinikoff, John P. McGeehin, Jossh Beann, Gary Skipp, Brian D. Marshall, Helen M. Roberts, William C. Johnson, Rachel Benton
Millimeter-scale geologic mapping using field spectroscopy techniques Millimeter-scale geologic mapping using field spectroscopy techniques
No abstract available.
Authors
David C. Buesch, Daniel E. Ragona, Mark C. Helmlinger