Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2524
New fusulinids from Lower Permian turbidites at Conglomerate Mesa, southeastern inyo Mountains, east-central California New fusulinids from Lower Permian turbidites at Conglomerate Mesa, southeastern inyo Mountains, east-central California
Seven previously unrecognized fusulinid species from Lower Permian (Wolfcampian and Leonardian) turbidites near Conglomerate Mesa in east-central California, four of which are named as new species, are here described and figured. The four new species are Schwagerina merriami, S. wildei, Parafusulina mackevetti, and Skinnerella rossi. These fusulinid species have close affinities to...
Authors
C.H. Stevens, P. Stone
New Permian durhaminid cerioid corals from east-central California New Permian durhaminid cerioid corals from east-central California
Permian colonial corals from Artinskian to Kungurian strata in the Conglomerate Mesa area, Inyo Mountains, east-central California, include five new species, one of which is assigned to a new genus. The new taxa are: Malpaisia maceyi n. gen. and n. sp., Pararachnastraea bellula n. sp., P. delicata n. sp., P. owensensis n. sp., and Cordillerastraea inyoensis n. sp. These species, several...
Authors
C.H. Stevens, P. Stone
Past climate variability and change in the Arctic and at high latitudes Past climate variability and change in the Arctic and at high latitudes
Paleoclimate records play a key role in our understanding of Earth's past and present climate system and in our confidence in predicting future climate changes. Paleoclimate data help to elucidate past and present active mechanisms of climate change by placing the short instrumental record into a longer term context and by permitting models to be tested beyond the limited time that...
Authors
Richard B. Alley, Julie Brigham-Grette, Gifford H. Miller, Leonid Polyak
Instrumental record of debris flow initiation during natural rainfall: Implications for modeling slope stability Instrumental record of debris flow initiation during natural rainfall: Implications for modeling slope stability
The middle of a hillslope hollow in the Oregon Coast Range failed and mobilized as a debris flow during heavy rainfall in November 1996. Automated pressure transducers recorded high spatial variability of pore water pressure within the area that mobilized as a debris flow, which initiated where local upward flow from bedrock developed into overlying colluvium. Postfailure observations of...
Authors
D. R. Montgomery, K. M. Schmidt, W. E. Dietrich, J. McKean
Audiomagnetotelluric investigation of Snake Valley, eastern Nevada and western Utah Audiomagnetotelluric investigation of Snake Valley, eastern Nevada and western Utah
Audiomagnetotelluric (AMT) data along four profiles in western Snake Valley and the corresponding two-dimensional (2-D) inverse models reveal subsurface structures that may be significant to ground-water investigations in the area. The AMT method is a valuable tool for estimating the electrical resistivity of the earth over depth ranges from a few meters to less than one kilometer. The...
Authors
Darcy McPhee, Keith Pari, Frank Baird
Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia Effects of experimental protocol on global vegetation model accuracy: a comparison of simulated and observed vegetation patterns for Asia
Prognostic vegetation models have been widely used to study the interactions between environmental change and biological systems. This study examines the sensitivity of vegetation model simulations to: (i) the selection of input climatologies representing different time periods and their associated atmospheric CO2 concentrations, (ii) the choice of observed vegetation data for evaluating...
Authors
Guoping Tang, Sarah L. Shafer, Patrick J. Barlein, Justin O. Holman
Geophysical setting of western Utah and eastern Nevada between latitudes 37°45′ and 40°N Geophysical setting of western Utah and eastern Nevada between latitudes 37°45′ and 40°N
Gravity and aeromagnetic data refine the structural setting for the region of western Utah and eastern Nevada between Snake and Hamlin Valleys on the west and Tule Valley on the east. These data are used here as part of a regional analysis. An isostatic gravity map shows large areas underlain by gravity lows, the most prominent of which is a large semi-circular low associated with the...
Authors
Edward A. Mankinen, Edwin H. McKee
Hydrologic characterization of desert soils with varying degrees of pedogenesis: 1. field experiments evaluating plant-relevant soil water behavior Hydrologic characterization of desert soils with varying degrees of pedogenesis: 1. field experiments evaluating plant-relevant soil water behavior
To assess the eff ect of pedogenesis on the soil moisture dynamics infl uencing the character and quality of ecological habitat, we conducted infi ltration and redistribution experiments on three alluvial deposits in the Mojave National Preserve: (i) recently deposited active wash sediments, (ii) a soil of early Holocene age, and (iii) a highly developed soil of late Pleistocene age. At...
Authors
John R. Nimmo, Kim S. Perkins, Kevin M. Schmidt, David M. Miller, Jonathan D. Stock, Kamini Singha
New approaches to stability analysis of steep coastal bluffs New approaches to stability analysis of steep coastal bluffs
We present a discussion on the limitations and needed improvements for existing slope stability analysis methods to accurately model steep coastal bluff failures resulting from both direct wave action at the toe in weakly cemented sands and precipitation-induced seepage failures in moderately cemented sands. Using a case-study detailing over 5 years of observations of coastal bluff...
Authors
Brian D. Collins, Nicholas Sitar
Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary, northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits, and the nascent Colorado River Cenozoic evolution of the abrupt Colorado Plateau–Basin and Range boundary, northwest Arizona: A tale of three basins, immense lacustrine-evaporite deposits, and the nascent Colorado River
In northwest Arizona, the relatively unextended Colorado Plateau gives way abruptly to the highly extended Colorado River extensional corridor within the Basin and Range province along a system of major west-dipping normal faults, including the Grand Wash fault zone and South Virgin–White Hills detachment fault. Large growth-fault basins developed in the hanging walls of these faults...
Authors
J. E. Faulds, Keith A. Howard, E. M. Duebendorfer
Linking soil organic matter dynamics and erosion-induced terrestrial carbon sequestration at different landform positions Linking soil organic matter dynamics and erosion-induced terrestrial carbon sequestration at different landform positions
Recently, the potential for terrestrial carbon (C) sequestration by soil erosion and deposition has received increased interest. Erosion and deposition constitute a sink for atmospheric carbon dioxide relative to a preerosional state or a noneroding scenario, if the posterosion watershed C balance is increased due to (1) partial replacement of eroded C by new photosynthate in the eroded...
Authors
Asmeret Asefaw Berhe, Jennifer W. Harden, Margaret S. Torn, John Harte
Temporal Geochemistry Data from Five Springs in the Cement Creek Watershed, San Juan County, Colorado Temporal Geochemistry Data from Five Springs in the Cement Creek Watershed, San Juan County, Colorado
Temporal data from five springs in the Cement Creek watershed, San Juan County, Colorado provide seasonal geochemical data for further research in the formation of ferricretes. In addition, these data can be used to help understand the ground-water flow system. The resulting data demonstrate the difficulty in gathering reliable seasonal data from springs, show the unique geochemistry of...
Authors
Raymond H. Johnson, Laurie Wirt, Kenneth J. Leib