Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2354
Identification of last interglacial deposits in eastern Beringia: a cautionary note from the Palisades, interior Alaska
Last interglacial sediments in unglaciated Alaska and Yukon (eastern Beringia) are commonly identified by palaeoecological indicators and stratigraphic position ~2-5m above the regionally prominent Old Crow tephra (124 + or - 10ka). We demonstrate that this approach can yield erroneous age assignments using data from a new exposure at the Palisades, a site in interior Alaska with numerous exposure
Authors
Alberto V. Reyes, Grant D. Zazula, Svetlana Kuzmina, Thomas A. Ager, Duane G. Froese
Physical, chemical, and mineralogical data from surficial deposits, groundwater levels, and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada
This report presents data and describes the methods used to determine the physical attributes, as well as the chemical and mineralogical composition of surficial deposits; groundwater levels; and water composition in the area of Franklin Lake playa and Ash Meadows, California and Nevada.
The results support studies that examine (1) the interaction between groundwater and the ground surface, and t
Authors
Harland L. Goldstein, George N. Breit, James C. Yount, Richard L. Reynolds, Marith C. Reheis, Gary L. Skipp, Eric M. Fisher, Paul J. Lamothe
Significance of zircon U-Pb ages from the Pescadero felsite, west-central California coast ranges
Weathered felsite is associated with the late Campanian–Maastrichtian Pigeon Point Formation near Pescadero, California. Poorly exposed, its age and correlation are uncertain. Is it part of the Pigeon Point section west of the San Gregorio–Hosgri fault? Does it rest on Nacimiento block basement? Is it dextrally offset from the Oligocene Cambria Felsite, ∼185 km to the southeast? Why is a calc-alka
Authors
Robert J. McLaughlin, Diane E. Moore, UWE C. Martens, J. C. Clark
Assessing open-system behavior of 14C in terrestrial gastropod shells
In order to assess open-system behavior of radiocarbon in fossil gastropod shells, we measured the 14C activity on 10 aliquots of shell material recovered from Illinoian (~190–130 ka) and pre-Illinoian (~800 ka) loess and lacustrine deposits in the Midwestern USA. Eight of the 10 aliquots yielded measurable 14C activities that ranged from 0.25 to 0.53 percent modern carbon (pMC), corresponding to
Authors
Jason A. Rech, Jeffrey S. Pigati, Sophie B. Lehmann, Chelsea N. McGimpsey, David A. Grimley, Jeffrey C. Nekola
Whole-rock and sulfide-mineral geochemical data for samples from volcanogenic massive sulfide deposits of the Bonnifield district, east-central Alaska
This Open-File Report presents geochemical data for outcrop and drill-core samples from volcanogenic massive sulfide deposits and associated metaigneous and metasedimentary rocks in the Wood River area of the Bonnifield mining district, northern Alaska Range, east-central Alaska. The data consist of major- and trace-element whole-rock geochemical analyses, and major- and trace-element analyses of
Authors
Cynthia Dusel-Bacon, John F. Slack, Alan E. Koenig, Nora K. Foley, Robert L. Oscarson, Kathleen D. Gans
Geology and geochemistry of volcanic centers within the eastern half of the Sonoma volcanic field, northern San Francisco Bay region, California
Volcanic rocks in the Sonoma volcanic field in the northern California Coast Ranges contain heterogeneous assemblages of a variety of compositionally diverse volcanic rocks. We have used field mapping, new and existing age determinations, and 343 new major and trace element analyses of whole-rock samples from lavas and tuff to define for the first time volcanic source areas for many parts of the S
Authors
Donald S. Sweetkind, James J. Rytuba, Victoria E. Langenheim, Robert J. Fleck
Computer programs for forward and inverse modeling of acoustic and electromagnetic data
A suite of computer programs was developed by U.S. Geological Survey personnel for forward and inverse modeling of acoustic and electromagnetic data. This report describes the computer resources that are needed to execute the programs, the installation of the programs, the program designs, some tests of their accuracy, and some suggested improvements.
Authors
Karl J. Ellefsen
Analytical results for municipal biosolids samples from a monitoring program near Deer Trail, Colorado (U.S.A.), 2010
Since late 1993, Metro Wastewater Reclamation District of Denver (Metro District), a large wastewater treatment plant in Denver, Colo., has applied Grade I, Class B biosolids to about 52,000 acres of nonirrigated farmland and rangeland near Deer Trail, Colo., U.S.A. In cooperation with the Metro District in 1993, the U.S. Geological Survey (USGS) began monitoring groundwater at part of this site.
Authors
J. G. Crock, D. B. Smith, T. J. B. Yager, C. J. Berry, M. G. Adams
A loess–paleosol record of climate and glacial history over the past two glacial–interglacial cycles (~ 150 ka), southern Jackson Hole, Wyoming
Loess accumulated on a Bull Lake outwash terrace of Marine Oxygen Isotope Stage 6 (MIS 6) age in southern Jackson Hole, Wyoming. The 9 m section displays eight intervals of loess deposition (Loess 1 to Loess 8, oldest), each followed by soil development. Our age-depth model is constrained by thermoluminescence, meteoric 10Be accumulation in soils, and cosmogenic 10Be surface exposure ages. We use
Authors
Kenneth L. Pierce, Daniel R. Muhs, Maynard A. Fosberg, Shannon A. Mahan, Joseph G. Rosenbaum, Joseph M. Licciardi, Milan J. Pavich
Seasonal dynamics of CO2 profiles across a soil chronosequence, Santa Cruz, California
Concentrations of CO2 in soil atmosphere and CO2 efflux were measured across a marine terrace soil chronosequence near Santa Cruz, California. Soil development, specifically the formation of an argillic horizon, has created a two-tier soil gas profile in the older terrace soils. The soil above the argillic horizon has seasonal variations in soil CO2 associated with plant respiration. The older soi
Authors
Marjorie S. Schulz, David A. Stonestrom, Guntram von Kiparski, Corey R. Lawrence, C.A. Masiello, Arthur F. White, John Fitzpatrick
Review of samples of water, sediment, tailings, and biota at the Little Bonanza mercury mine, San Luis Obispo County, California
Background and Objectives
The Little Bonanza mercury (Hg) mine, located in San Luis Obispo County, California, is a relatively small mine with, a historical total Hg production of about 1,000 flasks. The mine workings and tailings are located in the headwaters of the previously unnamed west fork of Las Tablas Creek (WF Las Tablas Creek), which flows into the Nacimiento Reservoir. Wasterock and ta
Authors
James J. Rytuba, Roger L. Hothem, Daniel N. Goldstein, Brianne E. Brussee, Jason T. May
Hydrologic conditions and terrestrial laser scanning of post-fire debris flows in the San Gabriel Mountains, CA, U.S.A.
To investigate rainfall-runoff conditions that generate post-wildfire debris flows, we instrumented and surveyed steep, small watersheds along the tectonically active front of the San Gabriel Mountains, California. Fortuitously, we recorded runoff-generated debris-flows triggered by one spatially restricted convective event with 28 mm of rainfall falling over 62 minutes. Our rain gages, nested hil
Authors
Kevin M. Schmidt, M. N. Hanshaw, James F. Howle, Jason W. Kean, Dennis M. Staley, Jonathan D. Stock, Gerald W. Bawden