Publications
Publications from the staff of the Geology, Minerals, Energy, and Geophysics Science Center
Filter Total Items: 2486
Geophysical framework of the northern San Francisco Bay region, California Geophysical framework of the northern San Francisco Bay region, California
We use geophysical data to examine the structural framework of the northern San Francisco Bay region, an area that hosts the northward continuation of the East Bay fault system. Although this fault system has accommodated ∼175 km of right-lateral offset since 12 Ma, how this offset is partitioned north of the bay is controversial and important for understanding where and how strain is...
Authors
Victoria E. Langenheim, Russell W. Graymer, Robert C. Jachens, Robert J. McLaughlin, D.L. Wagner, Donald S. Sweetkind
Rapid middle Miocene extension and unroofing of the southern Ruby Mountains, Nevada Rapid middle Miocene extension and unroofing of the southern Ruby Mountains, Nevada
Paleozoic rocks in the northern Ruby Mountains were metamorphosed during Mesozoic crustal shortening and Cenozoic magmatism, but equivalent strata in the southern Ruby Mountains were never buried deeper than stratigraphic depths prior to exhumation in the footwall of a west dipping brittle normal fault. In the southern Ruby Mountains, Miocene sedimentary rocks in the hanging wall of this...
Authors
Joseph P. Colgan, Keith A. Howard, Robert J. Fleck, Joseph L. Wooden
Marine tephrochronology of the Mt. Edgecumbe volcanic field, southeast Alaska, USA Marine tephrochronology of the Mt. Edgecumbe volcanic field, southeast Alaska, USA
The Mt. Edgecumbe Volcanic Field (MEVF), located on Kruzof Island near Sitka Sound in southeast Alaska, experienced a large multiple-stage eruption during the last glacial maximum (LGM)-Holocene transition that generated a regionally extensive series of compositionally similar rhyolite tephra horizons and a single well-dated dacite (MEd) tephra. Marine sediment cores collected from...
Authors
Jason A. Addison, James E. Beget, Thomas A. Ager, Bruce P. Finney
Calibration and filtering strategies for frequency domain electromagnetic data Calibration and filtering strategies for frequency domain electromagnetic data
echniques for processing frequency-domain electromagnetic (FDEM) data that address systematic instrument errors and random noise are presented, improving the ability to invert these data for meaningful earth models that can be quantitatively interpreted. A least-squares calibration method, originally developed for airborne electromagnetic datasets, is implemented for a ground-based...
Authors
Burke J. Minsley, Bruce D. Smith, Richard Hammack, James I. Sams, Garret Veloski
Depositional environments and cyclo- and chronostratigraphy of uppermost Carboniferous-Lower Triassic -lacustrine deposits, southern Bogda Mountains, NW China - A terrestrfluvialial paleoclimatic record of mid-latitude NE Pangea Depositional environments and cyclo- and chronostratigraphy of uppermost Carboniferous-Lower Triassic -lacustrine deposits, southern Bogda Mountains, NW China - A terrestrfluvialial paleoclimatic record of mid-latitude NE Pangea
Two uppermost Carboniferous–Lower Triassic fluvial–lacustrine sections in the Tarlong–Taodonggou half-graben, southern Bogda Mountains, NW China, comprise a 1834 m-thick, relatively complete sedimentary and paleoclimatic record of the east coast of mid-latitude NE Pangea. Depositional environmental interpretations identified three orders (high, intermediate, and low) of sedimentary...
Authors
W. Yang, Q. Feng, Yajing Liu, N. Tabor, D. Miggins, J.L. Crowley, J. Lin, S. Thomas
Using airborne geophysical surveys to improve groundwater resource management models Using airborne geophysical surveys to improve groundwater resource management models
Increasingly, groundwater management requires more accurate hydrogeologic frameworks for groundwater models. These complex issues have created the demand for innovative approaches to data collection. In complicated terrains, groundwater modelers benefit from continuous high‐resolution geologic maps and their related hydrogeologic‐parameter estimates. The USGS and its partners have...
Authors
Jared D. Abraham, James C. Cannia, Steven M. Peterson, Bruce D. Smith, Burke J. Minsley, Paul A. Bedrosian
History of the Greenland Ice Sheet: paleoclimatic insights History of the Greenland Ice Sheet: paleoclimatic insights
Paleoclimatic records show that the GreenlandIce Sheet consistently has lost mass in response to warming, and grown in response to cooling. Such changes have occurred even at times of slow or zero sea-level change, so changing sea level cannot have been the cause of at least some of the ice-sheet changes. In contrast, there are no documented major ice-sheet changes that occurred...
Authors
Richard B. Alley, John T. Andrews, J. Brigham-Grette, G.K.C. Clarke, Kurt M. Cuffey, J. J. Fitzpatrick, S. Funder, S.J. Marshall, G. H. Miller, J.X. Mitrovica, D.R. Muhs, B. L. Otto-Bliesner, L. Polyak, J.W.C. White
Time-averaged paleomagnetic field at the equator: Complete data and results from the Galapagos Islands, Ecuador Time-averaged paleomagnetic field at the equator: Complete data and results from the Galapagos Islands, Ecuador
We present here the complete paleomagnetic laboratory results from a collection of approximately 1500 oriented cores from all 16 of the Galapagos Islands, Ecuador, collected by Allan Cox in 1964–1965 but nearly all previously unpublished. The islands are located in the eastern Pacific Ocean within 1.4° of latitude from the equator and range in age from historically erupted to 3 Ma...
Authors
Sherman Gromme, Edward A. Mankinen, Michel Prevot
Beyond Colorado's Front Range - A new look at Laramide basin subsidence, sedimentation, and deformation in north-central Colorado Beyond Colorado's Front Range - A new look at Laramide basin subsidence, sedimentation, and deformation in north-central Colorado
This field trip highlights recent research into the Laramide uplift, erosion, and sedimentation on the western side of the northern Colorado Front Range. The Laramide history of the North Park-Middle Park basin (designated the Colorado Headwaters Basin in this paper) is distinctly different from that of the Denver basin on the eastern flank of the range. The Denver basin stratigraphy...
Authors
James C. Cole, James H. Trexler, Patricia H. Cashman, Ian M. Miller, Ralph R. Shroba, Michael A. Cosca, Jeremiah B. Workman
Geology of the Lake Mead region: An overview Geology of the Lake Mead region: An overview
The Lake Mead region contains major Miocene disruptions of structures formed during Mesozoic tectonic shortening. Erosion by the Colorado River and its tributaries has produced exceptional exposures of diverse structures and basin deposits recording the disruptions. Here we provide an overview of the results of studies of these features that started in earnest in 1934 when Chester...
Authors
R. Ernest Anderson, L. Sue Beard
Discussion on remote sensing for aquatic monitoring Discussion on remote sensing for aquatic monitoring
The special session on Remote Sensing for Aquatic Resource Monitoring concluded with an expert panel discussion. Panel members were Jennifer Bountry (hydraulic engineer, Bureau of Reclamation), Mimi D’Iorio (GIS analyst and database manager, National Oceanic and Atmospheric Administration), Russ Faux (president, Watershed Sciences, Inc.), Steve Lanigan (team leader, Aquatic and Riparian
Authors
Ralph A. Haugerud
First ever release of USGS offshore arctic resource assessment First ever release of USGS offshore arctic resource assessment
No abstract available.
Authors
Donald L. Gautier, Kenneth J. Bird, Ronald Charpentier, Arthur Grantz, David W. Houseknecht, Timothy R. Klett, Thomas E. Moore, Janet K. Pitman, Christopher J. Schenk, John H. Schuenemeyer, Kai Sorensen, Marilyn E. Tennyson