Robert J Fleck (Former Employee)
Science and Products
Filter Total Items: 43
Geologic map and database of the Chocolate Mountain Aerial Gunnery Range, Riverside and Imperial Counties, California Geologic map and database of the Chocolate Mountain Aerial Gunnery Range, Riverside and Imperial Counties, California
The northwest-trending Chocolate Mountains are situated along the northeastern margin of the southern Salton Trough. The Chocolate Mountain Aerial Gunnery Range occupies most of the 75-km-long part of the Chocolate Mountains that lies between Salt Creek to the north and California State Highway 78 to the south. Mapping studies in the Chocolate Mountains within the gunnery range are few...
Authors
Robert E. Powell, Robert J. Fleck, Pamela M. Cossette
Late Neogene–Quaternary tephrochronology, stratigraphy, and paleoclimate of Death Valley, California, USA Late Neogene–Quaternary tephrochronology, stratigraphy, and paleoclimate of Death Valley, California, USA
Sedimentary deposits in midlatitude continental basins often preserve a paleoclimate record complementary to marine-based records. However, deriving that paleoclimate record depends on having well-exposed deposits and establishing a sufficiently robust geochronology. After decades of research, we have been able to correlate 77 tephra beds exposed in multiple stratigraphic sections in the...
Authors
Jeffrey R. Knott, Michael N Machette, Elmira Wan, Ralph E. Klinger, Joseph C Liddicoat, Andrei M. Sarna-Wojcicki, Robert J. Fleck, Alan L. Deino, John W Geissman, Janet L. Slate, David Wahl, Brian P. Wernicke, Stephen G. Wells, John C. Tinsley, Jeffrey C Hathaway, Veva M. Weamer
Analysis of the age and paleomagnetic orientation of the Broadwell Mesa Basalt, Bristol Mountains, CA Analysis of the age and paleomagnetic orientation of the Broadwell Mesa Basalt, Bristol Mountains, CA
To add to the regional paleomagnetic data documenting block rotation in eastern California, we determined the age and paleomagnetic rotation of the Broadwell Mesa basalt, a basalt in the Bristol Mountains, CA as part of an effort to constrain the timing and rotation of blocks adjacent to the fault. The east-striking sinistral Broadwell Mesa fault cuts and separates the basalt into two...
Authors
Geoffrey Phelps, John Hillhouse, Robert J. Fleck, David M. Miller, David C. Buesch, Andrew J. Cyr, Kevin M. Schmidt
Paleomagnetism and 40Ar/39Ar geochronology of the Plio-Pleistocene Boring Volcanic Field: Implications for the geomagnetic polarity time scale and paleosecular variation Paleomagnetism and 40Ar/39Ar geochronology of the Plio-Pleistocene Boring Volcanic Field: Implications for the geomagnetic polarity time scale and paleosecular variation
Paleomagnetic directions and 40Ar/39Ar ages have been determined for samples of lava flows from the same outcrops, where possible, for 84 eruptive units ranging in age from 3200 ka to 60 ka within the Boring Volcanic Field (BVF) of the Pacific Northwest, USA. This study expands upon our previous results for the BVF, and compares the combined results with the current geomagnetic polarity...
Authors
Jonathan T. Hagstrum, Robert J. Fleck, Russell C. Evarts, Andrew T. Calvert
By
Geology, Energy, and Minerals Mission Area, Natural Hazards Mission Area, Energy Resources Program, Geomagnetism Program, Mineral Resources Program, National Cooperative Geologic Mapping Program, National Laboratories Program, Science and Decisions Center, Volcano Hazards Program, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center
Geologic and geophysical maps and volcanic history of the Kelton Pass SE and Monument Peak SW Quadrangles, Box Elder County, Utah Geologic and geophysical maps and volcanic history of the Kelton Pass SE and Monument Peak SW Quadrangles, Box Elder County, Utah
The Kelton Pass SE and Monument Peak SW 7.5' quadrangles are located in Box Elder County, northwestern Utah (figure 1; plate 1). The northern boundary of the map area is 8.5 miles (13.7 km) south of the Utah-Idaho border, and the southern boundary reaches the edge of mud flats at the north end of Great Salt Lake. Elevations range from 4218 feet (1286 m) along the mud flats to 5078 feet...
Authors
Tracey J. Felger, David M. Miller, Victoria E. Langenheim, Robert J. Fleck
Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada
The Bodie Hills is a ~40 by ~30 kilometer volcanic field that straddles the California-Nevada state boundary between Mono Lake and the East Walker River. Three precious metal mining districts and nine alteration zones are delineated in Tertiary-Quaternary volcanic and Mesozoic granitic and metamorphic rocks that comprise the volcanic field. Cumulative production from the mining districts...
Authors
Peter G. Vikre, David A. John, Edward A. du Bray, Robert J. Fleck
Science and Products
Filter Total Items: 43
Geologic map and database of the Chocolate Mountain Aerial Gunnery Range, Riverside and Imperial Counties, California Geologic map and database of the Chocolate Mountain Aerial Gunnery Range, Riverside and Imperial Counties, California
The northwest-trending Chocolate Mountains are situated along the northeastern margin of the southern Salton Trough. The Chocolate Mountain Aerial Gunnery Range occupies most of the 75-km-long part of the Chocolate Mountains that lies between Salt Creek to the north and California State Highway 78 to the south. Mapping studies in the Chocolate Mountains within the gunnery range are few...
Authors
Robert E. Powell, Robert J. Fleck, Pamela M. Cossette
Late Neogene–Quaternary tephrochronology, stratigraphy, and paleoclimate of Death Valley, California, USA Late Neogene–Quaternary tephrochronology, stratigraphy, and paleoclimate of Death Valley, California, USA
Sedimentary deposits in midlatitude continental basins often preserve a paleoclimate record complementary to marine-based records. However, deriving that paleoclimate record depends on having well-exposed deposits and establishing a sufficiently robust geochronology. After decades of research, we have been able to correlate 77 tephra beds exposed in multiple stratigraphic sections in the...
Authors
Jeffrey R. Knott, Michael N Machette, Elmira Wan, Ralph E. Klinger, Joseph C Liddicoat, Andrei M. Sarna-Wojcicki, Robert J. Fleck, Alan L. Deino, John W Geissman, Janet L. Slate, David Wahl, Brian P. Wernicke, Stephen G. Wells, John C. Tinsley, Jeffrey C Hathaway, Veva M. Weamer
Analysis of the age and paleomagnetic orientation of the Broadwell Mesa Basalt, Bristol Mountains, CA Analysis of the age and paleomagnetic orientation of the Broadwell Mesa Basalt, Bristol Mountains, CA
To add to the regional paleomagnetic data documenting block rotation in eastern California, we determined the age and paleomagnetic rotation of the Broadwell Mesa basalt, a basalt in the Bristol Mountains, CA as part of an effort to constrain the timing and rotation of blocks adjacent to the fault. The east-striking sinistral Broadwell Mesa fault cuts and separates the basalt into two...
Authors
Geoffrey Phelps, John Hillhouse, Robert J. Fleck, David M. Miller, David C. Buesch, Andrew J. Cyr, Kevin M. Schmidt
Paleomagnetism and 40Ar/39Ar geochronology of the Plio-Pleistocene Boring Volcanic Field: Implications for the geomagnetic polarity time scale and paleosecular variation Paleomagnetism and 40Ar/39Ar geochronology of the Plio-Pleistocene Boring Volcanic Field: Implications for the geomagnetic polarity time scale and paleosecular variation
Paleomagnetic directions and 40Ar/39Ar ages have been determined for samples of lava flows from the same outcrops, where possible, for 84 eruptive units ranging in age from 3200 ka to 60 ka within the Boring Volcanic Field (BVF) of the Pacific Northwest, USA. This study expands upon our previous results for the BVF, and compares the combined results with the current geomagnetic polarity...
Authors
Jonathan T. Hagstrum, Robert J. Fleck, Russell C. Evarts, Andrew T. Calvert
By
Geology, Energy, and Minerals Mission Area, Natural Hazards Mission Area, Energy Resources Program, Geomagnetism Program, Mineral Resources Program, National Cooperative Geologic Mapping Program, National Laboratories Program, Science and Decisions Center, Volcano Hazards Program, Geologic Hazards Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center, Volcano Science Center
Geologic and geophysical maps and volcanic history of the Kelton Pass SE and Monument Peak SW Quadrangles, Box Elder County, Utah Geologic and geophysical maps and volcanic history of the Kelton Pass SE and Monument Peak SW Quadrangles, Box Elder County, Utah
The Kelton Pass SE and Monument Peak SW 7.5' quadrangles are located in Box Elder County, northwestern Utah (figure 1; plate 1). The northern boundary of the map area is 8.5 miles (13.7 km) south of the Utah-Idaho border, and the southern boundary reaches the edge of mud flats at the north end of Great Salt Lake. Elevations range from 4218 feet (1286 m) along the mud flats to 5078 feet...
Authors
Tracey J. Felger, David M. Miller, Victoria E. Langenheim, Robert J. Fleck
Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada Gold-silver mining districts, alteration zones, and paleolandforms in the Miocene Bodie Hills Volcanic Field, California and Nevada
The Bodie Hills is a ~40 by ~30 kilometer volcanic field that straddles the California-Nevada state boundary between Mono Lake and the East Walker River. Three precious metal mining districts and nine alteration zones are delineated in Tertiary-Quaternary volcanic and Mesozoic granitic and metamorphic rocks that comprise the volcanic field. Cumulative production from the mining districts...
Authors
Peter G. Vikre, David A. John, Edward A. du Bray, Robert J. Fleck
*Disclaimer: Listing outside positions with professional scientific organizations on this Staff Profile are for informational purposes only and do not constitute an endorsement of those professional scientific organizations or their activities by the USGS, Department of the Interior, or U.S. Government