Edward A du Bray (Former Employee)
Science and Products
Filter Total Items: 16
Maps and interpretation of geochemical anomalies in the John Muir Wilderness, Fresno, Inyo, Madera and Mono counties, California
A geochemical survey of the John Muir Wilderness was conducted by the U.S. Geological Survey between 1969 and 1978. The 755-mi2 (1,956-km2) wilderness is located in the central Sierra Nevada, Calif. (fig. 1). Stream-sediment samples were collected at 1,434 sites in the wilderness and immediately adjacent areas. Analytical data for these samples and a map of smapling sites are presented by du Bra
Geologic map of the Golden Trout Wilderness, southern Sierra Nevada, California
No abstract available.
Filter Total Items: 99
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, Bodie, A
Authors
Peter G. Vikre, David John, Edward A. du Bray, Robert J. Fleck
Geochemical, modal, and geochronologic data for 1.4 Ga A-type granitoid intrusions of the conterminous United States
Introduction
The purpose of this report is to present available geochemical, modal, and geochronologic data for approximately 1.4 billion year (Ga) A-type granitoid intrusions of the United States and to make those data available to ongoing petrogenetic investigations of these rocks. A-type granites, as originally defined by Loiselle and Wones (1979), are iron-enriched granitoids (synonymous with
Authors
Edward A. du Bray, Christopher S. Holm-Denoma, Carma A. San Juan, Karen Lund, Wayne R. Premo, Ed DeWitt
Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California
Many epithermal gold-silver deposits are temporally and spatially associated with late Oligocene to Pliocene magmatism of the southern ancestral Cascade arc in western Nevada and eastern California. These deposits, which include both quartz-adularia (low- and intermediate-sulfidation; Comstock Lode, Tonopah, Bodie) and quartz-alunite (high-sulfidation; Goldfield, Paradise Peak) types, were major p
Authors
David John, Edward A. du Bray, Christopher D. Henry, Peter G. Vikre
By
Energy and Minerals Mission Area, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center
Geochronology of Cenozoic rocks in the Bodie Hills, California and Nevada
The purpose of this report is to present geochronologic data for unaltered volcanic rocks, hydrothermally altered volcanic rocks, and mineral deposits of the Miocene Bodie Hills and Pliocene to Pleistocene Aurora volcanic fields of east-central California and west-central Nevada. Most of the data presented here were derived from samples collected between 2000–13, but some of the geochronologic dat
Authors
Robert J. Fleck, Edward A. du Bray, David John, Peter G. Vikre, Michael A. Cosca, Lawrence W. Snee, Stephen E. Box
Geochemical and petrographic data for intrusions peripheral to the Big Timber Stock, Crazy Mountains, Montana
The Paleocene Fort Union Formation hosts a compositionally diverse array of Eocene plugs, dikes, and sills arrayed around the Eocene Big Timber stock in the Crazy Mountains of south-central Montana. The geochemistry and petrography of the sills have not previously been characterized or interpreted. The purpose of this report is (1) to present available geochemical and petrographic data for several
Authors
Edward A. du Bray, Anna B. Wilson, Bradley S. Van Gosen
Geochemical and modal data for igneous rocks associated with epithermal mineral deposits
The purposes of this report are to (1) present available geochemical and modal data for igneous rocks associated with epithermal mineral deposits and (2) to make those data widely and readily available for subsequent, more in-depth consideration and interpretation. Epithermal precious and base-metal deposits are commonly associated with subduction-related calc-alkaline to alkaline arc magmatism as
Authors
Edward A. du Bray
Geochronology and correlation of Tertiary volcanic and intrusive rocks in part of the southern Toquima Range, Nye County, Nevada
Extensive volcanic and intrusive igneous activity, partly localized along regional structural zones, characterized the southern Toquima Range, Nevada, in the late Eocene, Oligocene, and Miocene. The general chronology of igneous activity has been defined previously. This major episode of Tertiary magmatism began with emplacement of a variety of intrusive rocks, followed by formation of nine major
Authors
Daniel R. Shawe, Lawrence W. Snee, Frank M. Byers, Edward A. du Bray
Petrologic, tectonic, and metallogenic evolution of the southern segment of the ancestral Cascades magmatic arc, California and Nevada
Ongoing arc magmatism along western North America was preceded by ancestral arc magmatism that began ca. 45 Ma and evolved into modern arc volcanism. The southern ancestral arc segment, active from ca. 30 to 3 Ma, adjoins the northern segment in northern California across a proposed subducted slab tear. The east edge of the Walker Lane approximates the east edge of the southern arc whose products,
Authors
Edward A. du Bray, David John, Brian L. Cousens
Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada
Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada
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This report presents petrographic and geochemical data for samples collected during investigations of Tertiary volcanism in the Bodie Hills of California and Nevada. Igneous rocks in the area are principally 15–6 Ma subduction-related volcanic rocks of the Bodie Hills volcanic
Authors
Edward A. du Bray, David John, Stephen E. Box, Peter G. Vikre, Robert J. Fleck, Brian L. Cousens
Synthesis of petrographic, geochemical, and isotopic data for the Boulder batholith, southwest Montana
The Late Cretaceous Boulder batholith in southwest Montana consists of the Butte Granite and a group of associated smaller intrusions emplaced into Mesoproterozoic to Mesozoic sedimentary rocks and into the Late Cretaceous Elkhorn Mountains Volcanics. The Boulder batholith is dominated by the voluminous Butte Granite, which is surrounded by as many as a dozen individually named, peripheral intrusi
Authors
Edward A. du Bray, John N. Aleinikoff, Karen Lund
Miocene magmatism in the Bodie Hills volcanic field, California and Nevada: A long-lived eruptive center in the southern segment of the ancestral Cascades arc
The Middle to Late Miocene Bodie Hills volcanic field is a >700 km2, long-lived (∼9 Ma) but episodic eruptive center in the southern segment of the ancestral Cascades arc north of Mono Lake (California, U.S.). It consists of ∼20 major eruptive units, including 4 trachyandesite stratovolcanoes emplaced along the margins of the field, and numerous, more centrally located silicic trachyandesite to rh
Authors
David John, Edward A. du Bray, Richard J. Blakely, Robert J. Fleck, Peter G. Vikre, Stephen E. Box, Barry C. Moring
Petrologic, tectonic, and metallogenic evolution of the Ancestral Cascades magmatic arc, Washington, Oregon, and northern California
Present-day High Cascades arc magmatism was preceded by ∼40 m.y. of nearly cospatial magmatism represented by the ancestral Cascades arc in Washington, Oregon, and northernmost California (United States). Time-space-composition relations for the ancestral Cascades arc have been synthesized from a recent compilation of more than 4000 geochemical analyses and associated age data. Neither the composi
Authors
Edward A. du Bray, David John
Science and Products
Filter Total Items: 16
Maps and interpretation of geochemical anomalies in the John Muir Wilderness, Fresno, Inyo, Madera and Mono counties, California
A geochemical survey of the John Muir Wilderness was conducted by the U.S. Geological Survey between 1969 and 1978. The 755-mi2 (1,956-km2) wilderness is located in the central Sierra Nevada, Calif. (fig. 1). Stream-sediment samples were collected at 1,434 sites in the wilderness and immediately adjacent areas. Analytical data for these samples and a map of smapling sites are presented by du Bra
Geologic map of the Golden Trout Wilderness, southern Sierra Nevada, California
No abstract available.
Filter Total Items: 99
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, Bodie, A
Authors
Peter G. Vikre, David John, Edward A. du Bray, Robert J. Fleck
Geochemical, modal, and geochronologic data for 1.4 Ga A-type granitoid intrusions of the conterminous United States
Introduction
The purpose of this report is to present available geochemical, modal, and geochronologic data for approximately 1.4 billion year (Ga) A-type granitoid intrusions of the United States and to make those data available to ongoing petrogenetic investigations of these rocks. A-type granites, as originally defined by Loiselle and Wones (1979), are iron-enriched granitoids (synonymous with
Authors
Edward A. du Bray, Christopher S. Holm-Denoma, Carma A. San Juan, Karen Lund, Wayne R. Premo, Ed DeWitt
Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California
Many epithermal gold-silver deposits are temporally and spatially associated with late Oligocene to Pliocene magmatism of the southern ancestral Cascade arc in western Nevada and eastern California. These deposits, which include both quartz-adularia (low- and intermediate-sulfidation; Comstock Lode, Tonopah, Bodie) and quartz-alunite (high-sulfidation; Goldfield, Paradise Peak) types, were major p
Authors
David John, Edward A. du Bray, Christopher D. Henry, Peter G. Vikre
By
Energy and Minerals Mission Area, Energy Resources Program, Groundwater and Streamflow Information Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center
Geochronology of Cenozoic rocks in the Bodie Hills, California and Nevada
The purpose of this report is to present geochronologic data for unaltered volcanic rocks, hydrothermally altered volcanic rocks, and mineral deposits of the Miocene Bodie Hills and Pliocene to Pleistocene Aurora volcanic fields of east-central California and west-central Nevada. Most of the data presented here were derived from samples collected between 2000–13, but some of the geochronologic dat
Authors
Robert J. Fleck, Edward A. du Bray, David John, Peter G. Vikre, Michael A. Cosca, Lawrence W. Snee, Stephen E. Box
Geochemical and petrographic data for intrusions peripheral to the Big Timber Stock, Crazy Mountains, Montana
The Paleocene Fort Union Formation hosts a compositionally diverse array of Eocene plugs, dikes, and sills arrayed around the Eocene Big Timber stock in the Crazy Mountains of south-central Montana. The geochemistry and petrography of the sills have not previously been characterized or interpreted. The purpose of this report is (1) to present available geochemical and petrographic data for several
Authors
Edward A. du Bray, Anna B. Wilson, Bradley S. Van Gosen
Geochemical and modal data for igneous rocks associated with epithermal mineral deposits
The purposes of this report are to (1) present available geochemical and modal data for igneous rocks associated with epithermal mineral deposits and (2) to make those data widely and readily available for subsequent, more in-depth consideration and interpretation. Epithermal precious and base-metal deposits are commonly associated with subduction-related calc-alkaline to alkaline arc magmatism as
Authors
Edward A. du Bray
Geochronology and correlation of Tertiary volcanic and intrusive rocks in part of the southern Toquima Range, Nye County, Nevada
Extensive volcanic and intrusive igneous activity, partly localized along regional structural zones, characterized the southern Toquima Range, Nevada, in the late Eocene, Oligocene, and Miocene. The general chronology of igneous activity has been defined previously. This major episode of Tertiary magmatism began with emplacement of a variety of intrusive rocks, followed by formation of nine major
Authors
Daniel R. Shawe, Lawrence W. Snee, Frank M. Byers, Edward A. du Bray
Petrologic, tectonic, and metallogenic evolution of the southern segment of the ancestral Cascades magmatic arc, California and Nevada
Ongoing arc magmatism along western North America was preceded by ancestral arc magmatism that began ca. 45 Ma and evolved into modern arc volcanism. The southern ancestral arc segment, active from ca. 30 to 3 Ma, adjoins the northern segment in northern California across a proposed subducted slab tear. The east edge of the Walker Lane approximates the east edge of the southern arc whose products,
Authors
Edward A. du Bray, David John, Brian L. Cousens
Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada
Petrographic and geochemical data for Cenozoic volcanic rocks of the Bodie Hills, California and Nevada
//
//
This report presents petrographic and geochemical data for samples collected during investigations of Tertiary volcanism in the Bodie Hills of California and Nevada. Igneous rocks in the area are principally 15–6 Ma subduction-related volcanic rocks of the Bodie Hills volcanic
Authors
Edward A. du Bray, David John, Stephen E. Box, Peter G. Vikre, Robert J. Fleck, Brian L. Cousens
Synthesis of petrographic, geochemical, and isotopic data for the Boulder batholith, southwest Montana
The Late Cretaceous Boulder batholith in southwest Montana consists of the Butte Granite and a group of associated smaller intrusions emplaced into Mesoproterozoic to Mesozoic sedimentary rocks and into the Late Cretaceous Elkhorn Mountains Volcanics. The Boulder batholith is dominated by the voluminous Butte Granite, which is surrounded by as many as a dozen individually named, peripheral intrusi
Authors
Edward A. du Bray, John N. Aleinikoff, Karen Lund
Miocene magmatism in the Bodie Hills volcanic field, California and Nevada: A long-lived eruptive center in the southern segment of the ancestral Cascades arc
The Middle to Late Miocene Bodie Hills volcanic field is a >700 km2, long-lived (∼9 Ma) but episodic eruptive center in the southern segment of the ancestral Cascades arc north of Mono Lake (California, U.S.). It consists of ∼20 major eruptive units, including 4 trachyandesite stratovolcanoes emplaced along the margins of the field, and numerous, more centrally located silicic trachyandesite to rh
Authors
David John, Edward A. du Bray, Richard J. Blakely, Robert J. Fleck, Peter G. Vikre, Stephen E. Box, Barry C. Moring
Petrologic, tectonic, and metallogenic evolution of the Ancestral Cascades magmatic arc, Washington, Oregon, and northern California
Present-day High Cascades arc magmatism was preceded by ∼40 m.y. of nearly cospatial magmatism represented by the ancestral Cascades arc in Washington, Oregon, and northernmost California (United States). Time-space-composition relations for the ancestral Cascades arc have been synthesized from a recent compilation of more than 4000 geochemical analyses and associated age data. Neither the composi
Authors
Edward A. du Bray, David John