David A John
David is a Scientist Emeritus with the Geology, Minerals, Energy, and Geophysics Science Center
Science and Products
Magmatic-Tectonic History and Component Sources of Major Precious Metal Deposits in the Tonopah, Goldfield, and Comstock Lode Districts, NV
Project objectives are refinement of stratigraphy, structure, and magmatic-hydrothermal evolution of the Tonopah, Goldfield, and Comstock Lode districts, and determination of the sources of hydrothermal mineral components. Results are expected to include refined geologic and tectonic maps of important districts in the Walker Lane, reduced uncertainty in sources of elements in ore deposits...
Digital geospatial database for the Geologic map of the southern Stillwater Range, Nevada
This data set is a geospatial database for the 1:24,000 scale Geologic Map of the Southern Stillwater Range, Nevada (John and others, 2024). It contains all the geologic spatial information and text unit descriptions from the printed map, in the Geologic Map Schema (GeMS) format for digital geologic maps maintained by the USGS’ National Cooperative Geologic Mapping Program (NCMGP). Base...
Geochemical data for the Thunder Mountain volcanic field and dikes in the Stibnite-Yellow Pine district region
This dataset contains whole rock geochemical data for volcanic rocks, both extrusive rocks of the western part of the Thunder Mountain volcanic field and hypabyssal dikes in the Stibnite-Yellow Pine district and in the Pistol Creek dike swarm, which are in central Idaho. Major oxides and trace elements are included, which are reported as percentages and parts per million, respectively...
Zircon U-Pb age and trace element data for igneous rocks in the Cortez area, Nevada
The Cortez region in north-central Nevada hosts the second largest concentration of Carlin-type gold deposits in Nevada. The origin of these deposits is debated, and major questions remain concerning the role of magmatism in their formation. To understand the Mesozoic and Cenozoic magmatic history of the Cortez region, twenty-one samples of igneous rocks ranging from Jurassic to Eocene...
Geochemical and geochronologic data from the Stillwater Range, Clan Alpine, and Desatoya Mountains, Nevada (ver. 3.0, December 2023)
This dataset contains argon-argon and U-Pb geochronologic data collected from igneous rocks in the Stillwater Range, Clan Alpine, and Desatoya Mountains, western Nevada, USA.
Data to accompany U.S. Geological Survey Data Series 1099: Petrographic, geochemical and geochronologic data for Cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
This dataset is the assembled analytical results of geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada. Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during...
Geochemical and Geochronological Data for Hydrothermal Systems on Brokeoff Volcano and in the Maidu Volcanic Center, Lassen Peak area, northeastern California
This dataset contains 8 data tables provided in csv format that contain sample location data, whole-rock geochemical data, argon-argon geochronologic data, sulfur, oxygen, and hydrogen isotope data, and mineralogical data from shortwave infrared spectrography (SWIR) and X-ray diffraction (XRD) analyses collected from igneous rocks on Brokeoff and Maidu volcanoes, northeastern California...
GIS and Data Tables for Focus Areas for Potential Domestic Nonfuel Sources of Rare Earth Elements
In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.). Acquiring information on possible domestic sources of these critical minerals is the basis of the USGS...
Locatable Mineral Assessment Tracts for the U.S. Geological Survey Sagebrush Mineral Resource Assessment Project
The polygon (vector) feature class represents locatable mineral resource assessment tracts (tracts of land) associated with the Department of the Interior (DOI) Sagebrush Focal Areas in Montana, Wyoming and Utah, central Idaho, and the Oregon-Nevada-Idaho border area. The mineral resources tracts are geographic areas that were assessed by the U.S. Geological Survey (USGS) and were...
Geologic map of the southern Stillwater Range, Nevada
The southern Stillwater Range in west-central Nevada contains the western part of the Oligocene Stillwater-Clan Alpine caldera complex, which extends about 55 kilometers (km) east from the west side of the Stillwater Range to the northwestern Desatoya Mountains. The complex consists of at least seven nested ignimbrite calderas and subjacent plutonic rocks emplaced into a complex basement...
Geologic map of the Bodie Hills, California and Nevada
The Bodie Hills covers about 1,200 km2 straddling the California-Nevada state boundary just north of Mono Lake in the western part of the Basin and Range Province, about 20 km east of the central Sierra Nevada. The area is mostly underlain by the partly overlapping, middle to late Miocene Bodie Hills volcanic field and Pliocene to late Pleistocene Aurora volcanic field (John and others...
Geologic map of the Caetano caldera, Lander and Eureka counties, Nevada
The Eocene (34 Ma) Caetano caldera in north-central Nevada offers an exceptional opportunity to study the physical and petrogenetic evolution of a large (20 km by 10–18 km pre-extensional dimensions) silicic magma chamber, from precursor magmatism to caldera collapse and intrusion of resurgent plutons. Caldera-related rocks shown on this map include two units of crystal-rich intracaldera...
Geologic Map of the Izzenhood Spring Quadrangle, Lander County, Nevada
The Izzenhood Spring quadrangle covers about 145 km2 of the southwestern part of the Sheep Creek Range in northern Lander County, Nevada. The quadrangle is underlain by Lower Paleozoic rocks that are unconformably overlain and intruded by thick sequences of Miocene igneous rocks related to the northern Nevada rift (Stewart and McKee, 1977; Wallace and John, 1998; John and others, 2000)...
Geologic map of the Freel Peak 15-minute Quadrangle, California and Nevada
No abstract available.
Filter Total Items: 58
Critical minerals in subduction-related magmatic-hydrothermal systems of the United States
During the World War and Cold War eras (1910s–1990s), domestic consumption of numerous mineral commodities relied increasingly on imported supplies. Consumption reliance has since expanded to include 50 “critical minerals” (elements and mineral commodities) that are mostly to entirely imported and subject to curtailment by suppliers or supply chain disruption. New domestic supplies of...
Authors
Peter Vikre, David A. John, Niki E. Wintzer, Fleetwood R. Koutz, Frederick Graybeal, Chris Dail, David C. Annis
Timing of rhyolite intrusion and Carlin-type gold mineralization at the Cortez Hills Carlin-type deposit, Nevada, USA
Carlin-type gold deposits (CTDs) of Nevada are the largest producers of gold in the United States, a leader in world gold production. Although much has been resolved about the characteristics and origin of CTDs in Nevada, major questions remain, especially about (1) the role of magmatism, whether only a source of heat or also metals, (2) whether CTDs only formed in the Eocene, and (3)...
Authors
Christopher S. Henry, David A. John, Robert W. Leonardson, William T McIntosh, Matt T. Heizler, Joseph P. Colgan, Kathryn E. Watts
Porphyry and epithermal mineral deposits
Porphyry and epithermal mineral deposits form large economic ore bodies that provide the global economy with copper, molybdenum, gold, silver and other byproducts (Re, Te, Se). They form in the upper crust and are related to sulfur- and water-rich intermediate to silicic magmatic sources of hydrothermal fluids that move upward and produce extensive hydrolytic and alkali wall-rock...
Authors
John H. Dilles, David A. John
Why did Great Basin Eocene magmatism generate Carlin-type gold deposits when extensive Jurassic to Middle Miocene magmatism did not? Lessons from the Cortez Region, Northern Nevada, USA
No abstract available.
Authors
Christopher S. Henry, David A. John, Matt T. Heizler, Robert W. Leonardson, Joseph P. Colgan, Kathryn E. Watts, Michael W. Ressel, Brian L. Cousens
Characterization of the rhyolite of Bodie Hills and 40Ar/39Ar intercalibration with Ar mineral standards
The rhyolite of Bodie Hills (California) is characterized compositionally and the geochronology of selected phases is studied. Sanidine (BHs) from the rhyolite is well suited as a 40Ar/39Ar reference material with high K/Ca and radiogenic yield. Intercalibration with GA1550 biotite from the Dromedary igneous complex (New South Wales, Australia) yields an age of 9.7946 ± 0.0031 Ma for BHs...
Authors
Robert J. Fleck, Andrew T. Calvert, Matthew Coble, Joseph L. Wooden, Kip V. Hodges, Leslie A. Hayden, Matthijs C. van Soest, Edward A. du Bray, David A. John
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada
Miocene calc-alkaline volcanic rocks, part of the southern segment of the ancestral Cascades magmatic arc, are spatially, temporally, and likely genetically associated with precious metal epithermal deposits in the Tonopah, Divide, and Goldfield Districts of west-central Nevada. In the Tonopah mining district, volcanic rocks include the Mizpah Trachyte, Fraction Tuff, and Oddie Rhyolite...
Authors
Edward A. du Bray, David A. John, Joseph P. Colgan, Peter Vikre, Michael A. Cosca, Leah E. Morgan
Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
The purpose of this report is to summarize geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada (fig. 1). Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during...
Authors
Edward A. du Bray, David A. John, Peter Vikre, Joseph P. Colgan, Michael A. Cosca, Leah E. Morgan, Robert J. Fleck, Wayne R. Premo, Christopher S. Holm-Denoma
Pleistocene hydrothermal activity on Brokeoff volcano and in the Maidu volcanic center, Lassen Peak area, northeast California: Evolution of magmatic-hydrothermal systems on stratovolcanoes
Partially eroded stratovolcanoes worldwide, notably Mounts Rainier and Adams in the Cascades and several volcanoes in Japan, record episodic periods of eruption and geothermal activity that produce zones of hydrothermal alteration. The partly eroded core of late Pleistocene Brokeoff volcano on the south side of Lassen Peak exposes the upper 1 km of multiple ancient (ca. 410–300 ka)...
Authors
David A. John, Robert G. Lee, George N. Breit, John H. Dilles, Andrew T. Calvert, L.J. Patrick Muffler, Michael A. Clynne
Igneous rocks in the Fish Creek Mountains and environs, Battle Mountain area, north-central Nevada: A microcosm of Cenozoic igneous activity in the northern Great Basin, Basin and Range Province, USA
The Great Basin of the western United States, the northern component of the Basin and Range Province, is a region of Cenozoic lithospheric extension with multiple periods and types of igneous activity. The composition and volume of Cenozoic magmas reflect a complex interaction between mantle-derived magmas and highly diverse crust, where both mantle sources and magmatic processes were...
Authors
Brian L. Cousens, Christopher S. Henry, Christopher Stevens, Susan Varve, David A. John, Stacey Wetmore
Oxygen isotopic investigation of silicic magmatism in the Stillwater caldera complex, Nevada: Generation of large-volume, low-δ18O rhyolitic tuffs and assessment of their regional context in the Great Basin of the western United States
Successive caldera-forming eruptions from ca. 30 to 25 Ma generated a large nested caldera complex in western Nevada that was subsequently dissected by Basin and Range extension, providing extraordinary cross-sectional views through diverse volcanic and plutonic rocks. A high-resolution oxygen isotopic study was conducted on units that represent all major parts of the Job Canyon...
Authors
Kathryn E. Watts, David A. John, Joseph P. Colgan, Christopher S. Henry, Ilya N. Bindeman, John W. Valley
The Miocene Atastra Creek sinter (Bodie Hills volcanic field, California and Nevada): 4D evolution of a geomorphically intact siliceous hot spring deposit
The Atastra Creek siliceous hot spring deposit, or sinter, occurs in the Paramount-Bald Peak alteration zone, due north of the Bodie precious metals mining district in the Miocene Bodie Hills volcanic field, California and Nevada, U.S.A. Distinctive features include its geomorphically intact geyser vent mounds, the presence of growth-fault-stepped sinter terraces that developed westward...
Authors
Kathleen A. Campbell, Diego M. Guido, David A. John, Peter Vikre, David Rhys, Ayrton Hamilton
Descriptive models for epithermal gold-silver deposits
Epithermal gold-silver deposits are vein, stockwork, disseminated, and replacement deposits that are mined primarily for their gold and silver contents; some deposits also contain substantial resources of lead, zinc, copper, and (or) mercury. These deposits form in the uppermost parts of the crust, at depths less than about 1,500 meters below the water table, and at temperatures below...
Authors
David A. John, Peter Vikre, Edward A. du Bray, Richard J. Blakely, David L. Fey, Barnaby W. Rockwell, Jeffrey L. Mauk, Eric D. Anderson, Frederick Graybeal
By
Ecosystems Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Western Fisheries Research Center, Central Energy Resources Science Center
Science and Products
Magmatic-Tectonic History and Component Sources of Major Precious Metal Deposits in the Tonopah, Goldfield, and Comstock Lode Districts, NV
Project objectives are refinement of stratigraphy, structure, and magmatic-hydrothermal evolution of the Tonopah, Goldfield, and Comstock Lode districts, and determination of the sources of hydrothermal mineral components. Results are expected to include refined geologic and tectonic maps of important districts in the Walker Lane, reduced uncertainty in sources of elements in ore deposits...
Digital geospatial database for the Geologic map of the southern Stillwater Range, Nevada
This data set is a geospatial database for the 1:24,000 scale Geologic Map of the Southern Stillwater Range, Nevada (John and others, 2024). It contains all the geologic spatial information and text unit descriptions from the printed map, in the Geologic Map Schema (GeMS) format for digital geologic maps maintained by the USGS’ National Cooperative Geologic Mapping Program (NCMGP). Base...
Geochemical data for the Thunder Mountain volcanic field and dikes in the Stibnite-Yellow Pine district region
This dataset contains whole rock geochemical data for volcanic rocks, both extrusive rocks of the western part of the Thunder Mountain volcanic field and hypabyssal dikes in the Stibnite-Yellow Pine district and in the Pistol Creek dike swarm, which are in central Idaho. Major oxides and trace elements are included, which are reported as percentages and parts per million, respectively...
Zircon U-Pb age and trace element data for igneous rocks in the Cortez area, Nevada
The Cortez region in north-central Nevada hosts the second largest concentration of Carlin-type gold deposits in Nevada. The origin of these deposits is debated, and major questions remain concerning the role of magmatism in their formation. To understand the Mesozoic and Cenozoic magmatic history of the Cortez region, twenty-one samples of igneous rocks ranging from Jurassic to Eocene...
Geochemical and geochronologic data from the Stillwater Range, Clan Alpine, and Desatoya Mountains, Nevada (ver. 3.0, December 2023)
This dataset contains argon-argon and U-Pb geochronologic data collected from igneous rocks in the Stillwater Range, Clan Alpine, and Desatoya Mountains, western Nevada, USA.
Data to accompany U.S. Geological Survey Data Series 1099: Petrographic, geochemical and geochronologic data for Cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
This dataset is the assembled analytical results of geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada. Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during...
Geochemical and Geochronological Data for Hydrothermal Systems on Brokeoff Volcano and in the Maidu Volcanic Center, Lassen Peak area, northeastern California
This dataset contains 8 data tables provided in csv format that contain sample location data, whole-rock geochemical data, argon-argon geochronologic data, sulfur, oxygen, and hydrogen isotope data, and mineralogical data from shortwave infrared spectrography (SWIR) and X-ray diffraction (XRD) analyses collected from igneous rocks on Brokeoff and Maidu volcanoes, northeastern California...
GIS and Data Tables for Focus Areas for Potential Domestic Nonfuel Sources of Rare Earth Elements
In response to Executive Order 13817 of December 20, 2017, the U.S. Geological Survey (USGS) coordinated with the Bureau of Land Management (BLM) to identify 35 nonfuel minerals or mineral materials considered critical to the economic and national security of the United States (U.S.). Acquiring information on possible domestic sources of these critical minerals is the basis of the USGS...
Locatable Mineral Assessment Tracts for the U.S. Geological Survey Sagebrush Mineral Resource Assessment Project
The polygon (vector) feature class represents locatable mineral resource assessment tracts (tracts of land) associated with the Department of the Interior (DOI) Sagebrush Focal Areas in Montana, Wyoming and Utah, central Idaho, and the Oregon-Nevada-Idaho border area. The mineral resources tracts are geographic areas that were assessed by the U.S. Geological Survey (USGS) and were...
Geologic map of the southern Stillwater Range, Nevada
The southern Stillwater Range in west-central Nevada contains the western part of the Oligocene Stillwater-Clan Alpine caldera complex, which extends about 55 kilometers (km) east from the west side of the Stillwater Range to the northwestern Desatoya Mountains. The complex consists of at least seven nested ignimbrite calderas and subjacent plutonic rocks emplaced into a complex basement...
Geologic map of the Bodie Hills, California and Nevada
The Bodie Hills covers about 1,200 km2 straddling the California-Nevada state boundary just north of Mono Lake in the western part of the Basin and Range Province, about 20 km east of the central Sierra Nevada. The area is mostly underlain by the partly overlapping, middle to late Miocene Bodie Hills volcanic field and Pliocene to late Pleistocene Aurora volcanic field (John and others...
Geologic map of the Caetano caldera, Lander and Eureka counties, Nevada
The Eocene (34 Ma) Caetano caldera in north-central Nevada offers an exceptional opportunity to study the physical and petrogenetic evolution of a large (20 km by 10–18 km pre-extensional dimensions) silicic magma chamber, from precursor magmatism to caldera collapse and intrusion of resurgent plutons. Caldera-related rocks shown on this map include two units of crystal-rich intracaldera...
Geologic Map of the Izzenhood Spring Quadrangle, Lander County, Nevada
The Izzenhood Spring quadrangle covers about 145 km2 of the southwestern part of the Sheep Creek Range in northern Lander County, Nevada. The quadrangle is underlain by Lower Paleozoic rocks that are unconformably overlain and intruded by thick sequences of Miocene igneous rocks related to the northern Nevada rift (Stewart and McKee, 1977; Wallace and John, 1998; John and others, 2000)...
Geologic map of the Freel Peak 15-minute Quadrangle, California and Nevada
No abstract available.
Filter Total Items: 58
Critical minerals in subduction-related magmatic-hydrothermal systems of the United States
During the World War and Cold War eras (1910s–1990s), domestic consumption of numerous mineral commodities relied increasingly on imported supplies. Consumption reliance has since expanded to include 50 “critical minerals” (elements and mineral commodities) that are mostly to entirely imported and subject to curtailment by suppliers or supply chain disruption. New domestic supplies of...
Authors
Peter Vikre, David A. John, Niki E. Wintzer, Fleetwood R. Koutz, Frederick Graybeal, Chris Dail, David C. Annis
Timing of rhyolite intrusion and Carlin-type gold mineralization at the Cortez Hills Carlin-type deposit, Nevada, USA
Carlin-type gold deposits (CTDs) of Nevada are the largest producers of gold in the United States, a leader in world gold production. Although much has been resolved about the characteristics and origin of CTDs in Nevada, major questions remain, especially about (1) the role of magmatism, whether only a source of heat or also metals, (2) whether CTDs only formed in the Eocene, and (3)...
Authors
Christopher S. Henry, David A. John, Robert W. Leonardson, William T McIntosh, Matt T. Heizler, Joseph P. Colgan, Kathryn E. Watts
Porphyry and epithermal mineral deposits
Porphyry and epithermal mineral deposits form large economic ore bodies that provide the global economy with copper, molybdenum, gold, silver and other byproducts (Re, Te, Se). They form in the upper crust and are related to sulfur- and water-rich intermediate to silicic magmatic sources of hydrothermal fluids that move upward and produce extensive hydrolytic and alkali wall-rock...
Authors
John H. Dilles, David A. John
Why did Great Basin Eocene magmatism generate Carlin-type gold deposits when extensive Jurassic to Middle Miocene magmatism did not? Lessons from the Cortez Region, Northern Nevada, USA
No abstract available.
Authors
Christopher S. Henry, David A. John, Matt T. Heizler, Robert W. Leonardson, Joseph P. Colgan, Kathryn E. Watts, Michael W. Ressel, Brian L. Cousens
Characterization of the rhyolite of Bodie Hills and 40Ar/39Ar intercalibration with Ar mineral standards
The rhyolite of Bodie Hills (California) is characterized compositionally and the geochronology of selected phases is studied. Sanidine (BHs) from the rhyolite is well suited as a 40Ar/39Ar reference material with high K/Ca and radiogenic yield. Intercalibration with GA1550 biotite from the Dromedary igneous complex (New South Wales, Australia) yields an age of 9.7946 ± 0.0031 Ma for BHs...
Authors
Robert J. Fleck, Andrew T. Calvert, Matthew Coble, Joseph L. Wooden, Kip V. Hodges, Leslie A. Hayden, Matthijs C. van Soest, Edward A. du Bray, David A. John
Petrology of volcanic rocks associated with silver-gold (Ag-Au) epithermal deposits in the Tonopah, Divide, and Goldfield Mining Districts, Nevada
Miocene calc-alkaline volcanic rocks, part of the southern segment of the ancestral Cascades magmatic arc, are spatially, temporally, and likely genetically associated with precious metal epithermal deposits in the Tonopah, Divide, and Goldfield Districts of west-central Nevada. In the Tonopah mining district, volcanic rocks include the Mizpah Trachyte, Fraction Tuff, and Oddie Rhyolite...
Authors
Edward A. du Bray, David A. John, Joseph P. Colgan, Peter Vikre, Michael A. Cosca, Leah E. Morgan
Petrographic, geochemical, and geochronologic data for cenozoic volcanic rocks of the Tonopah, Divide, and Goldfield Mining Districts, Nevada
The purpose of this report is to summarize geochemical, petrographic, and geochronologic data for samples, principally those of unmineralized Tertiary volcanic rocks, from the Tonopah, Divide, and Goldfield mining districts of west-central Nevada (fig. 1). Much of the data presented here for the Tonopah and Divide districts are for samples collected by Bonham and Garside (1979) during...
Authors
Edward A. du Bray, David A. John, Peter Vikre, Joseph P. Colgan, Michael A. Cosca, Leah E. Morgan, Robert J. Fleck, Wayne R. Premo, Christopher S. Holm-Denoma
Pleistocene hydrothermal activity on Brokeoff volcano and in the Maidu volcanic center, Lassen Peak area, northeast California: Evolution of magmatic-hydrothermal systems on stratovolcanoes
Partially eroded stratovolcanoes worldwide, notably Mounts Rainier and Adams in the Cascades and several volcanoes in Japan, record episodic periods of eruption and geothermal activity that produce zones of hydrothermal alteration. The partly eroded core of late Pleistocene Brokeoff volcano on the south side of Lassen Peak exposes the upper 1 km of multiple ancient (ca. 410–300 ka)...
Authors
David A. John, Robert G. Lee, George N. Breit, John H. Dilles, Andrew T. Calvert, L.J. Patrick Muffler, Michael A. Clynne
Igneous rocks in the Fish Creek Mountains and environs, Battle Mountain area, north-central Nevada: A microcosm of Cenozoic igneous activity in the northern Great Basin, Basin and Range Province, USA
The Great Basin of the western United States, the northern component of the Basin and Range Province, is a region of Cenozoic lithospheric extension with multiple periods and types of igneous activity. The composition and volume of Cenozoic magmas reflect a complex interaction between mantle-derived magmas and highly diverse crust, where both mantle sources and magmatic processes were...
Authors
Brian L. Cousens, Christopher S. Henry, Christopher Stevens, Susan Varve, David A. John, Stacey Wetmore
Oxygen isotopic investigation of silicic magmatism in the Stillwater caldera complex, Nevada: Generation of large-volume, low-δ18O rhyolitic tuffs and assessment of their regional context in the Great Basin of the western United States
Successive caldera-forming eruptions from ca. 30 to 25 Ma generated a large nested caldera complex in western Nevada that was subsequently dissected by Basin and Range extension, providing extraordinary cross-sectional views through diverse volcanic and plutonic rocks. A high-resolution oxygen isotopic study was conducted on units that represent all major parts of the Job Canyon...
Authors
Kathryn E. Watts, David A. John, Joseph P. Colgan, Christopher S. Henry, Ilya N. Bindeman, John W. Valley
The Miocene Atastra Creek sinter (Bodie Hills volcanic field, California and Nevada): 4D evolution of a geomorphically intact siliceous hot spring deposit
The Atastra Creek siliceous hot spring deposit, or sinter, occurs in the Paramount-Bald Peak alteration zone, due north of the Bodie precious metals mining district in the Miocene Bodie Hills volcanic field, California and Nevada, U.S.A. Distinctive features include its geomorphically intact geyser vent mounds, the presence of growth-fault-stepped sinter terraces that developed westward...
Authors
Kathleen A. Campbell, Diego M. Guido, David A. John, Peter Vikre, David Rhys, Ayrton Hamilton
Descriptive models for epithermal gold-silver deposits
Epithermal gold-silver deposits are vein, stockwork, disseminated, and replacement deposits that are mined primarily for their gold and silver contents; some deposits also contain substantial resources of lead, zinc, copper, and (or) mercury. These deposits form in the uppermost parts of the crust, at depths less than about 1,500 meters below the water table, and at temperatures below...
Authors
David A. John, Peter Vikre, Edward A. du Bray, Richard J. Blakely, David L. Fey, Barnaby W. Rockwell, Jeffrey L. Mauk, Eric D. Anderson, Frederick Graybeal
By
Ecosystems Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Western Fisheries Research Center, Central Energy Resources Science Center