David A John
David is a Scientist Emeritus with the Geology, Minerals, Energy, and Geophysics Science Center
Science and Products
Filter Total Items: 59
Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada
Zircon geochronology is a critical tool for establishing geologic ages and time scales of processes in the Earth's crust. However, for zircons compromised by open system behavior, achieving robust dates can be difficult. Chemical abrasion (CA) is a routine step prior to thermal ionization mass spectrometry (TIMS) dating of zircon to remove radiation-damaged parts of grains that may have
Authors
Kathryn E. Watts, Matthew A. Coble, Jorge A. Vazquez, Christopher D. Henry, Joseph P. Colgan, David A. John
By
Geology, Energy, and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center
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
Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California 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...
Authors
David A. John, Edward A. du Bray, Christopher D. Henry, Peter G. Vikre
By
Geology, 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
Rhenium: a rare metal critical in modern transportation Rhenium: a rare metal critical in modern transportation
Rhenium is a silvery-white, metallic element with an extremely high melting point (3,180 degrees Celsius) and a heat-stable crystalline structure, making it exceptionally resistant to heat and wear. Since the late 1980s, rhenium has been critical for superalloys used in turbine blades and in catalysts used to produce lead-free gasoline. One of the rarest elements, rhenium has an average...
Authors
David A. John
Geochronology of Cenozoic rocks in the Bodie Hills, California and Nevada 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...
Authors
Robert J. Fleck, Edward A. du Bray, David A. John, Peter G. Vikre, Michael A. Cosca, Lawrence W. Snee, Stephen E. Box
Evidence for large-magnitude, post-Eocene extension in the northern Shoshone Range, Nevada, and its implications for Carlin-type gold deposits in the lower plate of the Roberts Mountains allochthon Evidence for large-magnitude, post-Eocene extension in the northern Shoshone Range, Nevada, and its implications for Carlin-type gold deposits in the lower plate of the Roberts Mountains allochthon
The northern Shoshone and Toiyabe Ranges in north-central Nevada expose numerous areas of mineralized Paleozoic rock, including major Carlin-type gold deposits at Pipeline and Cortez. Paleozoic rocks in these areas were previously interpreted to have undergone negligible postmineralization extension and tilting, but here we present new data that suggest major post-Eocene extension along...
Authors
Joseph P. Colgan, Christopher D. Henry, David A. John
By
Geology, 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
Science and Products
Filter Total Items: 59
Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada Chemical abrasion-SIMS (CA-SIMS) U-Pb dating of zircon from the late Eocene Caetano caldera, Nevada
Zircon geochronology is a critical tool for establishing geologic ages and time scales of processes in the Earth's crust. However, for zircons compromised by open system behavior, achieving robust dates can be difficult. Chemical abrasion (CA) is a routine step prior to thermal ionization mass spectrometry (TIMS) dating of zircon to remove radiation-damaged parts of grains that may have
Authors
Kathryn E. Watts, Matthew A. Coble, Jorge A. Vazquez, Christopher D. Henry, Joseph P. Colgan, David A. John
By
Geology, Energy, and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Groundwater and Streamflow Information Program, Geology, Minerals, Energy, and Geophysics Science Center, Geosciences and Environmental Change Science Center
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
Magmatism and Epithermal Gold-Silver Deposits of the Southern Ancestral Cascade Arc, Western Nevada and Eastern California 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...
Authors
David A. John, Edward A. du Bray, Christopher D. Henry, Peter G. Vikre
By
Geology, 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
Rhenium: a rare metal critical in modern transportation Rhenium: a rare metal critical in modern transportation
Rhenium is a silvery-white, metallic element with an extremely high melting point (3,180 degrees Celsius) and a heat-stable crystalline structure, making it exceptionally resistant to heat and wear. Since the late 1980s, rhenium has been critical for superalloys used in turbine blades and in catalysts used to produce lead-free gasoline. One of the rarest elements, rhenium has an average...
Authors
David A. John
Geochronology of Cenozoic rocks in the Bodie Hills, California and Nevada 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...
Authors
Robert J. Fleck, Edward A. du Bray, David A. John, Peter G. Vikre, Michael A. Cosca, Lawrence W. Snee, Stephen E. Box
Evidence for large-magnitude, post-Eocene extension in the northern Shoshone Range, Nevada, and its implications for Carlin-type gold deposits in the lower plate of the Roberts Mountains allochthon Evidence for large-magnitude, post-Eocene extension in the northern Shoshone Range, Nevada, and its implications for Carlin-type gold deposits in the lower plate of the Roberts Mountains allochthon
The northern Shoshone and Toiyabe Ranges in north-central Nevada expose numerous areas of mineralized Paleozoic rock, including major Carlin-type gold deposits at Pipeline and Cortez. Paleozoic rocks in these areas were previously interpreted to have undergone negligible postmineralization extension and tilting, but here we present new data that suggest major post-Eocene extension along...
Authors
Joseph P. Colgan, Christopher D. Henry, David A. John
By
Geology, 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