Ryan D Taylor
Ryan Taylor is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.
Science and Products
Filter Total Items: 31
Application of U-Th-Pb phosphate geochronology to young orogenic gold deposits: New age constraints on the formation of the Grass Valley gold district, Sierra Foothills province, California Application of U-Th-Pb phosphate geochronology to young orogenic gold deposits: New age constraints on the formation of the Grass Valley gold district, Sierra Foothills province, California
The Grass Valley orogenic gold district in the Sierra Nevada foothills province, central California, the largest historic gold producer of the North American Cordillera, comprises both steeply dipping east-west (E-W) veins located along lithologic contacts in accreted ca. 300 and 200 Ma oceanic rocks and shallowly dipping north-south (N-S) veins hosted by the Grass Valley granodiorite...
Authors
Ryan D. Taylor, Richard J. Goldfarb, Thomas Monecke, Ian R. Fletcher, Michael A. Cosca, Nigel M. Kelly
Targeting Cu–Au and Mo resources using multi-media exploration geochemistry: An example from Tyonek Quadrangle, Alaska Range, Alaska Targeting Cu–Au and Mo resources using multi-media exploration geochemistry: An example from Tyonek Quadrangle, Alaska Range, Alaska
Regional stream and pond sediment, panned concentrate, and water sampling at and around known mineral occurrences in the Tyonek quadrangle, Alaska Range, Alaska were undertaken to determine geochemical signatures in the different media. For sediment samples, two different size fractions (− 80 mesh and − 230 mesh) were analyzed. Elevated concentrations (mostly ~ 2 × median) of elements...
Authors
Garth E. Graham, Ryan D. Taylor, Gregory K. Lee, Dick Tripp
Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska
This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions...
Authors
Ryan D. Taylor, Garth E. Graham, Eric D. Anderson, David Selby
Phanerozoic continental growth and gold metallogeny of Asia Phanerozoic continental growth and gold metallogeny of Asia
The Asian continent formed during the past 800 m.y. during late Neoproterozoic through Jurassic closure of the Tethyan ocean basins, followed by late Mesozoic circum-Pacific and Cenozoic Himalayan orogenies. The oldest gold deposits in Asia reflect accretionary events along the margins of the Siberia, Kazakhstan, North China, Tarim–Karakum, South China, and Indochina Precambrian blocks...
Authors
Richard J. Goldfarb, Ryan D. Taylor, Gregory S. Collins, Nicolay A. Goryachev, Omero Felipe Orlandini
Stratiform chromite deposit model Stratiform chromite deposit model
A new descriptive stratiform chromite deposit model was prepared which will provide a framework for understanding the characteristics of stratiform chromite deposits worldwide. Previous stratiform chromite deposit models developed by the U.S. Geological Survey (USGS) have been referred to as Bushveld chromium, because the Bushveld Complex in South Africa is the only stratified, mafic...
Authors
Ruth F. Schulte, Ryan D. Taylor, Nadine M. Piatak, Robert R. Seal
Arc-related porphyry molybdenum deposit model Arc-related porphyry molybdenum deposit model
This report provides a descriptive model for arc-related porphyry molybdenum deposits. Presented within are geological, geochemical, and mineralogical characteristics that differentiate this deposit type from porphyry copper and alkali-feldspar rhyolite-granite porphyry molybdenum deposits. The U.S. Geological Survey's effort to update existing mineral deposit models spurred this...
Authors
Ryan D. Taylor, Jane M. Hammarstrom, Nadine M. Piatak, Robert R. Seal
Science and Products
Filter Total Items: 31
Application of U-Th-Pb phosphate geochronology to young orogenic gold deposits: New age constraints on the formation of the Grass Valley gold district, Sierra Foothills province, California Application of U-Th-Pb phosphate geochronology to young orogenic gold deposits: New age constraints on the formation of the Grass Valley gold district, Sierra Foothills province, California
The Grass Valley orogenic gold district in the Sierra Nevada foothills province, central California, the largest historic gold producer of the North American Cordillera, comprises both steeply dipping east-west (E-W) veins located along lithologic contacts in accreted ca. 300 and 200 Ma oceanic rocks and shallowly dipping north-south (N-S) veins hosted by the Grass Valley granodiorite...
Authors
Ryan D. Taylor, Richard J. Goldfarb, Thomas Monecke, Ian R. Fletcher, Michael A. Cosca, Nigel M. Kelly
Targeting Cu–Au and Mo resources using multi-media exploration geochemistry: An example from Tyonek Quadrangle, Alaska Range, Alaska Targeting Cu–Au and Mo resources using multi-media exploration geochemistry: An example from Tyonek Quadrangle, Alaska Range, Alaska
Regional stream and pond sediment, panned concentrate, and water sampling at and around known mineral occurrences in the Tyonek quadrangle, Alaska Range, Alaska were undertaken to determine geochemical signatures in the different media. For sediment samples, two different size fractions (− 80 mesh and − 230 mesh) were analyzed. Elevated concentrations (mostly ~ 2 × median) of elements...
Authors
Garth E. Graham, Ryan D. Taylor, Gregory K. Lee, Dick Tripp
Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska Timing of ore-related magmatism in the western Alaska Range, southwestern Alaska
This report presents isotopic age data from mineralized granitic plutons in an area of the Alaska Range located approximately 200 kilometers to the west-northwest of Anchorage in southwestern Alaska. Uranium-lead isotopic data and trace element concentrations of zircons were determined for 12 samples encompassing eight plutonic bodies ranging in age from approximately 76 to 57.4 millions...
Authors
Ryan D. Taylor, Garth E. Graham, Eric D. Anderson, David Selby
Phanerozoic continental growth and gold metallogeny of Asia Phanerozoic continental growth and gold metallogeny of Asia
The Asian continent formed during the past 800 m.y. during late Neoproterozoic through Jurassic closure of the Tethyan ocean basins, followed by late Mesozoic circum-Pacific and Cenozoic Himalayan orogenies. The oldest gold deposits in Asia reflect accretionary events along the margins of the Siberia, Kazakhstan, North China, Tarim–Karakum, South China, and Indochina Precambrian blocks...
Authors
Richard J. Goldfarb, Ryan D. Taylor, Gregory S. Collins, Nicolay A. Goryachev, Omero Felipe Orlandini
Stratiform chromite deposit model Stratiform chromite deposit model
A new descriptive stratiform chromite deposit model was prepared which will provide a framework for understanding the characteristics of stratiform chromite deposits worldwide. Previous stratiform chromite deposit models developed by the U.S. Geological Survey (USGS) have been referred to as Bushveld chromium, because the Bushveld Complex in South Africa is the only stratified, mafic...
Authors
Ruth F. Schulte, Ryan D. Taylor, Nadine M. Piatak, Robert R. Seal
Arc-related porphyry molybdenum deposit model Arc-related porphyry molybdenum deposit model
This report provides a descriptive model for arc-related porphyry molybdenum deposits. Presented within are geological, geochemical, and mineralogical characteristics that differentiate this deposit type from porphyry copper and alkali-feldspar rhyolite-granite porphyry molybdenum deposits. The U.S. Geological Survey's effort to update existing mineral deposit models spurred this...
Authors
Ryan D. Taylor, Jane M. Hammarstrom, Nadine M. Piatak, Robert R. Seal