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Ryan D Taylor

Ryan Taylor is a Research Geologist with the Geology, Geophysics, and Geochemistry Science Center.

Science and Products

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USGS science for a changing world

Mineral Resource Assessment Training

The USGS Mineral Resources Program conducts mineral resource assessments and is training USGS scientists in how to conduct these assessments for future work. As a practical exercise, the scientists will conduct an assessment for tungsten in the U.S.
By
Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center
link

Mineral Resource Assessment Training

The USGS Mineral Resources Program conducts mineral resource assessments and is training USGS scientists in how to conduct these assessments for future work. As a practical exercise, the scientists will conduct an assessment for tungsten in the U.S.
Learn More
link
critical mineral distribution map

Systems Approach to Critical Minerals Inventory, Research, and Assessment

This project supports the Earth Mapping Resources Initiative (EarthMRI) by developing a mineral systems approach for defining focus areas. This project is investigating domestic sources of critical minerals in three sequential stages: inventory, research, and assessment. 1) Inventory the abundance of critical minerals in ore, minerals, and processed materials from major deposits in each system...
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Earth Mapping Resources Initiative (Earth MRI)
link

Systems Approach to Critical Minerals Inventory, Research, and Assessment

This project supports the Earth Mapping Resources Initiative (EarthMRI) by developing a mineral systems approach for defining focus areas. This project is investigating domestic sources of critical minerals in three sequential stages: inventory, research, and assessment. 1) Inventory the abundance of critical minerals in ore, minerals, and processed materials from major deposits in each system...
Learn More
link
report cover

New Mineral Deposit Models for Gold, Phosphate Rare Earth Elements, and Placer Rare Earth Element-Titanium Resources

USGS Mineral Deposit Models are "an organized arrangement of information describing the essential characteristics or properties of a class of mineral deposits. Models themselves can be classified according to their essential attributes (for example: descriptive, grade-tonnage models, genetic, geoenvironmental, geophysical, probability of occurrence, and quantitative process models)." (Stoeser and...
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
link

New Mineral Deposit Models for Gold, Phosphate Rare Earth Elements, and Placer Rare Earth Element-Titanium Resources

USGS Mineral Deposit Models are "an organized arrangement of information describing the essential characteristics or properties of a class of mineral deposits. Models themselves can be classified according to their essential attributes (for example: descriptive, grade-tonnage models, genetic, geoenvironmental, geophysical, probability of occurrence, and quantitative process models)." (Stoeser and...
Learn More

Whole Rock Major and Trace Element Chemistry for Igneous Rocks from Tyonek, Lime Hills, Talkeetna, McGrath, and Lake Clark Quadrangles, Western Alaska Range, Alaska

This data release contains whole rock major and trace element data for 69 igneous rock samples collected from the Western Alaska Range between 2011 and 2012. The Series field relates to chronological units discussed in Jones et al. (2021, Geosphere) and Todd et al. (2022 IN PREP). Descriptions are from original collector notebooks and are provided here for informational purposes only.
By
Alaska Science Center

Whole rock geochemical data from the eastern part of the Yukon-Tanana Upland region, Alaska, USA

This data release is part of a 2016-2019 study on the geology, geochemistry and geochronology of ore systems in the eastern Yukon-Tanana Upland region, Alaska. Whole rock chemistry was conducted on 185 samples, mostly from Au prospects, with lesser samples from porphyry Cu prospects. Geographically, most samples are from gold prospects near the Pogo Au mine and east to Black Mountain in the Big De
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Geochemical analyses of rock samples collected from the Dora Bay peralkaline igneous complex, Prince of Wales Island, southeastern Alaska

This data release presents the major and trace element chemistry of rock samples collected by the U.S. Geological Survey (USGS) from surface exposures of the Dora Bay igneous complex (DBIC), located in the southern part of Prince of Wales Island, southeastern Alaska. The DBIC is Early Jurassic in age (Bala and others, 2014) and is U-Th-heavy rare earth element (HREE)-enriched like the Bokan Mounta
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Qualitative Mineral Potential Map of Tungsten Skarn in the Yukon-Tanana Uplands, Eastern Alaska, USA, 2021

This data release supports the paper titled, "Tungsten skarn potential of the Yukon-Tanana Uplands, Eastern Alaska, USA-A mineral resource assessment", published via open-access license in the Journal of Geochemical Exploration and available at: https://doi.org/10.1016/j.gexplo.2020.106700. The data release includes GIS data that map potential for tungsten skarn mineralization in permissive tracts
By
Alaska Science Center

Electron microprobe analyses of hydrothermal muscovite crystals from gold-bearing quartz veins of the Klamath Mountains, California, 2014 and 2019 (ver. 1.1, June 2022)

This data release provides geochemical results of in situ electron probe microanalyses of hydrothermal muscovite associated with gold-bearing quartz veins from the Klamath Mountains, California. Samples were collected from eight different mines in the summer of 2013 and electron probe microanalyses were carried out May 27, 2014 and November 12, 2019.
By
Geology, Geophysics, and Geochemistry Science Center

Electron microprobe geochemistry of apatite crystals in the iron oxide-apatite ores of the Adirondack Mountains, New York, 2016-2017

The iron oxide-apatite (IOA) deposits near Mineville in the Adirondack Mountains, New York, have been of interest for their rich magnetite ore since the mid-1700s but have attracted renewed attention due to their potential as rare earth element (REE) resources (McKeown and Klemic, 1956; Lupulescu and others, 2016; Taylor and others, 2018). Apatite is the main REE-host and is found in variable con
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

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 Earth Mappi
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Earth Mapping Resources Initiative (Earth MRI)

Geochemistry of ore, host rock, and mine waste pile samples of iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, in relation to potential rare earth elements resources, 2016-2018

Thirty-four ore, twenty-nine mine waste, seven host rock, two pegmatite, and one slag sample were collected from iron oxide-apatite (IOA) mines in the eastern Adirondack Highlands near Mineville and Ticonderoga, New York, from March 2016 to August 2018. The waste pile samples included twenty-five samples collected from rubble-sized mine waste piles and four samples from processed tailings piles.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015

In situ geochemical data were obtained for pyrite crystals and native gold from two distinct vein sets in the Grass Valley gold district, California. Samples of the N-S veins were collected underground at the Empire Mine State Historic Park and samples of the E-W veins were collected from drill core provided by the Idaho-Maryland Mining Corporation in 2008. These geochemical data were analyzed to
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

Electron microprobe data for monazite and xenotime used in consideration of gold deposit formation models (ver. 2.0, May 2023)

The genetic origin of many gold deposits, including Pogo in Alaska, remains controversial with questions as to whether they formed due to magmatic-hydrothermal or metamorphic-hydrothermal fluids. Gaining a better understanding of the formation mechanisms for these deposits is critical for defining proper exploration criteria in gold-bearing regions and production within these deposits. Monazite ar
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Filter Total Items: 28

Hydrothermal monazite and xenotime chemistry as genetic discriminators for intrusion-related and orogenic gold deposits: Implications for an orogenic origin of the Pogo gold deposit, Alaska

Attempts to geochemically distinguish between metamorphic-hydrothermal systems that form orogenic gold deposits and both reduced and oxidized magmatic-hydrothermal systems using isotopes or metal associations have proven ambiguous, particularly for orogenic gold and reduced intrusion-related gold systems. The absence of conclusive geochemical discriminators and the overlap in geologic characterist

Authors
Ryan Taylor, Garth E. Graham, Heather A. Lowers
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

Reconnaissance mineral and cathodoluminescence studies of gold occurrences in the Pogo-Black Mountain area, eastern interior Alaska, USA

The Pogo Au deposit is the largest of a number of gold occurrences in eastern interior Alaska, that occur along a broad trend from west of Pogo to Black Mountain. Some of these occurrences are hosted in amphibolite facies gneisses and others in mid-Cretaceous igneous rocks that intruded the older metamorphic rocks. All occurrences contain arsenopyrite and pyrite. Whole rock geochemical trends dist

Authors
Garth E. Graham, Erin E. Marsh, Heather A. Lowers, Ryan Taylor
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

Rocky Mountain Region Science Exchange 2020—EarthMAP and the Colorado River Basin

The U.S. Geological Survey (USGS) Rocky Mountain Region (RMR) hosted USGS scientists, managers, program coordinators, and leadership team members for a virtual Science Exchange during September 15–17, 2020. The Science Exchange had 216 registered participants and included 48 talks over the 3-day period. Invited speakers presented information about the novel USGS Earth Monitoring, Analysis, and Pre
Authors
Anne C. Tillery, Patrick J. Anderson, William J. Andrews, Katharine Dahm, Seth S. Haines, Robert Horton, David O'Leary, Ryan D. Taylor, Kathryn A. Thomas, Alicia Torregrosa
By
Ecosystems Mission Area, Water Resources Mission Area, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center, New Mexico Water Science Center, Oklahoma-Texas Water Science Center, Southwest Biological Science Center, Utah Water Science Center, Western Geographic Science Center, Colorado River Basin: Actionable and Strategic Integrated Science and Technology

Late Jurassic-Early Cretaceous orogenic gold mineralization in the Klamath Mountains, California: Constraints from 40Ar/39Ar dating of hydrothermal muscovite

The Klamath Mountains gold province is the second most important historical producer in California, having produced more than 7 Moz of gold from both lode and placer sources. Hydrothermal muscovite grains from gold-bearing veins provide the first 40Ar/39Ar age constraints indicative of a protracted period of mineralization in the Klamath Mountains. The data indicate that the window for orogenic go
Authors
Ryan D. Taylor, Leah E. Morgan, Fred Jourdan, Thomas Monecke, Erin E. Marsh, Richard J. Goldfarb
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Tungsten skarn potential of the Yukon-Tanana Upland, eastern Alaska, USA—A mineral resource assessment

Tungsten (W) is used in a variety of industrial and technological applications and has been identified as a critical mineral for the United States, India, the European Union, and other countries. These countries rely on W imports mostly from China, which leaves them vulnerable to supply disruption. Consequently, the U.S. government has a current initiative to understand domestic resource potential
Authors
George N. D. Case, Garth E. Graham, Erin E. Marsh, Ryan Taylor, Carlin J. Green, Philip J. Brown, Keith A. Labay
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, Alaska Science Center, Geology, Geophysics, and Geochemistry Science Center

Paragenesis of an orogenic gold deposit: New insights on mineralizing processes at the Grass Valley District, California

The Grass Valley orogenic gold district in the Sierra Nevada foothills province, central California, is the largest historical gold producer of the North American Cordillera. Gold mineralization is associated with shallowly dipping north-south veins hosted by the 160 Ma Grass Valley granodiorite to the southwest of the Grass Valley fault and steeply dipping east-west veins in accreted oceanic rock
Authors
Ryan Taylor, Thomas Monecke, T. James Reynolds, Jochen Monecke
By
Geology, Geophysics, and Geochemistry Science Center

Integrated geophysical imaging of rare-earth-element-bearing iron oxide-apatite deposits in the eastern Adirondack Highlands, New York

The eastern Adirondack Highlands of northern New York host dozens of iron oxide-apatite (IOA) deposits containing magnetite and rare earth element (REE)-bearing apatite. We use new aeromagnetic, aeroradiometric, ground gravity, and sample petrophysical and geochemical data to image and understand these deposits and their geologic framework. Aeromagnetic total field data reflect highly magnetic leu
Authors
Anjana K. Shah, Ryan D. Taylor, Gregory J. Walsh, Jeffrey Phillips
By
Geology, Geophysics, and Geochemistry Science Center

Geochemistry and geophysics of iron oxide-apatite deposits and associated waste piles with implications for potential rare earth element resources from ore and historic mine waste in the eastern Adirondack Highlands, New York, USA

The iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, are historical high-grade magnetite mines that contain variable concentrations of rare earth element (REE)-bearing apatite crystals. The majority of the deposits are hosted within sodically altered Lyon Mountain granite gneiss, although some deposits occur within paragneiss, gabbro, anorthosite, or potassically al
Authors
Ryan Taylor, Anjana K. Shah, Gregory J. Walsh, Cliff D. Taylor
By
Geology, Geophysics, and Geochemistry Science Center, Florence Bascom Geoscience Center

Discrete Zr and REE mineralization of the Baerzhe rare-metal deposit, China

Although REE (lanthanides + Y) mineralization in alkaline silicate systems is commonly accompanied with Zr mineralization worldwide, our understanding of the relationship between Zr and REE mineralization is still incomplete (e.g. Škoda and Novák, 2007; Linnen et al., 2014; Petrella et al., 2014; Möller and Williams-Jones, 2016; Wu et al., 2018). The Baerzhe deposit in NE China is a source of Zr,
Authors
Kunfeng Qiu, Haocheng Yu, Mingqian Wu, Jianzhen Geng, Xiangkun Ge, Zongyang Gou, Ryan Taylor
By
Geology, Geophysics, and Geochemistry Science Center

Formation mechanisms of quartz veins in orogenic gold deposits: Insights from Grass Valley, California, USA

The orogenic gold veins of Grass Valley, California, USA, compose the historically richest lode gold district in the North American Cordillera. Petrographically, the veins exhibit a range of primary textural relationships allowing the reconstruction of the paragenetic sequence of mineral formation. Two generations of quartz are distinguished by optical cathodoluminescence microscopy and fluid incl
Authors
Ryan Taylor, Thomas Monecke, T. James Reynolds
By
Geology, Geophysics, and Geochemistry Science Center

Quartz-pebble-conglomerate gold deposits

Quartz-pebble-conglomerate gold deposits represent the largest repository of gold on Earth, largely due to the deposits of the Witwatersrand Basin, which account for nearly 40 percent of the total gold produced throughout Earth’s history. This deposit type has had a controversial history in regards to genetic models. However, most researchers conclude that they are paleoplacer deposits that have b
Authors
Ryan D. Taylor, Eric D. Anderson
By
Geology, Geophysics, and Geochemistry Science Center

Geologic and geochemical insights into the formation of the Taiyangshan porphyry copper–molybdenum deposit, Western Qinling Orogenic Belt, China

Taiyangshan is a poorly studied copper–molybdenum deposit located in the Triassic Western Qinling collisional belt of northwest China. The intrusions exposed in the vicinity of the Taiyangshan deposit record episodic magmatism over 20–30 million years. Pre-mineralization quartz diorite porphyries, which host some of the deposit, were emplaced at 226.6 ± 6.2 Ma. Syn-collisional monzonite and quartz
Authors
Kun-Feng Qiu, Ryan D. Taylor, Yao-Hui Song, Hao-Cheng Yu, Kai-Rui Song, Nan Li
By
Energy and Minerals Mission Area, Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Mine Waste in the Eastern Adirondacks May be Untapped, Accessible Source of Rare Earth Element Minerals

Mine Waste in the Eastern Adirondacks May be Untapped, Accessible Source of Rare Earth Element Minerals

Waste rock from long-closed mines in the eastern Adirondack Mountains, New York, may prove valuable due to its rare earth element content, according...

Read Article

Science and Products

link
USGS science for a changing world

Mineral Resource Assessment Training

The USGS Mineral Resources Program conducts mineral resource assessments and is training USGS scientists in how to conduct these assessments for future work. As a practical exercise, the scientists will conduct an assessment for tungsten in the U.S.
By
Mineral Resources Program, Geology, Minerals, Energy, and Geophysics Science Center
link

Mineral Resource Assessment Training

The USGS Mineral Resources Program conducts mineral resource assessments and is training USGS scientists in how to conduct these assessments for future work. As a practical exercise, the scientists will conduct an assessment for tungsten in the U.S.
Learn More
link
critical mineral distribution map

Systems Approach to Critical Minerals Inventory, Research, and Assessment

This project supports the Earth Mapping Resources Initiative (EarthMRI) by developing a mineral systems approach for defining focus areas. This project is investigating domestic sources of critical minerals in three sequential stages: inventory, research, and assessment. 1) Inventory the abundance of critical minerals in ore, minerals, and processed materials from major deposits in each system...
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Earth Mapping Resources Initiative (Earth MRI)
link

Systems Approach to Critical Minerals Inventory, Research, and Assessment

This project supports the Earth Mapping Resources Initiative (EarthMRI) by developing a mineral systems approach for defining focus areas. This project is investigating domestic sources of critical minerals in three sequential stages: inventory, research, and assessment. 1) Inventory the abundance of critical minerals in ore, minerals, and processed materials from major deposits in each system...
Learn More
link
report cover

New Mineral Deposit Models for Gold, Phosphate Rare Earth Elements, and Placer Rare Earth Element-Titanium Resources

USGS Mineral Deposit Models are "an organized arrangement of information describing the essential characteristics or properties of a class of mineral deposits. Models themselves can be classified according to their essential attributes (for example: descriptive, grade-tonnage models, genetic, geoenvironmental, geophysical, probability of occurrence, and quantitative process models)." (Stoeser and...
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
link

New Mineral Deposit Models for Gold, Phosphate Rare Earth Elements, and Placer Rare Earth Element-Titanium Resources

USGS Mineral Deposit Models are "an organized arrangement of information describing the essential characteristics or properties of a class of mineral deposits. Models themselves can be classified according to their essential attributes (for example: descriptive, grade-tonnage models, genetic, geoenvironmental, geophysical, probability of occurrence, and quantitative process models)." (Stoeser and...
Learn More

Whole Rock Major and Trace Element Chemistry for Igneous Rocks from Tyonek, Lime Hills, Talkeetna, McGrath, and Lake Clark Quadrangles, Western Alaska Range, Alaska

This data release contains whole rock major and trace element data for 69 igneous rock samples collected from the Western Alaska Range between 2011 and 2012. The Series field relates to chronological units discussed in Jones et al. (2021, Geosphere) and Todd et al. (2022 IN PREP). Descriptions are from original collector notebooks and are provided here for informational purposes only.
By
Alaska Science Center

Whole rock geochemical data from the eastern part of the Yukon-Tanana Upland region, Alaska, USA

This data release is part of a 2016-2019 study on the geology, geochemistry and geochronology of ore systems in the eastern Yukon-Tanana Upland region, Alaska. Whole rock chemistry was conducted on 185 samples, mostly from Au prospects, with lesser samples from porphyry Cu prospects. Geographically, most samples are from gold prospects near the Pogo Au mine and east to Black Mountain in the Big De
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Geochemical analyses of rock samples collected from the Dora Bay peralkaline igneous complex, Prince of Wales Island, southeastern Alaska

This data release presents the major and trace element chemistry of rock samples collected by the U.S. Geological Survey (USGS) from surface exposures of the Dora Bay igneous complex (DBIC), located in the southern part of Prince of Wales Island, southeastern Alaska. The DBIC is Early Jurassic in age (Bala and others, 2014) and is U-Th-heavy rare earth element (HREE)-enriched like the Bokan Mounta
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Qualitative Mineral Potential Map of Tungsten Skarn in the Yukon-Tanana Uplands, Eastern Alaska, USA, 2021

This data release supports the paper titled, "Tungsten skarn potential of the Yukon-Tanana Uplands, Eastern Alaska, USA-A mineral resource assessment", published via open-access license in the Journal of Geochemical Exploration and available at: https://doi.org/10.1016/j.gexplo.2020.106700. The data release includes GIS data that map potential for tungsten skarn mineralization in permissive tracts
By
Alaska Science Center

Electron microprobe analyses of hydrothermal muscovite crystals from gold-bearing quartz veins of the Klamath Mountains, California, 2014 and 2019 (ver. 1.1, June 2022)

This data release provides geochemical results of in situ electron probe microanalyses of hydrothermal muscovite associated with gold-bearing quartz veins from the Klamath Mountains, California. Samples were collected from eight different mines in the summer of 2013 and electron probe microanalyses were carried out May 27, 2014 and November 12, 2019.
By
Geology, Geophysics, and Geochemistry Science Center

Electron microprobe geochemistry of apatite crystals in the iron oxide-apatite ores of the Adirondack Mountains, New York, 2016-2017

The iron oxide-apatite (IOA) deposits near Mineville in the Adirondack Mountains, New York, have been of interest for their rich magnetite ore since the mid-1700s but have attracted renewed attention due to their potential as rare earth element (REE) resources (McKeown and Klemic, 1956; Lupulescu and others, 2016; Taylor and others, 2018). Apatite is the main REE-host and is found in variable con
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

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 Earth Mappi
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Earth Mapping Resources Initiative (Earth MRI)

Geochemistry of ore, host rock, and mine waste pile samples of iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, in relation to potential rare earth elements resources, 2016-2018

Thirty-four ore, twenty-nine mine waste, seven host rock, two pegmatite, and one slag sample were collected from iron oxide-apatite (IOA) mines in the eastern Adirondack Highlands near Mineville and Ticonderoga, New York, from March 2016 to August 2018. The waste pile samples included twenty-five samples collected from rubble-sized mine waste piles and four samples from processed tailings piles.
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

In situ geochemical data related to the gold-quartz veins of Grass Valley, California, 2014-2015

In situ geochemical data were obtained for pyrite crystals and native gold from two distinct vein sets in the Grass Valley gold district, California. Samples of the N-S veins were collected underground at the Empire Mine State Historic Park and samples of the E-W veins were collected from drill core provided by the Idaho-Maryland Mining Corporation in 2008. These geochemical data were analyzed to
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

Electron microprobe data for monazite and xenotime used in consideration of gold deposit formation models (ver. 2.0, May 2023)

The genetic origin of many gold deposits, including Pogo in Alaska, remains controversial with questions as to whether they formed due to magmatic-hydrothermal or metamorphic-hydrothermal fluids. Gaining a better understanding of the formation mechanisms for these deposits is critical for defining proper exploration criteria in gold-bearing regions and production within these deposits. Monazite ar
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Filter Total Items: 28

Hydrothermal monazite and xenotime chemistry as genetic discriminators for intrusion-related and orogenic gold deposits: Implications for an orogenic origin of the Pogo gold deposit, Alaska

Attempts to geochemically distinguish between metamorphic-hydrothermal systems that form orogenic gold deposits and both reduced and oxidized magmatic-hydrothermal systems using isotopes or metal associations have proven ambiguous, particularly for orogenic gold and reduced intrusion-related gold systems. The absence of conclusive geochemical discriminators and the overlap in geologic characterist

Authors
Ryan Taylor, Garth E. Graham, Heather A. Lowers
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

Reconnaissance mineral and cathodoluminescence studies of gold occurrences in the Pogo-Black Mountain area, eastern interior Alaska, USA

The Pogo Au deposit is the largest of a number of gold occurrences in eastern interior Alaska, that occur along a broad trend from west of Pogo to Black Mountain. Some of these occurrences are hosted in amphibolite facies gneisses and others in mid-Cretaceous igneous rocks that intruded the older metamorphic rocks. All occurrences contain arsenopyrite and pyrite. Whole rock geochemical trends dist

Authors
Garth E. Graham, Erin E. Marsh, Heather A. Lowers, Ryan Taylor
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center, Denver Microbeam Laboratory

Rocky Mountain Region Science Exchange 2020—EarthMAP and the Colorado River Basin

The U.S. Geological Survey (USGS) Rocky Mountain Region (RMR) hosted USGS scientists, managers, program coordinators, and leadership team members for a virtual Science Exchange during September 15–17, 2020. The Science Exchange had 216 registered participants and included 48 talks over the 3-day period. Invited speakers presented information about the novel USGS Earth Monitoring, Analysis, and Pre
Authors
Anne C. Tillery, Patrick J. Anderson, William J. Andrews, Katharine Dahm, Seth S. Haines, Robert Horton, David O'Leary, Ryan D. Taylor, Kathryn A. Thomas, Alicia Torregrosa
By
Ecosystems Mission Area, Water Resources Mission Area, Fort Collins Science Center, Geology, Geophysics, and Geochemistry Science Center, New Mexico Water Science Center, Oklahoma-Texas Water Science Center, Southwest Biological Science Center, Utah Water Science Center, Western Geographic Science Center, Colorado River Basin: Actionable and Strategic Integrated Science and Technology

Late Jurassic-Early Cretaceous orogenic gold mineralization in the Klamath Mountains, California: Constraints from 40Ar/39Ar dating of hydrothermal muscovite

The Klamath Mountains gold province is the second most important historical producer in California, having produced more than 7 Moz of gold from both lode and placer sources. Hydrothermal muscovite grains from gold-bearing veins provide the first 40Ar/39Ar age constraints indicative of a protracted period of mineralization in the Klamath Mountains. The data indicate that the window for orogenic go
Authors
Ryan D. Taylor, Leah E. Morgan, Fred Jourdan, Thomas Monecke, Erin E. Marsh, Richard J. Goldfarb
By
Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center

Tungsten skarn potential of the Yukon-Tanana Upland, eastern Alaska, USA—A mineral resource assessment

Tungsten (W) is used in a variety of industrial and technological applications and has been identified as a critical mineral for the United States, India, the European Union, and other countries. These countries rely on W imports mostly from China, which leaves them vulnerable to supply disruption. Consequently, the U.S. government has a current initiative to understand domestic resource potential
Authors
George N. D. Case, Garth E. Graham, Erin E. Marsh, Ryan Taylor, Carlin J. Green, Philip J. Brown, Keith A. Labay
By
Mineral Resources Program, Geology, Energy & Minerals Science Center, Alaska Science Center, Geology, Geophysics, and Geochemistry Science Center

Paragenesis of an orogenic gold deposit: New insights on mineralizing processes at the Grass Valley District, California

The Grass Valley orogenic gold district in the Sierra Nevada foothills province, central California, is the largest historical gold producer of the North American Cordillera. Gold mineralization is associated with shallowly dipping north-south veins hosted by the 160 Ma Grass Valley granodiorite to the southwest of the Grass Valley fault and steeply dipping east-west veins in accreted oceanic rock
Authors
Ryan Taylor, Thomas Monecke, T. James Reynolds, Jochen Monecke
By
Geology, Geophysics, and Geochemistry Science Center

Integrated geophysical imaging of rare-earth-element-bearing iron oxide-apatite deposits in the eastern Adirondack Highlands, New York

The eastern Adirondack Highlands of northern New York host dozens of iron oxide-apatite (IOA) deposits containing magnetite and rare earth element (REE)-bearing apatite. We use new aeromagnetic, aeroradiometric, ground gravity, and sample petrophysical and geochemical data to image and understand these deposits and their geologic framework. Aeromagnetic total field data reflect highly magnetic leu
Authors
Anjana K. Shah, Ryan D. Taylor, Gregory J. Walsh, Jeffrey Phillips
By
Geology, Geophysics, and Geochemistry Science Center

Geochemistry and geophysics of iron oxide-apatite deposits and associated waste piles with implications for potential rare earth element resources from ore and historic mine waste in the eastern Adirondack Highlands, New York, USA

The iron oxide-apatite (IOA) deposits of the eastern Adirondack Highlands, New York, are historical high-grade magnetite mines that contain variable concentrations of rare earth element (REE)-bearing apatite crystals. The majority of the deposits are hosted within sodically altered Lyon Mountain granite gneiss, although some deposits occur within paragneiss, gabbro, anorthosite, or potassically al
Authors
Ryan Taylor, Anjana K. Shah, Gregory J. Walsh, Cliff D. Taylor
By
Geology, Geophysics, and Geochemistry Science Center, Florence Bascom Geoscience Center

Discrete Zr and REE mineralization of the Baerzhe rare-metal deposit, China

Although REE (lanthanides + Y) mineralization in alkaline silicate systems is commonly accompanied with Zr mineralization worldwide, our understanding of the relationship between Zr and REE mineralization is still incomplete (e.g. Škoda and Novák, 2007; Linnen et al., 2014; Petrella et al., 2014; Möller and Williams-Jones, 2016; Wu et al., 2018). The Baerzhe deposit in NE China is a source of Zr,
Authors
Kunfeng Qiu, Haocheng Yu, Mingqian Wu, Jianzhen Geng, Xiangkun Ge, Zongyang Gou, Ryan Taylor
By
Geology, Geophysics, and Geochemistry Science Center

Formation mechanisms of quartz veins in orogenic gold deposits: Insights from Grass Valley, California, USA

The orogenic gold veins of Grass Valley, California, USA, compose the historically richest lode gold district in the North American Cordillera. Petrographically, the veins exhibit a range of primary textural relationships allowing the reconstruction of the paragenetic sequence of mineral formation. Two generations of quartz are distinguished by optical cathodoluminescence microscopy and fluid incl
Authors
Ryan Taylor, Thomas Monecke, T. James Reynolds
By
Geology, Geophysics, and Geochemistry Science Center

Quartz-pebble-conglomerate gold deposits

Quartz-pebble-conglomerate gold deposits represent the largest repository of gold on Earth, largely due to the deposits of the Witwatersrand Basin, which account for nearly 40 percent of the total gold produced throughout Earth’s history. This deposit type has had a controversial history in regards to genetic models. However, most researchers conclude that they are paleoplacer deposits that have b
Authors
Ryan D. Taylor, Eric D. Anderson
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Geology, Geophysics, and Geochemistry Science Center

Geologic and geochemical insights into the formation of the Taiyangshan porphyry copper–molybdenum deposit, Western Qinling Orogenic Belt, China

Taiyangshan is a poorly studied copper–molybdenum deposit located in the Triassic Western Qinling collisional belt of northwest China. The intrusions exposed in the vicinity of the Taiyangshan deposit record episodic magmatism over 20–30 million years. Pre-mineralization quartz diorite porphyries, which host some of the deposit, were emplaced at 226.6 ± 6.2 Ma. Syn-collisional monzonite and quartz
Authors
Kun-Feng Qiu, Ryan D. Taylor, Yao-Hui Song, Hao-Cheng Yu, Kai-Rui Song, Nan Li
By
Energy and Minerals Mission Area, Mineral Resources Program, Geology, Geophysics, and Geochemistry Science Center
Mine Waste in the Eastern Adirondacks May be Untapped, Accessible Source of Rare Earth Element Minerals

Mine Waste in the Eastern Adirondacks May be Untapped, Accessible Source of Rare Earth Element Minerals

Waste rock from long-closed mines in the eastern Adirondack Mountains, New York, may prove valuable due to its rare earth element content, according...

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