Albert H Hofstra (Former Employee)
Science and Products
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...
Lithium from Source to Sink: Genesis and Evolution of Li Brines and Clays
The purpose of this project is to trace the lithium (Li) geochemical cycle in the Great Basin, with an emphasis on the pathways that lead to the development of lithium clay and brine resources.
National Geochemical Database on Ore Deposits: New data featuring fusion digestion analytical methods National Geochemical Database on Ore Deposits: New data featuring fusion digestion analytical methods
There is a growing demand for commodities (elements, compounds, minerals) used in today's advanced technologies. Critical minerals are usually found in ore deposits that are deemed vital to economic and national security. National Geochemical Database on Ore Deposits: New data featuring fusion digestion (NGDOD) analytical methods contains chemistry and geologic information for 16,579 ore...
Noble Gas Isotopic Data from Fluid Inclusions Contained in the Te-bearing Adularia-Sericite Epithermal Au-Ag Deposits in a Calc-Alkaline Magmatic Arc, NE China Noble Gas Isotopic Data from Fluid Inclusions Contained in the Te-bearing Adularia-Sericite Epithermal Au-Ag Deposits in a Calc-Alkaline Magmatic Arc, NE China
The contents of this data release represent the results of the noble gas composition analysis and are presented in support of the planned publication Gao et al., 2023, titled Lead and noble gas isotopic constraints on the origin of Te-bearing adularia-sericite epithermal Au-Ag deposits in a calc-alkaline magmatic arc. Tellurium (Te)-bearing adularia-sericite epithermal Au-Ag deposits are...
Trace element chemistry of sulfides and quartz, in situ sulfur isotope values of sulfides, cathodoluminescence of quartz, fluid inclusion microthermometry and raman, and radiogenic isotope and whole rock geochemistry from the Stibnite-Yellow Pine district Trace element chemistry of sulfides and quartz, in situ sulfur isotope values of sulfides, cathodoluminescence of quartz, fluid inclusion microthermometry and raman, and radiogenic isotope and whole rock geochemistry from the Stibnite-Yellow Pine district
This dataset is a collection of geochemical data on samples from the Stibnite-Yellow Pine district of Idaho. The datasets include: whole rock geochemistry; lead, strontium and neodymium isotope chemistry of sulfides and whole rock samples by isotope dilution-thermal-mass spectrometry (ID-TIMS); in situ sulfur isotope chemistry of sulfides by laser ablation-multi collector-inductively...
National Geochemical Database on Ore Deposits: Legacy data National Geochemical Database on Ore Deposits: Legacy data
There is a growing demand for commodities (elements, compounds, minerals) used in today's advanced technologies. Critical minerals are usually found in ore deposits that are deemed vital to economic and national security. The National Geochemical Database on Ore Deposits: Legacy data (NGDOD) contains chemistry and geologic information for nearly 30,000 historic ore and ore-related rock...
Melt inclusion and mineral geochemical analyses supporting the evaluation of petrogenesis, degassing, and metallogenic potential of mid-Cenozoic rhyolite magmas in northern Nevada, USA (ver. 2.0, March 2025) Melt inclusion and mineral geochemical analyses supporting the evaluation of petrogenesis, degassing, and metallogenic potential of mid-Cenozoic rhyolite magmas in northern Nevada, USA (ver. 2.0, March 2025)
This data release presents geochemical analyses of silicate melt inclusions, host quartz phenocrysts, and biotite phenocrysts in samples collected by the U.S. Geological Survey (USGS) from mid-Cenozoic rhyolitic rocks from northern Nevada. Igneous intrusions and volcanic rocks in this study encompass nineteen rhyolitic samples from five magmatic centers across northeastern Nevada...
Global Geochemical Database for Critical Minerals in Archived Mine Samples Global Geochemical Database for Critical Minerals in Archived Mine Samples
The Critical Minerals in Archived Mine Samples Database (CMDB) contains chemistry and geologic information for historic ore and ore-related rock samples from mineral deposits in the United States. In addition, the database contains samples from archetypal deposits from 27 other countries in North America, South America, Asia, Africa and Europe. Samples were obtained from archived ore...
GIS and Data Tables for Focus Areas for Potential Domestic Nonfuel Sources of Rare Earth Elements 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...
Fluid Inclusion Noble Gas Data From Goldfield and Tonopah Epithermal Au-Ag Deposits Fluid Inclusion Noble Gas Data From Goldfield and Tonopah Epithermal Au-Ag Deposits
Twenty-five ore and gangue mineral separates from the Miocene-age Goldfield and Tonopah epithermal Au-Ag deposits in southwestern Nevada were analyzed to determine the helium, neon, and argon (He, Ne, and Ar) isotopic compositions contained in fluid inclusions. Four mineral separates from the Butte Main Stage vein deposit and two from the Bingham pyrite-enargite vein deposits were also...
Locatable Mineral Assessment Tracts for the U.S. Geological Survey Sagebrush Mineral Resource Assessment Project 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...
Improved Automated Identification and Mapping of Iron Sulfate Minerals, Other Mineral Groups, and Vegetation using Landsat 8 Operational Land Imager Data, San Juan Mountains, Colorado, and Four Corners Region Improved Automated Identification and Mapping of Iron Sulfate Minerals, Other Mineral Groups, and Vegetation using Landsat 8 Operational Land Imager Data, San Juan Mountains, Colorado, and Four Corners Region
Multispectral remote sensing data acquired by the Landsat 8 Operational Land Imager (OLI) sensor were analyzed using a new, automated technique to generate a map of exposed mineral and vegetation groups in the western San Juan Mountains, Colo., and the Four Corners Region of the United States. Band ratio results were combined into displayed mineral and vegetation groups using Boolean...
Filter Total Items: 81
Pre-eruptive characteristics of “suspect” silicic magmas in Carlin-type Au-forming systems Pre-eruptive characteristics of “suspect” silicic magmas in Carlin-type Au-forming systems
World-class Carlin-type Au deposits hosted in sedimentary rock were formed when profuse Eocene silicic magmatism swept across northern Nevada in response to arc migration. Carlin-type Au deposits formed along with porphyry/skarn Cu-Mo-W-Au deposits, epithermal Ag-Au deposits, and distal disseminated Ag-Au deposits. But unlike these other Au-bearing deposits that have clear associations...
Authors
Celestine N. Mercer, Julie Roberge, Regina Marie Khoury, Albert H. Hofstra
Critical mineral inventory of select IOA-IOCG deposits, southwestern USA Critical mineral inventory of select IOA-IOCG deposits, southwestern USA
Critical minerals are necessary for modern technology and strategic purposes. Their increasing importance requires finding new and nontraditional resources. Samples of ore, altered, and unaltered host rock were collected from 26 iron mines and prospects in California, Nevada, and Utah to assess the potential of these deposits to host economic quantities of different critical minerals...
Authors
Ryan D. Taylor, Corey J. Meighan, Albert H. Hofstra
Critical minerals in orogenic (gold) and Coeur d’Alene-type mineral systems of the United States Critical minerals in orogenic (gold) and Coeur d’Alene-type mineral systems of the United States
Orogenic and Coeur d’Alene-type mineral systems are produced by metamorphic devolatilization of thick volcanic or siliciclastic sedimentary rock sequences and the focused flow of hydrothermal fluids upwards along crustal-scale faults. Most orogenic systems are found along the Cordilleran orogen, stretching from California northwards into Alaska, whereas most Coeur d’Alene-type systems...
Authors
Ryan D. Taylor, Albert H. Hofstra
Metal fingerprints of Eocene rhyolite magmas coincident with Carlin-type gold deposition in Nevada USA Metal fingerprints of Eocene rhyolite magmas coincident with Carlin-type gold deposition in Nevada USA
Eocene magmatic systems contemporaneous with world-class Carlin-type Au deposits in Nevada (USA) have been proposed by some researchers as a key ingredient for Au mineralization, though evidence conclusively demonstrating their genetic relationship remains tenuous. This study provides the first direct evidence of the pre-eruptive metal budget of volatile- and metal-charged silicic magmas
Authors
Celestine N. Mercer, Hannah R. Babel, Cameron Mark Mercer, Albert H. Hofstra
Critical Minerals in Ores (CMiO) database Critical Minerals in Ores (CMiO) database
Critical minerals are commodities essential to modern industrial and strategic technologies and are highly vulnerable to supply chain disruption. The Critical Minerals Mapping Initiative (CMMI) is a collaboration among the U.S. Geological Survey (USGS), the Geological Survey of Canada, and Geoscience Australia that aims to deepen global understanding of where critical minerals are...
Authors
George N.D. Case, Garth E. Graham, Christopher Lawley, Evgeniy Bastrakov, David Huston, Albert H. Hofstra, Vladimir Lisitsin, Steph Hawkins, Bronwen Wang
Critical minerals in Climax-type magmatic-hydrothermal systems Critical minerals in Climax-type magmatic-hydrothermal systems
Today’s global economy is challenged to meet the growing demand for commodities used in existing and emerging advanced technologies. Critical minerals are commodities found in a wide variety of ore deposits that are vital to the economic or national security of individual nations that are vulnerable to supply disruption. The U.S. Geological Survey is striving to advance understanding of...
Authors
Celestine N. Mercer, Mario A Guzman, Albert H. Hofstra, Joshua Mark Rosera
Stable isotope constraints on the source of ore fluids for the Hicks Dome REE+Y-HFSE-fluorspar deposit Stable isotope constraints on the source of ore fluids for the Hicks Dome REE+Y-HFSE-fluorspar deposit
Hicks Dome is comprised of coarse crystalline Mississippi Valley Type deposits at shallow levels and an enigmatic, fine-grained fluorite, rare earth elements, Y, high field strength elements, Be, and Ba rich deposit at deeper levels. Phyllosilicates from a lamprophyre dike and a breccia from two Hicks Dome drill cores were sampled to resolve the fluid history of the entire deposit using...
Authors
Julia A. McIntosh, Craig A. Johnson, Allen K. Andersen, Albert H. Hofstra
40Ar/39Ar geochronology of magmatic-steam alunite from Alunite Ridge and Deer Trail Mountain, Marysvale Volcanic Field, Utah: Timing and duration of miocene hydrothermal activity associated with concealed intrusions 40Ar/39Ar geochronology of magmatic-steam alunite from Alunite Ridge and Deer Trail Mountain, Marysvale Volcanic Field, Utah: Timing and duration of miocene hydrothermal activity associated with concealed intrusions
Porphyry and epithermal deposits are important sources of base and precious metals. Most actively mined deposits have been exhumed such that ore bodies are relatively close to the surface and are therefore locatable and economic to extract. Identifying and characterizing concealed deposits, particularly more deeply buried porphyry deposits, represents a far greater challenge for mineral
Authors
Cameron Mark Mercer, M. Cosca, Albert H. Hofstra, Wayne R. Premo, Robert O. Rye, Gary P. Landis
A case of Te-rich low-sulfidation epithermal Au-Ag deposits in a calc-alkaline magmatic arc, NE China A case of Te-rich low-sulfidation epithermal Au-Ag deposits in a calc-alkaline magmatic arc, NE China
Tellurium-bearing low-sulfidation epithermal Au-Ag deposits are significant producers of gold, silver, and potentially strategic elements if mineral processing methods are optimized for recovery. Although these deposits are generally related to alkaline magmatism, our study documents an unusual occurrence of Te-rich low-sulfidation epithermal systems in the North Heilongjiang Belt in...
Authors
Shen Gao, Albert H. Hofstra, K. Qin, H. Xue
Focus areas for data acquisition for potential domestic resources of 13 critical minerals in the conterminous United States and Puerto Rico — Antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadiu Focus areas for data acquisition for potential domestic resources of 13 critical minerals in the conterminous United States and Puerto Rico — Antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadiu
The Earth Mapping Resources Initiative (Earth MRI) is conducted in phases to identify areas for acquiring new geologic framework data to identify potential domestic resources of the 35 mineral materials designated as critical minerals for the United States. This report describes the data sources and summary results for 13 critical minerals evaluated in the conterminous United States and...
Authors
Jane M. Hammarstrom, Connie L. Dicken, Laurel G. Woodruff, Allen K. Andersen, Sean T. Brennan, Warren C. Day, Benjamin J. Drenth, Nora K. Foley, Susan Hall, Albert H. Hofstra, Anne E. McCafferty, Anjana K. Shah, David A. Ponce
By
Geology, Energy, and Minerals Mission Area, Mineral Resources Program, Central Energy Resources Science Center, Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Earth Mapping Resources Initiative (Earth MRI)
Deposit classification scheme for the Critical Minerals Mapping Initiative Global Geochemical Database Deposit classification scheme for the Critical Minerals Mapping Initiative Global Geochemical Database
A challenge for the global economy is to meet the growing demand for commodities used in today’s advanced technologies. Critical minerals are commodities (for example, elements, compounds, minerals) deemed vital to the economic and national security of individual countries that are vulnerable to supply disruption. The national geological agencies of Australia, Canada, and the United...
Authors
Albert H. Hofstra, Vladimir Lisitsin, Louise Corriveau, Suzanne Paradis, Jan Peter, Kathleen Lauziere, Christopher Lawley, Michael Gadd, Jean-Luc Pilote, Ian Honsberger, Evgeniy Bastrakov, David Champion, Karol Czarnota, Michael Doublier, David Huston, Oliver Raymond, Simon VanDerWielen, Poul Emsbo, Matthew Granitto, Douglas C. Kreiner
Focus areas for data acquisition for potential domestic resources of 11 critical minerals in the conterminous United States, Hawaii, and Puerto Rico—Aluminum, cobalt, graphite, lithium, niobium, platinum-group elements, rare earth elements, tantalum, tin, Focus areas for data acquisition for potential domestic resources of 11 critical minerals in the conterminous United States, Hawaii, and Puerto Rico—Aluminum, cobalt, graphite, lithium, niobium, platinum-group elements, rare earth elements, tantalum, tin,
In response to a need for information on potential domestic sources of critical minerals, the Earth Mapping Resources Initiative (Earth MRI) was established to identify and prioritize areas for acquisition of new geologic mapping, geophysical data, and elevation data to improve our knowledge of the geologic framework of the United States. Phase 1 of Earth MRI concentrated on those...
Authors
Jane M. Hammarstrom, Connie L. Dicken, Warren C. Day, Albert H. Hofstra, Benjamin J. Drenth, Anjana K. Shah, Anne E. McCafferty, Laurel G. Woodruff, Nora K. Foley, David A. Ponce, Thomas P. Frost, Lisa L. Stillings
Science and Products
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...
Lithium from Source to Sink: Genesis and Evolution of Li Brines and Clays
The purpose of this project is to trace the lithium (Li) geochemical cycle in the Great Basin, with an emphasis on the pathways that lead to the development of lithium clay and brine resources.
National Geochemical Database on Ore Deposits: New data featuring fusion digestion analytical methods National Geochemical Database on Ore Deposits: New data featuring fusion digestion analytical methods
There is a growing demand for commodities (elements, compounds, minerals) used in today's advanced technologies. Critical minerals are usually found in ore deposits that are deemed vital to economic and national security. National Geochemical Database on Ore Deposits: New data featuring fusion digestion (NGDOD) analytical methods contains chemistry and geologic information for 16,579 ore...
Noble Gas Isotopic Data from Fluid Inclusions Contained in the Te-bearing Adularia-Sericite Epithermal Au-Ag Deposits in a Calc-Alkaline Magmatic Arc, NE China Noble Gas Isotopic Data from Fluid Inclusions Contained in the Te-bearing Adularia-Sericite Epithermal Au-Ag Deposits in a Calc-Alkaline Magmatic Arc, NE China
The contents of this data release represent the results of the noble gas composition analysis and are presented in support of the planned publication Gao et al., 2023, titled Lead and noble gas isotopic constraints on the origin of Te-bearing adularia-sericite epithermal Au-Ag deposits in a calc-alkaline magmatic arc. Tellurium (Te)-bearing adularia-sericite epithermal Au-Ag deposits are...
Trace element chemistry of sulfides and quartz, in situ sulfur isotope values of sulfides, cathodoluminescence of quartz, fluid inclusion microthermometry and raman, and radiogenic isotope and whole rock geochemistry from the Stibnite-Yellow Pine district Trace element chemistry of sulfides and quartz, in situ sulfur isotope values of sulfides, cathodoluminescence of quartz, fluid inclusion microthermometry and raman, and radiogenic isotope and whole rock geochemistry from the Stibnite-Yellow Pine district
This dataset is a collection of geochemical data on samples from the Stibnite-Yellow Pine district of Idaho. The datasets include: whole rock geochemistry; lead, strontium and neodymium isotope chemistry of sulfides and whole rock samples by isotope dilution-thermal-mass spectrometry (ID-TIMS); in situ sulfur isotope chemistry of sulfides by laser ablation-multi collector-inductively...
National Geochemical Database on Ore Deposits: Legacy data National Geochemical Database on Ore Deposits: Legacy data
There is a growing demand for commodities (elements, compounds, minerals) used in today's advanced technologies. Critical minerals are usually found in ore deposits that are deemed vital to economic and national security. The National Geochemical Database on Ore Deposits: Legacy data (NGDOD) contains chemistry and geologic information for nearly 30,000 historic ore and ore-related rock...
Melt inclusion and mineral geochemical analyses supporting the evaluation of petrogenesis, degassing, and metallogenic potential of mid-Cenozoic rhyolite magmas in northern Nevada, USA (ver. 2.0, March 2025) Melt inclusion and mineral geochemical analyses supporting the evaluation of petrogenesis, degassing, and metallogenic potential of mid-Cenozoic rhyolite magmas in northern Nevada, USA (ver. 2.0, March 2025)
This data release presents geochemical analyses of silicate melt inclusions, host quartz phenocrysts, and biotite phenocrysts in samples collected by the U.S. Geological Survey (USGS) from mid-Cenozoic rhyolitic rocks from northern Nevada. Igneous intrusions and volcanic rocks in this study encompass nineteen rhyolitic samples from five magmatic centers across northeastern Nevada...
Global Geochemical Database for Critical Minerals in Archived Mine Samples Global Geochemical Database for Critical Minerals in Archived Mine Samples
The Critical Minerals in Archived Mine Samples Database (CMDB) contains chemistry and geologic information for historic ore and ore-related rock samples from mineral deposits in the United States. In addition, the database contains samples from archetypal deposits from 27 other countries in North America, South America, Asia, Africa and Europe. Samples were obtained from archived ore...
GIS and Data Tables for Focus Areas for Potential Domestic Nonfuel Sources of Rare Earth Elements 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...
Fluid Inclusion Noble Gas Data From Goldfield and Tonopah Epithermal Au-Ag Deposits Fluid Inclusion Noble Gas Data From Goldfield and Tonopah Epithermal Au-Ag Deposits
Twenty-five ore and gangue mineral separates from the Miocene-age Goldfield and Tonopah epithermal Au-Ag deposits in southwestern Nevada were analyzed to determine the helium, neon, and argon (He, Ne, and Ar) isotopic compositions contained in fluid inclusions. Four mineral separates from the Butte Main Stage vein deposit and two from the Bingham pyrite-enargite vein deposits were also...
Locatable Mineral Assessment Tracts for the U.S. Geological Survey Sagebrush Mineral Resource Assessment Project 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...
Improved Automated Identification and Mapping of Iron Sulfate Minerals, Other Mineral Groups, and Vegetation using Landsat 8 Operational Land Imager Data, San Juan Mountains, Colorado, and Four Corners Region Improved Automated Identification and Mapping of Iron Sulfate Minerals, Other Mineral Groups, and Vegetation using Landsat 8 Operational Land Imager Data, San Juan Mountains, Colorado, and Four Corners Region
Multispectral remote sensing data acquired by the Landsat 8 Operational Land Imager (OLI) sensor were analyzed using a new, automated technique to generate a map of exposed mineral and vegetation groups in the western San Juan Mountains, Colo., and the Four Corners Region of the United States. Band ratio results were combined into displayed mineral and vegetation groups using Boolean...
Filter Total Items: 81
Pre-eruptive characteristics of “suspect” silicic magmas in Carlin-type Au-forming systems Pre-eruptive characteristics of “suspect” silicic magmas in Carlin-type Au-forming systems
World-class Carlin-type Au deposits hosted in sedimentary rock were formed when profuse Eocene silicic magmatism swept across northern Nevada in response to arc migration. Carlin-type Au deposits formed along with porphyry/skarn Cu-Mo-W-Au deposits, epithermal Ag-Au deposits, and distal disseminated Ag-Au deposits. But unlike these other Au-bearing deposits that have clear associations...
Authors
Celestine N. Mercer, Julie Roberge, Regina Marie Khoury, Albert H. Hofstra
Critical mineral inventory of select IOA-IOCG deposits, southwestern USA Critical mineral inventory of select IOA-IOCG deposits, southwestern USA
Critical minerals are necessary for modern technology and strategic purposes. Their increasing importance requires finding new and nontraditional resources. Samples of ore, altered, and unaltered host rock were collected from 26 iron mines and prospects in California, Nevada, and Utah to assess the potential of these deposits to host economic quantities of different critical minerals...
Authors
Ryan D. Taylor, Corey J. Meighan, Albert H. Hofstra
Critical minerals in orogenic (gold) and Coeur d’Alene-type mineral systems of the United States Critical minerals in orogenic (gold) and Coeur d’Alene-type mineral systems of the United States
Orogenic and Coeur d’Alene-type mineral systems are produced by metamorphic devolatilization of thick volcanic or siliciclastic sedimentary rock sequences and the focused flow of hydrothermal fluids upwards along crustal-scale faults. Most orogenic systems are found along the Cordilleran orogen, stretching from California northwards into Alaska, whereas most Coeur d’Alene-type systems...
Authors
Ryan D. Taylor, Albert H. Hofstra
Metal fingerprints of Eocene rhyolite magmas coincident with Carlin-type gold deposition in Nevada USA Metal fingerprints of Eocene rhyolite magmas coincident with Carlin-type gold deposition in Nevada USA
Eocene magmatic systems contemporaneous with world-class Carlin-type Au deposits in Nevada (USA) have been proposed by some researchers as a key ingredient for Au mineralization, though evidence conclusively demonstrating their genetic relationship remains tenuous. This study provides the first direct evidence of the pre-eruptive metal budget of volatile- and metal-charged silicic magmas
Authors
Celestine N. Mercer, Hannah R. Babel, Cameron Mark Mercer, Albert H. Hofstra
Critical Minerals in Ores (CMiO) database Critical Minerals in Ores (CMiO) database
Critical minerals are commodities essential to modern industrial and strategic technologies and are highly vulnerable to supply chain disruption. The Critical Minerals Mapping Initiative (CMMI) is a collaboration among the U.S. Geological Survey (USGS), the Geological Survey of Canada, and Geoscience Australia that aims to deepen global understanding of where critical minerals are...
Authors
George N.D. Case, Garth E. Graham, Christopher Lawley, Evgeniy Bastrakov, David Huston, Albert H. Hofstra, Vladimir Lisitsin, Steph Hawkins, Bronwen Wang
Critical minerals in Climax-type magmatic-hydrothermal systems Critical minerals in Climax-type magmatic-hydrothermal systems
Today’s global economy is challenged to meet the growing demand for commodities used in existing and emerging advanced technologies. Critical minerals are commodities found in a wide variety of ore deposits that are vital to the economic or national security of individual nations that are vulnerable to supply disruption. The U.S. Geological Survey is striving to advance understanding of...
Authors
Celestine N. Mercer, Mario A Guzman, Albert H. Hofstra, Joshua Mark Rosera
Stable isotope constraints on the source of ore fluids for the Hicks Dome REE+Y-HFSE-fluorspar deposit Stable isotope constraints on the source of ore fluids for the Hicks Dome REE+Y-HFSE-fluorspar deposit
Hicks Dome is comprised of coarse crystalline Mississippi Valley Type deposits at shallow levels and an enigmatic, fine-grained fluorite, rare earth elements, Y, high field strength elements, Be, and Ba rich deposit at deeper levels. Phyllosilicates from a lamprophyre dike and a breccia from two Hicks Dome drill cores were sampled to resolve the fluid history of the entire deposit using...
Authors
Julia A. McIntosh, Craig A. Johnson, Allen K. Andersen, Albert H. Hofstra
40Ar/39Ar geochronology of magmatic-steam alunite from Alunite Ridge and Deer Trail Mountain, Marysvale Volcanic Field, Utah: Timing and duration of miocene hydrothermal activity associated with concealed intrusions 40Ar/39Ar geochronology of magmatic-steam alunite from Alunite Ridge and Deer Trail Mountain, Marysvale Volcanic Field, Utah: Timing and duration of miocene hydrothermal activity associated with concealed intrusions
Porphyry and epithermal deposits are important sources of base and precious metals. Most actively mined deposits have been exhumed such that ore bodies are relatively close to the surface and are therefore locatable and economic to extract. Identifying and characterizing concealed deposits, particularly more deeply buried porphyry deposits, represents a far greater challenge for mineral
Authors
Cameron Mark Mercer, M. Cosca, Albert H. Hofstra, Wayne R. Premo, Robert O. Rye, Gary P. Landis
A case of Te-rich low-sulfidation epithermal Au-Ag deposits in a calc-alkaline magmatic arc, NE China A case of Te-rich low-sulfidation epithermal Au-Ag deposits in a calc-alkaline magmatic arc, NE China
Tellurium-bearing low-sulfidation epithermal Au-Ag deposits are significant producers of gold, silver, and potentially strategic elements if mineral processing methods are optimized for recovery. Although these deposits are generally related to alkaline magmatism, our study documents an unusual occurrence of Te-rich low-sulfidation epithermal systems in the North Heilongjiang Belt in...
Authors
Shen Gao, Albert H. Hofstra, K. Qin, H. Xue
Focus areas for data acquisition for potential domestic resources of 13 critical minerals in the conterminous United States and Puerto Rico — Antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadiu Focus areas for data acquisition for potential domestic resources of 13 critical minerals in the conterminous United States and Puerto Rico — Antimony, barite, beryllium, chromium, fluorspar, hafnium, helium, magnesium, manganese, potash, uranium, vanadiu
The Earth Mapping Resources Initiative (Earth MRI) is conducted in phases to identify areas for acquiring new geologic framework data to identify potential domestic resources of the 35 mineral materials designated as critical minerals for the United States. This report describes the data sources and summary results for 13 critical minerals evaluated in the conterminous United States and...
Authors
Jane M. Hammarstrom, Connie L. Dicken, Laurel G. Woodruff, Allen K. Andersen, Sean T. Brennan, Warren C. Day, Benjamin J. Drenth, Nora K. Foley, Susan Hall, Albert H. Hofstra, Anne E. McCafferty, Anjana K. Shah, David A. Ponce
By
Geology, Energy, and Minerals Mission Area, Mineral Resources Program, Central Energy Resources Science Center, Geology, Energy & Minerals Science Center, Geology, Geophysics, and Geochemistry Science Center, Geology, Minerals, Energy, and Geophysics Science Center, Earth Mapping Resources Initiative (Earth MRI)
Deposit classification scheme for the Critical Minerals Mapping Initiative Global Geochemical Database Deposit classification scheme for the Critical Minerals Mapping Initiative Global Geochemical Database
A challenge for the global economy is to meet the growing demand for commodities used in today’s advanced technologies. Critical minerals are commodities (for example, elements, compounds, minerals) deemed vital to the economic and national security of individual countries that are vulnerable to supply disruption. The national geological agencies of Australia, Canada, and the United...
Authors
Albert H. Hofstra, Vladimir Lisitsin, Louise Corriveau, Suzanne Paradis, Jan Peter, Kathleen Lauziere, Christopher Lawley, Michael Gadd, Jean-Luc Pilote, Ian Honsberger, Evgeniy Bastrakov, David Champion, Karol Czarnota, Michael Doublier, David Huston, Oliver Raymond, Simon VanDerWielen, Poul Emsbo, Matthew Granitto, Douglas C. Kreiner
Focus areas for data acquisition for potential domestic resources of 11 critical minerals in the conterminous United States, Hawaii, and Puerto Rico—Aluminum, cobalt, graphite, lithium, niobium, platinum-group elements, rare earth elements, tantalum, tin, Focus areas for data acquisition for potential domestic resources of 11 critical minerals in the conterminous United States, Hawaii, and Puerto Rico—Aluminum, cobalt, graphite, lithium, niobium, platinum-group elements, rare earth elements, tantalum, tin,
In response to a need for information on potential domestic sources of critical minerals, the Earth Mapping Resources Initiative (Earth MRI) was established to identify and prioritize areas for acquisition of new geologic mapping, geophysical data, and elevation data to improve our knowledge of the geologic framework of the United States. Phase 1 of Earth MRI concentrated on those...
Authors
Jane M. Hammarstrom, Connie L. Dicken, Warren C. Day, Albert H. Hofstra, Benjamin J. Drenth, Anjana K. Shah, Anne E. McCafferty, Laurel G. Woodruff, Nora K. Foley, David A. Ponce, Thomas P. Frost, Lisa L. Stillings