Steve Ludington
Steve is a Geologist Emeritus at Geology, Minerals, Energy, and Geophysics Science Center in Menlo Park, CA. He is a graduate of Stanford University (B.S.) and the University of Colorado (M.S. and Ph.D.). He joined the USGS in 1974 and retired from full-time work in 2012. His skills are in petrology, volcanology, mineral deposit controls, and mineral-resource assessment.
Science and Products
Whole-Rock Geochemical Data for Cenozoic Silicic Igneous and Hydrothermal Rocks from Colorado, New Mexico, Arizona, Nevada, and California Whole-Rock Geochemical Data for Cenozoic Silicic Igneous and Hydrothermal Rocks from Colorado, New Mexico, Arizona, Nevada, and California
This data release presents whole-rock geochemical data for a suite of silicic igneous and magmatic-hydrothermal rocks from the western Cordillera of the United States. Samples were mainly collected from Eocene to Miocene high-silica igneous rocks and other nearby igneous and hydrothermal±magmatic rocks. These data were collected to help define highly evolved magma systems that can be...
Cenozoic Highly Evolved Rhyolites of the Western Cordillera of the Conterminous United States Cenozoic Highly Evolved Rhyolites of the Western Cordillera of the Conterminous United States
The use of data analytics and digital mineral prospectivity mapping has become increasingly important to mineral resource assessment in recent years. Necessary information for many forms of such modeling are expert-validated training sets. Previous work defined occurrence and grade and tonnage models for Climax-type porphyry molybdenum deposits (Singer and others, 1986; Ludington and...
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...
Filter Total Items: 17
Porphyry copper potential of the U.S. Southern Basin and Range using ASTER data integrated with geochemical and geologic datasets to assess potential near-surface deposits in well-explored permissive tracts Porphyry copper potential of the U.S. Southern Basin and Range using ASTER data integrated with geochemical and geologic datasets to assess potential near-surface deposits in well-explored permissive tracts
ArcGIS was used to spatially assess and rank potential porphyry copper deposits using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data together with geochemical and geologic datasets in order to estimate undiscovered deposits in the southern Basin and Range Province in the southwestern United States. The assessment was done using a traditional expert opinion...
Authors
John C. Mars, Robinson, Jane M. Hammarstrom, Lukas Zurcher, Helen A. Whitney, Federico Solano, Mark E. Gettings, Stephen Ludington
Tectono-magmatic evolution of porphyry belts in the central Tethys region of Turkey, the Caucasus, Iran, western Pakistan, and southern Afghanistan Tectono-magmatic evolution of porphyry belts in the central Tethys region of Turkey, the Caucasus, Iran, western Pakistan, and southern Afghanistan
Exploration in the central Tethys region of Turkey, Armenia, Azerbaijan, Georgia, Iran, and western Pakistan has led to the identification of the giant Reko Diq (24 Mt Cu and 1300 t Au), Sar Cheshmeh (8.9 Mt Cu and 0.46 Mt Mo), Sungun (5.1 Mt Cu and 0.20 Mt Mo), and Kadjaran (4.6 Mt Cu, 0.94 Mt Mo, and 1100 t Au), and 10 other large (1–2 Mt Cu) porphyry deposits including Saindak...
Authors
Lukas Zurcher, Arthur A. Bookstrom, Jane M. Hammarstrom, John C. Mars, Stephen Ludington, Michael L. Zientek, Pamela Dunlap, John Wallis
Probabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report Probabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report
The U.S. Geological Survey is partnering with the IberoAmerican Association of Geological and Mining Surveys (ASGMI) to conduct an assessment of undiscovered metallic and non-metallic resources in the Greater Antilles region. The assessment plans to provide science-based information on the geologic availability of these resources for development, land-use planning, and decision making...
Authors
Lukas Zurcher, Floyd Gray, Stephen Ludington, Frederic H. Wilson, Greta J. Orris, Mark D. Cocker, Mark E. Gettings, Timothy Hayes
New method to integrate remotely sensed hydrothermal alteration mapping into quantitative mineral resource assessments New method to integrate remotely sensed hydrothermal alteration mapping into quantitative mineral resource assessments
Hydrothermal alteration data mapped using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were compiled into hydrothermal alteration polygons for use in an assessment of porphyry copper mineral resource potential in the southwestern United States. Hydrothermal alteration polygons along with geochemistry, gravity and magnetic, lithologic, and deposit and...
Authors
John C. Mars, Jane M. Hammarstrom, Gilpin R. Robinson, Stephen Ludington, Lukas Zurcher, Helen W. Folger, Mark E. Gettings, Federico Solano, Thomas Kress
Undiscovered porphyry copper resources in the Urals—A probabilistic mineral resource assessment Undiscovered porphyry copper resources in the Urals—A probabilistic mineral resource assessment
A probabilistic mineral resource assessment of metal resources in undiscovered porphyry copper deposits of the Ural Mountains in Russia and Kazakhstan was done using a quantitative form of mineral resource assessment. Permissive tracts were delineated on the basis of mapped and inferred subsurface distributions of igneous rocks assigned to tectonic zones that include magmatic arcs where...
Authors
Jane M. Hammarstrom, Mark J. Mihalasky, Stephen Ludington, Jeffrey Phillips, Byron R. Berger, Paul Denning, Connie Dicken, John C. Mars, Michael L. Zientek, Richard J. Herrington, Reimar Seltmann
Geology and mineral resources of the Sheldon-Hart Mountain National Wildlife Refuge Complex (Oregon and Nevada), the Southeastern Oregon and North-Central Nevada, and the Southern Idaho and Northern Nevada (and Utah) Sagebrush Focal Areas: Chapter B in Geology and mineral resources of the Sheldon-Hart Mountain National Wildlife Refuge Complex (Oregon and Nevada), the Southeastern Oregon and North-Central Nevada, and the Southern Idaho and Northern Nevada (and Utah) Sagebrush Focal Areas: Chapter B in
Summary The U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see Scientific Investigations Report 2016–5089–A)...
Authors
Peter G. Vikre, Mary Ellen Benson, Donald I. Bleiwas, Joseph P. Colgan, Pamela M. Cossette, Jacob DeAngelo, Connie L. Dicken, Ronald M. Drake, Edward A. du Bray, Gregory L. Fernette, Jonathan M. G. Glen, Jon E. Haacke, Susan M. Hall, Albert H. Hofstra, David A. John, Stephen Ludington, Mark J. Mihalasky, James J. Rytuba, Brian N. Shaffer, Lisa L. Stillings, John C. Wallis, Colin F. Williams, Douglas B. Yager, Lukas Zürcher
By
Geology, Energy, and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, National Minerals Information Center
Science and Products
Whole-Rock Geochemical Data for Cenozoic Silicic Igneous and Hydrothermal Rocks from Colorado, New Mexico, Arizona, Nevada, and California Whole-Rock Geochemical Data for Cenozoic Silicic Igneous and Hydrothermal Rocks from Colorado, New Mexico, Arizona, Nevada, and California
This data release presents whole-rock geochemical data for a suite of silicic igneous and magmatic-hydrothermal rocks from the western Cordillera of the United States. Samples were mainly collected from Eocene to Miocene high-silica igneous rocks and other nearby igneous and hydrothermal±magmatic rocks. These data were collected to help define highly evolved magma systems that can be...
Cenozoic Highly Evolved Rhyolites of the Western Cordillera of the Conterminous United States Cenozoic Highly Evolved Rhyolites of the Western Cordillera of the Conterminous United States
The use of data analytics and digital mineral prospectivity mapping has become increasingly important to mineral resource assessment in recent years. Necessary information for many forms of such modeling are expert-validated training sets. Previous work defined occurrence and grade and tonnage models for Climax-type porphyry molybdenum deposits (Singer and others, 1986; Ludington and...
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...
Filter Total Items: 17
Porphyry copper potential of the U.S. Southern Basin and Range using ASTER data integrated with geochemical and geologic datasets to assess potential near-surface deposits in well-explored permissive tracts Porphyry copper potential of the U.S. Southern Basin and Range using ASTER data integrated with geochemical and geologic datasets to assess potential near-surface deposits in well-explored permissive tracts
ArcGIS was used to spatially assess and rank potential porphyry copper deposits using Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data together with geochemical and geologic datasets in order to estimate undiscovered deposits in the southern Basin and Range Province in the southwestern United States. The assessment was done using a traditional expert opinion...
Authors
John C. Mars, Robinson, Jane M. Hammarstrom, Lukas Zurcher, Helen A. Whitney, Federico Solano, Mark E. Gettings, Stephen Ludington
Tectono-magmatic evolution of porphyry belts in the central Tethys region of Turkey, the Caucasus, Iran, western Pakistan, and southern Afghanistan Tectono-magmatic evolution of porphyry belts in the central Tethys region of Turkey, the Caucasus, Iran, western Pakistan, and southern Afghanistan
Exploration in the central Tethys region of Turkey, Armenia, Azerbaijan, Georgia, Iran, and western Pakistan has led to the identification of the giant Reko Diq (24 Mt Cu and 1300 t Au), Sar Cheshmeh (8.9 Mt Cu and 0.46 Mt Mo), Sungun (5.1 Mt Cu and 0.20 Mt Mo), and Kadjaran (4.6 Mt Cu, 0.94 Mt Mo, and 1100 t Au), and 10 other large (1–2 Mt Cu) porphyry deposits including Saindak...
Authors
Lukas Zurcher, Arthur A. Bookstrom, Jane M. Hammarstrom, John C. Mars, Stephen Ludington, Michael L. Zientek, Pamela Dunlap, John Wallis
Probabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report Probabilistic mineral resource assessment of U.S. Territories of the Caribbean Basin and adjacent areas: Progress report
The U.S. Geological Survey is partnering with the IberoAmerican Association of Geological and Mining Surveys (ASGMI) to conduct an assessment of undiscovered metallic and non-metallic resources in the Greater Antilles region. The assessment plans to provide science-based information on the geologic availability of these resources for development, land-use planning, and decision making...
Authors
Lukas Zurcher, Floyd Gray, Stephen Ludington, Frederic H. Wilson, Greta J. Orris, Mark D. Cocker, Mark E. Gettings, Timothy Hayes
New method to integrate remotely sensed hydrothermal alteration mapping into quantitative mineral resource assessments New method to integrate remotely sensed hydrothermal alteration mapping into quantitative mineral resource assessments
Hydrothermal alteration data mapped using the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were compiled into hydrothermal alteration polygons for use in an assessment of porphyry copper mineral resource potential in the southwestern United States. Hydrothermal alteration polygons along with geochemistry, gravity and magnetic, lithologic, and deposit and...
Authors
John C. Mars, Jane M. Hammarstrom, Gilpin R. Robinson, Stephen Ludington, Lukas Zurcher, Helen W. Folger, Mark E. Gettings, Federico Solano, Thomas Kress
Undiscovered porphyry copper resources in the Urals—A probabilistic mineral resource assessment Undiscovered porphyry copper resources in the Urals—A probabilistic mineral resource assessment
A probabilistic mineral resource assessment of metal resources in undiscovered porphyry copper deposits of the Ural Mountains in Russia and Kazakhstan was done using a quantitative form of mineral resource assessment. Permissive tracts were delineated on the basis of mapped and inferred subsurface distributions of igneous rocks assigned to tectonic zones that include magmatic arcs where...
Authors
Jane M. Hammarstrom, Mark J. Mihalasky, Stephen Ludington, Jeffrey Phillips, Byron R. Berger, Paul Denning, Connie Dicken, John C. Mars, Michael L. Zientek, Richard J. Herrington, Reimar Seltmann
Geology and mineral resources of the Sheldon-Hart Mountain National Wildlife Refuge Complex (Oregon and Nevada), the Southeastern Oregon and North-Central Nevada, and the Southern Idaho and Northern Nevada (and Utah) Sagebrush Focal Areas: Chapter B in Geology and mineral resources of the Sheldon-Hart Mountain National Wildlife Refuge Complex (Oregon and Nevada), the Southeastern Oregon and North-Central Nevada, and the Southern Idaho and Northern Nevada (and Utah) Sagebrush Focal Areas: Chapter B in
Summary The U.S. Department of the Interior has proposed to withdraw approximately 10 million acres of Federal lands from mineral entry (subject to valid existing rights) from 12 million acres of lands defined as Sagebrush Focal Areas (SFAs) in Idaho, Montana, Nevada, Oregon, Utah, and Wyoming (for further discussion on the lands involved see Scientific Investigations Report 2016–5089–A)...
Authors
Peter G. Vikre, Mary Ellen Benson, Donald I. Bleiwas, Joseph P. Colgan, Pamela M. Cossette, Jacob DeAngelo, Connie L. Dicken, Ronald M. Drake, Edward A. du Bray, Gregory L. Fernette, Jonathan M. G. Glen, Jon E. Haacke, Susan M. Hall, Albert H. Hofstra, David A. John, Stephen Ludington, Mark J. Mihalasky, James J. Rytuba, Brian N. Shaffer, Lisa L. Stillings, John C. Wallis, Colin F. Williams, Douglas B. Yager, Lukas Zürcher
By
Geology, Energy, and Minerals Mission Area, Energy Resources Program, Mineral Resources Program, National Laboratories Program, Science and Decisions Center, Geology, Minerals, Energy, and Geophysics Science Center, Geology, Geophysics, and Geochemistry Science Center, National Minerals Information Center