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At least 1,189 records · Page 66Linked to original sources
USGS1990

Map showing distribution of cadmium and antimony in the nonmagnetic fraction of heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of cadmium and antimony in the nonmagnetic fraction of drainage-sediment samples. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing distribution of silver in the nonmagnetic fraction of heavy-mineral concentrates, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of silver in the nonmagnetic fraction of heavy-mineral concentrates of drainage-sediment samples. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing distribution of barium in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle shows the regional distribution of barium in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing distribution of bismuth and cadmium in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle shows the regional distribution of bismuth and cadimum in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing distribution of copper in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle shows the regional distribution of copper in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing distribution of gold in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of gold in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the Selected References of this report. The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of molybdenum in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of lead in the less-than-0.180-mm (minus-80-mesh) fraction of stream sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of molybdenum in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of molybdenum in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of silver in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of silver in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of thorium in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of thorium in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of tin in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of tin in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of uranium in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of uranium in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1990

Map showing the distribution of zinc in stream-sediment samples, Richfield 1° x 2° quadrangle, Utah

This map of the Richfield 1° x 2° quadrangle, Utah, shows the regional distribution of zinc in the less-than-0.180-mm (minus-80-mesh) fraction of stream-sediments. It is part of a folio of maps of the Richfield 1° x 2° quadrangle, Utah, prepared under the Conterminuous United States Mineral Assessment Program. Other published geochemical maps in this folio are listed in the references (this publication). The Richfield quadrangle is located in west-central Utah and includes the eastern part of the Pioche-Marysvale igneous and mineral belt, which extends from the vicinity of Pioche in southeastern Nevada, east-northeastward for 155 miles into central Utah. The western two-thirds of the Richfield quadrangle is part of the Basin and Range province, whereas the eastern third is part of the High Plateaus of Utah, a subprovince of the Colorado Plateau. Bedrock in the northern part of the Richfield quadrangle consists predominantly of Late Proterozoic and Paleozoic sedimentary strata that were thrust eastward during the Sevier orogeny in Cretaceous time onto an autochthon of Mesozoic sedimentary rocks located in the eastern part of the quadrangle. The southern part of the quadrangle is largely underlain by Oligocene and younger volcanic rocks and related intrusions. Extensional tectonism in late Cenozoic time broke the bedrock terrain into a series of north-trending fault blocks; the uplifted mountain areas were eroded to various degrees and the resulting debris was deposited in adjacent basins. Most of the mineral deposits in the Pioche-Marysvale mineral belt were formed as a result of igneous activity in the middle and late Cenozoic time. A more complete description of the geology and a mineral-resource appraisal of the Richfield quadrangle appears in Steven and Morris (1984 and 1987). The regional sampling program was designed to define broad geochemical patterns and trends that can be utilized along with geological and geophysical data to assess the mineral-resource potential for this quadrangle. Reconnaissance geochemical surveys are valuable tools in mineral exploration, especially when used in conjunction with data obtained from other earth science disciplines. Identifying specific exploration targets generally involves additional, more detailed investigations.

Utah↗
USGS1953

Geologic map of Lake Valley manganese district, Sierra County, New Mexico

The Lake Valley district was originally developed as a manganese-silver district, but the known silver-bearing ore bodies have long since been worked out. The critical shortage of manganese during World War II renewed interest in the manganese deposits; from October 1941 through June 1942 the U. S. Geological Survey and the U.S. Bureau of Mines conducted a cooperative exploration program in the district. This exploration demonstrated that the Lake Valley district contained about 175,000 tons of ore; approximately 37,000 tons has subsequently been mined. The present reserves are estimated to be approximately 140,000 tones of ore with a manganese content of more than 10 percent and an average content of 16.4 percent; about 75,000 tons of the ore has manganese content of more than 15 percent and an average content of 20.7 percent.

New Mexico↗
USGS1975

Map showing fluorspar deposits in Colorado

Increased fluorine consumption (U.S. Bureau of Mines, 1946-1971) coupled with limited proved reserves has stimulated extensive exploration for fluorine and intensive research into developing new sources of fluorine or substitutes. A summary of the distribution, geochemical and geologic environments, and production history of selected fluorspar occurrences, deposits, and districts is provided here with the hope that this information will help to stimulate exploration and discovery of additional fluorspar resources in Colorado to augment our dwindling domestic supply.

Colorado↗
USGS2000

Analytical results for total-digestions, EPA-1312 leach, and net acid production for twenty-three abandoned metal-mining related wastes in the Boulder River watershed, northern Jefferson County, Montana

Introduction Metal-mining related wastes in the Boulder River basin study area in northern Jefferson County, Montana, have been implicated in their detrimental effects on water quality with regard to acid generation and toxic-metal solubilization during snow melt and storm water runoff events. This degradation of water quality is defined chiefly by the “Class 1 Aquatic Life Standards” that give limits for certain dissolved metal concentrations according to water alkalinity. Veins enriched in base- and precious metals were explored and mined in the Basin, Cataract Creek, and High Ore Creek drainages over a period of more than 70 years. Extracted minerals included galena, sphalerite, pyrite, chalcopyrite, tetrahedrite and arsenopyrite. Most of the metal-mining wastes in the study area were identified and described by the Montana Bureau of Mines and Geology. In 1997, the U.S. Geological Survey collected 20 composite samples of mine-dump or tailings waste from ten sites in the Basin and Cataract Creek drainages, and two samples from one site in the High Ore Creek drainage. Desborough and Fey presented data concerning acid generation potential, mineralogy, concentrations of certain metals by energy-dispersive X-ray fluorescence (EDXRF), and trace-element leachability of mine and exploration wastes from the ten sites of the Basin and Cataract Creek drainages. The present report presents total-digestion major- and trace-element analyses, net acid production (NAP), and results from the EPA-1312 synthetic precipitation leach procedure (SPLP) performed on the same composite samples from the ten sites from the Basin and Cataract Creek drainages, and two composite samples from the site in the High Ore Creek drainage.

Montana↗
USGS2003

Descriptions of mineral occurrences and interpretation of mineralized rock geochemical data in the Stikine geophysical survey area, Southeastern Alaska

Detailed descriptions of some of the more significant mineral occurrences in the Stikine Airborne Geophysical Survey Project Area are presented based upon site-specific examinations by the U.S. Geological Survey in May of 1998. Reconnaissance geochemical data on unmineralized igneous and sedimentary host rocks, and mineralized rocks are also presented and are accompanied by a brief analysis of geochemical signatures typical of each occurrence. Consistent with the stated goal of the geophysical survey; to stimulate exploration for polymetallic massive sulfides similar to the Greens Creek deposit, the majority of the described occurrences are possible members of a belt of Late Triassic mineral deposits that are distributed along the eastern edge of the Alexander terrane in southeastern Alaska. Many of the described occurrences in the Duncan Canal-Zarembo Island area share similarities to the Greens Creek deposit. When considered as a whole, the geology, mineralogy, and geochemistry of these occurrences help to define a transitional portion of the Late Triassic mineral belt where changes in shallow to deeper water stratigraphy and arc-like to rift-related igneous rocks are accompanied by concomitant changes in the size, morphology, and metal endowments of the mineral occurrences. As a result, Late Triassic mineral occurrences in the area appear as: 1) small, discontinuous, structurally controlled stockwork veins in mafic volcanic rocks, 2) small, irregular replacements and stratabound horizons of diagenetic semi-massive sulfides in dolostones and calcareous shales, and as 3) larger, recognizably stratiform accumulations of baritic, semi-massive to massive sulfides at and near the contact between mafic volcanic rocks and overlying sedimentary rocks. Empirical exploration guidelines for Greens Creek-like polymetallic massive sulfide deposits in southeastern Alaska include: 1) a Late Triassic volcano-sedimentary host sequence exhibiting evidence of succession from tectonic activity to quiescence (such as conglomeratic and/or mafic volcaniclastics or flows overlain by platform carbonate or shale sequences), 2) presence and proximity to Late Triassic mafic-ultramafic intrusions, 3) presence of quartz-carbonate-fuchsite altered ultramafic bodies, 4) pyritic, graphitic shales, 5) presence of barite and/or iron-manganese-rich carbonates, 6) low-iron sphalerite and antimony-rich sulfosalt minerals, 7) a geochemical signature including Fe-Zn-Pb-Cu-Ag-Au-Sb-Hg-As-Cd-Ba-Mn-Mo-Tl and the ultramafic-related suite of elements Ni-Cr-Co, and 8) a geophysical signature characterized by the coincidence of a sharp resistivity contrast with evidence for buried intrusive rocks. Critical factors for the development of larger, economic orebodies are significant thickness of pyritic, graphitic shale indicating that a locally reducing sedimentary setting was established and that accumulation of an insulating shale blank occurred, and proximity to Late Triassic aged hypabyssal mafic-ultramafic intrusive rocks.

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USGS2003

Assessment of the Mesaverde Total Petroleum System in Southwestern Wyoming Province: a petroleum system approach to assessing undiscovered oil and gas resources

The U.S. Geological Survey, in a recent assessment of the undiscovered oil and gas resources in the Southwestern Wyoming Province using a Total Petroleum System (TPS) approach, estimated a mean of 84.6 trillion cubic feet of gas (TCFG), 131 million barrels of oil (MMBO) and 2.6 billion barrels of natural gas liquids (BBNGL) that have the potential to be added to reserves over the next 30 years. Only a fraction of this, however, may be economically recoverable . Of the total estimate of 84.6 TCFG, a mean of 25.78 TCFG is in continuous-type reservoirs in the Mesaverde TPS. The Mesaverde TPS is defined as all reservoirs predominantly containing gas derived from the Mesaverde Group east of the pinchout of the Lewis Shale, which acts as a top seal separating the Mesaverde TPS from the overlying Lewis TPS. Continuous-type reservoirs in the Mesaverde TPS were subdivided into the Almond Continuous Gas Assessment Unit (AU) (mean of 13.35 TCFG), Rock Springs-Ericson Continuous Gas AU (mean of 12.18 TCFG), and the Mesaverde Coalbed Gas AU (mean of 0.25 TCFG). Geologic analysis was used to determine the favorable ?sweet spots? for potential gas resources. The Almond AU has been heavily explored at depths less than 11,000 ft, thus additions to reserves will most likely be the result of infill drilling in existing fields and the discovery of sweet spots at depths greater than 11,000 ft. There is much uncertainty in the size of undiscovered resource in the Rock Springs-Ericson AU because potential reservoirs are only sparsely explored. Only a small fraction of in-place coal-bed gas is considered to be recoverable because of low permeability and problems posed by produced water.

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