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At least 883 records · Page 49Linked to original sources
USGS1984

Maps showing ground-water units and withdrawal, Basin and Range Province, Nevada

This report on ground-water units and withdrawal in the Basin and Range province of Nevada (see index map) was prepared as part of a program of the U.S. Geological Survey to identify prospective regions for further study relative to isolation of high-level nuclear waste (Bedinger f Sargent, and Reed, 1984), utilizing program guidelines defined in Sargent and Bedinger (1984). Also included in this report are selected references on pertinent geologic and hydrologic studies of the region. Other map reports in this series contain detailed data on ground-water quality, surface distribution of selected rock types, tectonic conditions, areal geophysics, Pleistocene lakes and marshes, and mineral and energy resources.

Nevada↗
USGS1982

The Alaska Mineral Resource Assessment Program: Guide to information about the geology and mineral resources of the Ketchikan and Prince Rupert quadrangles, southeastern Alaska

The Ketchikan and Prince Rupert 1-degree by 2-degree quadrangles, which encompass about 16,000 km2 at the south tip of southeastern Alaska, have been investigated by integrated field and laboratory studies in the disciplines of geology, geochemistry, geophysics, and Landsat data interpretation to determine their mineral-resource potential. Mineral deposits in the study area have been mined or prospected intermittently since about 1900, and production of small tonnages of ores containing gold, silver, copper, lead, zinc, and tungsten has been recorded. Extensive exploration and development currently (1981) is underway at a molybdenum prospect about 65 km east of Ketchikan. Our mineral-resource assessment indicates that the area contains potentially significant amounts of those metallic commodities, as well as of molybdenum, iron, antimony, and barite. The results of these studies have been published in a folio of maps accompanied by descriptive texts, diagrams, tables, and pertinent references. The present report serves as a guide to these investigations, provides relevant background information, and integrates the component maps and reports. It also describes revisions to the geology based on studies completed since the folio was published and includes a list of specific and general references on the geology and mineral deposits of the study area.

Alaska↗
USGS2010

Publications of the Volcano Hazards Program 2008

The Volcano Hazards Program of the U.S. Geological Survey (USGS) is part of the Geologic Hazards Assessments subactivity as funded by Congressional appropriation. Investigations are carried out in the Geology and Hydrology Disciplines of the USGS and with cooperators at the Alaska Division of Geological and Geophysical Surveys, University of Alaska Fairbanks Geophysical Institute, University of Hawaii Manoa and Hilo, University of Utah, and University of Washington Geophysics Program. This report lists publications from all these institutions. This report contains only published papers and maps; numerous abstracts produced for presentations at scientific meetings have not been included. Publications are included based on date of publication with no attempt to assign them to Fiscal Year.

Open-File Report↗
USGS1984

Aeromagnetic, Bouguer gravity, and interpretation maps of the Sheep Hole-Cadiz Wilderness Study Area (CDCA-305), San Bernardino County, California

The Federal Land Policy and Management Act (Public Law 94-579, October 21, 1976) requires the U.S. Geological Survey and the U.S. Bureau of Mines to conduct mineral surveys on certain areas to determine their mineral resource potential. Results must be made available to the public and be submitted to the President and the Congress. These maps presents the results of a mineral survey of the Sheep Hole-Cadiz Wilderness Study Area (CDCA-305), California Desert Conservation Area, San Bernardino County, California. The U.S. Bureau of Mines conducted a mineral survey of the Sheep Hole-Cadiz Wilderness Study Area, which encompasses approximately 200,000 acres including enclosed private lands, in south-central San Bernardino County, California. The U.S. Bureau of Mines studied the mineral resources of mines, prospects, and mineralized areas; geologic, geochemical, and geophysical investigations were conducted by the U.S. Geological Survey. The study area is located in the Mojave Desert 13 miles east of Amboy, California, 20 miles east of Twentynine Palms, California, and 90 miles east of San Bernardino, and encompasses parts of the Dale Lake, Bristol Lake, Cadiz Valley and Cadiz Lake 15-minute quadrangles. Its borders are defined by the Amboy Road and a gas pipeline service road on the northwest, the unimproved Cadiz Valley access road on the east, State Route 62 along the south, and the Iron Age mine road and an unimproved powerline service road on the west. Major access from the east and west is provided by State Route 62 and access from the north is provided by the Amboy Road. Companion reports to this one describe the mineral resource potential (March and others, 1982), the geology (Howard and John, 1984), and hydrothermal alteration studies (Raines, 1983).

California↗
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 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↗
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↗
USGS2016

Hydrogeologic investigations of the Miocene Nogales Formation in the Nogales Area, Upper Santa Cruz Basin, Arizona

Hydrogeologic investigations were conducted to evaluate the groundwater resource potential for the Miocene Nogales Formation in the Nogales area, southern Arizona. Results indicate that parts of the formation may provide new, deeper sources of groundwater for the area. Geologic mapping determined the hydrogeologic framework of the formation by defining lithologic, mineralogic, and stratigraphic characteristics; identifying potential aquifers and confining units; and mapping faults and fractures which likely influence groundwater flow. Geophysical modeling was used to determine the basin geometry and thickness of the Nogales Formation and younger alluvial aquifers and to identify target areas (deep subbasins) which may prove to be productive aquifers. Volcaniclastic sandstone samples from the formation were analyzed for porosity, bulk density, saturated hydraulic conductivity, and fabric. Effective porosity ranges from 16 to 42 percent, bulk density from 1.6 to 2.47 grams per cubic centimeter, and saturated hydraulic conductivity (SHC) from 4 to 57 centimeters per day (4.9×10 -5 to 6.7×10 -4 centimeters per second). Thin sections show that sandstone framework grains consist of quartz, feldspar, biotite, hornblende, pumice, volcanic glass, and opaque minerals. The matrix in most samples consists of pumice fragments, and some contain predominantly silt and clay. Samples with a mostly silt and clay matrix have lower porosity and SHC compared to samples with mostly pumice, which have higher and wider ranges of porosity and SHC. Pore space in the Nogales Formation sediments includes moldic, intercrystalline, and fracture porosity. Some intercrystalline pore space is partially filled with calcite cement. About one third of the samples contain fractures, which correspond to fractures noted in outcrops in all members of the formation. Scanning electron microscope (SEM) and x-ray diffraction (XRD) analyses indicate that most of the samples contained the zeolite clinoptilolite and mixed-layer clay. X-ray diffraction analyses verified clinoptilolite as the only zeolite in Nogales Formation samples; they also verified the presence of smectite and illite clay and some kaolinite. Samples which contain greater amounts of clinoptilolite and lesser amounts of smectite have high porosity and SHC in narrow ranges. However, samples with abundant smectite and lesser amounts of clinoptilolite span the entire ranges of porosity and SHC for the formation. All members of the Nogales Formation are fractured and faulted as a result of Tertiary Basin and Range extensional deformation, which was broadly contemporaneous with deposition of the formation. These structures may have significant influence on groundwater flow in the upper Santa Cruz basin because, although many of the sediments in the formation have characteristics indicating they may be productive aquifers based only on porous-media flow, fracturing in these sediments may further enhance permeability and groundwater flow in these basin-fill aquifers by orders of magnitude.

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