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• 1. [Image] Gravity and Ground Magnetic Surveys of the Central Mineral Mountains, Utah. Volume 6: Final Report

  	During the summers of 1974 and 1975, gravity and ground magnetic surveys were made over the central part of the Mineral Mountains and vicinity, Utah. The gravity survey comprised 627 gravity stations over ...
  	Citation × Citation Citation Abstract Copy Title: Gravity and Ground Magnetic Surveys of the Central Mineral Mountains, Utah. Volume 6: Final Report Author: Crebs, T.J. Year: 1976 During the summers of 1974 and 1975, gravity and ground magnetic surveys were made over the central part of the Mineral Mountains and vicinity, Utah. The gravity survey comprised 627 gravity stations over an area of approximately 660 sq km, and included 8 gravity profiles over the Roosevelt Hot Springs KGRA. The magnetic survey comprised over 400 magnetic stations within 4 magnetic profiles. The gravity data were compiled as a terrain-corrected Bouguer gravity anomaly map with a contour interval of 2 mgal. The gravity features include: (1) generally northward-trending gravity contours with gradients along the margins of the Mineral Range, indicating that the range is a horst bounded on the east and west by the Beaver and Milford valley grabens, respectively, where the Milford Valley graben shows pronounced gravity low, which indicates a valley-fill thickness of about 1.8km; and (2) a northward-trending gravity high extends along the western flank of the Mineral Range (probably caused by high-density metamorphic rocks) Title: Gravity and Ground Magnetic Surveys of the Central Mineral Mountains, Utah. Volume 6: Final Report Author: Crebs, T.J. Year: 1976 During the summers of 1974 and 1975, gravity and ground magnetic surveys were made over the central part of the Mineral Mountains and vicinity, Utah. The gravity survey comprised 627 gravity stations over an area of approximately 660 sq km, and included 8 gravity profiles over the Roosevelt Hot Springs KGRA. The magnetic survey comprised over 400 magnetic stations within 4 magnetic profiles. The gravity data were compiled as a terrain-corrected Bouguer gravity anomaly map with a contour interval of 2 mgal. The gravity features include: (1) generally northward-trending gravity contours with gradients along the margins of the Mineral Range, indicating that the range is a horst bounded on the east and west by the Beaver and Milford valley grabens, respectively, where the Milford Valley graben shows pronounced gravity low, which indicates a valley-fill thickness of about 1.8km; and (2) a northward-trending gravity high extends along the western flank of the Mineral Range (probably caused by high-density metamorphic rocks) Close

• 2. [Image] Geothermal exploration assessment and interpretation, Klamath Basin, Oregon: Swan Lake and Klamath Hills area

  	A synthesis and preliminary interpretation of predominantly geophysical information relating to the Klamath Basin geothermal resource is presented. The Swan Lake Valley area, northeast of Klamath Falls, ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal exploration assessment and interpretation, Klamath Basin, Oregon: Swan Lake and Klamath Hills area Author: Stark, M. Year: 1979 A synthesis and preliminary interpretation of predominantly geophysical information relating to the Klamath Basin geothermal resource is presented. The Swan Lake Valley area, northeast of Klamath Falls, and the Klamath Hills area, south of Klamath Falls, are discussed in detail. Available geophysical data, including gravity, magnetic, electrical resistivity, microearthquake, roving dipole resistivity, audio-magnetotelluric (AMT) and magnetotelluric (MT) data sets, are examined and reinterpreted for these areas. One- and two-dimensional modeling techniques are applied, and general agreement among overlapping data sets is achieved. The MT method appears well suited to this type of exploration, although interpretation is difficult in the complex geology. Roving dipole and AMT are useful in reconnaissance, while gravity and magnetics help in defining structure. For the Swan Lake Valley the data suggest buried electrically conductive zones beneath Meadow Lake Valley and Swan Lake, connected by a conductive layer at 1 kilometer depth. In the Klamath Hills area, the data suggest a conductive zone centered near the northwestern tip of Stukel Mountain, associated with a concealed northeast-trending cross-fault. Another conductive zone appears near some producing hot wells at the southwestern edge of the Klamath Hills. These conductive zones may represent geothermal reservoirs. Follow-up work is recommended for each target area; LBL-8186 Title: Geothermal exploration assessment and interpretation, Klamath Basin, Oregon: Swan Lake and Klamath Hills area Author: Stark, M. Year: 1979 A synthesis and preliminary interpretation of predominantly geophysical information relating to the Klamath Basin geothermal resource is presented. The Swan Lake Valley area, northeast of Klamath Falls, and the Klamath Hills area, south of Klamath Falls, are discussed in detail. Available geophysical data, including gravity, magnetic, electrical resistivity, microearthquake, roving dipole resistivity, audio-magnetotelluric (AMT) and magnetotelluric (MT) data sets, are examined and reinterpreted for these areas. One- and two-dimensional modeling techniques are applied, and general agreement among overlapping data sets is achieved. The MT method appears well suited to this type of exploration, although interpretation is difficult in the complex geology. Roving dipole and AMT are useful in reconnaissance, while gravity and magnetics help in defining structure. For the Swan Lake Valley the data suggest buried electrically conductive zones beneath Meadow Lake Valley and Swan Lake, connected by a conductive layer at 1 kilometer depth. In the Klamath Hills area, the data suggest a conductive zone centered near the northwestern tip of Stukel Mountain, associated with a concealed northeast-trending cross-fault. Another conductive zone appears near some producing hot wells at the southwestern edge of the Klamath Hills. These conductive zones may represent geothermal reservoirs. Follow-up work is recommended for each target area; LBL-8186 Close

• 3. [Image] Geology of the Colado Geothermal Area, Pershing County, Nevada

  	The Colado geothermal area in south-central Pershing County, Nevada is defined by hot water wells in alluvium just west of the West Humboldt Range. Geothermal gradient holes have encountered temperatures ...
  	Citation × Citation Citation Abstract Copy Title: Geology of the Colado Geothermal Area, Pershing County, Nevada Author: Sibbett, B.S. Year: 1980 The Colado geothermal area in south-central Pershing County, Nevada is defined by hot water wells in alluvium just west of the West Humboldt Range. Geothermal gradient holes have encountered temperatures up to 113.5/sup 0/C at a depth of 76 m (250 ft) with a gradient reversal in the alluvium below this depth. The West Humboldt Range consists mainly of Triassic to Jurassic slaty shale to quartzite of the Auld Lang Syne Group. Carbonate rocks of the Jurassic Lovelock Formation have been thrust over pelitic rocks on the south end of the area. Erosional remnants of Tertiary tuffs and sediments overlay the metasediments in the West Humboldt Range. The principal structures are high-angle faults striking north-northwest, northeast and north-south. The horst-to-graben transition along the range front consists of several step faults trending irregularly north. The structural pattern in the west edge of the range probably continues to the west under the Quaterary alluvium where the source of the hot water is located. Thermal waters probably rise along a major fault intersection in the Mesozoic rocks then spread out in an aquifer in the alluvium. Several thrust faults are exposed south of Coal Canyon, and a structural break in the Mesozoic rock exists under the canyon. Several low-angle faults are present north of Coal Canyon but their effect, if any, on the geothermal occurrence is not known; DOE/ID/12079-8; ESL-38 Title: Geology of the Colado Geothermal Area, Pershing County, Nevada Author: Sibbett, B.S. Year: 1980 The Colado geothermal area in south-central Pershing County, Nevada is defined by hot water wells in alluvium just west of the West Humboldt Range. Geothermal gradient holes have encountered temperatures up to 113.5/sup 0/C at a depth of 76 m (250 ft) with a gradient reversal in the alluvium below this depth. The West Humboldt Range consists mainly of Triassic to Jurassic slaty shale to quartzite of the Auld Lang Syne Group. Carbonate rocks of the Jurassic Lovelock Formation have been thrust over pelitic rocks on the south end of the area. Erosional remnants of Tertiary tuffs and sediments overlay the metasediments in the West Humboldt Range. The principal structures are high-angle faults striking north-northwest, northeast and north-south. The horst-to-graben transition along the range front consists of several step faults trending irregularly north. The structural pattern in the west edge of the range probably continues to the west under the Quaterary alluvium where the source of the hot water is located. Thermal waters probably rise along a major fault intersection in the Mesozoic rocks then spread out in an aquifer in the alluvium. Several thrust faults are exposed south of Coal Canyon, and a structural break in the Mesozoic rock exists under the canyon. Several low-angle faults are present north of Coal Canyon but their effect, if any, on the geothermal occurrence is not known; DOE/ID/12079-8; ESL-38 Close