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• 1. [Image] Geochemistry of the Colado geothermal area, Pershing County, Nevada

  	Multielement geochemical analysis of drill cuttings from 18 shallow and 2 intermediate-depth temperature gradient holes outlines an area of anomalous geochemistry related to the fluid flow and temperature ...
  	Citation × Citation Citation Abstract Copy Title: Geochemistry of the Colado geothermal area, Pershing County, Nevada Author: Christensen, O.D. Year: 1980 Multielement geochemical analysis of drill cuttings from 18 shallow and 2 intermediate-depth temperature gradient holes outlines an area of anomalous geochemistry related to the fluid flow and temperature distribution within the Colado geothermal area. The concentrations of Hg, As, Li, and Be belong to more than one statistical population and provide the clearest expression of hydrothermal processes. Enrichments of these four elements define anomalous zones which are spatially coincident with a measured temperature anomaly. The spatial distribution suggests that thermal fluid rises into alluvium in the vicinity of a major Basin and Range fault to depths of 200 to 400 feet (60 to 120 m), then flows laterally within shallow alluvial aquifers down the local hydrologic gradient. As the fluid cools, Li, Be, As, and Hg are deposited in response to changing physical and chemical conditions. As and Be appear to be deposited early in higher temperature zones; Li begins to deposit early but forms a rather dispersed geochemical anomaly; Hg is anomalous throughout the entire geothermal area but is concentrated in a shallow halo above the As and Be anomalies. The distributions suggest that the entry of thermal fluids from depth into the alluvium is spatially restricted to a small area and that the larger area of the observed thermal anomaly is due to the flow of warm fluid within shallow aquifers; DOE/ID/12079-9; ESL-39 Title: Geochemistry of the Colado geothermal area, Pershing County, Nevada Author: Christensen, O.D. Year: 1980 Multielement geochemical analysis of drill cuttings from 18 shallow and 2 intermediate-depth temperature gradient holes outlines an area of anomalous geochemistry related to the fluid flow and temperature distribution within the Colado geothermal area. The concentrations of Hg, As, Li, and Be belong to more than one statistical population and provide the clearest expression of hydrothermal processes. Enrichments of these four elements define anomalous zones which are spatially coincident with a measured temperature anomaly. The spatial distribution suggests that thermal fluid rises into alluvium in the vicinity of a major Basin and Range fault to depths of 200 to 400 feet (60 to 120 m), then flows laterally within shallow alluvial aquifers down the local hydrologic gradient. As the fluid cools, Li, Be, As, and Hg are deposited in response to changing physical and chemical conditions. As and Be appear to be deposited early in higher temperature zones; Li begins to deposit early but forms a rather dispersed geochemical anomaly; Hg is anomalous throughout the entire geothermal area but is concentrated in a shallow halo above the As and Be anomalies. The distributions suggest that the entry of thermal fluids from depth into the alluvium is spatially restricted to a small area and that the larger area of the observed thermal anomaly is due to the flow of warm fluid within shallow aquifers; DOE/ID/12079-9; ESL-39 Close

• 2. [Image] Low-Temperature Geothermal Potential of the Ojo Caliente Warm Springs Area, Northern New Mexico

  	A detailed geochemical investigation of 17 waters (thermal and cold, mineralized and dilute) was performed in the Ojo Caliente-La Madera area. Two types of thermomineral waters have separate and distinctive ...
  	Citation × Citation Citation Abstract Copy Title: Low-Temperature Geothermal Potential of the Ojo Caliente Warm Springs Area, Northern New Mexico Author: Vuataz, F.D. Year: 1984 A detailed geochemical investigation of 17 waters (thermal and cold, mineralized and dilute) was performed in the Ojo Caliente-La Madera area. Two types of thermomineral waters have separate and distinctive geologic, geochemical, and geothermal characteristics. The water from Ojo Caliente Resort emerges with temperatures less than or equal to 54/sup 0/C from a Precambrian metarhyolite. Its chemistry, typically Na-HCO/sub 3/, has a total mineralization of 3600 mg/l. Isotopic studies have shown that the thermal water emerges from the springs and a hot well without significant mixing with the cold shallow aquifer of the valley alluvium. However, the cold aquifer adjacent to the resort does contain varying amounts of thermal water that originates from the warm spring system. Geothermometry calculations indicate that the thermal water may be as hot as 85/sup 0/C at depth before its ascent toward surface. Thermodynamic computations on the reaction states of numerous mineral phases suggest that the thermal water will not cause major scaling problems if the hot water is utilized for direct-use geothermal applications. By means of a network of very shallow holes, temperature and electrical conductivity anomalies have been found elsewhere in the valley around Ojo Caliente, and resistivity soundings have confirmed the presence of a plume of thermal water entering the shallow aquifer. The group of lukewarm springs around La Madera, with temperatures less than or equal to 29/sup 0/C, chemical type of NaCaMg-HCO/sub 3/Cl and with a total mineralization less than or equal to 1500 mg/l behaves as a different system without any Apparent relation to the Ojo Caliente system. Its temperature at depth is not believed to exceed 35 to 40/sup 0/C Title: Low-Temperature Geothermal Potential of the Ojo Caliente Warm Springs Area, Northern New Mexico Author: Vuataz, F.D. Year: 1984 A detailed geochemical investigation of 17 waters (thermal and cold, mineralized and dilute) was performed in the Ojo Caliente-La Madera area. Two types of thermomineral waters have separate and distinctive geologic, geochemical, and geothermal characteristics. The water from Ojo Caliente Resort emerges with temperatures less than or equal to 54/sup 0/C from a Precambrian metarhyolite. Its chemistry, typically Na-HCO/sub 3/, has a total mineralization of 3600 mg/l. Isotopic studies have shown that the thermal water emerges from the springs and a hot well without significant mixing with the cold shallow aquifer of the valley alluvium. However, the cold aquifer adjacent to the resort does contain varying amounts of thermal water that originates from the warm spring system. Geothermometry calculations indicate that the thermal water may be as hot as 85/sup 0/C at depth before its ascent toward surface. Thermodynamic computations on the reaction states of numerous mineral phases suggest that the thermal water will not cause major scaling problems if the hot water is utilized for direct-use geothermal applications. By means of a network of very shallow holes, temperature and electrical conductivity anomalies have been found elsewhere in the valley around Ojo Caliente, and resistivity soundings have confirmed the presence of a plume of thermal water entering the shallow aquifer. The group of lukewarm springs around La Madera, with temperatures less than or equal to 29/sup 0/C, chemical type of NaCaMg-HCO/sub 3/Cl and with a total mineralization less than or equal to 1500 mg/l behaves as a different system without any Apparent relation to the Ojo Caliente system. Its temperature at depth is not believed to exceed 35 to 40/sup 0/C Close

• 3. [Image] Geothermal Resource Exploration in Boise, Idaho

  	Exploratory drilling in Boise, Idaho, in the vicinity of the Boise Front Fault has confirmed the presence of a 170/sup 0/F (77/sup 0/C) geothermal resource below about 800 ft (244 m) near the Veterans ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal Resource Exploration in Boise, Idaho Author: Nelson, L.B. Year: 1980 Exploratory drilling in Boise, Idaho, in the vicinity of the Boise Front Fault has confirmed the presence of a 170/sup 0/F (77/sup 0/C) geothermal resource below about 800 ft (244 m) near the Veterans Hospital of the Military Reserve Park. The Idaho National Engineering Laboratory (INEL), sponsored by the Department of Energy, drilled three exploratory slim holes and two deep exploratory test wells. Study results based on tests of the two exploratory-test wells are reported. Faulting related to the Boise Front Fault defines a major physiographic break in the area that acts as a subsurface conduit through which geothermal water circulates. Hydrologic tests indicate that rocks disturbed by the Boise Front Fault may be as much as ten times more permeable than those removed from the major structural lineament Title: Geothermal Resource Exploration in Boise, Idaho Author: Nelson, L.B. Year: 1980 Exploratory drilling in Boise, Idaho, in the vicinity of the Boise Front Fault has confirmed the presence of a 170/sup 0/F (77/sup 0/C) geothermal resource below about 800 ft (244 m) near the Veterans Hospital of the Military Reserve Park. The Idaho National Engineering Laboratory (INEL), sponsored by the Department of Energy, drilled three exploratory slim holes and two deep exploratory test wells. Study results based on tests of the two exploratory-test wells are reported. Faulting related to the Boise Front Fault defines a major physiographic break in the area that acts as a subsurface conduit through which geothermal water circulates. Hydrologic tests indicate that rocks disturbed by the Boise Front Fault may be as much as ten times more permeable than those removed from the major structural lineament Close

• 4. [Image] Geothermal Investigations in Idaho. Part 8. Heat Flow Study of the Snake River Plain Region, Idaho

  	The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal Investigations in Idaho. Part 8. Heat Flow Study of the Snake River Plain Region, Idaho Author: Brott, C.A. Year: 1976 The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, allows a better definition of the geothermal resource and evaluation of the geothermal potential. Local geothermal anomalies were not the objects of this study and have not been studied in detail. The quality of the heat flow values obtained varies as interpretation was necessary to determine geothermal gradients for many of the holes which had disturbances. A major problem in determining the heat flow values is the lack of knowledge of the in situ porosity of the rocks. The heat flow values obtained for the Eastern Snake River Plain are from shallow wells (< 200 m), hence the heat flow there is low (< 0.5 HFU) because of the water movement in the Snake Plain aquifer. The anomalous regional heat flow pattern around the Snake River Plain, together with other geophysical and geological data, suggest the presence of a major crustal heat source. With the exception of the area of the Snake Plain aquifer, high geothermal gradients were found in all areas of southern Idaho (40 to 100/sup 0/C/km). Temperatures hot enough for space heating can be found most anywhere in the Plain at relatively shallow depths (1 to 2 km). Temperatures hot enough for electrical power generation (200/sup 0/C) can be found beneath southern Idaho almost anywhere at depths of 3 to 4 kilometers. The Plain is fault bounded and hot water circulating along the fault zones from depths can be a very important geothermal resource at shallow depths. The margins of the Plain have the highest heat flow values, are the most faulted, and have possibly the highest geothermal resource potential Title: Geothermal Investigations in Idaho. Part 8. Heat Flow Study of the Snake River Plain Region, Idaho Author: Brott, C.A. Year: 1976 The Snake River Plain of Idaho has recent lava flows and a large number of thermal springs and wells. A heat flow study was initiated which, together with available geological and geophysical information, allows a better definition of the geothermal resource and evaluation of the geothermal potential. Local geothermal anomalies were not the objects of this study and have not been studied in detail. The quality of the heat flow values obtained varies as interpretation was necessary to determine geothermal gradients for many of the holes which had disturbances. A major problem in determining the heat flow values is the lack of knowledge of the in situ porosity of the rocks. The heat flow values obtained for the Eastern Snake River Plain are from shallow wells (< 200 m), hence the heat flow there is low (< 0.5 HFU) because of the water movement in the Snake Plain aquifer. The anomalous regional heat flow pattern around the Snake River Plain, together with other geophysical and geological data, suggest the presence of a major crustal heat source. With the exception of the area of the Snake Plain aquifer, high geothermal gradients were found in all areas of southern Idaho (40 to 100/sup 0/C/km). Temperatures hot enough for space heating can be found most anywhere in the Plain at relatively shallow depths (1 to 2 km). Temperatures hot enough for electrical power generation (200/sup 0/C) can be found beneath southern Idaho almost anywhere at depths of 3 to 4 kilometers. The Plain is fault bounded and hot water circulating along the fault zones from depths can be a very important geothermal resource at shallow depths. The margins of the Plain have the highest heat flow values, are the most faulted, and have possibly the highest geothermal resource potential Close

• 5. [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