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• 1. [Image] Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California

  	The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and ...
  	Citation × Citation Citation Abstract Copy Title: Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Author: Galbraith, R.M. Year: 1978 The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of Drilling were most Useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet Title: Geological and Geophysical Analysis of Coso Geothermal Exploration Hole No. 1 (CGEH-1), Coso Hot Springs KGRA, California Author: Galbraith, R.M. Year: 1978 The Coso Geothermal Exploration Hole number one (CGEH-1) was drilled in the Coso Hot Springs KGRA, California from September 2 to December 2, 1977. Chip samples were collected at ten foot intervals and extensive geophysical logging surveys were conducted to document the geologic character of the geothermal system as penetrated by CGEH-1. The major rock units encountered include a mafic metamorphic sequence and a leucogranite which intruded the metamorphic rocks. Only weak hydrothermal alteration was noted in these rocks. Drillhole surveys and drilling rate data indicate that the geothermal system is structurally controlled and that the drillhole itself was strongly influenced by structural zones. Water chemistry indicates that this geothermal resource is a hot-water rather than a vapor-dominated system. Several geophysical logs were employed to characterize the drillhole geology. The natural gamma and neutron porosity logs indicate gross rock type and the acoustic logs indicate fractured rock and potentially permeable zones. A series of temperature logs run as a function of time during and after the completion of Drilling were most Useful in delineating the zones of maximum heat flux. Convective heat flow and temperatures greater than 350/sup 0/F appear to occur only along an open fracture system encountered between depths of 1850 and 2775 feet. Temperature logs indicate a negative thermal gradient below 3000 feet Close

• 2. [Image] Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13

  	Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that ...
  	Citation × Citation Citation Abstract Copy Title: Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13 Author: Hannah, J.L. Year: 1975 Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS) Title: Potential of Low-Temperature Geothermal Resources in Northern California. Report No. TR13 Author: Hannah, J.L. Year: 1975 Economically feasible uses for geothermal heat at temperatures too low for conventional electrical power generation at present are delineated. Several geothermal resource areas in northern California that have development potential are described, and applications of the heat found in each area are suggested. Plates are included of the following field study areas: the east side of the Sierra-Cascade Range north of Bishop, and the northern Coast Range from San Francisco Bay to Clear Lake. The counties included in the study area are Mo doc, Lassen, Sierra, Plumas, Placer, Alpine, Mono, Mendocino, Lake, and Sonoma. (LBS) 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] Stratigraphy and Alteration, 15 Shallow Thermal Gradient Holes, Roosevelt Hot Springs KGRA and Vicinity, Millard and Beaver Counties, Utah

  	Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks ...
  	Citation × Citation Citation Abstract Copy Title: Stratigraphy and Alteration, 15 Shallow Thermal Gradient Holes, Roosevelt Hot Springs KGRA and Vicinity, Millard and Beaver Counties, Utah Author: Hulen, J.B. Year: 1978 Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks and Precambrian gneiss east of the KGRA. Seven holes completed entirely in alluvium near the southwestern corner of the KGRA encountered a near-surface marker horizon of Pleistocene pumice and perlite. Maximum calculated alluvial sedimentation rates since initial deposition of this pumice and perlite range from 1 foot in 12,500 years to 1 foot in 2,300 years. Three holes east of the Mineral Mountains penetrated late Cenozoic basaltic andesite beneath a thin veneer of alluvium. All 15 GPCR drill holes appear to be peripheral to a central zone of anomalously high thermal gradient and low resisitivity delineated by previous investigations. GPCR-8 and -14, however, are characterized by high heat flow and relatively abundant manganese oxide mineralization, which may reflect a favorable hydrologic system controlling thermal fluid flow at depth. These holes thus seem most encouraging for discovery of a deeper high-temperature geothermal resource Title: Stratigraphy and Alteration, 15 Shallow Thermal Gradient Holes, Roosevelt Hot Springs KGRA and Vicinity, Millard and Beaver Counties, Utah Author: Hulen, J.B. Year: 1978 Fifteen shallow thermal gradient drill holes were recently completed by Geothermal Power Corporation (GPCR) in the vicinity of the Roosevelt Hot Springs KGRA. Five holes penetrated Tertiary granitic rocks and Precambrian gneiss east of the KGRA. Seven holes completed entirely in alluvium near the southwestern corner of the KGRA encountered a near-surface marker horizon of Pleistocene pumice and perlite. Maximum calculated alluvial sedimentation rates since initial deposition of this pumice and perlite range from 1 foot in 12,500 years to 1 foot in 2,300 years. Three holes east of the Mineral Mountains penetrated late Cenozoic basaltic andesite beneath a thin veneer of alluvium. All 15 GPCR drill holes appear to be peripheral to a central zone of anomalously high thermal gradient and low resisitivity delineated by previous investigations. GPCR-8 and -14, however, are characterized by high heat flow and relatively abundant manganese oxide mineralization, which may reflect a favorable hydrologic system controlling thermal fluid flow at depth. These holes thus seem most encouraging for discovery of a deeper high-temperature geothermal resource Close

• 5. [Image] Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States Progress Report, Apr 1, 1977--Jun 30, 1977

  	The objective of this research is to develop and apply targeting procedures for the evaluation of low-temperature radiogenically-derived geothermal resources in the eastern United States utilizing geological, ...
  	Citation × Citation Citation Abstract Copy Title: Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States Progress Report, Apr 1, 1977--Jun 30, 1977 Author: Costain, J.K. Year: 1977 The objective of this research is to develop and apply targeting procedures for the evaluation of low-temperature radiogenically-derived geothermal resources in the eastern United States utilizing geological, geochemical, and geophysical data. Detailed study of the Winnsboro complex, South Carolina, is continuing as part of a broader project to provide insight into the behavior of uranium and thorium in syn- and postmetamorphic granitic plutons Title: Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States Progress Report, Apr 1, 1977--Jun 30, 1977 Author: Costain, J.K. Year: 1977 The objective of this research is to develop and apply targeting procedures for the evaluation of low-temperature radiogenically-derived geothermal resources in the eastern United States utilizing geological, geochemical, and geophysical data. Detailed study of the Winnsboro complex, South Carolina, is continuing as part of a broader project to provide insight into the behavior of uranium and thorium in syn- and postmetamorphic granitic plutons Close

• 6. [Image] Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States. Progress Report, October 1--December 31, 1977

  	Progress in the evaluation of low-temperature geothermal resources in the eastern United States utilizing geological, geochemical, and geophysical data is reported. Primary programmatic emphasis is now ...
  	Citation × Citation Citation Abstract Copy Title: Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States. Progress Report, October 1--December 31, 1977 Author: Costain, J.K. Year: 1978 Progress in the evaluation of low-temperature geothermal resources in the eastern United States utilizing geological, geochemical, and geophysical data is reported. Primary programmatic emphasis is now being placed on the confirmation of radiogenic resources beneath sediments of the Atlantic Coastal Plain. Collation of existing gravity and magnetic data available for the Atlantic Coastal Plain is complete, and modeling of selected negative gravity anomalies of the Cuffytown Creek (Edgefield) pluton, S.C., the Rolesville batholith, N.C., and the Petersburg granite, Va., is in progress. Maps showing the distribution of gravity stations for the states of Georgia, South Carolina, and North Carolina were prepared. A reconnaissance geologic map is being prepared of the Raleigh belt and Carolina slate belt rocks. The purpose of this study is to determine the relationship of the Rolesville batholith to the surrounding country rocks, and to provide a geologic base for the geophysical interpretation of Piedmont stratigraphy underlying Atlantic Coastal Plain sediments to the east Title: Evaluation and Targeting of Geothermal Energy Resources in the Southeastern United States. Progress Report, October 1--December 31, 1977 Author: Costain, J.K. Year: 1978 Progress in the evaluation of low-temperature geothermal resources in the eastern United States utilizing geological, geochemical, and geophysical data is reported. Primary programmatic emphasis is now being placed on the confirmation of radiogenic resources beneath sediments of the Atlantic Coastal Plain. Collation of existing gravity and magnetic data available for the Atlantic Coastal Plain is complete, and modeling of selected negative gravity anomalies of the Cuffytown Creek (Edgefield) pluton, S.C., the Rolesville batholith, N.C., and the Petersburg granite, Va., is in progress. Maps showing the distribution of gravity stations for the states of Georgia, South Carolina, and North Carolina were prepared. A reconnaissance geologic map is being prepared of the Raleigh belt and Carolina slate belt rocks. The purpose of this study is to determine the relationship of the Rolesville batholith to the surrounding country rocks, and to provide a geologic base for the geophysical interpretation of Piedmont stratigraphy underlying Atlantic Coastal Plain sediments to the east Close

• 7. [Image] Hydrothermal Alteration in Well Baca 22, Baca Geothermal Area, Valles Caldera, New Mexico

  	The Baca geothermal area is located in the Valles caldera in the Jemez Mountains of north-central New Mexico. Union Geothermal Company drilled a number of exploration wells to supply steam for a proposed ...
  	Citation × Citation Citation Abstract Copy Title: Hydrothermal Alteration in Well Baca 22, Baca Geothermal Area, Valles Caldera, New Mexico Author: Fox, D. J. Year: 1984 The Baca geothermal area is located in the Valles caldera in the Jemez Mountains of north-central New Mexico. Union Geothermal Company drilled a number of exploration wells to supply steam for a proposed electric generating plant. Drill cuttings from one of these wells, Baca 22 (see Figure 1), were studied with a petrographic microscope and by x-ray diffraction to determine the nature of the original rocks and of the hydrothermal alteration. The hydrothermal alteration will be used to determine the temperatures of alteration which can then be compared with borehole temperatures to determine if the mineral assemblages are compatible with present day temperatures. It will be shown that there is evidence indicating that the upper 2000 feet of borehole is cooler now than it has been in the past Title: Hydrothermal Alteration in Well Baca 22, Baca Geothermal Area, Valles Caldera, New Mexico Author: Fox, D. J. Year: 1984 The Baca geothermal area is located in the Valles caldera in the Jemez Mountains of north-central New Mexico. Union Geothermal Company drilled a number of exploration wells to supply steam for a proposed electric generating plant. Drill cuttings from one of these wells, Baca 22 (see Figure 1), were studied with a petrographic microscope and by x-ray diffraction to determine the nature of the original rocks and of the hydrothermal alteration. The hydrothermal alteration will be used to determine the temperatures of alteration which can then be compared with borehole temperatures to determine if the mineral assemblages are compatible with present day temperatures. It will be shown that there is evidence indicating that the upper 2000 feet of borehole is cooler now than it has been in the past Close

• 8. [Image] Geological and Geophysical Study of the Origin of the Warm Springs in Bath County, Virginia. Final Report, June 1, 1975--April 30, 1976

  	The results of heat flow determinations and a reconnaissance dipole electrical resistivity survey in Bath County are described. A geologic map was compiled based on published maps and supported by reconnaissance ...
  	Citation × Citation Citation Abstract Copy Title: Geological and Geophysical Study of the Origin of the Warm Springs in Bath County, Virginia. Final Report, June 1, 1975--April 30, 1976 Author: Costain, J.K. Year: 1976 The results of heat flow determinations and a reconnaissance dipole electrical resistivity survey in Bath County are described. A geologic map was compiled based on published maps and supported by reconnaissance geologic mapping in areas where published maps were not available. A regional bipole--dipole electrical resistivity survey was made in order to detect the presence of resistivity lows that might be associated with a geothermal system at depth. A single hole was drilled to a depth of approximately 300 m (approx. 1000 feet) to obtain a heat flow value that is representative of the area. The data were used to attempt to arrive at a model that unambiguously explains the origin of the thermal springs Title: Geological and Geophysical Study of the Origin of the Warm Springs in Bath County, Virginia. Final Report, June 1, 1975--April 30, 1976 Author: Costain, J.K. Year: 1976 The results of heat flow determinations and a reconnaissance dipole electrical resistivity survey in Bath County are described. A geologic map was compiled based on published maps and supported by reconnaissance geologic mapping in areas where published maps were not available. A regional bipole--dipole electrical resistivity survey was made in order to detect the presence of resistivity lows that might be associated with a geothermal system at depth. A single hole was drilled to a depth of approximately 300 m (approx. 1000 feet) to obtain a heat flow value that is representative of the area. The data were used to attempt to arrive at a model that unambiguously explains the origin of the thermal springs Close

• 9. [Image] Low-Temperature Geothermal Reservoir Site Evaluation in Arizona. Quarterly Progress Report, August 1, 1977--October 31, 1977

  	Progress in the development of a cost-effective exploration program for low- to moderate-temperature geothermal resources is reported. As part of this program two or three demonstration projects in Arizona ...
  	Citation × Citation Citation Abstract Copy Title: Low-Temperature Geothermal Reservoir Site Evaluation in Arizona. Quarterly Progress Report, August 1, 1977--October 31, 1977 Author: Hahman, W.R. Sr. Year: 1977 Progress in the development of a cost-effective exploration program for low- to moderate-temperature geothermal resources is reported. As part of this program two or three demonstration projects in Arizona will be brought on stream. The site-specific exploration, evaluation and development program as well as the state wide reconnaissance exploration program is continuing. The compilation of data for a geothermal energy resource map of Arizona has commenced. Geological field work was directed towards obtaining a broad overview of Arizona geology and regional reconnaissance in the Springerville - St. Johns area. All outside projects are on schedule and the Landsat lineament map and report have been completed Title: Low-Temperature Geothermal Reservoir Site Evaluation in Arizona. Quarterly Progress Report, August 1, 1977--October 31, 1977 Author: Hahman, W.R. Sr. Year: 1977 Progress in the development of a cost-effective exploration program for low- to moderate-temperature geothermal resources is reported. As part of this program two or three demonstration projects in Arizona will be brought on stream. The site-specific exploration, evaluation and development program as well as the state wide reconnaissance exploration program is continuing. The compilation of data for a geothermal energy resource map of Arizona has commenced. Geological field work was directed towards obtaining a broad overview of Arizona geology and regional reconnaissance in the Springerville - St. Johns area. All outside projects are on schedule and the Landsat lineament map and report have been completed Close

• 10. [Image] Geothermal Energy in Nevada

  	This report is a brief informative on what geothermal energy is, where it can be found and how it can be used. The location here is specifically focused on the Nevada region
  	Citation × Citation Citation Abstract Copy Title: Geothermal Energy in Nevada Author: Nevada Department of Energy Year: 1980 This report is a brief informative on what geothermal energy is, where it can be found and how it can be used. The location here is specifically focused on the Nevada region Title: Geothermal Energy in Nevada Author: Nevada Department of Energy Year: 1980 This report is a brief informative on what geothermal energy is, where it can be found and how it can be used. The location here is specifically focused on the Nevada region Close