摘要 :
A large amount of geological and geophysical data, including thermal, geochemical, geodetic, magnetic, and seismic measurements and a shallow drill hole, was acquired during the 1975 field season. Data reduction and analysis are i...
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A large amount of geological and geophysical data, including thermal, geochemical, geodetic, magnetic, and seismic measurements and a shallow drill hole, was acquired during the 1975 field season. Data reduction and analysis are in progress. (ERA citation 03:017349)
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摘要 :
The McCoy geothermal prospect is located in north-central Nevada at the junction of the Augusta Mountains, Clan Alpine Mountains and the New Pass Range. Geothermal exploration on the prospect consisted of an integrated program of ...
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The McCoy geothermal prospect is located in north-central Nevada at the junction of the Augusta Mountains, Clan Alpine Mountains and the New Pass Range. Geothermal exploration on the prospect consisted of an integrated program of geologic, geochemical and geophysical studies. The geochemical studies included hydrogeochemistry, soil geochemistry, and drill cuttings geochemistry. Geophysical exploration included heatflow studies, aeromagnetic, self-potential, gravity, passive seismic, dipole-dipole resistivity, electromagnetic and magnetotelluric surveys. Exploration drilling includes fifty-two (52) shallow thermal gradient holes and five (5) intermediate depth temperature gradient wells. Shallow low-temperature geothermal reservoirs were encountered in two areas. In the McCoy Mine area the resource was found in the Permo-Pennsylvanian rocks. In the southern part of the prospect a resource with temperatures of 100 exp 0 C was encountered in the basal conglomeratic sandstone of the Triassic section. (ERA citation 08:020154)
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A wide variety of geophysical methods were employed to study a proposed nuclear waste site at Syncline Ridge on the Nevada Test Site, Nevada. Detailed and regional gravity work revealed complex structure at the site. Magnetics hel...
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A wide variety of geophysical methods were employed to study a proposed nuclear waste site at Syncline Ridge on the Nevada Test Site, Nevada. Detailed and regional gravity work revealed complex structure at the site. Magnetics helped only in identifying small areas of Tertiary volcanic rocks because of low magnetization. Seismic refraction assisted in identifying near surface faulting and bedrock structure. Difficulty was experienced in obtaining good quality reflection data, implying significant structural complexity. Electrical methods were used for fault identification and for mapping of a thick argillaceous unit of the Eleana Formation in which nuclear waste was to be emplaced. The geophysical studies indicate that major faults along the axis of Syncline Ridge and on both margins have large vertical offsets displacing units so as not only to make mining difficult, but also providing potential paths for waste migration to underlying carbonate aquifers. The Eleana Formation appeared heterogeneous, which was inferred to be due to structural complexity. Only a small region in the northwest part of the study area was found to contain a thick and relatively undisturbed volume of host rock. Deep electrical soundings identified a very conductive region in the crust below Syncline Ridge at depths shallower than 10 km. Similar conductive regions have been observed associated with geothermal systems in the western United States and imply the potential for a blind geothermal system below Syncline Ridge. The geophysical studies provided negative evidence for the suitability of the site for a nuclear waste repository. (ERA citation 07:049398)
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The Colado geothermal area is evidenced by hot water wells in alluvium along the west flank of the West Humboldt Range. The exploration of this geothermal system has progressed into advanced stages with completion of shallow therm...
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The Colado geothermal area is evidenced by hot water wells in alluvium along the west flank of the West Humboldt Range. The exploration of this geothermal system has progressed into advanced stages with completion of shallow thermal gradient drilling, two intermediate-depth exploration drill holes, one deep exploration drill hole, detailed geologic mapping, dipole-dipole resistivity, gravity, ground magnetics, MT-AMT, TDEM and assorted uncommon electrical resistivity techniques. A thermal anomaly was outlined by the shallow drilling. Dipole-dipole resistivity and gravity data along with detailed geologic mapping have suggested that this anomaly is structurally controlled. Other geophysical techniques employed do not appear to contribute to an understanding of the geothermal anomaly. The two intermediate-depth exploration holes (IGH-1, IGH-2) and the one deep hole (44x-10) may not have been located in the most favorable portions of the geothermal anomaly. The area having the greatest exploration potential for intermediate-depth drilling appears to be centered on the shallow drill hole 14 to 22. An intermediate-depth drill hole located near DH14-22 is most likely to encounter one of the conduits that allow thermal waters to rise near the surface. (ERA citation 07:053513)
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摘要 :
The Colado geothermal area is evidenced by hot water wells in alluvium along the west flank of the West Humboldt Range. The exploration of this geothermal system has progressed into advanced stages with completion of shallow therm...
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The Colado geothermal area is evidenced by hot water wells in alluvium along the west flank of the West Humboldt Range. The exploration of this geothermal system has progressed into advanced stages with completion of shallow thermal gradient drilling, two intermediate-depth exploration drill holes, one deep exploration drill hole, detailed geologic mapping, dipole-dipole resistivity, gravity, ground magnetics, MT-AMT, TDEM and assorted uncommon electrical resistivity techniques. A thermal anomaly was outlined by the shallow drilling. Dipole-dipole resistivity and gravity data along with detailed geologic mapping have suggested that this anomaly is structurally controlled. Other geophysical techniques employed do not appear to contribute to an understanding of the geothermal anomaly. The two intermediate-depth exploration holes (IGH-1, IGH-2) and the one deep hole (44x-10) may not have been located in the most favorable portions of the geothermal anomaly. The area having the greatest exploration potential for intermediate-depth drilling appears to be centered on the shallow drill hole 14 to 22. An intermediate-depth drill hole located near DH14-22 is most likely to encounter one of the conduits that allow thermal waters to rise near the surface. (ERA citation 07:053513)
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An assessment of the Steamboat Springs region in northwest Colorado was initiated and carried out in 1980 and 1981. The goal of this program was to delineate the geological features controlling the occurrence of the thermal waters...
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An assessment of the Steamboat Springs region in northwest Colorado was initiated and carried out in 1980 and 1981. The goal of this program was to delineate the geological features controlling the occurrence of the thermal waters (temperatures in excess of 68 exp 0 F (20 exp 0 C)) in this area at Steamboat Springs and 8 miles (12.8 km) north at Routt Hot Springs. Thermal waters from Heart Spring, the only developed thermal water source in the study area, are used in the municipal swimming pool in Steamboat Springs. The assessment program was a fully integrated program consisting of: dipole-dipole, Audio-magnetotelluric, telluric, self potential and gravity geophysical surveys, soil mercury and soil helium geochemical surveys; shallow temperature measurements; and prepartion of geological maps. The investigation showed that all the thermal springs appear to be fault controlled. Based on the chemical composition of the thermal waters it appears that Heart Spring in Steamboat Springs is hydrologically related to the Routt Hot Springs. This relationship was further confirmed when it was reported that thermal waters were encountered during the construction of the new high school in Strawberry Park on the north side of Steamboat Springs. In addition, residents stated that Strawberry Park appears to be warmer than the surrounding country side. Geological mapping has determined that a major fault extends from the Routt Hot Springs area into Strawberry Park. (ERA citation 08:023368)
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摘要 :
The McCoy geothermal prospect is located in north-central Nevada at the junction of the Augusta Mountains, Clan Alpine Mountains and the New Pass Range. Geothermal exploration on the prospect consisted of an integrated program of ...
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The McCoy geothermal prospect is located in north-central Nevada at the junction of the Augusta Mountains, Clan Alpine Mountains and the New Pass Range. Geothermal exploration on the prospect consisted of an integrated program of geologic, geochemical and geophysical studies. The geochemical studies included hydrogeochemistry, soil geochemistry, and drill cuttings geochemistry. Geophysical exploration included heatflow studies, aeromagnetic, self-potential, gravity, passive seismic, dipole-dipole resistivity, electromagnetic and magnetotelluric surveys. Exploration drilling includes fifty-two (52) shallow thermal gradient holes and five (5) intermediate depth temperature gradient wells. Shallow low-temperature geothermal reservoirs were encountered in two areas. In the McCoy Mine area the resource was found in the Permo-Pennsylvanian rocks. In the southern part of the prospect a resource with temperatures of 100 exp 0 C was encountered in the basal conglomeratic sandstone of the Triassic section. (ERA citation 08:020154)
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Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure we...
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Geological investigations at Momotombo included photogeology, field mapping, binocular microscope examination of cuttings, and drillhole correlations. Among the geophysical techniques used to investigate the field sub-structure were: Schlumberger and electromagnetic soundings, dipole mapping and audio-magnetotelluric surveys, gravity and magnetic measurements, frequency domain soundings, self-potential surveys, and subsurface temperature determinations. The geochemical program analyzed the thermal fluids of the surface and in the wells. The description and results of exploration methods used during the investigative stages of the Momotombo Geothermal Field are presented. A conceptual model of the geothermal field was drawn from the information available at each exploration phase. The exploration methods have been evaluated with respect to their contributions to the understanding of the field and their utilization in planning further development. (ERA citation 08:012199)
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The Tuscarora prospect is located at the north end of Independence Valley approximately 90 km north-northwest of Elko, Nevada. Geothermal exploration on the prospect consisted of an integrated program of geologic, hydrogeochemical...
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The Tuscarora prospect is located at the north end of Independence Valley approximately 90 km north-northwest of Elko, Nevada. Geothermal exploration on the prospect consisted of an integrated program of geologic, hydrogeochemical and soil geochemistry studies. Geophysical exploration included heatflow studies, aeromagnetic, self-potential, gravity, dipole-dipole resistivity and magnetotelluric surveys. Exploration drilling includes thirty-two shallow thermal gradient holes, six intermediate depth temperature gradient wells and one 5454 foot test for discovery well. Shallow low-temperature reservoirs were encountered in the Tertiary rocks and in the Paleozoic rocks immediately beneath the Tertiary. Drilling problems forced the deep well to be stopped before the high-temperature reservoir was reached. (ERA citation 07:003877)
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The Tyonek Quadrangle in south-central Alaska was evaluated to identify geologic environments favorable for the occurrence of uranium deposits. Published geologic maps and reports, aerial radiometric surveys, geochemical surveys, ...
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The Tyonek Quadrangle in south-central Alaska was evaluated to identify geologic environments favorable for the occurrence of uranium deposits. Published geologic maps and reports, aerial radiometric surveys, geochemical surveys, and ground geologic examination were used in the evaluation. The western two-thirds of the Tyonek Quadrangle is a part of the Alaska Range orogenic belt. It consists largely of a Mesozoic flysch and mafic volcanic sequence and Mesozoic and Tertiary granitic plutonic rocks. The eastern one-third of the quadrangle is mainly underlain by rocks and deposits of the Cook Inlet-Susitna Basin of Tertiary age. No areas or units in the quadrangle were found to be favorable for uranium deposits. Sediment samples from streams draining the Mount Estelle pluton in the northwest corner of the quadrangle contained up to 40 ppM U sub 3 O sub 8 . In addition, radiometric data and high geochemical factor scores characterized the Mount Estelle unit, but no uranium occurrences were found in reconnaissance-level ground examination. Radiometric and geochemical levels in the rest of the exposed bedrock environments in the quadrangle were low. The Cenozoic basins of the quadrangle have some similarity to those which host sandstone uranium deposits elsewhere. Their potential, however, remains unevaluated because of their water-saturated surficial cover. Placer occurrences of uranium likewise remain unevaluated. (ERA citation 07:045845)
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