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• 1. [Image] Geothermal Exploration of the Puga and Chumathang Geothermal Fields, Ladakh, India

  	Puga and Chumathang Geothermal fields are situated near the collided junction of the Indian and Asian Crystal plates and thermal activity in these fields is attributed to the widespread igneous activity ...
  	Citation × Citation Citation Abstract Copy Title: Geothermal Exploration of the Puga and Chumathang Geothermal Fields, Ladakh, India Author: Shanker, R. Puga and Chumathang Geothermal fields are situated near the collided junction of the Indian and Asian Crystal plates and thermal activity in these fields is attributed to the widespread igneous activity of Upper Cretaceous to late Tertiary age. A deep suture zone, recognised in between these two fields and the associated faults provide channels for the upward migration of the thermal fluids. High concentrations of Cl, F, Si02, B, Na, Li, Rb, Cs in thermal fluids signify contribution of magmatic bodies towards heat, and fluid supply. These fields are characterized by high heat flow conditions (13 HFU), abnormal shallow geothermal gradients (0.7 - 2.5 c/m) , high base temperature (220 - 270 C) as obtained by alkalia and Ne-K-Ca geothermometry and low resistivity values (2-20 ohm.m.). Low resistivity zones occupy on an area of three and one sq.km. and extend down to maximum depths of 300 m. and 130 m. at Puga and Chumathang respectively. Shallow drilling (28-130 m.) has established the existence of wet steam reservoirs under moderate pressure (2-4.5 kg/cm^2). Hot fluid (95-135 C) discharges from eight flowing wells ranged from 7.5 to 30 t/h. These thermal fluids are stored in the partly consolidated fluvioglacial deposits of Quarternary to Recent age. The occurrence of a limestone layer in the country rock at Puga brightens the prospects of getting good reservoir at depth. In both these fields two aquifers have been recognised, each having sizeable potential for retaining ground water. The ground water recharge is mainly through snow melt from glaciers in the case of Puga field and principally from Indus river in the case of Chumathangfield Title: Geothermal Exploration of the Puga and Chumathang Geothermal Fields, Ladakh, India Author: Shanker, R. Puga and Chumathang Geothermal fields are situated near the collided junction of the Indian and Asian Crystal plates and thermal activity in these fields is attributed to the widespread igneous activity of Upper Cretaceous to late Tertiary age. A deep suture zone, recognised in between these two fields and the associated faults provide channels for the upward migration of the thermal fluids. High concentrations of Cl, F, Si02, B, Na, Li, Rb, Cs in thermal fluids signify contribution of magmatic bodies towards heat, and fluid supply. These fields are characterized by high heat flow conditions (13 HFU), abnormal shallow geothermal gradients (0.7 - 2.5 c/m) , high base temperature (220 - 270 C) as obtained by alkalia and Ne-K-Ca geothermometry and low resistivity values (2-20 ohm.m.). Low resistivity zones occupy on an area of three and one sq.km. and extend down to maximum depths of 300 m. and 130 m. at Puga and Chumathang respectively. Shallow drilling (28-130 m.) has established the existence of wet steam reservoirs under moderate pressure (2-4.5 kg/cm^2). Hot fluid (95-135 C) discharges from eight flowing wells ranged from 7.5 to 30 t/h. These thermal fluids are stored in the partly consolidated fluvioglacial deposits of Quarternary to Recent age. The occurrence of a limestone layer in the country rock at Puga brightens the prospects of getting good reservoir at depth. In both these fields two aquifers have been recognised, each having sizeable potential for retaining ground water. The ground water recharge is mainly through snow melt from glaciers in the case of Puga field and principally from Indus river in the case of Chumathangfield Close

• 2. [Image] Geophysical Lineaments of Arizona

  	Photolineaments seen on satellite images are usually expressions of deep crustal ruptures. However, photolineaments are omnipresent and an independent expression of regional discontinuities is needed to ...
  	Citation × Citation Citation Abstract Copy Title: Geophysical Lineaments of Arizona Author: Lepley, L.K. Year: 1979 Photolineaments seen on satellite images are usually expressions of deep crustal ruptures. However, photolineaments are omnipresent and an independent expression of regional discontinuities is needed to help rank the photolineaments. Published gravity and magnetic contour maps of Arizona were analyzed to produce a single geophysical lineament map to indicate trends of regional basement structures. This map shows that the southwestern quarter of Arizona is dominated by a NNW-ENE orthogonal system whereas the remainder of the state is gridded by a NW-NE system. North-south systems are present throughout the state, as are EW lineaments. Arizona is transected by the WNW Texas Strand, but other shorter systems trending in the Texas direction are found throughout the state south of the Strand. The major lineament systems as seen on Landsat, gravity, and magnetic maps correlate reasonably Well with known geothermal manifestations. Many other systems are Precambrian, Paleozoic, and/or Mesozoic in age but appear to control the location of Quaternary Volcanic systems Title: Geophysical Lineaments of Arizona Author: Lepley, L.K. Year: 1979 Photolineaments seen on satellite images are usually expressions of deep crustal ruptures. However, photolineaments are omnipresent and an independent expression of regional discontinuities is needed to help rank the photolineaments. Published gravity and magnetic contour maps of Arizona were analyzed to produce a single geophysical lineament map to indicate trends of regional basement structures. This map shows that the southwestern quarter of Arizona is dominated by a NNW-ENE orthogonal system whereas the remainder of the state is gridded by a NW-NE system. North-south systems are present throughout the state, as are EW lineaments. Arizona is transected by the WNW Texas Strand, but other shorter systems trending in the Texas direction are found throughout the state south of the Strand. The major lineament systems as seen on Landsat, gravity, and magnetic maps correlate reasonably Well with known geothermal manifestations. Many other systems are Precambrian, Paleozoic, and/or Mesozoic in age but appear to control the location of Quaternary Volcanic systems Close

• 3. [Image] Hawaii Geothermal Resource Assessment Program: western state cooperative direct heat resource assessment, Phase I. Final report

  	A regional geothermal resource assessment has been conducted for the major islands in the Hawaiian chain. The assessment was made through the compilation and evaluation of the readily accessible geological, ...
  	Citation × Citation Citation Abstract Copy Title: Hawaii Geothermal Resource Assessment Program: western state cooperative direct heat resource assessment, Phase I. Final report Year: 1978 A regional geothermal resource assessment has been conducted for the major islands in the Hawaiian chain. The assessment was made through the compilation and evaluation of the readily accessible geological, geochemical, and geophysical data for the Hawaiian archipelago which has been acquired during the last two decades. The geologic criteria used in the identification of possible geothermal reservoirs were: age and location of most recent volcanism on the island and the geologic structure of each island. The geochemical anomalies used as traces for geothermally altered ground water were: elevated silica concentrations and elevated chloride/magnesium ion ratios. Geophysical data used to identify subsurface structure which may have geothermal potential were: aeromagnetic anomalies, gravity anomalies, and higher than normal well and basal spring discharge temperatures. Geophysical and geochemical anomalies which may be the result of subsurface thermal effects have been identified on the islands of Hawaii, Maui, Molokai and Oahu; DOE/ID/01713-4 Title: Hawaii Geothermal Resource Assessment Program: western state cooperative direct heat resource assessment, Phase I. Final report Year: 1978 A regional geothermal resource assessment has been conducted for the major islands in the Hawaiian chain. The assessment was made through the compilation and evaluation of the readily accessible geological, geochemical, and geophysical data for the Hawaiian archipelago which has been acquired during the last two decades. The geologic criteria used in the identification of possible geothermal reservoirs were: age and location of most recent volcanism on the island and the geologic structure of each island. The geochemical anomalies used as traces for geothermally altered ground water were: elevated silica concentrations and elevated chloride/magnesium ion ratios. Geophysical data used to identify subsurface structure which may have geothermal potential were: aeromagnetic anomalies, gravity anomalies, and higher than normal well and basal spring discharge temperatures. Geophysical and geochemical anomalies which may be the result of subsurface thermal effects have been identified on the islands of Hawaii, Maui, Molokai and Oahu; DOE/ID/01713-4 Close