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Investigation of the Downwelling LW Differences Between the Niamey AMF Main and Supplementary Sites

Description: The overall average downwelling longwave (LW) measured at the Niamey supplementary facility (S1) is 6-8 Wm-2 less than that measured by the two instruments located at the ARM Mobile Facility (AMF) main (N1) site. Examination of all other data available at both sites does not reveal any overarching differences that suggest this should be the case. However, examination of the pyrgeometer case and dome temperatures do suggest that the S1 values are also anomalously low, which in turn would explain the downwelling LW anomaly since the LW is calculated using these temperatures. Our recommendation then is to normalize the S1 data to the average N1 value by applying an adjustment factor to the S1 downwelling pyrgeometer case and dome temperatures (in Kelvin), then recalculating the downwelling LW values. The adjustment factor (0.00305) has been determined as that factor that brings the overall average S1 LWdn to agree with the overall average of the two N1 LWdn data series. We note that there is no reason to expect that the two site averages would actually be exactly equal to one another, and thus our recommendation is viewed as likely moving the S1 data in the right direction and by normalizing to the N1 average will help facilitate more meaningful temporal variability studies at least. It is also strongly recommended that for all future AMF deployments where supplementary sites will also be deployed, that the supplementary instrument systems (complete) be assembled as they will be operated in the field and run for at least a few days beside the corresponding AMF main site instruments, both at the beginning and end of the AMF field campaign. This is absolutely crucial so that all the measurements can be compared pre- and post-experiment to properly relate these measurements and systems, and to detect measurement anomalies ...
Date: April 1, 2008
Creator: Long, CN; Gotseff, P & Dutton, EG
Partner: UNT Libraries Government Documents Department

A CO2-Silica Geothermometer for Low Temperature Geothermal Resource Assessment, with Application to Resources in the Safford Basin, Arizona

Description: Geothermics is the study of the earth's heat energy, it's affect on subsurface temperature distribution, it's physical and chemical sources, and it's role in dynamic geologic processes. The term, geothermometry, is applied to the determination of equilibrium temperatures of natural chemical systems, including rock, mineral, and liquid phases. An assemblage of minerals or a chemical system whose phase composition is a function of temperature and pressure can be used as a geothermometer. Thus a geothermometer is useful to determine the formation temperature of rock or the last equilibrium temperature of a flowing aqueous solution such as ground water and hydrothermal fluids.
Date: November 1, 1983
Creator: Witcher, James C. & Stone, Claudia
Partner: UNT Libraries Government Documents Department

A Field Study of Tracer and Geochemistry Behavior During Hydraulic Fracturing of a Hot Dry Rock Geothermal Reservoir

Description: Tracer and geochemistry measurements in fractured Hot Dry Rock (HDR) geothermal reservoirs are usually performed after a fracture connection has been established and constant, nearly equal inlet and outlet flow rates have been achieved. however, during hydraulic fracturing experiments designed to create a low-impedance fracture connection between two wells, the inlet and outlet flow rates can be dramatically different and can vary during the test, forcing us to revise the common analytical methods for interpreting tracer response curves and geochemistry behavior. This study presents tracer and geochemistry data from several hydraulic fracturing experiments at the Fenton Hill, NM, HDR geothermal reservoir. Tracers have been injected at various times during these tests: (1) initially, before any flow communication existing between the wells; (2) shortly after a flow connection was established; and (3) after the outlet flow had increased to its steady state value. An idealized flow model consisting of a combination of main fracture flow paths and fluid leakoff into secondary permeability explains the different tracer response curves for these cases, and allows us to predict the fracture volume of the main paths. The geochemistry during these experiments supports our previously developed models postulating the existence of a high concentration indigenous ''pore fluid''. Also, the quartz and Na-K-Ca geothermometers have been used successfully to identify the temperatures and depths at which fluid traveled while in the reservoir. The quartz geothermometer is somewhat more reliable because at these high temperatures (about 250 C) the injected fluid can come to equilibrium with quartz in the reservoir. The Na-K-Ca geothermometer relies on obtaining a sample of the indigenous pore fluid, and thus is somewhat susceptible to problems of dilution with the injection fluid.
Date: January 21, 1986
Creator: Robinson, Bruce A.
Partner: UNT Libraries Government Documents Department

Thermal extraction analysis of five Los Azufres production wells

Description: Thermal energy extraction from five wells supplying 5-MWe wellhead generators in three zones of the Los Azufres geothermal field has been examined from production and chemical data compiled over 14-years of operation. The data, as annual means, are useful in observing small-scale changes in reservoir performance with continuous production. The chemical components are chloride for quality control and the geothermometer elements for reservoir temperatures. The flowrate and fluid enthalpy data are used to calculate the thermal extraction rates. Integration of these data provides an estimate of the total energy extracted from the zone surrounding the well. The combined production and chemical geothermometer data are used to model the produced fluid as coming from just-penetrating wells for which the annual produced mass originates from a series of concentric hemispheric shells moving out into the reservoir. Estimates are made of the drawdown distance into the reservoir and the far-field conditions.
Date: January 26, 1995
Creator: Kruger, Paul & Quijano, Luis
Partner: UNT Libraries Government Documents Department

Session 10: The Cerro Prieto Geothermal Field, Mexico: The Experiences Gained from Its Exploration and Development

Description: The Cerro Prieto case study demonstrated the value of a multidisciplinary effort for exploring and developing a geothermal field. There was no problem in recognizing the geothermal potential of the Cerro Prieto area because of the many obvious surface manifestations. However, the delineation of the geothermal reservoir at depth was not so straightforward. Wells drilled near the abundant surface manifestations only produced fluids of relatively low enthalpy. Later it was determined that these zones of high heat loss corresponded to discharge areas where faults and fractures allowed thermal fluids to leak to the surface, and not to the main geothermal reservoir. The early gravity and seismic refraction surveys provided important information on the general structure of the area. Unaware of the existence of a higher density zone of hydrothermally altered sediments capping the geothermal reservoir, CFE interpreted a basement horst in the western part of the field and hypothesized that the bounding faults were controlling the upward flow of thermal fluids. Attempting to penetrate the sedimentary column to reach the ''basement horst'', CFE discovered the {alpha} geothermal reservoir (in well M-5). The continuation of the geothermal aquifer (actually the {beta} reservoir) east of the original well field was later confirmed by a deep exploration well (M-53). The experience of Cerro Prieto showed the importance of chemical ratios, and geothermometers in general, in establishing the subsurface temperatures and fluid flow patterns. Fluid chemical and isotopic compositions have also been helpful to determine the origin of the fluids, fluid-production mechanisms and production induced effects on the reservoir.
Date: December 1, 1983
Creator: Lippman, M.J.; Goldstein, N.E.; Halfman, S.E. & Witherspoon, P.A.
Partner: UNT Libraries Government Documents Department

Phase 2 and 3 Slim Hole Drilling and Testing at the Lake City, California Geothermal Field

Description: During Phases 2 and 3 of the Lake City GRED II project two slim holes were cored to depths of 1728 and 4727 ft. Injection and production tests with temperature and pressure logging were performed on the OH-1 and LCSH-5 core holes. OH-1 was permanently modified by cementing an NQ tubing string in place below a depth of 947 ft. The LCSH-1a hole was drilled in Quaternary blue clay to a depth of 1727 ft and reached a temperature of 193 oF at a depth of 1649 ft. This hole failed to find evidence of a shallow geothermal system east of the Mud Volcano but the conductive temperature profile indicates temperatures near 325 oF could be present below depth of 4000 ft. The LCSH-5 hole was drilled to a depth of 4727 ft and encountered a significant shallow permeability between depths of 1443 and 1923 ft and below 3955 ft. LCSH-5 drilled impermeable Quaternary fanglomerate to a depth of 1270 ft. Below 1270 ft the rocks consist primarily of Tertiary sedimentary rocks. The most significant formation deep in LCSH-5 appears to be a series of poikoilitic mafic lava flows below a depth of 4244 ft that host the major deep permeable fracture encountered. The maximum static temperature deep in LCSH-5 is 323 oF and the maximum flowing temperature is 329 oF. This hole extended the known length of the geothermal system by ¾ of a mile toward the north and is located over ½ mile north of the northernmost hot spring. The OH-1 hole was briefly flow tested prior to cementing the NQ rods in place. This flow test confirmed the zone at 947 ft is the dominant permeability in the hole. The waters produced during testing of OH-1 and LCSH-5 are generally intermediate in character between the deep geothermal ...
Date: October 27, 2005
Creator: Benoit, Dick; Blackwell, David; Moore, Joe & Goranson, Colin
Partner: UNT Libraries Government Documents Department

Final Report: Phase II Geothermal Exploration and Geothermal Power Plant Update for Ascension Island, South Atlantic Ocean

Description: The Phase I study of the geothermal potential of Ascension Island concluded that the possibility of a geothermal resource existing under the island was excellent. This conclusion was based on the presence of young volcanic rocks (a heat source close to the surface), an ample supply of water from the sea, and high permeability of many of the rocks which make up the island. The assumption was made that the resource would be similar to geothermal systems in the Azores or Japan, and a conceptual design of a power plant to utilize the resource was prepared upon which cost estimates and an economic analysis were subsequently performed. The results of the economic analysis were very favorable, and the Air Force decided to proceed into Phase II of the project. Under Phase II, an exploration program was designed and carried out. The purpose of the program was to ascertain whether or not a geothermal resource existed beneath Ascension island and, to the extent possible, to evaluate the quality of that resource. The exploration involved a detailed aeromagnetic survey of the island, reconnaissance and detailed electrical resistivity surveys, and drilling of holes for the measurement of temperatures. These methods have confirmed the existence of geothermal activity beneath Ascension. Measured temperature gradients and bottom hole temperatures as well as chemical geothermometers indicate temperatures sufficient for the generation of electricity within reasonable drilling depths. This report documents those conclusions and the supporting data. This report also documents the results of the power plant update with new data supplied from the Phase II exploration activities on the island. The power plant scenario has been changed to reflect the fact that the resource temperature may not be as high as that originally assumed in the Phase I study, the location of the production wells will in ...
Date: July 1, 1984
Creator: Nielson, D.L.; Sibbett, B.S.; Shane, M.K. & Whitbeck, J.F.
Partner: UNT Libraries Government Documents Department

Improvements in geothermometry. Final technical report. Rev

Description: Alkali and alkaline earth geothermometers are useful for estimating geothermal reservoir temperatures, though a general theoretical basis has yet to be established and experimental calibration needs improvement. Equilibrium cation exchange between feldspars provided the original basis for the Na-K and Na-K-Ca geothermometers (Fournier and Truesdell, 1973), but theoretical, field and experimental evidence prove that neither equilibrium nor feldspars are necessary. Here, evidence is summarized in support of these observations, concluding that these geothermometers can be expected to have a surprisingly wide range of applicability, but that the reasons behind such broad applicability are not yet understood. Early experimental work proved that water-rock interactions are slow at low temperatures, so experimental calibration at temperatures below 150/sup 0/ is impractical. Theoretical methods and field data were used instead for all work at low temperatures. Experimental methods were emphasized for temperatures above 150/sup 0/C, and the simplest possible solid and solution compositions were used to permit investigation of one process or question at a time. Unexpected results in experimental work prevented complete integration of the various portions of the investigation.
Date: August 1, 1982
Creator: Potter, J.; Dibble, W.; Parks, G. & Nur, A.
Partner: UNT Libraries Government Documents Department

Magnesium correction for the Na-K-Ca chemical geothermometer

Description: Graphs and equations have been devised to correct for the adverse effects of magnesium upon the Na-K-Ca geothermometer. Either the graphs or equations can be used to determine temperature corrections when given waters have Na-K-Ca calculated temperatures above 70/sup 0/C and values of R less than 50, where R = (Mg/(Mg + Ca + K)) x 100 in equivalents. Water with values of R greater than 50 probably come from relatively cool aquifers with temperatures about equal to the measured spring temperature, irrespective of much higher calculated Na-K-Ca temperatures.
Date: January 1, 1978
Creator: Fournier, R.O. & Potter, R.W. II
Partner: UNT Libraries Government Documents Department

Apacheta, a new geothermal prospect in Northern Chile

Description: The discovery of two high-temperature fumaroles, with gas geochemistry compatible with an economic geothermal system, established Apacheta as one of the most attractive geothermal exploration prospects in northern Chile. These remote fumaroles at 5,150 m elevation were first sampled in 1999 by ENAP and its partners, following up on the reports of a CODELCO water exploration well that flowed small amounts of dry steam at 4,540 m elevation in the valley 4.5 km east of the fumaroles. The prospect is associated with a Plio-Pleistocene volcanic complex located within a NW-trending graben along the axis of the high Andes. The regional water table is 4,200 masl. There are no hot springs, just the 88 degrees C steam well and the 109 degrees and 118 degrees C fumaroles with gas compositions that indicate reservoir temperatures of greater than or equal to 250 degrees C, using a variety of gas geothermometers. An MT-TDEM survey was completed in 2001-2002 by Geotermica del Norte (SDN), an ENAP-C ODELCO partnership, to explore the Apacheta geothermal concession. The survey results indicated that base of the low resistivity clay cap has a structural apex just west of the fumaroles, a pattern typically associated with shallow permeability within a high temperature geothermal resource. SGN plans to drill at least one exploration well in 2002-03 to characterize a possible economic resource at Apacheta.
Date: May 24, 2002
Creator: Urzua, Luis; Powell, Tom; Cumming, William B. & Dobson, Patrick
Partner: UNT Libraries Government Documents Department

The use of Ahuachapan fluid chemistry to indicate natural state conditions and reservoir processes during exploitation

Description: Chemical analyses of production fluids from Ahuachapan, El Salvador, have been used to indicate natural state reservoir fluid temperatures and chloride concentrations and reservoir processes resulting from exploitation. Geothermometer temperatures (Na--K--Ca and SiO{sub 2}) and calculated aquifer Cl for early flows show a gradient from about 265{degree}C and 9000 ppM Cl in the western part of the well field to 235{degree}C and 6000 ppM Cl in the eastern part. The geochemical temperatures are 10--20{degree}C higher than early downhole measurements. Since exploitation started, pressures have declined over most of the drilled area with boiling and excess-enthalpy discharges in the eastern and western parts. In the center of the field, a number of wells show mixing with cooler, less-saline water. These wells are nearly coincident with a major NE-SW oriented fault that may be the conduit for downward recharge of cooler fluids from an overlying aquifer. 12 refs., 9 figs., 1 tab.
Date: January 1, 1989
Creator: Treusdell, A.H. (Geological Survey, Menlo Park, CA (USA)); Aunzo, Z.; Bodvarsson, G. (Lawrence Berkeley Lab., CA (USA)); Alonso, J. & Campos, A. (Comision Ejecutiva Hidroelectrica del Rio Lempa (CEL) (El Salvador))
Partner: UNT Libraries Government Documents Department

Exploration of the Upper Hot Creek Ranch Geothermal Resource, Nye County, Nevada

Description: The Upper Hot Creek Ranch (UHCR) geothermal system had seen no significant exploration activity prior to initiation of this GRED III project. Geochemical geothermometers calculated from previously available but questionable quality analyses of the UHCR hot spring waters indicated possible subsurface temperatures of +320 oF. A complex Quaternary and Holocene faulting pattern associated with a six mile step over of the Hot Creek Range near the UHCR also indicated that this area was worthy of some exploration activity. Permitting activities began in Dec. 2004 for the temperature-gradient holes but took much longer than expected with all drilling permits finally being received in early August 2005. The drilling and geochemical sampling occurred in August 2005. Ten temperature gradient holes up to 500’ deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five. Four of the five holes drilled to depths of 300 to 400’ encountered temperatures close to the expected regional thermal background conditions. These four holes failed to find any evidence of a large thermal anomaly surrounding the UHCR hot springs. The fifth hole, located within a narrow part of Hot Creek Canyon, encountered a maximum temperature of 81 oF at a depth of 105’ but had cooler temperatures at greater depth. Temperature data from this hole can not be extrapolated to greater depths. Any thermal anomaly associated with the UHCR geothermal system is apparently confined to the immediate vicinity of Hot Creek Canyon where challenges such as topography, a wilderness study area, and wetlands issues will make further exploration time consuming and costly. Ten water samples were collected for chemical analysis and interpretation. Analyses of three samples of the UHCR thermal give predicted subsurface temperatures ranging from 317 to 334 oF from the Na-K-Ca, silica (quartz), ...
Date: October 31, 2005
Creator: Benoit, Dick & Blackwell, David
Partner: UNT Libraries Government Documents Department

Exploration of the Upper Hot Creek Ranch Geothermal Resource, Nye County, Nevada

Description: The Upper Hot Creek Ranch (UHCR) geothermal system had seen no significant exploration activity prior to initiation of this GRED III project. Geochemical geothermometers calculated from previously available but questionable quality analyses of the UHCR hot spring waters indicated possible subsurface temperatures of +320 oF. A complex Quaternary and Holocene faulting pattern associated with a six mile step over of the Hot Creek Range near the UHCR also indicated that this area was worthy of some exploration activity. Permitting activities began in Dec. 2004 for the temperature-gradient holes but took much longer than expected with all drilling permits finally being received in early August 2005. The drilling and geochemical sampling occurred in August 2005. Ten temperature gradient holes up to 500’ deep were initially planned but higher than anticipated drilling and permitting costs within a fixed budget reduced the number of holes to five. Four of the five holes drilled to depths of 300 to 400’ encountered temperatures close to the expected regional thermal background conditions. These four holes failed to find any evidence of a large thermal anomaly surrounding the UHCR hot springs. The fifth hole, located within a narrow part of Hot Creek Canyon, encountered a maximum temperature of 81 oF at a depth of 105’ but had cooler temperatures at greater depth. Temperature data from this hole can not be extrapolated to greater depths. Any thermal anomaly associated with the UHCR geothermal system is apparently confined to the immediate vicinity of Hot Creek Canyon where challenges such as topography, a wilderness study area, and wetlands issues will make further exploration time consuming and costly. Ten water samples were collected for chemical analysis and interpretation. Analyses of three samples of the UHCR thermal give predicted subsurface temperatures ranging from 317 to 334 oF from the Na-K-Ca, silica (quartz), ...
Date: January 1, 2006
Creator: Benoit, Dick & Blackwell, David
Partner: UNT Libraries Government Documents Department

Water information bulletin No. 30 geothermal investigations in Idaho

Description: There are 899 thermal water occurrences known in Idaho, including 258 springs and 641 wells having temperatures ranging from 20 to 93/sup 0/C. Fifty-one cities or towns in Idaho containing 30% of the state's population are within 5 km of known geothermal springs or wells. These include several of Idaho's major cities such as Lewiston, Caldwell, Nampa, Boise, Twin Falls, Pocatello, and Idaho Falls. Fourteen sites appear to have subsurface temperatures of 140/sup 0/C or higher according to the several chemical geothermometers applied to thermal water discharges. These include Weiser, Big Creek, White Licks, Vulcan, Roystone, Bonneville, Crane Creek, Cove Creek, Indian Creek, and Deer Creek hot springs, and Raft River, Preston, and Magic Reservoir areas. These sites could be industrial sites, but several are in remote areas away from major transportation and, therefore, would probably be best utilized for electrical power generation using the binary cycle or Magma Max process. Present uses range from space heating to power generation. Six areas are known where commercial greenhouse operations are conducted for growing cut and potted flowers and vegetables. Space heating is substantial in only two places (Boise and Ketchum) although numerous individuals scattered throughout the state make use of thermal water for space heating and private swimming facilities. There are 22 operating resorts using thermal water and two commercial warm-water fish-rearing operations.
Date: June 1, 1980
Creator: Mitchell, J.C.; Johnson, L.L.; Anderson, J.E.; Spencer, S.G. & Sullivan, J.F.
Partner: UNT Libraries Government Documents Department

Colorado's hydrothermal resource base: an assessment

Description: As part of its effort to more accurately describe the nations geothrmal resource potential, the US Department of Energy/Division of Geothermal Energy contracted with the Colorado Geological survey to appraise the hydrothermal (hot water) geothermal resources of Colorado. Part of this effort required that the amount of energy that could possibly be contained in the various hydrothermal systems in Colorado be estimated. The findings of that assessment are presented. To make these estimates the geothermometer reservoir temperatures estimated by Barrett and Pearl (1978) were used. In addition, the possible reservoir size and extent were estimated and used. This assessment shows that the total energy content of the thermal systems in Colorado could range from 4.872 x 10{sup 15} BTU's to 13.2386 x 10{sup 15} BTU's.
Date: January 1, 1981
Creator: Pearl, R.H.
Partner: UNT Libraries Government Documents Department

Thermodynamic model of the hydrolysis of microcline in acid-sulfate solutions

Description: A theoretical model of the hydrolysis of microcline by a hydrothermal solution has been determined for a closed system at constant temperature. Hypothetical solution compositions and temperatures were chosen to match the known geothermal system at Roosevelt Hot Springs, Utah. The calculated reaction paths indicate that the overall reaction process is an exchange of potassium from the reactant mineral, microcline, for hydrogen from the solution. Aluminum is nearly conserved among solid phases. The amount of microcline reacted per kilogram of solution before overall equilibrium is reached is a function of temperature and inituial solution pH. Since the system is closed and at constant temperature natural conditions are not reproduced well enough to apply the model as a geothermometer. The reaction paths suggest qualitative models of alteration mineral zoning patterns that are similar to zoning at Roosevelt Hot Springs, Utah; Steamboat Springs, Nevada, and Butte, Montana. The models presented view alteration zoning as a function of temperature and pH gradients within homogeneous host rocks where microcline and quartz are abundant.
Date: December 1, 1976
Creator: Dedolph, R.E. & Parry, W.T.
Partner: UNT Libraries Government Documents Department

Geochemical studies at four northern Nevada hot spring areas. [Kyle Hot Springs, Leach Hot Springs, Buffalo Hot Springs, and Beowave Hot Springs]

Description: Water samples from both hot and cold sources in the hydrologic areas surrounding the hot springs were collected and analyzed. Analyses of major, trace, and radio-element abundances of the water samples and of associated rock samples are presented. From this study it is possible that trace- and major-element abundances and/or ratios may be discerned which are diagnostic as chemical geothermometers, complementing those of silica and alkali elements that are presently used. Brief discussions of mixing calculations, possible new chemical geothermometers, and interelement relationships are also included.
Date: August 1, 1977
Creator: Wollenberg, H.; Bowman, H. & Asaro, F.
Partner: UNT Libraries Government Documents Department

Water geochemistry of the Lucero Uplift, New Mexico: geothermal investigation of low-temperature mineralized fluids

Description: A detailed geochemical investigation of 27 waters of the Lucero uplift, central New Mexico, was performed to determine if the fluids originate from a high-temperature geothermal system along the Rio Grande rift. Two types of mineralized water issue from the Lucero region: a relatively saline (high-Cl, high-SO/sub 4/) type and a relatively dilute (low-Cl, high-SO/sub 4/) type. Emergence temperatures of both types range from 12 to 26/sup 0/C. Chemical data and thermodynamic and geothermometer calculations all indicate that both water types are in equilibrium with carbonate and evaporite minerals found in local Colorado Plateau rocks at surface temperatures or slightly higher. Stable isotope data do not indicate high-temperature rock-water interaction. Although evidence is seen for mixing between mineralized waters and dilute surface waters, no evidence for mixing of a deep hot fluid and surface waters is seen. Dilute mineral waters, which issue from a large area of Chinle Formation on the west side of the Lucero uplift, may be useful for low-temperature geothermal applications with appropriate design of equipment. Saline mineral waters, which leak from a zone of faulted and folded rocks along the Comanche fault zone, do not appear to have much, if any, geothermal potential due to their low-temperature, restricted distribution, and high concentration of dissolved solids. No evidence that saline mineral waters are associated with Quaternary faults of the Rio Grande rift or Quaternary basaltic volcanism within the immediate area is seen.
Date: April 1, 1983
Creator: Goff, F.; McCormick, T.; Gardner, J.N.; Trujillo, P.E.; Counce, D.; Vidale, R. et al.
Partner: UNT Libraries Government Documents Department

Regional geothermal exploration in north central New Mexico. Final report

Description: A broad-based geothermal resource reconnaissance study covering Bernalillo, Los Alamos, Rio Arriba, San Miguel, Sandoval, Santa Fe, Taos, Torrance, and Valencia counties in north central New Mexico was conducted from June 15, 1981, through September 30, 1983. Specific activities included the compilation of actual temperature, bottom-hole temperature gradient, and geotemperature data; tabulation of water chemistry data; field collection of temperature-depth data from existing wells; and drilling of temperature gradient holes in the Ojo Caliente, San Ysidro, Rio Puerco, and Polvadera areas. The data collected were used to perform: (1) a regional analysis of the geothermal energy potential of north central New Mexico; (2) two site-specific studies of the potential relationship between groundwater constrictions and geothermal resources; (3) an evaluation of the geothermal energy potential at Santa Ana Pueblo; (4) a general analysis of the geothermal energy resources of the Rio Grande Rift, including specific data on the Valles Caldera; and (5) an evaluation of the use of geothermometers on New Mexico groundwaters. Separate abstracts were prepared for individual chapters.
Date: February 1, 1984
Creator: Icerman, L. (ed.)
Partner: UNT Libraries Government Documents Department

Geothermal hydrology of Warner Valley, Oregon: a reconnaissance study

Description: Warner Valley and its southern extension, Coleman Valley, are two of several high-desert valleys in the Basin and Range province of south-central Oregon that contain thermal waters. At least 20 thermal springs, defined as having temperatures of 20/sup 0/C or more, issue from Tertiary basaltic flows and tuffs in and near the valleys. Many shallow wells also produce thermal waters. The highest measured temperature is 127/sup 0/C, reported from a well known as Crump geyser, at a depth of 200 meters. The hottest spring, located near Crump geyser, has a surface temperature of 78/sup 0/C. The occurrence of these thermal waters is closely related to faults and fault intersections in the graben and horst structure of the valleys. Chemical analyses show that the thermal waters are of two types: sodium chloride and sodium bicarbonate waters. Chemical indicators show that the geothermal system is a hot-water rather than a vapor-dominated system. Conductive heat flow in areas of the valley unaffected by hydrothermal convection is probably about 75 milliwatts per square meter. The normal thermal gradient in valley-fill dpeosits in these areas may be about 40/sup 0/C per kilometer. Geothermometers and mixing models indicate that temperatures of equilibration are at least 170/sup 0/C for the thermal components of the hotter waters. The size and location of geothermal reservoirs are unknown.
Date: January 1, 1981
Creator: Sammel, E.A. & Craig, R.W.
Partner: UNT Libraries Government Documents Department