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in subjects: "Usa Geothermal Legacy 150200* -- Geology & Hydrology Of Geothermal Systems"

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Thermal Regimes of Major Volcanic Centers: Magnetotelluric Constraints

The interpretation of geophysical/electromagnetic field data has been used to study dynamical processes in the crust beneath three of the major tectono-volcanic features in North America: the Long Valley/Mono Craters Volcanic Complex in eastern California, the Cascades Volcanic Belt in Oregon, and the Rio Grande Rift in the area of Socorro, New Mexico. Primary accomplishments have been in the area of creating and implementing a variety of 2-D generalized inverse computer codes, and the applicat… more

Date: October 2, 1989

Creator: Hermance, J. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Numerical simulation of magma energy extraction

The Magma Energy Program is a speculative endeavor regarding practical utility of electrical power production from the thermal energy which reside in magma. The systematic investigation has identified an number of research areas which have application to the utilization of magma energy and to the field of geothermal energy. Eight topics were identified which involve thermal processes and which are areas for the application of the techniques of numerical simulation. These areas are: (1) two-phas… more

Date: January 1, 1991

Creator: Hickox, C. E.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Geothermal resource analysis in Twin Falls County, Idaho

Thermal water is prevalent throughout central Twin Falls County. Most wells and springs that occur in the area produce thermal water from fractures in the Idavada Volcanics. However, in an area east of Hollister, thermal water issues from fractures in the Paleozoic rocks. In an attempt to explain the hydrothermal relationship between these two reservoir rocks, one composite model for the entire geothermal system in the area is proposed. As with other conceptual models of the system, available g… more

Date: October 1, 1990

Creator: Baker, S.J. & Castelin, P.M.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Study of the geothermal production potential in the Williston Basin, North Dakota

Preliminary studies of geothermal production potential for the North Dakota portion of the Williston Basin have been carried out. Reservoir data such as formation depth, subsurface temperatures, and water quality were reviewed for geothermal brine production predictions. This study, in addition, provides important information about net pay thickness, porosity, volume of geothermal water available, and productivity index for future geothermal direct-use development. Preliminary results show that… more

Date: September 10, 1991

Creator: Chu, Min H.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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K-Ar dating of young volcanic rocks

Potassium-Argon (K-Ar) age dates were determined for forty-two young geologic samples by the Laboratory of Isotope Geochemistry, Department of Geosciences, in the period February 1, 1986 to June 30, 1989. Under the terms of Department of Energy Grant No. FG07-86ID12622, The University of Arizona was to provide state-of-the-art K-Ar age dating services, including sample preparation, analytical procedures, and computations, for forty-two young geologic samples submitted by DOE geothermal research… more

Date: January 31, 1991

Creator: Damon, Paul E. & Shafiqullah, Muhammad

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Fluid flow, element migration, and petrotectonic evolution of the early Mesozoic Central Klamath island arc, northwesternmost California

No Description Available.

Date: June 13, 1991

Creator: Ernst, W.G.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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History of the youngest members of the Valles Rhyolite, Valles caldera, New Mexico using ESR dating method

The cooling history of the Valles caldera was studied by the electron spin resonance (ESR) dating method using Al and Ti centers in quartz grains which were separated from the youngest units of the Valles Rhyolite. The ESR apparent ages are much younger than fission track ages and {sup 39}Ar- {sup 40}Ar ages. Three possibilities are suggested, the first is that the ESR ages are real, the second is that ESR method did not work for these samples, and the third is that about 10--40 ka, the signal … more

Date: January 1, 1991

Creator: Ogoh, K.; Toyoda, S.; Ikeda, S.; Ikeya, M. (Osaka Univ., Toyonaka (Japan). Dept. of Physics) & Goff, F. (Los Alamos National Lab., NM (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Orientation of minimum principal stress in the hot dry rock geothermal reservoir at Fenton Hill, New Mexico

The stress field at the source of microearthquakes in the interior of the hot dry rock geothermal reservoir at Fenton Hill appears to be different to the far field stress outside the reservoir. The stress field seems to be re-oriented prior to failure, during the course of processes that inflate the reservoir. The state of stress, both inside and outside, the hot dry rock (HDR) geothermal reservoir at Fenton Hill, is important in predicting the course of stress-dependent processes, and in trans… more

Date: January 1, 1991

Creator: Burns, K.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Stratabound geothermal resources in North Dakota and South Dakota

Analysis of all geothermal aquifers in North Dakota and South Dakota indicates an accessible resource base of approximately 21.25 exajoules (10{sup 18} J = 1 exajoule, 10{sup 18} J{approximately}10{sup 15} Btu=1 quad) in North Dakota and approximately 12.25 exajoules in South Dakota. Resource temperatures range from 40{degree}C at depths of about 700 m to 150{degree}C at 4500 m. This resource assessment increases the identified accessible resource base by 31% over the previous assessments. Thes… more

Date: August 1, 1991

Creator: Gosnold, W.D. Jr.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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The geological structure at Clearlake, California: A preliminary review

The compilation of geologic exploration data from a complex Franciscan terrain near Clearlake, California, was systematized by dividing the geology into three constituent geometric systems, which are a fault system, a lithotope, and a structural vector field. It is inferred the high heat flow is due to a deepseated magma that fed a line of cinder cones and andesite flows. The country rock of the proposed Hot Dry Rock facility will be autochthonous Franciscan metagreywackes on the south limb of … more

Date: January 1, 1992

Creator: Burns, K.L.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Experimental and theoretical investigation of the production of HCl and some metal chlorides in magmatic/hydrothermal systems

In the calculations we have assumed that all apatites are magmatic. The presence of chlorite and altered plagioclase within the granite and quartz-monzodiorite suggests that alteration may play a role in leading to erroneous estimates of initial melt Cl and F for 2 reasons: (1) the apatites may in fact not be magmatic in origin, but are hydrothermal, and (2) the halogen signature of magmatic apatite may be changed due to subsolidus exchange with a hydrothermal fluid. We are currently endeavorin… more

Date: January 1, 1992

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Aspects of forced convective heat transfer in geothermal systems

A knowledge of convective heat transfer is essential to understanding geothermal systems and other systems of moving groundwater. A simple, kinematic approach toward convective heat transfer is taken here. Concern is not with the cause of the groundwater motion but only with the fact that the water is moving and transferring heat. The mathematical basis of convective heat transfer is the energy equation which is a statement of the first law of thermodynamics. The general solution of this equati… more

Date: July 1, 1978

Creator: Kilty, K.; Chapman, D. S. & Mase, C.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Petrologic considerations for hot dry rock geothermal site selection in the Clear Lake Region, California

The Clear Lake area is well known for anomalous heat flow, thermal springs, hydrothermal mineral deposits, and Quaternary volcanism. These factors, along with the apparent lack of a large reservoir of geothermal fluid north of Collayomi fault make the Clear Lake area an attractive target for hot dry rock (HDR) geothermal development. Petrologic considerations provide some constraints on site selection for HDR development. Spatial and temporal trends in volcanism in the Coast Ranges indicate tha… more

Date: January 1, 1992

Creator: Stimac, J.; Goff, F. (Los Alamos National Lab., NM (United States)) & Hearn, B. C. Jr. (US Geological Survey, Reston, VA, Branch of Lithospheric Processes (United States))

Item Type: Article

Partner: UNT Libraries Government Documents Department

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Dipole-dipole resistivity surveys, Roosevelt Hot Springs KGRA. Final report, Volume 2

Dipole-dipole resistivity surveys were conducted at Roosevelt Hot Springs KGRA. Three different dipole spacings were used; 99km of traverse line were surveyed with 100m dipoles, 50km with 300m dipoles, and 44km with 1km dipoles. The objectives of the resistivity surveying were to detect and delineate regions of low resistivity associated with fracturing, brines, high temperatures, and clay alteration. The resistivity of rocks that are typical of hydrothermal environments is due to two main cond… more

Date: June 1, 1976

Creator: Ward, S. H. & Sill, W. R.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Thermal Regimes of Major Volcanic Centers: Magnetotelluric Constraints

The focus of activity at this laboratory is on applying natural electromagnetic methods along with other geophysical techniques to studying the dynamical processes and thermal regimes associated with centers of major volcanic activity. We are presently emphasizing studies of the Long Valley/Mono Craters Volcanic Complex, the Cascades Volcanic Belt, and the Valles Caldera. This work addresses questions regarding geothermal energy, chemical transport of minerals in the crust, emplacement of econo… more

Date: November 13, 1987

Creator: Hermance, J. F.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Geothermal regimes at Clearlake California: A preliminary review

Three distinct geothermal regimes are inferred in the vicinity of the city of Clearlake, California. The first is a conductive heat flow regime, the second is a fault-controlled hot spring flow of magmatic'' fluids, and the third is a resurgent flow of meteoric warm water. The conductive heat flow results in flat, horizontal isotherms. The hot spring generates a localized spike in the isotherms. The advective disturbance carries heat laterally to a fault-line resurgence, lowering the apparent h… more

Date: January 1, 1992

Creator: Burns, K. L.; Potter, R. M. & Zyvoloski, G.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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A numerical study of convection in a layered porous medium heated from below

As part of the Magma Energy Project being pursued at Sandia National Laboratories, a drilling program has been initiated within the Long Valley caldera near Mammoth Lakes, California. Seismological evidence obtained in this region suggests the presence of a relatively shallow magma body. We have performed a numerical simulation for a simplified model of the Long Valley geothermal system in order to elucidate the nature of the large-scale thermal structure within the system and to assess implica… more

Date: January 1, 1990

Creator: Hickox, C.E. & Chu, Tze Yao.

Item Type: Article

Partner: UNT Libraries Government Documents Department

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HRTEM/AEM study of trace metal behavior, sheet silicate reactions, and fluid/solid mass balances in porphyry copper hydrothermal systems

Transmission electron microscopy has been used to investigate copper (Cu) incorporation into silicates and alteration reactions in porphyry copper deposits. High Cu in biotites results from submicroscopic inclusions of native Cu. The incorporation of Cu in low-temperature alteration lamellae suggests that Cu enrichment occurs during weathering, rather than during the hydrothermal event. Drill core from Cyprus Casa Grande, Arizona, shows systematic variation of Cu in sheet silicates as a functio… more

Date: April 1989

Creator: Veblen, D. R. & Ilton, E. S.

Item Type: Report

Partner: UNT Libraries Government Documents Department

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Development and Application of a Computer Model for Simulating a Geothermal System in New Mexico. (Final Report, 2/1/78 - 1/30/80)

The development and testing of a computer based mathematical model simulating simultaneous transport of heat (or a dissolved solute) and water in a saturated single-phase groundwater flow system are described. The formulation of the underlying flow and transport equations is presented and the discretization of these equations is developed using the standard Galerkin finite element method, and the upstream weighted residual finite element technique. A computer code is developed to solve the disc… more

Date: January 1, 1981

Creator: Huyakorn, Pongsari

Item Type: Book

Partner: UNT Libraries Government Documents Department