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Regional geology and geophysics of the Jemez Mountains

Description: The western margin of the Rocky Mountain tectonic belt is the initial site for the Los Alamos Geothermal Project. lgneous activity in the area culminated with the formation of a collapsed volcanic caldera and the deposition of thick beds of tuff. Geophysical studies indicate that the region is one of relatively highterrestrial heat flow, low-crustal density, low-crustal seismic velocities, low-crustal magnetoelectric impedance, and thin crust. 34 references. (auth)
Date: August 1, 1973
Creator: West, F.G.
Partner: UNT Libraries Government Documents Department

Exploration methods for hot dry rock. Report of the panel held June 22, 1976

Description: The geological and geophysical characteristics of hot dry rock (HDR) necessary for an effective exploration program were discussed. The type of HDR project discussed, that being developed by the Los Alamos Scientific Laboratory (LASL), would utilize hydraulic fracturing to develop a large surface area in rock of low permeability, 10/sup -6/ darcys, and at temperatures greater than 200/sup 0/C. A better definition of the thermal regime in the crust and mantle at reconnaissance (hundreds to tens of kilometers) and exploration (tens of kilometers to 1 km) scales is needed. Geophysical methods capable of deep investigation would be used with the near-surface geologic information to extrapolate conditions at the depth of interest. Detection of HDR per se may be difficult because the contrast in physical properties of HDR and other rock is not always unambiguous, but boundaries between rock environments can be delineated. When patterns and coincidence of various types of geophysical anomalies and geologic maps are used, the probability of the detection of HDR is greatly increased, especially when a consistent picture is described. Various geophysical methods are required to detect these anomalies: (a) electromagnetic techniques can map deep electrically conductive structures, which to some extent can be used to infer isotherms. (b) Bouguer gravity maps corrected for regional topography are found to correlate with large silicic intrusive bodies, which are often associated with high heat flow. (c) isotherms and open crack systems at depth can be inferred from seismic wave attenuations, dispersions, and delay times. (d) heat flow measurements are useful as a primary tool and as a check on the results of other methods. Abstracts for individual presentations by the twelve panel members are included. 111 references.
Date: March 1, 1977
Creator: West, F. G. & Shankland, T. J. (comps.)
Partner: UNT Libraries Government Documents Department

Zuni Mountains, New Mexico as a potential dry hot rock geothermal energy Site

Description: Many of the criteria for the successful exploitation of energy from dry hot rock are met in the Zuni Mountains, New Mexico. This area falls within a broad region of abnormally high heat flow on the Colorado Plateau. Within this region, a variety of evidence indicates that local ''hot spots'' may be present. These ''hot spots'' are prime targets for dry hot rock exploration. A site-evaluation program utilizing geological, geochemical-geochronological, and geophysical techniques is proposed to delineate the optimal sites for subsequent exploratory drilling.
Date: December 1, 1975
Creator: Laughlin, A. W. & West, F. G.
Partner: UNT Libraries Government Documents Department

Seismic reconnaissance of the Los Alamos Scientific Laboratory's Dry Hot Rock Geothermal Project area

Description: Active seismic methods using high-explosive sources and nondestructive energy sources were used to determine seismic velocities, signal detectability, and subsurface geologic structure in the vicinity of the Los Alamos Scientific Laboratory's (LASL) Dry Hot Rock Geothermal Project area. Positions of several faults have been determined. A synthetic seismogram has been created that shows good agreement with recorded reflection records taken near exploratory borehole GT-2.
Date: July 1, 1976
Creator: Kintzinger, P. R. & West, F. G.
Partner: UNT Libraries Government Documents Department

Aquarious Mountain Area, Arizona: APossible HDR Prospect

Description: Exploration for Hot Dry Rock (HDR) requires the ability to delineate areas of thermal enhancement. It is likely that some of these areas will exhibit various sorts of anomalous conditions such as seismic transmission delays, low seismic velocities, high attenuation of seismic waves, high electrical conductivity in the crust, and a relatively shallow depth to Curie point of Magnetization. The Aquarius Mountain area of northwest Arizona exhibits all of these anomalies. The area is also a regional Bouguer gravity low, which may indicate the presence of high silica type rocks that often have high rates of radioactive heat generation. The one deficiency of the area as a HDR prospect is the lack of a thermal insulating blanket.
Date: May 1, 1979
Creator: West, F.G. & Laughlin, A.W.
Partner: UNT Libraries Government Documents Department

Downhole electrical detection of hydraulic fractures in GT-2 and EE-1

Description: Electrical geophysical methods including mise a la masse and self-potential (SP) for determination of hydraulic fracture characteristics were used at the hot dry rock geothermal project. Electrical and induction logs indicated that the resistivity contrast between the granite and 200/sup 0/C water at the 2926-m (9600-ft) depth is a factor of 1000 or more. Thus the water in a hydraulic fracture, formed to connect two adjacent deep holes, is a good conductor compared to the confining granite. Mise a la masse-type measurements were made to help determine the characteristics for hydraulic fractures formed in each of the two geothermal holes GT-2 and EE-1. Once a hydraulic fracture has been formed, mise a la masse effects are obtained both with the fracture pressurized above hydrostatic and when depressurized to hydrostatic. This indicates that once the fracture has been created, enough natural propping exists that a conductive zone persists even when the fracture is deflated. A fracture was formed in a 18-m (60-ft) zone immediately below 1957 m (6420 ft) in EE-1. Later a set of SP logs was run in this zone with no pressure, with pressure building, with pressure decreasing, and again with the fracture depressurized. Results show that during times of change of parameters in hydraulically fractured regions in the hole, natural SP logging helps to determine the position of the fracture. However, after a fracture has come to equilibrium with fluid parameters such as temperature, pressure, salinity, and pH, an effect of the fracture may not be evident. Self-potential logs provide an excellent method for locating the bottom of steel casing that has been set in the hole.
Date: July 1, 1977
Creator: Kintzinger, P.R.; West, F.G. & Aamodt, R.L.
Partner: UNT Libraries Government Documents Department

Residual bouguer gravity anomaly map of northern New Mexico

Description: The map is computer contoured from equidistant grid and bicubic spline interpolated surface. Bouguer gravity anomaly correction applied is g/sub BC/ = (0.034) x (elevation - regional elevation), with density 2.67 g/cc. Overall dimensions are 41/sup 1///sub 2/'' x 43''; scale is 1 : 500,000. (JGB)
Date: March 1, 1977
Creator: Aiken, C. L. V.; Laughlin, A. W. & West, F. G.
Partner: UNT Libraries Government Documents Department

Preliminary study of the quality of water in the drainage area of the Jemez River and Rio Guadalupe

Description: A preliminary study of the quality of surface and ground water was made in the area of a proposed geothermal test hole and experiment by Los Alamos Scientific Laboratory. The study was made to establish background data prior to the geothermal experiment by the Laboratory. The data compiled prior to 1971 were taken from a literature search while data from 1971 through 1973 were collected from field surveys. Analyses are reported from 17 surface water stations, 15 mineral and thermal springs, and 53 ground water stations (wells, test holes, and springs). A general description of sampling stations is presented with a brief description of the chemical quality of the water based on concentrations of dissolved solids. Additional water quality data will be collected prior to, during, and after the experiment.
Date: April 1, 1974
Creator: Purtymun, W. D.; West, F. G. & Adams, W. H.
Partner: UNT Libraries Government Documents Department

Water quality in vicinity of Fenton Hill Site, 1975

Description: Water quality at 9 surface water stations, 14 ground water stations, and drilling and testing operations at the Fenton Hill Site has been studied as a measure of the environmental impact on the Los Alamos Scientific Laboratory's geothermal site in the Jemez Mountains. Slight variations in the chemical quality of the water at individual stations were observed during the year. Predominant ions and total dissolved solids in the surface and ground water declined slightly in comparison to previous data. These variations in quality are not considered significant considering seasonal and annual stream flow variations. Surface water discharge records from three U.S. Geological Survey gaging stations on the Rio Guadalupe and Jemez River were analyzed to provide background data for the impact study. Direct correlations were determined between mean annual discharge at each of two stations in the upper reach of the drainage and at the station in the lower reach.
Date: September 1, 1976
Creator: Purtymun, W. D.; Adams, W. H.; Stoker, A. K. & West, F. G.
Partner: UNT Libraries Government Documents Department