Earth and Planetary Sciences ETDs

Publication Date

7-19-1977

Abstract

Three electrical resistivity exploration programs have been made at areas of known but unassessed geothermal resources in the Rio Grande rift and Basin and Range province of southern New Mexico: Radium Springs Known Geothermal Resource Area (KGRA), Las Alturas Estates, and Lightning Dock KGRA. The experiments are the framework for a thorough reconnaissance electrical evaluation of these geothermal resource areas. A preliminary experiment was made at Rio Rancho Estates, near Albuquerque, in order to evaluate the applicability and resolution of electrical methods in an area of known subsurface geology within the Rio Grande rift. The interpreted depth to electrical basement, 3,210 m, differs by only 4 percent from the depth to Precambrian rock, 3,339 m encountered in an oil test well. At an interpreted depth of 380 m a resistivity contrast was detected which corresponds to a ground water quality change interpreted from borehole logs. The hot springs at Radium Springs rise along a mapped Basin and Range fault which may penetrate a Laramide anticline of Paleozoic sedimentary rocks. Total field apparent resistivity maps are interpreted to reveal that the hot springs have no hydraulic connection with the Jornada del Muerto, a vast potential reservoir 4 km to the north. A 50-180 m thick conductive layer (< 6 ohm-m) at a depth greater than 100 m as detected throughout the Mesilla Valley near Radium Springs. This layer is believed to contain a thermal aquifer associated with the hot springs. Orthogonal Schlumberger soundings at Las Alturas Estates, near Las Cruces, indicate that a thermal aquifer may be 160-210 m thick at a depth of 95-14S m. The aquifer does not appear to extend more than 2 km east, north, and west of the hot wells. The extent of and the thickness and depth to the aquifer may increase to the south. It apparently overlies a highly resistive limestone that crops out slightly less than 2 km northeast of the hottest of the hot wells. At least two interpretations of the geophysical data are plausible: 1) the limestone is faulted immediately wet of the outcrop; 2) it dips at approximately 15°W below the hot wells. The preferred interpretation, the fault, relies upon the resistivity data. The Lightning Dock geothermal anomaly is the hottest occurrence of hot water studied, 101 °C at a well depth of 27 m. It may also be the most promising for energy development. The resistivity data are interpreted to indicate that the shallow hot water is confined to a conduit that is associated with a high resistivity ridge. This ridge is interpreted to be a series of volcanic domes associated with the ring-fracture zone of a buried caldera complex. The boiling water appears to emerge at the intersection of a Holocene fault and the high resistivity ridge.

Degree Name

Earth and Planetary Sciences

Level of Degree

Masters

Department Name

Department of Earth and Planetary Sciences

First Committee Member (Chair)

George Roger Jiracek

Second Committee Member

Wolfgang Eugene Elston

Third Committee Member

Unknown

Fourth Committee Member

Unknown

Language

English

Document Type

Thesis

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