Hydrological investigations near Socorro, New Mexico, using electrical resistivity
George R. Jiracek
Since, in the near-surface and ground-water environment of the earth, water is by far the most important factor determining the bulk electrical properties, resistivity is the most widely used geophysical method in hydrological investigations. As a portion of the U.S. Geological Survey's Southwest Alluvial Basins Study the University of New Mexico was engaged to perform resistivity tests in the middle Rio Grande valley in New Mexico. The objectives of the studies were to evaluate resistivity methods in investigating the ground-water depth, flow barriers, and water quality in selected areas. This paper presents results of these studies at two areas near Socorro, New Mexico. Complete results from other sites, including a large area west of Albuquerque, may be found in Jiracek (1982).
Our tests in the Socorro area utilized Schlumberger and equatorial resistivity arrays. An excellent discussion of these and other arrays as specifically applied to ground-water studies is included in Zohdy and others (1974). Our measurements were extended to effective spacings of many kilometers which enabled interpretations to be made to depths in excess of the water-saturated zones.
Zohdy (1969) and Zohdy and others (1969) have quantitatively interpreted the depth of the freshwater/saltwater contact in southern New Mexico and near El Paso, Texas; however, they did not hazard estimates of water-table depth, porosity values, or water salinity. Such estimates have been attempted in our study not because we possess any advanced methodology but simply to offer a comparison with known data.
- Jiracek, George R., 1983, Hydrological investigations near Socorro, New Mexico, using electrical resistivity, in: Socorro region II, Chapin, C. E., New Mexico Geological Society, Guidebook, 34th Field Conference, pp. 319-324.