Geophysical Studies Related to the Proposed Low Level Readioactive Waste Repository Hudspeth County, Texas

Geologic characterization of sites for low-level radioactive waste repositories generally requires qualitative and quantitative estimates of variations in rock properties between test wells. Seismic reflection surveys are an accepted technique for providing a qualitative picture of structural and/or stratigraphic variation when tied closely to control information from wells. Reflection surveys also are useful in identifying areas where additional well control may be needed to adequately characterize geologic variations.

Ten miles (16 km) of reconnaissance seismic data were collected and interpreted by Phillips et al. (1986) in the vicinity of the proposed repository site near Fort Hancock, Hudspeth County, Texas. Three lines were collected perpendicular to the major structural trends, and a fourth line tied these three together. These data typically resolve variations in stratigraphic thickness that are more than 20 ft (6 m) thick, one-fourth the dominant time wavelength, and that are more than 90 ft (27 m) deep. These data can image horizontal variations greater than 110 ft (34 m), with 8 common depth point samples per wavenumber.