Geologic mapping and fracture analysis of the Lower Cretaceous Edwards aquifer strata near Georgetown and Round Rock, Texas, were performed to provide a better understanding of the geologic framework of the Balcones Fault Zone and to provide information for assessing ground-water flow characteristics.

Remotely sensed features such as linear drainages, escarpments, ridges, and aligned playas have been identified on Landsat imagery (scale 1:250,000) of the Texas Panhandle and adjacent regions to allow comparison of these features with detailed regional and site-specific geologic data.

The Ellenburger Group (Lower Ordovician) of Texas is a laterally extensive peritidal carbonate shelf sequence. It forms a major deep oil reservoir, having estimated reserves of 1.15 billion barrels of oil, and it also contains an estimated 2.2 billion barrels of oil equivalent.

Horizontal drilling in a mature hydrocarbon province such as Texas can increase recovery from reservoirs in which a significant proportion of oil or gas in place remains unrecovered by conventional means.