Central Texas Overthrust: vital new frontier? (oil and gas exploration)

Central Texas Overthrust: Vital new frontier

Recent integrated geophysical investigations into potential exploration plays in Central Texas have revealed compelling evidence which suggests an entirely different structural history for the San Marcos platform than has traditionally been accepted.

The geophysical studies, which include magnetotelluric, gravity, magnetic, and seismic surveys, have been conducted over the past 5 years and have been concentrated over parts of San Saba, Mills, and Lampasas counties, north of the Llano uplift. Results of the multidisciplinary studies predict a westward extension of the Ouachita Overthrust, 70-100 miles farther west than the conventionally mapped thrust belt.

Traditional geologic framework. The Precambrian metasediments and granitic intrusives exposed in outcrop at the Llano uplift have long been considered the basement of Central Texas, a basement which has been shown in countless geological publications to deepen gradually, in all directions, away from the uplift.

For decades explorationists have avoided the thin veneer of Cambrian through Cretaceous sediments overlying the Bend arch, which extends northward of the Llano uplift, in favor of the …