Vermiculite deposits in the Central Mineral region of Texas, chiefly in Precambrian metamorphic rocks, are situated in Llano County and adjacent parts of Mason, Gillespie, and Burnet counties with minor occurrences in Blanco and San Saba counties.

At the northern end of the Coahuila platform, the thinned Comanchean sequence consists of the newly named Sixshooter group of carbonate formations underlain by the newly named Yearwood formation.

Texas' Hudspeth County talc mining, begun in 1952 when Southwestern Talc Corp. carried out pioneer exploratory operations, has expanded during the last five years and can today claim six active operations. These Include (1) Southwestern Talc Corp., Llano, Texas, (2) West Texas Talc Corp.

The rim rock of the Vieja Rim, the quartz pantellerite of Lord, is named the Bracks Rhyolite.

The Colorado River Industrial Development Association area consists of ten counties [Bastrop, Blanco, Burnet, Colorado, Fayette, Llano, Matagorda, San Saba, Travis, and Wharton counties] in the lower watershed of Colorado River in Texas.

The first entry in the Guidebook Series details a field excursion to the Eastern Llano Region of Central Texas in 1958. Retrace the footsteps of Virgil Barnes and the other state geologists in attendance: 

Stop 1. Honeycut Bend

Uranium was discovered near Tordilla Hill in Karnes County, south-central Texas, in the fall of 1954, in the upper part of the Jackson formation of late Eocene age.

The Devonian-Mississippian transition outcrops of central Texas are here described summarily and assigned to a new stratigraphic unit, the Houy Formation. The beds included are mainly Upper Devonian, but partly Lower Mississippian. Locally a basal fraction may be Middle Devonian.

The eastern margin of the High Plains in central western Texas affords particularly good opportunity for study of late Cenozoic geology.