The rim rock of the Vieja Rim, the quartz pantellerite of Lord, is named the Bracks Rhyolite. Beneath the Bracks, the "Vieja series" of Vaughn (1900), which is newly subdivided into five formations named, in descending order, the Chambers Tuff, Buckshot Ignimbrite, Colmena Tuff, Gill Breccia, and Jeff Conglomerate, rests unconformably on Upper Cretaceous formations. The Vieja Group is expanded to include also the Bracks and three overlying formations, named, in ascending order, the Capote Mountain Tuff, the Brite Ignimbrite, the Petan Basalt.

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 rocks exposed in the upriver part of the area include Precambrian metamorphic and igneous rocks and Paleozoic and Lower Cretaceous sedimentary rocks. In the Austin region Upper Cretaceous sedimentary rocks are exposed. In the downstream part of the area the rocks are of Tertiary and Quaternary ages.

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

Stop 2. High-calcium reef, Marble Falls area, Burnet County

Stop 3. Granite Mountain, Marble Falls area, Burnet County

Stop 4. Base of Cambrian, Slaughter Gap, Marble Falls area, Burnet County

Stop 5. Texas Construction Material Company...Burnet County

Optional Stop. Mormon Mill locatlity, Burnet County

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. The Sixshooter group consists, in descending order, of the Buda limestone, the newly named Boracho limestone composed of the newly named San Martine and Levinson members, and the Finlay limestone at the base.