Middle and Upper Cambrian rocks and locally up to 90 feet of Lower Ordovician rocks in Central Texas, are here named the Moore Hollow Group.

Geologic map that depicts the surface geology of Mills County and parts of Runnels, Coleman, Brown, Comanche, Erath, Hamilton, Coryell, Lampasas, San Saba, McCulloch, Concho, and Menard Counties. The 21-page booklet indicates geologic formations, abbreviations, and ages.

The Lake Travis vicinity lies predominantly within a carbonate rock terrane and is the site of ongoing intensive residential development.

Geologic map that depicts the surface geology of Burleson, Lee, Washington, and Brazos Counties and parts of Burnet, Bell, Milam, Robertson, Madison, Grimes, Waller, Austin, Fayette, Bastrop, Caldwell, Hays, Travis, and Williamson Counties.

This Guidebook represents an updating of Bureau of Economic Geology Guidebook No. 5, Field Excursion-Geology of Llano Region and Austin Area. It also represents a modification of Geology of the Llano Region and Austin Area, Texas, published by the Shreveport Geological Society in 1971.

The stratigraphic record of the Lower Cretaceous Trinity Division in Central Texas, as revealed by extensive outcrop investigation, is that of a shallow sea transgressing the southern flank of the ancient Llano Uplift.

Geologic maps that depicts the surface geology of McLennan, Limestone, and Falls Counties and parts of Bosque, Hill, Navarro, Freestone, Leon, Madison, Robertson, Milam, Bell, Lampasas, Coryell, and Hamilton Counties, Texas.

Trilobites collected during the past 20 years from the Morgan Creek, Point Peak, and San Saba Members of the Wilberns Formation comprise 89 species assigned to 45 genera belonging to zones of the upper Franconian and Trempealeauan Stages of the Upper Cambrian Croixan Series.