Geologic map that depicts surface geology of Tarrant, Dallas, Kaufman, Ellis, Johnson, Somervell, and Rockwall Counties and parts of Parker, Hood, Erath, Bosque, Hill, Navarro, Henderson, Van Zandt, and Hunt Counties, Texas.

Paleoenvironmental analysis of the alternating beds of the basal Cretaceous Glen Rose Formation in Central Texas indicates a cyclical alternation of subtidal through supratidal facies.

The Lower Cretaceous Hosston and Hensel Sandstones are important sources of ground water in North-Central Texas.

Based on need for convenient, small-scale cartographic units, the basal Cretaceous rocks in Texas from Red River to Burnet County and on the Callahan Divide are herein divided into three distinctive lithologic sequences.

Lower Cretaceous sands have long been important aquifers in Central, North-Central, and North Texas. In recent years these sands also have been sources of high-silica industrial or specialty-purpose sand.