The Sligo and Hosston Formations of Aptian age occur over thousands of square miles in the subsurface of South Texas.

The publication comprises 24 structural dip cross sections, spaced 15 to 20 mi apart along the Texas coast, and 4 structural strike cross sections. Dip sections extend from near the Wilcox outcrop to the coastline.

The Catahoula Formation of the Texas Gulf Coastal Plain consists of two depositional systems--the Gueydan bedload fluvial system of the Rio Grande embayment and the Chita-Corrigan mixed load fluvial system of the Houston embayment.

The increasing demand for uranium combined with the improving economics of uranium production have resulted in a significant upsurge in exploration and mining efforts in the South Texas Coastal Plain uranium province. Texas ranks third in U.S. uranium production.

Cracked pavements, undulating road surfaces, broken curbs, stairstep fractures of brick and stone building walls, and tilted power poles are common occurrences in areas underlain by cracking, expansive clay soils of the Vertisol order.

Geologic map that depicts the surface geology of Colorado, Lavaca, and Gonzales Counties, and parts of Hays, Caldwell, Bastrop, Fayette, Austin, Waller, Fort Bend, Wharton, Matagorda, Jackson, Victoria, De Witt, Karnes, Wilson, and Guadalupe Counties, Texas.

Tuff, tuffaceous sand and clay, bentonite, and sandstone containing abundant volcanic rock detritus are present in Gulf Coast Tertiary rocks ranging in age from Eocene to Pliocene.