Between 1951 and 1996, groundwater pumpage from the Carrizo-Wilcox aquifer, one of Texas' major aquifer systems, increased in the area between the Colorado and Brazos Rivers from approximately 10,600 to 37,900 acre-ft/yr, primarily as a result of mining needs.

Environmental geologic maps of the Texas lignite belt were prepared in response to renewed production of lignite in Texas and enactment of Federal and State laws governing coal and lignite surface mining.

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.

This report provides a data base for decisions about lignite mining and reclamation in the Wilcox Group of East Texas. Kaiser (1974, 1978) estimates that about 12.2 billion short tons of potentially strip-minable lignite resources occur in East and South Texas.

Bastrop, Blanco, Burnet, Caldwell, Fayette, Hays, Lee, Llano, Travis, and Williamson Counties make up the Capital Area Planning Council (CAPCO) region in Central Texas (fig. 1). The region covers 8,427 square miles (21,826 km2) and includes land of great physical diversity.

Papers in this volume were presented at the Gulf Coast Lignite Conference held in Austin, Texas, June 1976.
Papers were edited, in some cases extensively, and subjectively grouped by discipline, paralleling that of their presentation at the Conference.

In east-central Texas, or the area between the Colorado
and Trinity Rivers, the Wilcox Group (lower Eocene) is divided
into three formations. Up section they are the Hooper,
Simsboro, and Calvert Bluff. At Alcoa and Butler, lower Calvert

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.

At five places along the outcrop of the Wellborn Formation in Lee and Burleson counties, Texas, anomalously high gamma radiation is associated with concentrations of heavy minerals. The most abundant heavy minerals are ilmenite, magnetite, and zircon.