Geologic map that depicts the surface geology of parts of Presidio, Brewster, and Terrell Counties, Texas. The 14-page booklet indicates geologic formations, abbreviations, and ages.

The Washita Group in North-Central Texas and southeastern Oklahoma consists of up to 114 m of intercalated shale, limestone, and sandstone that accumulated in the shallow, epicontinental sea of the East Texas Basin. The Ouachita-Arbuckle Mountains to the north supplied terrigenous sediments, and the Central Texas platform to the south was a site of carbonate deposition leeward of the shelf margin of the Stuart City trend. Eleven lithofacies of the Washita were deposited within a repeatedly subsiding shelf basin that received an intermittent supply of terrigenous sediment.

Lignite occurs in three Eocene stratigraphic units--the Wilcox Group, Yegua Formation, and Jackson Group--and in three ancient depositional systems-fluvial, deltaic, and strandplain/lagoonal. Sand-body geometry and lignite occurrence in these systems are revealed by regional sand-percent, net-sand, maximum-sand, and lignite-isopleth maps made from 3,050 electric and induction logs.

Land and water resources have been analyzed in the Corpus Christi area--Aransas, Nueces, Refugio, and San Patricio Counties along the central Texas coast. The city and port of Corpus Christi compose the largest metropolitan center in the area. This report analyzes the types, extent, and distribution of land and water resources in the Corpus Christi area.