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.

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.

Aquifers in the Houston-Galveston area are composed principally of fluvial-deltaic sediments. The Alta Loma Sand is a complexly faulted, high-sand-percent unit that represents a seaward progression of fluvial, delta-plain, and delta-front facies.

Geologic map that depicts surface geology of Kinney County and parts of Terrell, Val Verde, Edwards, Real, Uvalde, and Maverick Counties, Texas.