Lignites of the Texas Gulf Coastal Plain

One of the basic mineral resources of Texas is abundant deposits of lignite in Eocene rocks of the Gulf Coastal Plain. Currently, Texas lignites are utilized as sources of industrial fuel, activated carbon and, locally, drilling mud additives; research indicates significant future nonfuel uses of lignite and lignitic coals. Principal deposits of lignite in the Texas Gulf Coastal Plain occur in the Wilcox Group and locally in the Yegua and Manning Formations. Southwestward along the outcrop, lignites increase in content of ash, decrease in content of volatile matter and fixed carbon, and decrease in calorific value. Highest quality lignites generally occur in the Wilcox Group in the area north of the Colorado River. Yegua and Manning lignites, and Wilcox lignites south of the Colorado River, are characterized by relatively high ash content. Existing estimates of lignite reserves in Texas are generalized owing to lack of data. Latest estimates list total recoverable, measured, and indicated reserves at approximately 4.3billion short tons [in 1963]. Principal deposits of lignite occur in the following areas: (1) southern Titus County, (2) east-central Hopkins County, (3) southwestern Wood and southeastern Rains counties, (4) south-central Van Zandt County, (5) western Henderson County, (6) southern Harrison and northwestern Panola counties, (7) northwestern Shelby and northeastern Nacogdoches counties, (8) northwestern Leon and southern Freestone counties, (9) southeastern Houston and northcentral Trinity counties, (10) southwestern Houston County, (11) Milam and northwestern Robertson counties, (12) central Bastrop County, (13) central Fayette County, (14) junction of Medina, Bexar, and Atascosa counties, (15) north-central Atascosa County, and (16) northwestern McMullen and south-central Atascosa counties.