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

The Smackover and lower part of the Buckner Formations (Oxfordian) comprise a thick regressive sedimentary sequence deposited on a Jurassic carbonate ramp. Four major depositional systems are recognized: (1) basinal, (2) low-energy open shelf, (3) high-energy shoal, and (4) sabkha.

The environmentally sensitive trace elements molybdenum, arsenic, and selenium are concentrated with uranium in ore deposits in South Texas. Cattle grazing in some pastures in mining areas have contracted molybdenosis, a cattle disease resulting from an imbalance of molybdenum and copper.

Oversize color geologic map that depicts surface geology of Dimmit, LaSalle, and McMullen Counties and parts of Maverick, Zavala, Frio, Atascosa, Karnes, Wilson, Live Oak, Jim Wells, Duval, and Webb Counties, Texas. The 6-page booklet indicates geologic formations, abbreviations, and ages.

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.

Geologic map that depicts the surface geology of Goliad, Refugio, and Calhoun Counties and parts of Karnes, De Witt, Victoria, Jackson, Matagorda, Aransas, San Patricio, Bee, and Live Oak Counties. The 4-page booklet indicates geologic formations, abbreviations, and ages.

Knowledge of the regional sand distribution and its relationship to formation temperature and pressure is a preliminary step in evaluating the geothermal resources of the Frio Formation.

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.

This report is a compilation of all available data on mineral resources (exclusive of oil and gas) in 39 south Texas counties. Information from published and unpublished sources was checked and supplemented by field investigations.