The San Angelo Formation is a mid-Permian sandstone and mudstone sequence about 100 feet thick that crops out in North Texas and dips westward into the Midland Basin; it is composed of two superposed members: the basal Duncan Sandstone Member and the overlying Flowerpot Mudstone Member. Depositional systems within the Duncan Member include the Copper Breaks deltaic system in the north, the Old Glory fluvial-deltaic system in the south, and the intermediate, strike-fed Buzzard Peak sand-rich tidal-flat system.

The Texas Coastal Zone is marked by diversity in geography, resources, climate, and industry. It is richly endowed with extensive petroleum reserves, sulfur, and salt, seaports, intracoastal waterways, a mild climate, good water supplies, abundant wildlife, rich agricultural lands, commercial fishing resources, unusual recreational potential, and large tracts of uncrowded land.

Fluorspar is a basic raw material used in the chemical, metallurgical, and ceramic industries. This handbook describes the occurrence, grades, geology, uses, and prospects for development of fluorspar in Texas.

Lignite or low-rank coal is a major energy resource in Texas, providing energy since 1850. Prior to 1930, and the advent of abundant natural gas and oil, lignite was a major energy source. Today it is again assuming a substantial role in energy generation with the operation or scheduled construction by 1980 of lignite-fueled, steam-electric plants (up to 1500-megawatt capacities) near Alcoa, Fairfield, Athens, Mt. Pleasant, and Tatum. Future utilization of Texas lignite is likely in the production of synthetic gases, liquid fuels, and chemical feed stocks.