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.

Geologic map that depicts the surface geology of Tom Green, Irion, and Reagan Counties and parts of Midland, Glasscock, Sterling, Coke, Runnels, Concho, Menard, Schleicher, Crockett, and Upton Counties, Texas.

Geologic map that depicts the surface geology of Comal, Bandera, Bexar, and Medina Counties and parts of Real, Kerr, Kendall, Hays, Guadalupe, Wilson, Atascosa, Frio, Zavala, and Uvalde Counties, Texas. The 9-page booklet indicates geologic formations, abbreviations, and ages.

The Allamoore district of Hudspeth and Culberson counties, Texas, has become one of the most significant talc-producing areas of the United States. Exploitation of talc deposits in the district began in 1952 with a cumulative production of 120,000 tons through 1957 (Flawn, 1958).

The Texas Coastal Zone is marked by diversity in geography, resources, climate, and industry.

This field guide is designed to provide an opportunity to observe a variety of facies that are the fundamental blocks with which principal depositional systems have been fabricated. Available data is provided and a genetic interpretation is proposed.

The Fredericksburg Group is one of three groups of rocks which comprise the outcropping Lower Cretaceous sediments in north central Texas. Four formations form this group; from the base upward these are the Paluxy, Walnut, Comanche Peak and Edwards (fig. 1).