The Houston-Galveston Area Council of Governments (HGAC) encompasses over 12,000 square miles of southeast Texas (fig. 1).

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.

Historical monitoring along Brazos and south Padre Islands records the nature and magnitude of changes in position of the shoreline and vegetation line and provides insight into the factors affecting those changes.

Nelson and others (1962) define a bank as " ... a skeletal deposit formed by organisms which do not have the ecologic potential to erect a rigid wave-resistant structure." They explain that a bank may have any geometry.

Lower Cretaceous shallow-water carbonates accumulated on a broad shelf which completely encircled the Gulf of Mexico. Biogenic growth climaxed along the basinward edge, or shelf margin, where a complex of reefs, banks, bars, and islands developed.

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.

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.