Studies along the southern and southeastern borders of the High Plains have demonstrated the presence of outliers of fossiliferous Ogallala Formation in Borden and Scurry counties and have documented the occurrence of Pliocene deposition as far southeast as Sterling County. The limit of characteristic Ash Hollow seed floras is extended to the southeast. An abandoned Pliocene and Pleistocene valley is described across a prong of Edwards Plateau south of Big Spring, and the drainage of the late Pleistocene Lake Lomax is determined to have occurred in pre-Bradyian Wisconsinan time.

Geologic map that depicts the surface geology of Rains, Wood, Upshur, Marion, Harrison, Smith, and Gregg Counties and parts of Camp, Cass, Panola, Rusk, Cherokee, Anderson, Henderson, Van Zandt, Hunt, Morris, Franklin, and Hopkins Counties, Texas.

Texas has a great variety of rocks and minerals some are common and others are not. This book is designed to aquaint you with some of them and to tell you in a nontechnical way what they are like, some of the places where they are found, and how they are used. Although we do not know exactly how all of the rocks and minerals formed, some of the ideas about their origin are mentioned. If you would like to learn more about rocks and minerals in general, the names of several reference books are listed on page 100.

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.

The Red River rises in northeastern New Mexico and extends across northern Texas and east of the Panhandle serves as the northern border of that State. The late Cenozoic geology of the Red River basin has been studied intensively in northwestern Texas and in Louisiana. This report summarizes the results of our studies of the late Cenozoic geology of the Red River basin in Texas. Late Tertiary terrace deposits have been identified as far east as Montague County and deposits of Nebraskan age have been recognized somewhat farther east.