Hye quadrangle includes part of the southeastern Llano region and part of the eastern margin of the Edwards Plateau where most of the Plateau surface has been destroyed by erosion. In the southern part of the quadrangle a narrow lobe of the Edwards Plateau trends east-northeastward from near the southwest quadrangle corner. The area to the north is in the broad gently rolling Pedernales River basin, and that to the south is in a fairly rugged marginal part of the Blanco River drainage area. The geology of the Hye quadrangle is shown on a U. S.

When a reference is made to the mineral resources of Texas, most people think of oil and gas, and some few also of sulfur. And, of course, it is true that of the whopping $4.4 billion dollars’ worth of minerals produced in Texas in 1963, 92% was oil, gas, and natural gas liquids. In 1963, for the 29th year, Texas led the Nation as a producer of minerals. Value of mineral products was twice the value of agricultural products, equal to the value of manufactured products, and equal to about one-half the value of all retail trade.

Since the days of R. T. Hill (1901) two Upper Cretaceous lithic units have been used as formations but have remained unnamed. These two units have usually been called the "Lower Taylor Marl” and the “Upper Taylor Marl.” If Taylor is used as a group, both of these formations belong in the Taylor Group.

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.