In the past 100 years, more than 100 names have been used to designate parts or all of the outcropping Midway and Wilcox rocks in the Gulf Coastal Plain; less than half of these names are used currently by Coastal Plain geologists, and the validity of some of the remaining named rock units has be

At five places along the outcrop of the Wellborn Formation in Lee and Burleson counties, Texas, anomalously high gamma radiation is associated with concentrations of heavy minerals. The most abundant heavy minerals are ilmenite, magnetite, and zircon.

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.