Limestone is one of the most important nonfuel mineral resources in Texas. Annual production exceeds $30 million; value added in the manufacture of such products as cement and lime amounts to about $100 million annually.
This report treats the sedimentary petrology and history of the Haymond Formation, a monotonous sequence of interbedded sandstone and shale that has a maximum preserved thickness of 4,300 feet.
Based on need for convenient, small-scale cartographic units, the basal Cretaceous rocks in Texas from Red River to Burnet County and on the Callahan Divide are herein divided into three distinctive lithologic sequences.
The wedge-shaped Black Gap area in southern Brewsier County, Texas, occupies approximately 4,50 square miles east of the Big Bend National Park.