This classic publication is a syllabus published in conjunction with a Research Colloquium of the Bureau of Economic Geology, August 27-29,1969. It includes discussion notes, 168 maps and other text figures, and a list of 321 selected references pertaining to modern and ancient delta systems.

Lower Cretaceous sands have long been important aquifers in Central, North-Central, and North Texas. In recent years these sands also have been sources of high-silica industrial or specialty-purpose sand.

Regional investigation of the lower part of the Wilcox Group in Texas in outcrop and subsurface indicates seven principal depositional systems. These include: (1) Mt.

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.

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.

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

Incidence of bloating among approximately 600 clay samples from East Texas, ranging in age from Gulfian (Late Cretaceous) to Recent, correlates principally with clay mineralogy-and pH--together an indication of bulk composition--and to a lesser extent with texture, loss on ignition, and content o

Minerals play a vital role in the economy of an industrial State. In Texas, where annual production of minerals currently amounts to more than $4.