In cooperation with several State and Federal agencies, the Bureau of Economic Geology has conducted several projects on the geology, origin, and extent of uranium resources in Texas. This volume, which was prepared in conjunction with a research colloquium sponsored by the Bureau, reviews and synthesizes the results of this research and demonstrates their applicability to the interpretation of uranium deposits.

Precambrian sedimentary rocks and associated mafic and silicic igneous rocks in Central Texas underwent a single episode of regional metamorphism about 1,050 million years (m.y.) ago. In the final stages of metamorphism great masses of granite and innumerable small pegmatite bodies intruded the older sedimentary and igneous rocks.

Approximately 800 sediment samples from stream beds and bay bottoms of water bodies that compose the Matagorda Bay system were collected and analyzed. Shell-sand-mud ratios and total organic carbon content were determined, and 20 trace elements were detected. In general, highest concentrations of trace elements coincide with deep areas of- water bodies, areas of mud accumulation, and areas with high total organic carbon content. Zirconium, calcium, strontium, and mercury do not follow the distribution patterns of most other elements.