National Uranium Resource Evaluation program. Uranium geochemical survey in the Crystal City and Beeville Quadrangles, Texas

A uranium geochemical survey was conducted in the Crystal City and western half of the Beeville Quadrangles, Texas, an area of approximately 34,000 km2. Using the Texas Gulf Coast Uranium Province as a study area, this survey demonstrates the applicability of a 2 phase hierarchical sampling program with multielement analysis of the samples for regional geochemical reconnaissance for uranium. Phase I samples of stream sediment, stream water, and well water were collected from drainage basins with a target drainage of 250 km2 to identify uranium province lines which define the area in which closer spaced Phase II sampling should be conducted. Phase II samples of stream sediment, stream water, well water, and tree branches were collected from drainage basins with a target drainage of 25 km2 in order to identify uranium district lines. Stream sediment, stream water, well water, and ash of tree branches were analyzed for approximately 25 parameters. The most useful sample type for identifying potential uranium mineralization in the Texas Gulf Coast is well water. Wells were found to accurately distinguish both province lines at Phase I sample spacing and district lines at Phase II sample spacing by several methods of evaluation. Results of the survey indicate that the concept of 2 phase sampling with multielement analyses of samples, developed by the ORGDP Project, may yield good results for the remainder of the area to be surveyed by ORGDP with modifications for different geologic regions