Frontier Areas and Exploration Techniques: Frontier Uranium Exploration in the South-Central United States

Abstract

Abstract Selected areas of the South-Central United States outside the known uranium trends of South Texas have a largely untested potential for the occurrence of significant uranium mineralization. These areas, underlain by Tertiary and older sediments, include parts of Texas, Oklahoma, Arkansas, Louisiana, Mississippi and Alabama. The commonly accepted criteria employed in uranium exploration are applicable to these frontier areas but special consideration must also be given to the atypical geologic aspects of such areas as they may apply to relatively unique types of uranium mineralization or to the development of special exploration criteria for common types of roll-front and fault-and dome-related uranium mineralization. The procedures used in evaluating frontier areas should be based on comprehensive evaluations involving: 1) location and analysis of potential source rocks (e.g. intrusive igneous rocks, bentonitic sediments, unique complexes, etc.); 2) definition of regional variations in the potential host sediments (e.g. marginal marine to nonmarine environments of deposition); 3) review of all available radiometric data in Tertiary or older rocks; 4) local ground-water sampling (using a specific suite of major and minor elements selected on the basis of the regional ground-water geochemistry; 5) widely-spaced reconnaissance (or stratigraphic) drilling, coring and borehole geophysical logging to define sedimentary facies and to establish the specific lithologic character of the sediments; and 6) detailed petrographic evaluation of all available samples to define the environment of deposition and diagenetic history of favorable sediments. If procedures produce results, suggesting that conditions for the formation of uranium mineralization are present in the area under consideration, an expanded exploration program is justified. Depths up to 3,000 feet should be anticipated if up-dip information is favorable. Selected areas are discussed that have: 1) source and host rocks; 2) age; 3) regional and local structure; and 4) radiometric characteristics for uranium mineralization of potentially economic grade and reserves in the areas.