Aerial radiometric and magnetic reconnaissance survey of portions of the Great Plains and Central Lowlands, Sioux City Quadrangle

The results of a high-sensitivity aerial gamma-ray spectrometer survey of the Sioux City Quadrangle, Nebraska, are presented. The work was done by Texas Instruments Incorporated under Bendix Field Engineering Corporation Subcontract No. 77-072-L as part of the U.S. Department of Energy National Uranium Resource Evaluation (NURE) Program. Descriptions of instrumentation and methods are given in Volume 1 of this final report. Statistical and geologic analysis of the radiometric data revealed 36 uranium anomalies worthy of field checking as possible prospects. Another five statistically significant anomalies are suspected of being road fill or outcrop of shale along road cuts, and these should be verified. The clusters of anomalies in the northwest and north-central part of the quadrangle appear to be associated with outcrops of the Ogallala Formation or possibly the Dakota Sandstone (in subcrop) which are believed to have the best potential for possible economic uranium deposits. The Pierre Shale may have long-range potential as a low-grade uranium source if the Sharon Springs Member is present in this quadrangle