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Title: Aerial radiometric and magnetic reconnaissance survey of portions of Arizona, Idaho, Montana, New Mexico, South Dakota and Washington. Volume 2-B. Shelby Quadrangle. Final report

Technical Report ·
OSTI ID:5956072

The results of a high-sensitivity, aerial, gamma-ray spectrometer and magnetometer survey of the Shelby Quadrangle, Montana, are presented. Statistical and geological analysis of the radiometric data revealed 75 uranium anomalies worthy of field-checking as possible prospects. Nine anomlies are associated with the Judith River Formation. Lignite beds in this formation may have created an environment favorable for the precipitation of uranium from uranium-rich ground waters. Possible sources for uranium include volcanic ash and bentonite in Tertiary sediments, the Hell Creek Formation, Bearpaw, Claggett, and Colorado Shales, as well as the alkaline igneous rocks of the Sweet Grass Hills. Eight anomalies related to the Eagle and Virgelle sandstones may reflect the presence of sandstone-type uranium deposits in these units. These anomalies are particularly strong and extensive in the southeastern part of the quadrangle. Twenty-four anomalies in the Colorado Shale may be indicative of sedimentary uranium deposits. The anomalies in the northwest associated with this unit may be a consequence of radioactive residues in oil-well sumps. Two anomalies in the quadrangle pertain to Tertiary rocks. The anomaly near East Butte in the Sweet Grass Hills may be indicative of vein-type deposits in alkaline igneous rocks. The second anomaly may mark the site of epigenetic uranium in lignites. Anomalies related to Quaternary deposits may be significant in that they could reflect uranium-rich source rocks that may contain uranium mineralization.

Research Organization:
Texas Instruments, Inc., Dallas (USA)
DOE Contract Number:
EY-76-C-13-1664
OSTI ID:
5956072
Report Number(s):
GJBX-126(79)(Vol.2-B)(Shelby); TRN: 79-018266
Country of Publication:
United States
Language:
English