A RECONNAISSANCE FOR URANIUM IN CARBONACEOUS ROCKS IN SOUTHWESTERN COLORADO AND PARTS OF NEW MEXICO

摘要

Coal and carbonaceous shale of the Dakota formation of Cretaceous age were examined for radioactivity in the Colorado Plateau of southwestern Colorado and northwestern New Mexico during the summer of 1953. Older and younger sedimentary rocks and some igneous rocks also were examined, but in less detail. Weak radioactivity was detected at many places but no new deposits of apparent economic importance were discovered. The highest radioactivity of carbonaceous rocks was detected in black shale, siltstone, and sandstone of the Paradox member of the Hermosa formation of Pennsylvanian age. A sample collected from this member at the Bald Eagle prospect in Gypsum Valley, San Miguel County, Colo., contains 0.10 percent uranium.