Thirteen core holes, totaling 2,023 feet, were drilled during the fall of 1953 to explore the grade and extent of uranium-bearing beds of carbonaceous shale and lignite in the east-central part of the Goose Creek district, Cassia County, Idaho. The beds tested are interbedded with volcanic ash, bentonite, greenish-gray shale, sandstone, and conglomerate in two fairly well defined zones in the lower part of the Salt Lake formation of lower Pliocene age. Nine holes penetrated carbonaceous shale beds in the Barrett zone, and one hole penetrated carbonaceous shale and lignite beds in zone B, 160 feet stratigraphically below the Barrett zone. The highest concentration of uranium found by drilling is 0.10 percent in the upper part of a 4-foot bed of carbonaceous shale and lignite in zone B. The grade of carbonaceous shale beds in the Barrett zone ranges from 0.044 percent to less than 0.003 percent uranium. Inferred reserves in the district are estimated to be 790,000 tons in beds 1 foot or more thick containing an average of 0.014 percent or 120 tons of uranium.

Idaho↗

USGS1952

Results of reconnaissance for uraniferous coal, lignite, and carbonaceous shale in western Montana

A reconnaissance search for uraniferous lignite and carbonaceous shale was made in western Montana and adjacent parts of Idaho during the summer of 1951. Particular emphasis in the examination was placed on coal and carbonaceous shale associated with volcanic rocks, as volcanic rocks in many area appear to have released uranium to circulating ground water from which it was concentrated in carbonaceous material. Twenty-two area in Montana and one area of Idaho were examine. The coal in five of these area is of Cretaceous age. The coal and carbonaceous shale in the remaining 18 area occur in Tertiary "lake-bed" deposits of Oligocene and younger age. Both the Cretaceous and Tertiary coal and carbonaceous shale are associated with contemporaneous or younger volcanic rocks and pyroclastic sequences. A sample of carbonaceous shale from the Prickly Pear Valley northeast of Helena, Montana, contained 0.013 percent uranium. A sample of carbonaceous shale from the Flint Creek Valley southwest of Drummond, Montana, contained 0.006 percent uranium. All other samples of both Cretaceous and Tertiary coal and carbonaceous shale were essentially non-radioactive. No further work is planned on the Cretaceous and Tertiary coal and carbonaceous shale in western Montana. A few localities in Idaho will be visited in the course of other work.

Idaho;Montana↗