Uranium occurrences of the Nacimiento-Jemez region, Sandoval and Rio Arriba counties, New Mexico
Uranium in the Nacimiento-Jemez region of north-central New Mexico occurs in rocks of Pennsylvanian, Permian, Triassic, Jurassic, Cretaceous, and Tertiary age. Deposits consist of uranium minerals disseminated in sandstone, siltstone, carbonaceous shale, coal, and limestone and in association with carbonized plant debris in sandstone and in "red bed" copper deposits. Uranium minerals fill interstices of a silicified rhyolite breccia at a single occurrence. Known deposits are small and subeconomic. Slightly more than 600 tons of ore have been produced to date.