Critical-mineral-bearing paleoplacers in the basal Cambrian Flathead Sandstone and other radioactive conglomerates

Fluvial placers are potential sources of critical and economic minerals. In Wyoming, historical data suggest paleo- placers in the Middle Cambrian Flathead Sandstone, Paleoproterozoic Jack Creek Quartzite, Paleoproterozoic Magnolia Formation, and Eocene Wind River Formation are enriched in rare earth and other elements. With the goal of acquiring analyses of these typically radioactive conglomerates using modern geochemical and mineralogi- cal methods, 66 samples were collected and analyzed from known or potential occurrences throughout Wyoming.