Most of the rocks in the Great Smoky Mountains consist of Late Precambrian rocks that are part of a formation known as the Ocoee Supergroup. The Ocoee Supergroup consists primarily of slightly metamorphosed sandstones, phyllites, schists, and slate. Early Precambrian rocks, which include the oldest rocks in the Smokies, comprise the dominant rock type in the Raven Fork Valley (in the Oconaluftee valley) and lower Tuckasegee River between Cherokee and Bryson City. They consist primarily of metamorphic gneiss, granite, and schist. Cambrian sedimentary rocks are found among the outer reaches of the Foothills to the northwest and in limestone coves such as Cades Cove.