 Situated to the south of in the Blue Mountains and the Kanangra-Boyd National Parks, this folded belt or "Rim Rock" area is markedly different from the Permo-Triassic sandstone dominated landforms which comprise the rest of the Blue Mountains.There are isolated residual cappings of Permian sandstone in a few places but here the Palaeozoic basement rocks, which are elsewhere buried well below the Permo-Triassic Measures, are on the surface as high land.Rock types include quartzite, diorite, Devonian rhyolites, rhyo-dacites, Silurian phyllites, slates, siltstones and tuff limestones.