 To the east of the Ritscherflya Supergroup, lies the Proterozoic metamorphic terrane of H.U.Sverdrupfjella, which is composed of para- and orthogneisses.The Sør Rondane Mountains are underlain by Late Proterozoic metamorphic rocks of the Teltet-Vengen Group and the Nils Larsen Group gneisses, which are intruded by latest Proterozoic to Early Paleozoic plutonic rocks and dykes.