The Tewa Group is a sequence of mostly rhyolite pyroclastic flows and domes that underlies much of the Valles Caldera and forms extensive outflow sheets surrounding the caldera. It has a maximum thickness of . It overlies the Santa Fe, Keres, and Polvadera Groups to the east and south of the caldera and older rocks ranging in age from Paleoproterozoic to Permian to the west and north. It forms the upper surfaces of the Pajarito Plateau east of the caldera and the Jemez Plateau west of the caldera.