A major ignimbrite is found in the Escorial area and extends in a butterfly shape over with a thickness of c. . Probably erupted from Cerro Escorial, it extends away from Escorial. It has a total volume of c. and consists of crystal rich dacite with large amounts of xenoliths. Where the ignimbrite was dammed by older lava flows, it formed internal wave structures. The surface of the ignimbrite is grooved and rippled in appearance and is heavily influenced by aeolian activity. Dating is uncertain, with older dates including 1.3 ± 0.6 mya but a more precise recent date is 0.457 ± 0.013 mya. This ignimbrite was likely formed by a column collapse and is known as the Caletones Cori Ignimbrite.