Cerro Escorial is a stratovolcano at the border of Argentina and Chile. It is part of the Corrida de Cori volcanic group and its youngest member. A well-preserved 1-kilometre-wide (0.6 mi) crater forms its summit area. Lava flows are found on the Chilean and smaller ones on the Argentinian side, the former reaching as far as 3–4 kilometres (1.9–2.5 mi) from the volcano. One of these is dated 342,000 years ago by argon-argon dating. A sulfur mine lies 4 kilometres (2.5 mi) southwest of Escorial. Mining ceased about 1983.