Question: how did puyehue-cordon caulle form?
Answer: Like most stratovolcanoes in the Southern Volcanic Zone of the Andean Volcanic Belt, Puyehue and Cordón Caulle are along the intersection of a traverse fracture with the larger north-south Liquiñe-Ofqui Fault. ... Cordón Caulle erupted shortly after the 1960 Valdivia earthquake, the largest recorded earthquake in history.