 It is part of the Central Volcanic Zone of the Andes, one out of several volcanic belts found in South America.It is one of several major caldera systems in the Central Volcanic Zone, some of which are grouped into the Altiplano–Puna volcanic complex.Volcanic activity at Galán is the indirect consequence of the subduction of the Nazca Plate beneath the South America Plate, and involves the infiltration of melts into the crust and the formation of secondary magmas which after storage in the crust give rise to the dacitic to rhyodacitic rocks erupted by the volcano.