What is "incapillo"

Incapillo is a Pleistocene caldera, a depression formed by the collapse of a volcano, in the La Rioja province of Argentina. Part of the Argentine Andes, it is considered the southernmost volcanic centre in the Central Volcanic Zone of the Andes with Pleistocene activity. Incapillo is one of several ignimbritic or calderic systems that, along with 44 active stratovolcanoes, are part of the Central Volcanic Zone.

Subduction of the Nazca Plate beneath the South America plate is responsible for most of the volcanism in the Central Volcanic Zone. After activity in the western Maricunga Belt volcanic arc ceased six million years ago, volcanism started up in the Incapillo region, forming the high volcanoes Monte Pissis, Cerro Bonete Chico and Sierra de Veladero. Later, a number of lava domes formed between these volcanoes.

Incapillo is the source of the Incapillo ignimbrite, a medium-sized deposit comparable to the Katmai ignimbrite. With a volume of about , the Incapillo ignimbrite was erupted 0.52 ± 0.03 and 0.51 ± 0.04 million years ago. A caldera with dimensions of was formed during the eruption. Later volcanism generated more lava domes within the caldera and a debris flow in the Sierra de Veladero. The lake within the caldera may overlie an area of ongoing hydrothermal activity.