Socompa is a large complex

Complex volcano

A complex volcano, also called a compound volcano, is a volcano with more than one feature. They form because changes of their eruptive characteristics or the location of multiple vents in an area...

 stratovolcano

Stratovolcano

A stratovolcano, also known as a composite volcano, is a tall, conical volcano built up by many layers of hardened lava, tephra, pumice, and volcanic ash. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile and periodic, explosive eruptions...

 at the border of Argentina

Argentina

Argentina , officially the Argentine Republic , is the second largest country in South America by land area, after Brazil. It is constituted as a federation of 23 provinces and an autonomous city, Buenos Aires...

 and Chile

Chile

Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

. It is best known for its large debris avalanche deposit, which is widely accepted as the best-preserved example of this type of deposit in the world, and also notable as the home of the world's most elevated known microbial ecosystems.

The western rim of the volcano borders the Monturaqui Basin, which is draped with the aforementioned deposit.