The Aguas Calientes caldera is located on a Precambrian basement that was thrust over more recent (Cretaceous and younger) layers of sediment.

Aguas Calientes caldera lies in the northwestern Salta Province of Argentina, in the San Antonio de los Cobres district[4] to the southeast of the town of the same name.

[5] Aguas Calientes caldera is part of the Central Volcanic Zone (CVC), which is located in southern Peru, northern Chile, southwestern Bolivia and northwestern Argentina in highlands over 4,000 metres (13,000 ft) high.

[7] The largest eruption in historical times in the CVZ occurred in 1600 on Huaynaputina volcano in Peru.

This subduction process is responsible for the formation of the Andes and the volcanic activity on the eastern margin of the South American continent.

[6] Estimates of the volumes erupted and surface areas covered by the CVZ volcanoes in the Neogene vary.

[6] Aguas Calientes caldera is located on the Late Neoproterozoic to Early Cambrian Puncoviscana Formation with turbiditic sandstone that was affected by metamorphism.

[3] The volcano is linked to the major Calama–Olacapato–El Toro fault system that cuts the Andean chain in a northwest–southeast direction.

[11] Aguas Calientes caldera was between 11 and 10 Ma the source of large scale ignimbrite sheets.

[13] Minerals in the Tajamar ignimbrite include biotite, hornblende, plagioclase, quartz and some augite.

[15] The La Poma-Incachule mining district northeast of the caldera is part of the volcanic system and contains argentiferous galena, sphalerite, antimonite and arsenopyrite.

These deposits formed through hydrothermal, deuteric alteration and supergene processes and were influenced during their formation by local fault systems.

The Chorrilos deposits are gray coloured and have pumice fragments of less than 5 cm diameter; they also contain breccia lenses.