Llullaillaco is part of the Central Volcanic Zone. At least 44 volcanic centres with historical activity and 18 large caldera-forming volcanoes have been identified in the Central Volcanic Zone. Volcanism in the Central Volcanic Zone mostly occurs on the Altiplano and the Cordillera Occidental. A number of volcanoes there reach heights of over above sea level. Large Miocene ignimbrites that cover large surfaces are also part of the regional geology. Llullaillaco is located about east of the Peru-Chile Trench. The Wadati-Benioff zone is deep.