Licancabur () is a stratovolcano on the border between Bolivia and Chile, south of the Sairecabur volcano and west of Juriques. Part of the Andean Central Volcanic Zone, it has a prominent, -high cone. A summit crater containing Licancabur Lake, a crater lake which is among the highest lakes in the world, caps the volcano. Three stages of lava flows emanate from the edifice. Licancabur formed atop of Pleistocene ignimbrites and has been active during the Holocene, after the ice ages. Although no historic eruptions of the volcano are known, lava flows extending into Laguna Verde have been dated to 13,240 ± 100 BP. The volcano has primarily erupted andesite, with small amounts of dacite and basaltic andesite. Its climate is cold, dry and very sunny, with high levels of ultraviolet radiation. Licancabur is not covered by glaciers. Cushion plants and shrubs form the vegetation lower on its slopes. Chinchillas were formerly hunted on the volcano. Licancabur is considered a holy mountain by the Atacameno people, which consider it a relative of Cerro Quimal mountain in northern Chile. Archeological sites have been found on its slopes and in the summit crater, which was possibly a prehistoric watchtower. Name "Licancabur" derives from the Kunza words used by the Atacameño people to refer to the volcano: ("people", or pueblo) and ("mountain"); thus, "mountain of the people". It is also known as "Volcan de Atacama" and "Licancaur". The border between Bolivia and Chile, defined by the 1904 Treaty of Peace and Friendship, crosses the volcano. Geography and geology General setting Off the western coast of South America, the Nazca Plate subducts into the Peru-Chile Trench beneath the South American Plate. The Andean Volcanic Belt consists of three main volcanic zones: the Northern Volcanic Zone (from 2° N to 5° S), the Central Volcanic Zone (16° to 28° S) and the Southern Volcanic Zone (33° to 46° S). These volcanic zones are separated by gaps without volcanic activity, where the subducting plate is shallower. These shallower zones have been attributed to the high speed of the plate collision, the young age of the subducting oceanic lithosphere and the curvature of the subducting plate. The most plausible theory is that variations in buoyancy of a subducting plate creates a flat subduction zone. The Cocos, Juan Fernandez and Nazca Ridges are associated with such volcanic gaps where they collide with the oceanic trench. The subduction of