| Lastarria | |
|---|---|
 Lastarria seen from Mina La Casualidad | |
| Highest point | |
| Elevation | 5,706 m (18,720 ft)[1] |
| Coordinates | 25°10′S 68°31′W / 25.167°S 68.517°W[1] |
| Geography | |
| Region, Province | Antofagasta Region Salta Province |
| Parent range | Central Andes |
| Geology | |
| Rock age | Pleistocene-Holocene (900,000 to 2400 years BP) |
| Mountain type | Stratovolcano |
| Volcanic belt | Central Volcanic Zone |
| Last eruption | 2460 ± 50/60 years BP |
Lastarria is a 5,697 metres (18,691 ft) high stratovolcano that lies on the border between Chile and Argentina. It is remote, and the surroundings are uninhabited but can be reached through an unpaved road. The volcano is part of the Central Volcanic Zone, one of the four segments of the volcanic arc of the Andes. Over a thousand volcanoes—of which about 50 are active—lie in this over 1,500 kilometres (930 mi) long chain of volcanoes, which is generated by subduction of the Nazca Plate beneath the South American Plate.
The volcano is constituted by two volcanic edifices that form a ridge, and one subsidiary lava flow field southwest of the main volcanoes. The main edifice features several aligned craters that form a line. There is no recorded eruptive activity, but the volcano displays vigorous fumarolic activity on its northern side and within the craters. It is located on top of older volcanic rocks and features both andesite and dacite.
Lastarria produced a large landslide deposit when part of its southeastern flank collapsed. From a 1 kilometre (0.62 mi) wide collapse scar, the landslide descended over a distance of 8 kilometres (5.0 mi). The intense fumarolic activity makes the volcano the largest source of volcanic gases in the region, and has produced fumarolic vent deposits as well as flows of molten sulfur. A progressive uplift of the terrain around Lastarria and farther south has been recognized; it appears to reflect a deep magma intrusion in the region.
- ^ a b Froger et al. 2007, p. 150.