Isluga

Isluga
The broad Isluga volcanic complex is visible in the upper left corner of this Expedition 9 image.
Highest point
Elevation	5,550 m (18,210 ft)
Coordinates	19°09′S 68°50′W / 19.150°S 68.833°W / -19.150; -68.833
Geography
Location	Chile
Parent range	Andes
Geology
Mountain type	Stratovolcano
Last eruption	1913

Isluga (Spanish pronunciation: [isˈluɣa]) is a stratovolcano located in Colchane, 7 km west of the Chile/Bolivia border and at the west end of a group of volcanoes lined up in an east-west direction, which also includes the volcanoes Cabaray and Tata Sabaya. Isluga has an elongated summit area and lies within the borders of Volcán Isluga National Park in Chile's Tarapacá Region.

Isluga is part of the Andean Volcanic Belt, the volcanic zone on the western side of South America where the Nazca plate is subducted beneath the South American plate. Isluga is part of the segment named the Central Volcanic Zone.

There are several volcanic units in the Isluga area. A pre-Isluga unit containing Cabay volcano, northeastern Carcanchuni and southern Cerro Blanco are not stratigraphically controlled. The Enquelga unit is the first Isluga unit proper.

Being about 1,200 m (3,900 ft) high over its base, Isluga has five craters, a main crater 400 m wide at the end of snowcovered summit ridge and underwent caldera collapse. The volcano itself is constructed from lava domes and flows on top of Miocene ignimbrites. Several stages of eruptive activity are recognized, some of them exposed through erosion. A northwestern debris avalanche has been found on Isluga, on top of which the recent volcano is constructed. The fumarolically active crater region has been buried with surge deposits from phreatomagmatic activity, and the northern ridge is covered by Holocene lavas. A glaciated dacitic lava flow is dated 0.096±0.006 Ma by K-Ar analysis. North of Isluga lies the dissected Quimsachatas volcano, which has been dated at 0.566±0.017 Ma. Both the summit crater and the area below the crater on the southern flank are faintly fumarolically active, with yellow sulfur deposits observed.