The late-Pleistocene to Holocene Callaqui stratovolcano has a profile of an overturned canoe due to its construction
along an 11-km-long, SW-NE fissure above a 1.2-0.3 million year old Pleistocene edifice.
The ice-capped, 3164-m-high basaltic-andesite Callaqui volcano contains well-preserved volcanic cones and lava flows, which have traveled up to 14 km. Small craters 100-500 m in diameter are primarily found along a fissure extending
down the SW flank. Intense solfataric activity occurs at the southern part of the summit; in 1966 and 1978,
red glow was observed in fumarolic areas.
Periods of intense fumarolic activity have dominated at Callaqui, and few historical eruptions are known.
An explosive eruption was reported in 1751, there were uncertain accounts of eruptions in 1864 and 1937,
and a small phreatic ash emission was noted in 1980.
January 6th, 2012.