Acotango

Geological summary

Acotango, along with Volcán Humarata to the north and Cerro Capurata (also known as Cerro Elena Capurata) to the south, comprises the Nevados de Quimsachata volcano group. Quimsachata means "three" in the Andean Aymará language, and 5730-m-high Humarata, Acotango, and 5990-m-high Cerro Capurata straddle the Chile-Bolivia boundary along a roughly N-S line. The 6052-m-high Acotango stratovolcano is the central and highest of the three stratovolcanoes. It is in a fairly advanced stage of dissection, but a morphologically youthful lava flow on its northern flank suggested Holocene activity (de Silva and Francis, 1991). Later higher resolution imagery implied a Pleistocene age (de Silva 2007, pers. comm.). Humarata, with a summit crater breached to the ESE, and Capurata, a complex of lava domes and associated pyroclastic-flow deposits, may also have been active during the Holocene.