Glacier-clad, 6310-m-high Chimborazo, Ecuador's highest volcano, anchors the southern end of the country's "Avenue of Volcanoes" 30 km NW of the city of Riobamba. The dominantly andesitic-to-dacitic structure is mostly of Pliocene-to-Pleistocene age. The volcano collapsed about 35,000 years ago, producing a major debris avalanche, whose deposits underlie Riobamba and temporarily dammed the Río Chambo, producing an ephemeral lake. Subsequent eruptions have been dominantly andesitic and constructed three edifices along an east-west line, the youngest and westernmost of which forms the current summit of Chimborazo. Although activity was at one time thought to have ceased during the very latest Pleistocene, recent work indicates that it erupted more than a half dozen times during the Holocene, producing pyroclastic surges that reached down to 3800 m elevation.
Glacier-clad, 6310-m-high Chimborazo is Ecuador's highest volcano. It is seen here from the NE with Carihuairazo volcano forming the lower, mostly snow-free peak to the left. The youngest and westernmost of three edifices constructed along an E-W line forms the current summit of Chimborazo. Although activity was once thought to have ceased during the very latest Pleistocene, recent work indicates that Chimborazo erupted several times during the Holocene.
Photo by Patricio Ramon, 2004 (Instituto Geofisca, Escuela Politecnica Nacional).
Last updated 2019-12-17 09:00:03