Sierra Velluda is a massive

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

stratovolcano A stratovolcano, also known as a composite volcano, is a typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

located immediately southwest of the Antuco Volcano, in the Bío Bío Region of

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

. The heavily glaciated mountain has two main summits and is the tallest mountain in Laguna del Laja National Park. Sierra Velluda was formed in two stages. The first stage occurred 495,000 years ago and is formed by about of

breccia Breccia ( , ; ) is a rock composed of large angular broken fragments of minerals or Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

and lava flows, with sporadic

pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of b ...

s. The second is dated to 381,000 years ago and is made out of breccia and lava. Subsequently, glacial erosion exposed the older layers.

References

Volcanoes of Biobío Region Velluda Sierra Three-thousanders of the Andes Pleistocene stratovolcanoes Stratovolcanoes of Chile {{Biobío-geo-stub

See also

References