Sierra Velluda is a massive

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...

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

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

. 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 rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of ...

and

lava flows Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

, 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