Nevado de Longaví

關於

Nevado de Longaví is a volcano in the Andes of central Chile. The 3,242 m (10,636 ft) high volcano lies in the Linares Province, which is part of the Maule Region. It features a summit crater and several parasitic vents. The volcano is constructed principally from lava flows. Two collapses of the edifice have carved collapse scars into the volcano, one on the eastern slope known as Lomas Limpias and another on the southwestern slope known as Los Bueye. The volcano features a glacier and the Achibueno and Blanco rivers originate on the mountain.

The oldest volcanic activity occurred one million years ago. After a first phase characterized by the production of basaltic andesite, the bulk of the edifice was constructed by andesitic lava flows. The volcanic rock that makes up Nevado de Longaví features an unusual magma chemistry that resembles adakite (having geochemical characteristics of magma thought to have formed by partial melting of altered basalt that is subducted below volcanic arcs). It may be the consequence of the magma being unusually water-rich, which may occur because the Mocha fracture zone subducts beneath the volcano.

Nevado de Longaví was active during the Holocene. 6,835 ± 65 or 7,500 years before present an explosive eruption deposited pumice more than 20 kilometres (12 mi) away from the volcano. A lava flow was then erupted over the pumice. The last eruption occurred about 5,700 years ago and formed a lava dome. The volcano has no historic eruptions but fumarolic activity is ongoing. Nevado de Longaví is monitored by the National Geology and Mining Service of Chile.

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