Cerro Macá is a

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 to the north of the Aisén Fjord and to the east of the Moraleda Channel, in the Aysén del General Carlos Ibáñez del Campo 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 ...

. This glacier-covered volcano lies along the regional Liquiñe-Ofqui Fault Zone. Cerro Macá is a relatively small volcano with a volume of only . It has a summit elevation of approximately 2,300 m above sea level and features

glacier A glacier (; or ) is a persistent body of dense ice, a form of rock, that is constantly moving downhill under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires ...

s that in 2011 covered an area of . The edifice is partially eroded and a sector collapse is probably the origin of a large steep sided depression in the summit area. Pyroclastic cones with associated

lava flow Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

s are found on its southwestern flank but also on the other slopes of the volcano, as far down as sea level and in the Bahia Aysen. The volcano is part of the southernmost Southern Volcanic Zone of Chile, where volcanism is caused by the

subduction Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second p ...

of the

Nazca Plate The Nazca plate or Nasca plate, named after the Nazca region of southern Peru, is an oceanic list of tectonic plates, tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru– ...

. Other volcanoes in the area are Melimoyu, Mentolat, Cay and Cerro Hudson. Macá specifically is formed by

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

and basaltic andesite. 1,440 ± 40 calibrated radiocarbon years ago a moderate

explosive eruption In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a Viscosity, viscous ...

deposited the MAC1

tephra Tephra is fragmental material produced by a Volcano, volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, ...

, which reaches thicknesses of east of Macá. Ash from past eruptions has been tentatively identified close to Cochrane Lake. A more recent eruption occurred from the Bahía Pérez

cinder cone A cinder cone or scoria cone is a steep, volcanic cone, conical landform of loose pyroclastic rock, pyroclastic fragments, such as volcanic ash, clinkers, or scoria that has been built around a volcanic vent. The pyroclastic fragments are forme ...

on the southwestern flank in 1560 ± 110 years. In the early 20th century volcanic activity was observed at Ensenada Pérez, close to the southwestern flank of Macá.

Footnotes

References

"Monte Maca, Chile" on Peakbagger
Volcanoes of Aysén Region Mountains of Aysén Region Stratovolcanoes of Chile Holocene stratovolcanoes Two-thousanders of the Andes {{Chile-mountain-stub

See also

Footnotes

References