Lauca (volcano)

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Lauca
Lauca is located in Chile
Lauca
Lauca
Location of Lauca in Chile
Highest point
Elevation 5,140 m (16,860 ft) [1]
Coordinates 18°20′S 69°23′W / 18.333°S 69.383°W / -18.333; -69.383Coordinates: 18°20′S 69°23′W / 18.333°S 69.383°W / -18.333; -69.383[2]
Naming
Translation Aquatic grass (Aymara)
Geography
Location Putre, Arica y Parinacota Region
 Chile
Parent range Altiplano, Andes
Geology
Age of rock Miocene-Pliocene
Mountain type Stratovolcano
Volcanic belt Central Volcanic Zone
Last eruption Pliocene

Lauca is a 5,140 metres (16,860 ft)[1] high andesitic stratovolcano in the Central Volcanic Zone of the Andes on the Altiplano in northern Chile. Administratively it is located in Putre, Arica y Parinacota Region. The volcano was active during the Late Miocene from 10.5 million years ago onwards. A major ignimbrite collapsed the volcano in the Late Pliocene.

Geology[edit]

Andesites from the Lauca volcano, active in the Late Miocene as of 10.5 million years ago,[3] exist in two groups, plagioclase rich ones which underwent alteration and fine grained silicic ones that are fresher.[1] The territory is underpinned with a crust formed from rocks of Precambrian to Cretaceous age, with thicknesses up to 70 kilometres (43 mi).[2] Amphibole rich lava flows formed a uniform volcanic cone. A later major ignimbrite eruption caused the collapse of the centre and formed the Lauca ignimbrite.[1] A caldera is present, with a lava dome at the northeastern rim.[1]

The Lauca ignimbrite has a thickness up to 150 metres (490 ft), covering the El Diablo Formation in parts and filling the Lluta Canyon. Ar-Ar ages for this rhyolitic ignimbrite have been determined at 2.73 ± 0.02 Ma based on sanidine analysis and 2.87 ± 0.05 Ma from biotite.[4] The Lauca ignimbrite has been correlated to the Pérez ignimbrite in Bolivia and the Pachía ignimbrite in southern Peru.[5] Along the Copaquilla-Tignámar Fault, uplifting the eastern side over the western side,[6] the Lauca ignimbrite has been displaced over 100 to 150 metres (330 to 490 ft), indicative of tectonic activity after deposition in the Late Pliocene.[7] In parts, the Lauca ignimbrite is covered by conglomeratic terrace deposits.[8]

See also[edit]

References[edit]

  1. ^ a b c d e Wigger et al., 2012, p.81
  2. ^ a b Wörner et al., 1992
  3. ^ Kött et al., 1995
  4. ^ García et al., 2011, p.1053
  5. ^ Charrier et al., 2013, p.245
  6. ^ Charrier et al., 2013, p.255
  7. ^ Charrier et al., 2013, p.247
  8. ^ Schlunegger et al., 2010, p.S132

Bibliography[edit]