Antofagasta de la Sierra

Last updated
Antofagasta de la Sierra
Volcan Antofagasta.jpg
Alumbrera cinder cone viewed from a lava field
Highest point
Elevation 4,000 metres (13,123 ft) (uncertain) [1]
Coordinates 26°05′S67°30′W / 26.08°S 67.50°W / -26.08; -67.50 [1]
Geography
Relief Map of Argentina.jpg
Red triangle with thick white border.svg
Antofagasta de la Sierra
Parent range Andes
Geology
Age of rock Holocene
Mountain type Scoria cones
Last eruption Unknown [1]

Antofagasta de la Sierra is a volcanic field in Argentina. The main type of volcanic edifice in the area are scoria cones, it is formed by the La Laguna, Jote and Alumbrera volcanoes. The first and last of these form a sub-group which is better researched. Various dating methods have yielded ages from several million to several hundred thousand years ago, but some vents appear to be of Holocene age.

Contents

Geology

Regional

Volcanic activity in the Andes occurs in four regions, the Northern Volcanic Zone, the Central Volcanic Zone, the Southern Volcanic Zone and the Austral Volcanic Zone. The first three of these are found where the Nazca Plate subducts beneath the South America Plate, while the last zone occurs at the subduction zone of the Antarctic Plate. [2] The Andean Central Volcanic Zone runs along the Western Cordillera of the Andes and along the Altiplano. During the Neogene, the position of this volcanic arc moved eastward and the arc became broader, probably due to a change in the tilt of the slab of the Nazca Plate. Volcanic activity during this time was heavily influenced by local strike-slip faults which acted to channel the magma flows. About 7 million years ago, tectonics and volcanic activity changed in the region probably in response to the delamination of the crust beneath the region: Large scale ignimbrites were erupted at Galán and small back-arc volcanoes erupted mafic basaltic andesite lavas. These small volcanic centres consist of lava domes, lava flows, maars, scoria cones and tuff rings. [3]

Local

The Antofagasta de la Sierra volcanic field lies within the north–south trending tectonic depression of the same name, [3] in the Catamarca Province. [4] Of the individual vents the La Laguna and Alumbrera cones are the best studied ones, [5] they lie about 5–7 kilometres (3.1–4.3 mi) south of Antofagasta de la Sierra. [6] These volcanoes are associated with black lava flow fields. [4] The Jote volcanoes consist of a cluster of cinder cones and lava flows [7] and are located south of the Antofagasta de la Sierra lake. To their northwest lies Cachamani. [8]

Alumbrera cone is 164 metres (538 ft) high and has an elliptical shape with a maximum length of 1.3 kilometres (0.81 mi), probably due to wind influencing the growth of the cone. The cone shows signs of having been gravitationally unstable, including a sector collapse on its northwestern flank. The cone has a 50 metres (160 ft) wide crater and a few fissure vents. Alumbrera has a volume of 0.12 cubic kilometres (0.029 cu mi) and is the source of a 0.29 cubic kilometres (0.070 cu mi) large lava flow field which covers a surface of 41.3 square kilometres (15.9 sq mi) [9] and surrounds the Alumbrera cone. Lapilli fill the crater of Alumbrera, which has alum, ochre and sulfur colours. [10]

La Laguna is smaller than Alumbrera: The cone is only 153 metres (502 ft) high and 1.1 cubic kilometres (0.26 cu mi) wide, with a 23.5 metres (77 ft) deep crater. As with Alumbrera La Laguna features one fissure vent and a lava flow field, with a smaller volume of 0.12 cubic kilometres (0.029 cu mi) and surface area of 6.8 square kilometres (2.6 sq mi). [9]

Both La Laguna and Alumbrera were fed by northwest-striking fissures, which is unusual as most lineaments in the area strike northeastwards or north–south. The surfaces of erupted rocks have been subject to various degrees of wind-driven erosion which has left grooves in the most altered units. [9] Most likely the magma supply at these two vents was so large that the rising dykes were able to force pre-existent lineaments open and to pass through them. [11]

Composition

Alumbrera and La Laguna has erupted alkaline to sub-alkaline basaltic trachyandesite to trachybasalt with a porphyritic texture. Phenocrysts within the rock include olivine and plagioclase or clinopyroxene, which form also the bulk of the matrix. [12] [13] The Jote lavas have similar composition to the La Laguna rocks. The chemical composition of the old and the new La Laguna volcanoes is different, with the old lavas showing a more volcanic arc-like composition. [7] Various minerals, [14] including "alum" (in reality a mixture of aluminium sulfate and magnesium sulfate) found at Alumbrera, were mined by the local population. [15]

Eruptive history

Eruptions at Alumbrera occurred in two phases, the first formed toothpaste lava and aa lava and the second in addition to lava small pyroclastic flows and a tephra blanket. A scoria fallout is found as far as 15 kilometres (9.3 mi) east of Alumbrera. During this second phase, the sector collapse at Alumbrera occurred and was followed by the emission of lava bombs during Strombolian eruptions. [12] La Laguna at first erupted several now heavily eroded lava flows and formed an old cone. [13] Later during a second phase of activity lava bombs and scoria formed a newer cone and two lava flow fields. [16] At both volcanoes, phreatomagmatic activity may have occurred after the magma pressure dropped so far that water could enter the conduit. The eruptions probably lasted several weeks to several years. [17]

A lava flow at La Laguna cone has been dated to 340,000 ± 60,000 years before present, [2] consistent with its older appearance. [18] A large-scale research project in the Puna yielded a number of Ar-Ar and K-Ar dates, including 3.2 and 4.5 million years ago for Jote and 0.3 and 7.3 million years ago for Alumbrera and La Laguna. [19] The older age appears to refer to a mesa just west of the Alumbrera lava field. [20] The youngest age was obtained on Alumbrera cone by argon-argon dating: 37,000 ± 2,000. [21]

Historical activity is unknown, [2] and Lorenzo Sundt in 1911 reported that there is no sign of activity. [22] In 1907 the volcanoes were considered to be extinct, [23] but the field may have had eruptions during the Holocene; [2] the young appearance of Alumbrera suggests a Holocene age for this cone. [18] Renewed activity in the field could cause ash to fall over hundreds of square kilometres of adjoining land and generate dangerous pyroclastic density currents close to the vent. [17]

Other

Between the Antofagasta and Alumbrera volcanoes lies the Antofagasta lake. The vegetation in the area is shrub steppe, and fairly sunny and dry. [24] The Antofagasta River coming from the north forms a large wetland before the relatively deep Antofagasta lake; the Alumbrera volcano borders the lake in the south. [25] The lake in 1911 consisted of two halves, joined by a canal. [26] Before the emplacement of the volcanic field, which dammed the lake, the river may have continued south to Carachipampa. [27] A major archeological site is emplaced on the Antofagasta volcano. [28]

See also

Related Research Articles

<span class="mw-page-title-main">Volcanic field</span> Area of Earths crust prone to localized volcanic activity

A volcanic field or crater row is an area of Earth's crust that is prone to localized volcanic activity. The type and number of volcanoes required to be called a "field" is not well-defined. Volcanic fields usually consist of clusters of up to 100 volcanoes such as cinder cones. Lava flows may also occur. They may occur as a monogenetic volcanic field or a polygenetic volcanic field.

<span class="mw-page-title-main">Cerro El Cóndor</span> Mountain in Argentina

Cerro El Cóndor is a stratovolcano in Argentina.

<span class="mw-page-title-main">Peinado</span> Mountain in Argentina

Peinado is a stratovolcano in Catamarca Province, Argentina. It consists of a volcanic cone with a summit crater, surrounded at its foot by lava flows erupted from flank vents. It began erupting about 100,000 years ago, with the last eruption about 36,800 years ago. Future eruptions are possible.

<span class="mw-page-title-main">Incahuasi</span> Mountain in Argentina

Incahuasi is a volcanic mountain in the Andes of South America. It lies on the border of the Catamarca Province of Argentina and the Atacama Region of Chile. Incahuasi has a summit elevation of 6,621 metres (21,722 ft) above sea level.

<span class="mw-page-title-main">Galán</span> Mountain in Argentina

Cerro Galán is a caldera in the Catamarca Province of Argentina. It is one of the largest exposed calderas in the world and forms part of the Central Volcanic Zone of the Andes, one of the three volcanic belts found in South America. One of several major caldera systems in the Central Volcanic Zone, the mountain is grouped into the Altiplano–Puna volcanic complex.

<span class="mw-page-title-main">Quetrupillán</span> Mountain in Chile

Quetrupillán is a stratovolcano located in Los Ríos Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is located in a tectonic basement block between the main traces of Liquiñe-Ofqui Fault and Reigolil-Pirihueico Fault.

<span class="mw-page-title-main">Paniri</span> Mountain in Chile

Paniri is a stratovolcano located in El Loa Province, Antofagasta Region, Chile, and near the border with Bolivia. To its northwest lie the twin volcanoes San Pedro and San Pablo, and to its southeast lies Cerro del León, from which it is separated by the huge Chao lava dome.

<span class="mw-page-title-main">San Pedro (Chile volcano)</span> One of the tallest active volcanoes in the world

San Pedro is a Holocene composite volcano in northern Chile and at 6,155 metres (20,194 ft) in elevation one of the highest active volcanoes in the world. Part of the Chilean Andes' volcanic segment, it is part of the Central Volcanic Zone of the Andes, one of the four tracts of the Andean Volcanic Belt. This region of volcanism includes the world's two highest volcanoes Ojos del Salado and Llullaillaco. San Pedro, like other Andean volcanoes, was formed by the subduction of the Nazca Plate beneath the South America Plate. It has a neighbouring volcano, San Pablo, and is itself formed by two separate edifices usually known as the Old Cone and the Young Cone. These edifices are formed by rocks ranging from basaltic andesite over andesite to dacite and are emplaced on a basement formed by Miocene volcanic rocks.

<span class="mw-page-title-main">Andagua volcanic field</span> Volcanic field in Peru

The Andagua volcanic field is a volcanic field in southern Peru which includes a number of cinder cones, lava domes and lava flows which have filled the Andagua Valley. The volcanic field is part of a larger volcanic province that clusters around the Colca River and is mostly of Pleistocene age, although the Andagua sector also features volcanic cones with historical activity, with the last eruption about 370 years ago. Eruptions were mostly effusive, generating lava flows, cones and small eruption columns. Future eruptions are possible, and there is ongoing fumarolic activity. Volcanic activity in the field has flooded the Andahua valley with lava flows, damming local watersheds in the Laguna de Chachas, Laguna Mamacocha and Laguna Pumajallo lakes and burying the course of the Andagua River. The Andahua valley segment of the larger volcanic province was declared a geopark in 2015.

<span class="mw-page-title-main">Cerro Blanco (volcano)</span> Caldera in Catamarca Province, Argentina

Cerro Blanco is a caldera in the Andes of the Catamarca Province in Argentina. Part of the Central Volcanic Zone of the Andes, it is a volcano collapse structure located at an altitude of 4,670 metres (15,320 ft) in a depression. The caldera is associated with a less well-defined caldera to the south and several lava domes.

Negro de Chorrillos is a volcano in the Andes.

<span class="mw-page-title-main">Pali-Aike volcanic field</span> Cluster of volcanoes in Argentina and Chile

The Pali-Aike volcanic field is a volcanic field along the Argentina–Chile border. It is part of a family of back-arc volcanoes in Patagonia, which formed from processes involving the collision of the Chile Ridge with the Peru–Chile Trench. It lies farther east than the Austral Volcanic Zone, the volcanic arc that makes up the Andean Volcanic Belt at this latitude. Pali-Aike formed over sedimentary rock of Magallanes Basin, a Jurassic-age basin starting from the late Miocene as a consequence of regional tectonic events.

San Jerónimo is a volcano in Argentina. It is located 18 kilometres (11 mi) from San Antonio de los Cobres and the lava flows are visible from the road.

Tocomar is a Pleistocene volcano in the Jujuy Province, Argentina. It is part of the Andean Volcanic Belt, more specifically to its sub-belt the Central Volcanic Zone. The Central Volcanic Zone consists of about 44 active volcanoes and large calderas of the Altiplano-Puna volcanic complex. Volcanism there is caused by the subduction of the Nazca Plate beneath the South America Plate in the Peru-Chile Trench. At Tocomar, volcanism is further influenced by a large fault zone, the Calama-Olacapato-El Toro fault, which runs diagonally across the volcanic arc.

<span class="mw-page-title-main">Antofalla</span> Mountain in Argentina

Antofalla is a Miocene-Pliocene volcano in Argentina's Catamarca Province. It is part of the volcanic segment of the Andes in Argentina, and it is considered to be part of the Central Volcanic Zone, one of the volcanic zones of the Andes. Antofalla forms a group of volcanoes that are aligned on and behind the main volcanic arc. Antofalla itself is a remote volcano.

Cueros de Purulla is a volcano in Argentina. It consists of a lava dome and an associated ignimbrite. A large eruption dated to c. 7820 BP deposited ash into the Valles Calchaquies.

Pasto Ventura is an area in the Catamarca Province of Argentina. It features about 14 small Pleistocene volcanoes, mostly cinder cones with associated lava flows but also lava domes, tuff rings and two maars. The volcanoes are accompanied by pyroclastic deposits and their total volume reaches about 0.42 cubic kilometres (0.10 cu mi). Argon-argon dating has yielded ages ranging from 1.3 million years to about 270,000 years for volcanic rocks in the field.

Cerro Tuzgle is a dormant stratovolcano in the Susques Department of Jujuy Province in northwestern Argentina. Tuzgle is a prominent volcano of the back arc of the Andes and lies about 280 kilometres (170 mi) east of the main volcanic arc. Part of the Central Volcanic Zone of the Andes, its summit is 5,486 metres (17,999 ft) above sea level and it grew during different stages over a caldera and lava domes. Some major lava flows emanate from the summit crater, and one confirmed and one possible flank collapse unit as well as an ignimbrite sheet are associated with Tuzgle.

<span class="mw-page-title-main">Tocorpuri</span> Volcano in Bolivia and Chile

Tocorpuri is a volcano in Chile, close to the border with Bolivia. Its peak height is most recently given as 5,808 metres (19,055 ft) and it features a 1.3 kilometres (0.81 mi) wide summit crater. The volcano consists mainly of lava flows and pyroclastic deposits and is subdivided into two separate edifices. Just west of Tocorpuri, the La Torta lava dome is a 200 metres (660 ft) high flat-topped structure. The volcanoes are formed by andesitic, dacitic and rhyolitic rocks.

<span class="mw-page-title-main">Carachipampa</span>

Carachipampa is a Pleistocene volcanic cone in Argentina. Part of a wider, regional volcanic field, it has produced lava flows consisting of andesite. It is surrounded by a lake and a salt flat, the former of which features an ecosystem formed by microbes.

References

  1. 1 2 3 "Antofagasta de la Sierra". Global Volcanism Program . Smithsonian Institution . Retrieved 2007-03-30.
  2. 1 2 3 4 Báez et al. 2017, p.313
  3. 1 2 Báez et al. 2017, p.312
  4. 1 2 Parra, Lorenzo (24 April 2015). "En Catamarca estamos muy cerca de grandes volcanes". elancasti.com.ar.
  5. ↑ Báez et al. 2017, p.313-314
  6. ↑ Elías, Alejandra M.; Glascock, Michael D. (2013-07-04). "PRIMEROS AVANCES EN LA CARACTERIZACIÓN GEOQUÍMICA DE VULCANITAS DE AFLORAMIENTOS DE ANTOFAGASTA DE LA SIERRA (PROV. DE CATAMARCA, ARGENTINA) / First advances in the geochemical characteristics of volcanic outcrops of Antofagasta de la Sierra (Catamarca)". Revista del Museo de Antropología. 6 (1): 43. ISSN   1852-4826.
  7. 1 2 Kay, Suzanne Mahlburg; Ramos, Víctor A. (2008-01-01). Field Trip Guides to the Backbone of the Americas in the Southern and Central Andes: Ridge Collision, Shallow Subduction, and Plateau Uplift. Geological Society of America. p. 156. ISBN   9780813700137.
  8. ↑ Estrada, Carlos (1999). Proyecto de optimización de uso del recurso hídrico del río Punilla con fines agropecuarios en el paraje de Paicuqui, departamento Antofagasta de la Sierra, provincia de Catamarca (Report) (in Spanish). p. 151.
  9. 1 2 3 Báez et al. 2017, p.314
  10. ↑ Von Wolff, F (1929). Der Volcanismus II Band: Spezieller Teil 1 Teil Die Neue Welt (Pazifische Erdhalfte) der Pazifische Ozean und Seine Randgebiete (in German). Stuttgart: Ferdinand Enke. p. 352.
  11. ↑ Báez et al. 2017, p.328
  12. 1 2 Báez et al. 2017, p.319-323
  13. 1 2 Báez et al. 2017, p.325
  14. ↑ Sundt 1911, p.96
  15. ↑ Reichert 1907, p.80-81
  16. ↑ Báez et al. 2017, p.326-327
  17. 1 2 Báez et al. 2017, p.332
  18. 1 2 Báez et al. 2017, p.327
  19. ↑ Risse et al. 2008, p.4-5
  20. ↑ Risse et al. 2008, p.10
  21. ↑ Fernandez-Turiel, J. L.; Saavedra, J.; Perez-Torrado, F. J.; Rodriguez-Gonzalez, A.; Rejas, M.; Guillou, H.; Aulinas, M. (1 August 2021). "New ages, morphometric and geochemical data on recent shoshonitic volcanism of the Puna, Central Volcanic Zone of Andes: San Jerónimo and Negro de Chorrillos volcanoes". Journal of South American Earth Sciences. 109: 16. Bibcode:2021JSAES.10903270F. doi: 10.1016/j.jsames.2021.103270 . hdl: 10261/246123 . ISSN   0895-9811. S2CID   233645165.
  22. ↑ Sundt 1911, p.96
  23. ↑ Reichert 1907, p.79
  24. ↑ "An insight into the integral ceramics of Formative pottery in southern Puna". ResearchGate. Retrieved 2017-07-13.
  25. ↑ Muñoz, Santiago (1894). Jeografía descriptiva de las provincias de Atacama i Antofagasta (in Spanish). Impr. Gutenberg.
  26. ↑ Sundt 1911, p.85
  27. ↑ Sundt 1911, p.86
  28. ↑ Elías, Alejandra M.; Glascock, Michael D.; Olivera, Daniel E. (1 October 2018). "Obsidian circulation in south-central Andes after ca. 1100 BP: A contribution based on geochemical studies in Argentinean Southern Puna Plateau". Journal of Archaeological Science: Reports. 21: 344. doi:10.1016/j.jasrep.2018.08.002. ISSN   2352-409X. S2CID   134586458.
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.