Nevado Tres Cruces

Nevado Tres Cruces is a massif of volcanic origin in the Andes Mountains on the border of Argentina and Chile. It has two main summits, Tres Cruces Sur at 6,748 metres (22,139 ft) and Tres Cruces Centro at 6,629 m (21,749 ft) and a third minor summit, Tres Cruces Norte 6,030 m (19,780 ft). Tres Cruces Sur is the sixth highest mountain in the Andes.

Nevado Tres Cruces
Tres Cruces from Ojos del Salado to the east. The higher south summit is on the left, the central summit on the right.
Highest point
Elevation6,748 m (22,139 ft)
Prominence1,422 m (4,665 ft) Edit this on Wikidata
Coordinates27.08°S 68.8°W / -27.08; -68.8[1]
Geography
Nevado Tres Cruces is located in Chile
Nevado Tres Cruces
Nevado Tres Cruces
Geology
Age of rockPleistocene

The volcano has an extended history of activity, going back at least 1.5 million years. A number of lava domes surround the complex and a number of craters lie on its summits. The main volcano is of rhyodacitic composition and has generated two major ignimbritic eruptions, one 1.5 million years ago and a second 67,000 years ago. The last eruption was 28,000 years ago, but the volcano is a candidate source for a Holocene eruption and could erupt again in the future.

Geography and geomorphology

Nevado Tres Cruces is located in the High Andes of Copiapo[2] and straddles the boundary between Chile (Atacama Region) and Argentina (Catamarca Province).[3][1] The Salar de Maricunga is located west of Nevado Tres Cruces,[2] the Almagro valley north and its tributary the Barrancas Blancas valley northeast of it. The international road between Chile and Argentina from Paso de San Francisco passes north of Nevado Tres Cruces; an unpaved road runs through the Barrancas Blancas valley.[4]

The volcano is massive, covering an area of about 1,000 square kilometres (390 sq mi),[1] and consists of a 10 kilometres (6.2 mi) long and 5 kilometres (3.1 mi) wide[2] north-south trending chain made up of at least three overlapping volcanoes.[5] These volcanoes have diameters of 4–5 kilometres (2.5–3.1 mi) and rise about 800–1,600 metres (2,600–5,200 ft) above the surrounding terrain.[6] The highest summit, and sixth-highest summit of South America,[7] of Nevado Tres Cruces is the 6,748 metres (22,139 ft) high[lower-alpha 1] southern summit, which is also the least eroded of the three volcanoes that make up Nevado Tres Cruces. The southern summit consists of two overlapping cones, the western and older one of which has two explosion craters while the eastern one is capped by a summit lava dome. The central volcano reaches an elevation of 6,629 metres (21,749 ft), has the steepest slopes and is tilted to the west.[6] The northern volcano has a summit elevation of 6,206 metres (20,361 ft)[11] and is capped by a glacially eroded, 1 kilometre (0.62 mi) wide crater.[6] There are two even more minor summits at the north end of the massif, Punta Torre 6,320 m (20,730 ft) and Punta Atacama 6,206 m (20,361 ft).[11]

The volcanoes are formed by explosion craters, lava domes including couleés, lava flows, tephra, and base surge and pyroclastic flow deposits.[5] Fallout of explosive eruptions cover the slopes of the southern summit[6] and deposits of a large Plinian eruption and its eruption column cover much of Nevado Tres Cruces and its surroundings.[12] Normal faults[lower-alpha 2] cut across the volcanic structures[2] and a north-northwest trending fault system appears to have directed the development of the three volcanoes.[14]

Domo del Indio on the southeastern flank is 3.2 by 1.8 kilometres (2.0 mi × 1.1 mi) wide and 235 metres (771 ft) high. Between it and Nevado Tres Cruces lies a 2 by 1.5 kilometres (1.24 mi × 0.93 mi) wide and 150 metres (490 ft) deep explosion crater that contains the La Espinilla dome, which is 45 metres (148 ft) high and 200–250 metres (660–820 ft) wide.[15] Another lava dome is known as Domo las Vicuñas.[16] The Tres Cruces Ignimbrite was erupted by Nevado Tres Cruces[17] and lies between Nevado Tres Cruces and Ojos del Salado and reaches a thickness of 100 metres (330 ft).[18] It covers a surface area of 81.31 square kilometres (31.39 sq mi).[19] The ignimbrite consists of pumice and volcanic ash,[17] is poorly welded and has a low crystal content.[19]

These edifices rise over older volcanoes, which crop out north of Nevado Tres Cruces in the form of the volcanoes Cristi (5,900 metres (19,400 ft) high[16]), Lemp and Rodrigo.[2] The latter has a caldera at 5,950 metres (19,520 ft) elevation.[16] Lemp is located just south of Rodrigo.[20] Puntiagudo crops out south of Nevado Tres Cruces.[2] The older structures are smoothened by erosion and lack primary features.[21] A thick and large lava flow crops out west of the volcano; it has a surface area of 3.5 by 5.5 square kilometres (1.4 sq mi × 2.1 sq mi) and a thickness of 150–200 metres (490–660 ft).[2] Three older lava domes, all heavily eroded, are found on the western flank.[22]

Glaciation

Small glaciers occur on Nevado Tres Cruces[23] on the eastern and southern sides[24] above 5,500 metres (18,000 ft) elevation. They are best developed above 5,750 metres (18,860 ft) elevation and consist of small ice bodies (none exceeding 1 square kilometre (0.39 sq mi)) in glacial cirques and at the edges of lava flows.[2] One of these is hosted in a cirque on the southeastern flank of the southern summit.[6] Ice area was constant between 1937 and 1956[25] but declined by almost half between 1985 and 2016.[26] Non-moving ice without crevasses has been found on the northern summit,[27] and there are debris-covered glaciers on the volcanoes. [28] Some sources however deny that any glacier occurs on Nevado Tres Cruces.[29]

Moraines occur above 4,400 metres (14,400 ft) elevation[2] and a well-developed terminal moraine at the foot of Nevado Tres Cruces, at 4,200 metres (13,800 ft) elevation, has been broken by the Lamas River.[30] There are cirques at 5,500 metres (18,000 ft) on the eastern sides of Nevado Tres Cruces[31] and traces of periglacial occur.[32] Presently, the equilibrium line altitude lies at about 5,800 metres (19,000 ft); during the last glacial maximum the equilibrium line altitude descended to 5,500 metres (18,000 ft).[8]

Geology

Off the western coast of South America, the Nazca Plate subducts into the Peru-Chile Trench underneath the South America Plate at a rate of 7–9 centimetres per year (2.8–3.5 in/year). The subduction has given rise to three volcanic belts in the Andes, from north to south these are the Northern Volcanic Zone, the Central Volcanic Zone (CVZ) and the Southern Volcanic Zone. These are separated by gaps where Pleistocene and Holocene volcanism is absent and where the downgoing plate sinks into the mantle at a shallow angle,[33] squeezing out the overlying asthenosphere.[34]

Nevado Tres Cruces is part of the CVZ,[35] which spans Peru, Bolivia, Argentina and Chile and features over 1100 volcanoes. These old but uneroded volcanoes[36] comprise both stratovolcanoes and lava dome complexes, as well as monogenetic volcanoes and calderas which have produced large ignimbrites. Among the better known volcanoes are Acamarachi, Aguas Calientes, Arintica, Aucanquilcha, Cerro Bajo, Cerro Escorial, Chiliques, Colachi, Cordon de Puntas Negras, Escalante, Guallatiri, Guayaques, Irruputuncu, Isluga, Lascar, Lastarria, Licancabur, Llullaillaco, Olca-Paruma, Ollagüe, Ojos del Salado, Parinacota, Pular, Putana, San Pedro, Sierra Nevada de Lagunas Bravas, Socompa, Taapaca and Tacora. These volcanoes are remote and thus, aside from potential impacts of ash clouds on aerial travel, they do not constitute a major threat to humans.[35]

Nevado Tres Cruces together with neighbouring El Fraile, El Muertito, El Muerto, El Solo, Nevado de Incahuasi, Nevado San Francisco and Ojos del Salado forms the Ojos del Salado volcanic chain. It is a group of mostly dacitic[37] volcanoes that is oblique with respect to the local trend of Pleistocene-Holocene volcanoes[5] and was active during the last one million years.[38] During the Oligocene and Miocene volcanic activity occurred in the Maricunga Belt, then around 6 million years ago it migrated eastward.[34] South of Nevado Tres Cruces lies the Los Patos volcano.[39]

Composition

Nevado Tres Cruces has erupted rocks ranging from dacite to rhyodacite[5] which define a potassium-rich calc-alkaline suite.[15] They feature biotite and hornblende phenocrysts and there is evidence that magma mixing took place during the genesis of the magmas.[6] Older volcanic rocks are andesites with clinopyroxene, hornblende, labradorite and orthopyroxene as phenocryst phases.[21] The occurrence of obsidian has been reported.[40]

Climate and vegetation

Strong winds, intense insolation, high diurnal and seasonal temperature variations characterize the region. At high elevations, precipitation falls mainly in winter in the form of snow and hail.[41] The lack of visible life in the hyperarid region has led to numerous travellers deeming it a "lunar landscape".[10] There are wetlands associated with the Rio Lamas on Nevado Tres Cruces. The area is part of the Nevado Tres Cruces National Park[42] created in 1994.[43]

Human history

The volcano was climbed on February 24, 1937, by members of the Second Polish Andean Expedition, Stefan Osiecki and Witold Paryski.[44]

Eruption history

Nevado Tres Cruces was active during the Pliocene and Pleistocene,[1] with the oldest activity pre-dating 1.5 million years ago.[5] Potassium-argon dating has yielded ages of 3.4±0.5 and 4.9±0.4 million years ago.[21] Rodrigo erupted 4.4±0.6 million years ago,[45] Lemp 2.8±0.3 million years ago and Cristi 2.5±1.3 million years ago.[14] The three western lava domes were emplaced 2.1±0.3 million years ago.[15] The western lava flow is dated to be 1.4±0.4 million years old.[6] The well-preserved Indio and La Espinilla lava domes were erupted 350,000±40,000 and 168,000±6,000 years ago, respectively.[15] Volcanic activity took place in two stages separated by a long pause,.[46] The time-averaged growth rate of 0.01–0.02 cubic kilometres per millennium (0.0024–0.0048 cu mi/ka)[47] is slow for a volcano on a convergent margin.[15]

1.5 million years ago an explosive eruption produced pyroclastic flows in the western part of the volcano. The flows are now covered with glacial and alluvial sediments and form a fan. A large explosive eruption 67,000±9,000 years ago deposited pyroclastic flows east and southeast of Nevado Tres Cruces. These pyroclastic flows form deposits extensive surrounding Ojos del Salado - to which they were originally attributed - and a 15 metres (49 ft) thick base surge deposit is also linked to this eruption.[5][12][lower-alpha 3]

Most recent eruption and hazards

The last eruption 28,000±22,000 years ago[49] produced the summit dome of the southern summit.[6] There are no known historical eruptions and the volcano is not considered to be active.[5] In light of the long repose periods relative to the date of the last eruption, future eruptions are possible but are unlikely to have high impact, as there is virtually no infrastructure in the region[15] other than the International Route CH-31.[50]

Based on geochemical data, Nevado Tres Cruces has been proposed as the source of a tephra layer in the Bolson de Fiambalá[51] that has also been identified in the Tafi del Valle area and the Valles Calchaquies.[52] The eruption producing this tephra fall took place about 600-700 AD.[53] Archeological observations in the Fiambalá region indicates that this tephra fall event had substantial impact on local communities.[54]

Notes
  1. Other estimates are 6,330 metres (20,770 ft)[8] and 6,620 metres (21,720 ft),[1] and 6,030 metres (19,780 ft) for the northern summit.[9] Owing to the region being extremely remote, elevations are often uncertain.[10]
  2. A normal fault is an usually steep fault where the hanging wall is moving downward with respect to the footwall.[13]
  3. In light of the descriptions in Moreno and Gibbons 2007,[5] Kay, Coira and Mpodozis 2008[14] and Rubiolo et al. 2003 this eruption appears to be the source of the Tres Cruces Ignimbrite.[17] Other dates for that ignimbrite, obtained by argon-argon dating, are 190,000±30,000, 520,000±150,000[17] and 520,000±70,000 years ago.[48]

References
  1. "Tres Cruces". Global Volcanism Program. Smithsonian Institution.
  2. Gardeweg et al. 2000, p. 291.
  3. Parajón, Hernán (11 August 2019). "EL RESCATE. LA TOMA RÁPIDA DE DECISIONES CON BAJOS MÁRGENES DE ERROR". Perspectivas de las Ciencias Económicas y Jurídicas (in Spanish). 9 (2): 95. ISSN 2250-4087.
  4. Nüsser & Dame 2015, p. 68.
  5. Moreno & Gibbons 2007, p. 154.
  6. Gardeweg et al. 2000, p. 292.
  7. Rundel, Philip W.; Kleier, Catherine C. (2014). "Parque Nacional Nevado de Tres Cruces, Chile: A Significant Coldspot of Biodiversity in a High Andean Ecosystem" (PDF). fs.fed.us. p. 3.
  8. Mark, B.G.; Harrison, S.P.; Spessa, A.; New, M.; Evans, D.J.A.; Helmens, K.F. (September 2005). "Tropical snowline changes at the last glacial maximum: A global assessment". Quaternary International. 138–139: 18. Bibcode:2005QuInt.138..168M. doi:10.1016/j.quaint.2005.02.012. ISSN 1040-6182.
  9. Gspurning, Lazar & Sulzer 2006, p. 61.
  10. Nüsser & Dame 2015, p. 66.
  11. Almaraz, Guillermo. "Tres Cruces Norte".
  12. Gardeweg et al. 2000, p. 293.
  13. Nahm, A. L. (2015). "Normal Fault". In Hargitai, H.; Kereszturi, Á. (eds.). Encyclopedia of Planetary Landforms. Springer. pp. 1458–1466. doi:10.1007/978-1-4614-3134-3_519. ISBN 978-1-4614-3133-6.
  14. Kay, Coira & Mpodozis 2008, p. 170.
  15. Gardeweg et al. 2000, p. 294.
  16. "Tres Cruces". Global Volcanism Program. Smithsonian Institution., Synonyms & Subfeatures
  17. Rubiolo et al. 2003, p. 45.
  18. Rubiolo et al. 2003, p. 44.
  19. Guzmán et al. 2014, p. 176.
  20. Gardeweg et al. 2000, p. 295.
  21. Rubiolo et al. 2003, p. 40.
  22. Gardeweg et al. 2000, pp. 293–294.
  23. Barcaza, Gonzalo; Nussbaumer, Samuel U.; Tapia, Guillermo; Valdés, Javier; García, Juan-Luis; Videla, Yohan; Albornoz, Amapola; Arias, Víctor (July 2017). "Glacier inventory and recent glacier variations in the Andes of Chile, South America". Annals of Glaciology. 58 (75pt2): 174. Bibcode:2017AnGla..58..166B. doi:10.1017/aog.2017.28. ISSN 0260-3055.
  24. Nüsser & Dame 2015, pp. 68–69.
  25. Lliboutry, L.; González, O.; Simken, J. (1958). "Les glaciers du désert chilien". Extrait des Comptes Rendus et Rapports. Assemblee Generale de Toronto (in French). 4: 298.
  26. Flores, Betzabé; García, Ayón; Ulloa, Christopher (December 2018). Evolución espacial y temporal de glaciares descubiertos en la Región de Atacama, Chile (PDF). 15th Chilean Geological Congress (in Spanish). p. 742. Retrieved 13 November 2022.
  27. Gspurning, Lazar & Sulzer 2006, p. 69.
  28. García et al. 2017, p. 7.
  29. Rivera, Andrés; Casassa, Gino; Acuña, César; Lange, Heiner (1 January 2000). "Variaciones recientes de glaciares en Chile". Investigaciones Geográficas (in Spanish) (34): ág. 29–60. doi:10.5354/0719-5370.2000.27709. ISSN 0719-5370.
  30. Brüggen, J. (1 April 1929). "Zur Glazialgeologie der chilenischen Anden". Geologische Rundschau (in German). 20 (1): 5. Bibcode:1929GeoRu..20....1B. doi:10.1007/BF01805072. ISSN 1432-1149. S2CID 128436981.
  31. Haselton, Kirk; Hilley, George; Strecker, Manfred R. (March 2002). "Average Pleistocene Climatic Patterns in the Southern Central Andes: Controls on Mountain Glaciation and Paleoclimate Implications". The Journal of Geology. 110 (2): 221. Bibcode:2002JG....110..211H. doi:10.1086/338414. ISSN 0022-1376. S2CID 18111576.
  32. García et al. 2017, p. 10.
  33. Moreno & Gibbons 2007, p. 148.
  34. Goss, Kay & Mpodozis 2011, p. 103.
  35. Moreno & Gibbons 2007, p. 150.
  36. Moreno & Gibbons 2007, p. 147.
  37. Grosse et al. 2018, p. 5.
  38. Goss, Kay & Mpodozis 2011, p. 104.
  39. Kay, Coira & Mpodozis 2008, p. 166.
  40. Seelenfreund, Andrea; Miranda, Javier; Dinator, María Inés; Morales, J. Roberto (December 2005). "CARACTERIZACIÓN DE OBSIDIANAS DEL NORTE Y CENTRO SUR DE CHILE MEDIANTE ANÁLISIS DE FLUORESCENCIA DE RAYOS X". Chungará (Arica). 37 (2): 247. doi:10.4067/S0717-73562005000200009. ISSN 0717-7356.
  41. Nüsser & Dame 2015, p. 67.
  42. Espinosa, Marión; Bustamante, Ana María; Orellana, Lesly; Henríquez, Gabriel; Ortíz, Gabriel; Altamirano A., Tania V.; Poblete, Verónica; Cárdenas Gasmuri, María Ilia; Mancilla, Bárbara (2013). Recorriendo los humedales altoandinos de Arica a Atacama : vida y refugio de la biodiversidad. (Pub. CIREN N°175) (Report) (in Spanish).
  43. Nüsser & Dame 2015, p. 74.
  44. Marek, Aneta (2016). "Andy jako rejon eksploracji górskiej Polaków do 1989 r." (PDF). Słupskie Prace Geograficzne (in Polish). 13: 89. Archived from the original (PDF) on 16 June 2023.
  45. Goss, Adam R.; Kay, Suzanne Mahlburg; Mpodozis, Constantino (November 2013). "Andean Adakite-like high-Mg Andesites on the Northern Margin of the Chilean–Pampean Flat-slab (27–28·5°S) Associated with Frontal Arc Migration and Fore-arc Subduction Erosion". Journal of Petrology. 54 (11): 2198. doi:10.1093/petrology/egt044.
  46. Grosse et al. 2018, p. 19.
  47. Grosse et al. 2018, p. 20.
  48. Guzmán et al. 2014, p. 187.
  49. Grosse et al. 2018, p. 21.
  50. Amigo, Álvaro R.; Bertin, Daniel U.; Orozco, Gabriel L. (2012). Peligros volcánicos de la Zona Norte de Chile (PDF) (Report). Carta geológica de Chile: Serie Geología Ambiental (in Spanish). Vol. 17. SERVICIO NACIONAL DE GEOLOGÍA Y MINERÍA. p. 23. ISSN 0717-7305. Retrieved 20 August 2021.
  51. Fernandez-Turiel et al. 2019, p. 22.
  52. Fernandez-Turiel et al. 2019, p. 23.
  53. Ratto, Norma Rosa; Aranda, Claudia; Luna, Leandro (30 June 2019). "Bioarqueología de Las Papas (Departamento Tinogasta, Catamarca): primeros resultados". Revista del Museo de La Plata (in Spanish). 4 (1): 103–120. doi:10.24215/25456377e071. ISSN 2545-6377. S2CID 198756179.
  54. Ratto, Norma; Orgaz, Martín; Coll, Luis; Feely, Anabel (December 2019). "Vulcanismo regional y su impacto en el bolsón de Fiambalá (Departamento Tinogasta, Catamarca): el caso del sitio Cardoso". Relaciones de la Sociedad Argentina de Antropología (in Spanish). tomo 44 (2): 327. ISSN 1852-1479.

Sources
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