Cueros de Purulla

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.

Cueros de Purulla
Cueros de Purulla
Highest point
Coordinates26°33′S 67°49′W [1]

Geography and geomorphology

The volcano lies in Catamarca Province of Argentina[2] 60–70 kilometres (37–43 mi) southeast of Antofagasta de la Sierra.[3] Cerro Blanco volcano lies 25 kilometres (16 mi) south of Cueros de Purulla.[1]

It is the northern of two lava domes which lie at the southern end of the Sierra de Calalaste.[4] The dome is accompanied by ignimbrites[1] and a debris deposit consisting of obsidian lies at the foot of the dome.[4] Two volcanic fallout units are associated with Cueros de Purulla. A lower fallout unit consisting of lapilli and volcanic ash extends several kilometres from the volcano, and remnants occur as far as 180 kilometres (110 mi) from it.[5] The upper unit is formed by ignimbrites and pyroclastic density current deposits.[6]

Composition and ores

Volcanic rocks erupted at Cueros de Purulla include rhyolite. Mineralogically, the rocks contain allanite, amphibole, apatite, biotite, clinopyroxene, epidote, feldspar, ilmenite, magnetite, muscovite, quartz, titanite and zircon.[6] For the past five millennia,[7] the volcano has been used as a source of obsidian, which occurs at 4,380 metres (14,370 ft) in the form of blocks and nodules of various colours, and is of high quality.[3] Reportedly, gold and silver can be found at the volcano.[8][9]

Eruption history

The lava dome at Cueros de Purulla is 400,000 ± 100,000 years old.[10] A large eruption occurred during the Holocene, 7820 years before present (i.e. about 5870 BC).[11] Deposits from this eruption form the Cerro Paranilla Ash in the Calchaquí Valleys.[12] The eruption was highly explosive, forming a buoyant cloud[13] and depositing tephra as far as Cafayate in the Salta Province.[14]

References
  1. Fernandez-Turiel et al. 2019, p. 4.
  2. Escola, Elías & Cohen 2016, p. 216.
  3. Flores, Marina Cecilia; Balesta, Bárbara María (2014). "Avances en la Identificación de Obsidianas Utilizadas en el Valle de Hualfín (Depto. De Belén, Catamarca, Argentina) Durante el Periodo de Desarrollos Regionales/Inka". Estudios Atacameños (49): 5–18. doi:10.4067/S0718-10432014000300002. ISSN 0718-1043.
  4. Seggiaro, Raúl E.; Hongn, Fernando D.; Castillo, Alfredo; Pereyra, Fernando Xavier; Villegas, Daniela; Martínez, Liliana; González, Osvaldo Edgar (2006). Hoja Geológica 2769-II Paso San Francisco. Servicio Geológico Minero Argentino. Instituto de Geología y Recursos Minerales. p. 26.
  5. Fernandez-Turiel et al. 2019, p. 6.
  6. Fernandez-Turiel et al. 2019, p. 7.
  7. Escola, Elías & Cohen 2016, p. 219.
  8. Donnari, Eva I.; Peralta, Eduardo H.; Segal, Susana J.; Zanettini, Juan Carlos M.; Maksaev, Víctor; Mpdozis, Constantino (1994). "Mapa Metalogenético de la Frontera Argentino-Chilena entre los 22º y 34º de Latitud Sur". Anales del SEGEMAR: 22.
  9. Roy, R.; Cassard, D.; Cobbold, P. R.; Rossello, E. A.; Billa, M.; Bailly, L.; Lips, A. L. W. (1 November 2006). "Predictive mapping for copper–gold magmatic-hydrothermal systems in NW Argentina: Use of a regional-scale GIS, application of an expert-guided data-driven approach, and comparison with results from a continental-scale GIS". Ore Geology Reviews. 29 (3): 286. doi:10.1016/j.oregeorev.2005.10.002. ISSN 0169-1368.
  10. Kay, Suzanne Mahlburg; Coira, Beatriz; Mpodozis, Constantino (August 2006). LATE NEOGENE VOLCANISM IN THE CERRO BLANCO REGIONOF THE PUNA AUSTRAL, ARGENTINA (~26.5°S, ~67.5°W) (PDF). XI Congreso Geologico Chileno. Retrieved 23 January 2020.
  11. Osterrieth, Margarita; Alvarez, María Fernanda; Gallardo, Juan Fernando; Saavedra, Julio; Fernandez-Turiel, Jose-Luis; Rodriguez-Gonzalez, Alejandro; Perez-Torrado, Francisco J.; Rejas, Marta (10 July 2019). "Palaeoenvironmental use of silicophytoliths in soils and palaeosols associated with Holocene volcanic ash deposits in north-western Argentina". Quaternary International. 522: 103. Bibcode:2019QuInt.522..103O. doi:10.1016/j.quaint.2019.07.001. ISSN 1040-6182.
  12. Osterrieth, Margarita; Alvarez, María Fernanda; Gallardo, Juan Fernando; Saavedra, Julio; Fernandez-Turiel, Jose-Luis; Rodriguez-Gonzalez, Alejandro; Perez-Torrado, Francisco J.; Rejas, Marta (10 July 2019). "Palaeoenvironmental use of silicophytoliths in soils and palaeosols associated with Holocene volcanic ash deposits in north-western Argentina". Quaternary International. 522: 104. Bibcode:2019QuInt.522..103O. doi:10.1016/j.quaint.2019.07.001. ISSN 1040-6182.
  13. Fernandez-Turiel et al. 2019, p. 21.
  14. Fernandez-Turiel et al. 2019, p. 3.

Sources
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