Earth:La Hoyada volcanic complex
Template:Coord/display/intitle La Hoyada is a volcanic complex in the Andes, directly southwest of Cerro Blanco.[1]
The volcanic complex reaches an altitude of approximately 3,800 metres (12,500 ft).[2] Breccia, ignimbrites, lava domes and lava flows have been described at La Hoyada.[1] The ignimbrites cover a surface area of 5 square kilometres (1.9 sq mi).[3] The volcanic complex has been affected by faulting.[4]
Ignimbrites erupted at La Hoyada have been described as moderately welded andesites,[3] of green-grey colour.[5] The intermediate composition of dykes at La Hoyada contrasts with that of other volcanic rocks associated with extensional tectonics in the Puna, which tend to be of mafic composition.[6] Some of the rocks underwent supergene mineralization later.[4] The La Hoyada mine has yielded Cu and Pt.[7]
Paleozoic rocks form the basement beneath Cerro Blanco, which also partly covers La Hoyada.[8] Neoproterozoic and Ordovician sequences are also found at La Hoyada.[9] Sometimes both volcanic centres are considered to be the same volcano.[2] La Hoyada is usually considered a back-arc volcanic centre,[10] and has been associated with extensional tectonics.[6]
The volcanic complex was active in the Miocene and Pliocene.[1] An age of 7.04 ± 0.03 million years ago has been determined for the ignimbrites.[5] Another date for the complex is 9.8 ± 0.6 million years ago.[11] Two distinct volcanic events have been dated 7.4-2.42 million years ago.[12]
References
- ↑ 1.0 1.1 1.2 Brunori et al. 2013, p. 280.
- ↑ 2.0 2.1 de Silva, S. L.; Spagnuolo, M. G.; Bridges, N. T.; Zimbelman, J. R. (31 October 2013). "Gravel-mantled megaripples of the Argentinean Puna: A model for their origin and growth with implications for Mars". Geological Society of America Bulletin 125 (11–12): 1913. doi:10.1130/B30916.1.
- ↑ 3.0 3.1 Guzmán et al. 2014, p. 175.
- ↑ 4.0 4.1 Montero Lopez et al. 2010, p. 55.
- ↑ 5.0 5.1 Guzmán et al. 2014, p. 185.
- ↑ 6.0 6.1 Montero Lopez et al. 2010, p. 48.
- ↑ Beder, Roberto (April 1927). "Los yacimientos minerales de la Republica Argentina relacionados con las rocas igneas de las diferentes epocas geologicas" (in es). https://revistas.unc.edu.ar/index.php/REUNC/article/viewFile/6707/7788.
- ↑ Brunori et al. 2013, p. 281.
- ↑ Montero Lopez et al. 2010, p. 51.
- ↑ Álvarez, Orlando; Gimenez, Mario; Folguera, Andres; Spagnotto, Silvana; Bustos, Emilce; Baez, Walter; Braitenberg, Carla (November 2015). "New evidence about the subduction of the Copiapó ridge beneath South America, and its connection with the Chilean-Pampean flat slab, tracked by satellite GOCE and EGM2008 models". Journal of Geodynamics 91: 78. doi:10.1016/j.jog.2015.08.002.
- ↑ Schoenbohm, Lindsay M.; Strecker, Manfred R. (October 2009). "Normal faulting along the southern margin of the Puna Plateau, northwest Argentina". Tectonics 28 (5): 5. doi:10.1029/2008TC002341.
- ↑ Montero Lopez et al. 2010, p. 71.
Sources
- Montero Lopez, M.C.; Hongn, Fernando D.; Strecker, Manfred R.; Marrett, Randall; Seggiaro, Raúl; Sudo, Masafumi (October 2010). "Late Miocene–early Pliocene onset of N–S extension along the southern margin of the Central Andean Puna Plateau: Evidence from magmatic, geochronological and structural observations". Tectonophysics 494 (1–2): 48–63. doi:10.1016/j.tecto.2010.08.010.
- Guzmán, Silvina; Grosse, Pablo; Montero-López, Carolina; Hongn, Fernando; Pilger, Rex; Petrinovic, Ivan; Seggiaro, Raúl; Aramayo, Alejandro (December 2014). "Spatial–temporal distribution of explosive volcanism in the 25–28°S segment of the Andean Central Volcanic Zone". Tectonophysics 636: 170–189. doi:10.1016/j.tecto.2014.08.013.
- Brunori, C.A.; Bignami, C.; Stramondo, S.; Bustos, E. (August 2013). "20 years of active deformation on volcano caldera: Joint analysis of InSAR and AInSAR techniques". International Journal of Applied Earth Observation and Geoinformation 23: 279–287. doi:10.1016/j.jag.2012.10.003.
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