Purupuruni
{{short description|Group of lava domes in southern Peru}}
{{Good article}}
{{Infobox mountain
| name = Purupuruni
| other_name = Purupurini
| photo =
| photo_size =
| photo_caption =
| elevation_m = 5315
| prominence_m =
| prominence_ref =
| range = Andes
| listing =
| translation =
| language =
| location = Peru, Tacna Region
| map = Peru
| range_coordinates =
| map_caption = Peru
| map_size = 200
| label_position =
| coordinates = {{coord|17.32|S|69.9|W|type:mountain_region:PE_scale:100000|format=dms|display=inline,title}}
| topo =
| type =
| age = Holocene
| first_ascent =
| easiest_route =
}}
Purupuruni is a group of lava domes in southern Peru and a correlative geological formation. They are among the many volcanoes that exist in Peru and whose activity has been associated with the subduction of the Nazca Plate beneath the South America Plate. Purupuruni is associated with a geothermal field and a caldera. Volcanic activity occurred during the Pleistocene 53,000 ± 8,000 years ago but also during the Holocene about 5,300 ± 1,100 years ago; today the volcano is considered to be a low hazard volcano but is being monitored nevertheless.
Geography and geomorphology
Purupuruni lies in the Cordillera Occidental{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=1}} {{convert|48|km}} north of the border with Chile,{{sfn|Vela|Cáceres|Calderón|Chijcheapaza|2016|p=20}} about {{convert|85|km}} away from Tacna{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=4}} and only about {{convert|70|km}} from the town of Tarata. The volcano is part of the {{lang|es|Monumento Natural de Los Volcanes de Mauri}} geopark.{{sfn|INGEMMET|2000|pp=277-278}} The term {{lang|ay|Phuru}} means dung in Aymara.
The Purupuruni volcano, also known as Purupurini,{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=4}} is a {{convert|0.85|km}} wide complex{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}} of four large lava domes at an elevation of {{convert|5117|m}}{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=4}} or {{convert|5315|m}}.{{sfn|Vela|Cáceres|Calderón|Chijcheapaza|2016|p=20}} The domes cover an area of about {{convert|3.5|-|7|km2}},{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=4}} are up to {{convert|200|m}}{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=17}}-{{convert|500|m}} high{{sfn|Cruz|Flores|Otero|Velarde|2024|p=23}} and are isolated and little eroded. The domes are accompanied by intrusions{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=4}} and lava and pyroclastic flow deposits.{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}}
The volcanism appears to come from fissure vents{{sfn|INGEMMET|2000|p=278}} and the volcanoes have been affected by faulting,{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}} such as the Pacollo fault.{{sfn|Cruz|Flores|Otero|Velarde|2024|p=9}} These deposits reach thicknesses of {{convert|10|m}} and also occur on neighbouring volcanic centres.{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=17}} Purupuruni has formed on the rim of a depression, which is surrounded by eroded Quaternary volcanoes and appears to be a {{convert|13|km}} wide caldera{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=4}} southwest of the domes.{{sfn|Velarde Quispe|Tavera|Vargas Alva|Villegas Lanza|2020|p=6}} The volcano lies east-southeast from Yucamane volcano and just south of the Mauri River;{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|loc=Maps}} the Mauri River is part of the Lake Titicaca watershed.{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}}
The Borateras geothermal field with about 40 separate manifestations is associated with Purupuruni and neighbouring volcanoes such as Coverane and Jaruma{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}} across the Mauri River and west from Purupuruni respectively.{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|loc=Map2}} The Borateras field is used as a spa at the Calachaca spa.{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=54}} The landscape is relatively dry and cold and thus vegetation is scarce.{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=1}}
Geology
The volcanic rocks are mainly andesitic{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}} and dacitic, and contain amphibole, biotite,{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=17}} olivine, plagioclase and pyroxene{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}} and are among the most differentiated volcanics in the area. They are part of the wider "Purupurini Volcanics", which are named after Purupuruni and also form other volcanoes in the region.{{sfn|Mendívil Echevarría|1965|p=58}}
= Geological context =
Rock formations in the region include the Mesozoic Yura Group sediments, the Toquepala intrusive rocks, the 30-24 million years old Tacaza volcanic rocks,{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=17}} the 24-10 million years old Huaylillas volcanic rocks and the 10-3 million years old Barroso volcanic rocks; Purupuruni is considered to be part of this Barroso formation.{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=19}} Purupuruni and neighbouring volcanic centres have formed on the Cretaceous sedimentary basement.{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=1}}
Volcanism in Peru occurs mainly in the southern part of the country, where there are about 300 separate volcanic systems including El Misti, Ubinas, Ticsani, Sabancaya and Huaynaputina.{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=8}} In the Tacna Region of Peru alone there are over 60 separate volcanoes, two of which, Tutupaca and Yucamane, have been active in historical time. In addition, there are a number of geothermal systems with temperatures of over {{convert|200|C}} which could be used to produce geothermal energy. Volcanic and geothermal activity in the region is a consequence of the subduction of the Nazca Plate beneath the South America Plate{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=1}} at a rate of about {{convert|7|-|9|cm/year|in/year}}.{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=2}}
Geologic history
The volcanic centres in the area including Purupuruni are of Miocene to Pliocene age,{{sfn|Chirif Rivera|Rivera Porras|Antayhua Vera|Cruz Pauccara|2012|p=1}} and appear to be of Pleistocene age.{{sfn|Vela|Cáceres|Calderón|Chijcheapaza|2016|p=20}} Purupuruni formed during the last 100,000 years and appears to have developed between two interglacials;{{sfn|Mendívil Echevarría|1965|p=22}} fission-track dating on glasses from Purupuruni has yielded ages of 53,000 ± 8,000 years ago but more recent surface exposure dating has yielded an age of 5,300 ± 1,100 years before present on one of the southern domes.{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=7}} The volcano is considered to be a low-hazard system{{sfn|Vela|Cáceres|Calderón|Chijcheapaza|2016|p=29}} and in 2018 the Peruvian Geological Institute announced it would begin monitoring Purupuruni and nine other volcanoes. Earthquake swarms in 2020 and 2021 do not appear to have been caused by volcanism;{{sfn|Antayhua Vera|Velarde Quispe|Vargas Alva|Tavera|2021|p=3}} they are instead linked to local fault activity.{{sfn|Antayhua Vera|Velarde Quispe|Vargas Alva|Tavera|2021|p=11}} Purupuruni appears to be the heat source for the Kovire geothermal field.{{sfn|Cruz|Flores|Otero|Velarde|2024|p=92}}
Glacial erosion took place on Purupuruni during the Pleistocene,{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=19}} leaving moraines on the domes{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=38}} although research published in 2019 has found that the domes have not been eroded by glaciers even though evidence of glaciation occurs in the wider area.{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=9}} Alluvial, glacial and fluvial deposits occur in the region,{{sfn|Cacya Dueñas|Vargas Rodríguez|Cruz Pauccara|2013|p=19}} with aeolian sediments consisting of volcanic ash mantling the volcanic structures.{{sfn|Bromley|Thouret|Schimmelpfennig|Mariño|2019|p=9}}
References
= Sources =
{{refbegin}}
- {{cite report|last1=Antayhua Vera |first1=Yanet Teresa |last2=Velarde Quispe |first2=Lizbeth |last3=Vargas Alva |first3=Katherine Andrea |last4=Tavera |first4=Hernando |last5=Villegas Lanza |first5=Juan Carlos |title=Actividad sísmica en el entorno de la falla Pacollo y volcanes Purupuruni – Casiri (2020 – 2021) |date=May 2021 |url=https://repositorio.igp.gob.pe/handle/20.500.12816/4944}}
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{{refend}}
{{Andean volcanoes}}
Category:Five-thousanders of the Andes