Acotango

{{Short description|Mountain shared by Bolivia and Chile}}

{{Infobox mountain

| name = Acotango

| photo = Volcan Acotango and Cerro Capurata.jpg

| photo_caption = The volcanoes Acotango (left) and Capurata (right)

| elevation_m = 6052

| elevation_ref =

| parent_peak = Guallatiri

| prominence_m = 859

| prominence_ref=

| listing = List of mountains in the Andes

| location = Bolivia-Chile

| range = Andes

| map = Bolivia

| map_size = 250

| label_position = right

| coordinates = {{coord|18|22|56|S|69|02|52|W|type:mountain_region:CL_scale:100000|format=dms|display=inline,title}}

| range_coordinates =

| coordinates_ref =

| topo =

| type = Stratovolcano

| age =

| last_eruption = Pleistocene

| first_ascent = 10/14/1965 (first modern ascent) - Sergio Kunstmann, Pedro Rosende and Claudio Meier (Chile){{Cite journal|last=|first=|date=1966|title=AAJ (American Alpine Journal)|url=|journal=AAJ (American Alpine Journal)|volume=|pages=183|via=}}

| easiest_route = snow/ice climb

}}

Acotango is the central and highest of a group of stratovolcanoes straddling the border of Bolivia and Chile.{{Cite web|title=Catálogo GeoBolivia - GeoBolivia|url=https://geo.gob.bo/geonetwork/srv/spa/catalog.search#/search?resultType=details&sortBy=relevance&any=provincias&from=1&to=20|access-date=2020-04-30|website=geo.gob.bo}}{{Cite web|last=rbenavente|title=Biblioteca del Congreso Nacional {{!}} SIIT {{!}} Mapas vectoriales|url=https://www.bcn.cl/siit/mapas_vectoriales/index_html|access-date=2020-04-30|website=bcn.cl|language=en}} It is {{Convert|6052|m|ft|0}} high.{{Cite book|last=Biggar|first=John|url=https://www.worldcat.org/oclc/1260820889|title=The Andes a guide for climbers|date=2020|isbn=978-0-9536087-7-5|edition=5th|location=Castle Douglas, Scotland|oclc=1260820889}}{{efn|Other data from digital elevation models: SRTM yields {{convert|6037|m}}, ASTER {{convert|6023|m}} and TanDEM-X {{convert|6074|m}}.}}{{efn|The height of the nearest key col is {{convert|5201|m}}, leading to a topographic prominence of {{convert|859|m}} with a topographical dominance of 14.17%. Its parent peak is Guallatiri and the Topographic isolation is {{convert|6.2|km}}.}} The group is known as Kimsa Chata and consists of three mountains: Acotango, Umurata ({{Convert|5730|m|ft|0}}) north of it and Capurata ({{Convert|5990|m|ft|0}}) south of it.

The group lies along a north–south alignment. The Acotango volcano is heavily eroded, but a lava flow on its northern flank is morphologically young, suggesting Acotango was active in the Holocene."Acotango Volcano" nd Volcano Discovery http://www.volcanodiscovery.com/acotango.html Later research has suggested that lava flow may be of Pleistocene age.{{Cite GVP|name=Acotango|vn=355813}} Argon-argon dating has yielded ages of 192,000±8,000 and 241,000±27,000 years on dacites from Acotango.{{cite journal |last1=Sepúlveda |first1=José Pablo |last2=Aguilera |first2=Felipe |last3=Inostroza |first3=Manuel |last4=Reyes |first4=María Paz |title=Geological evolution of the Guallatiri volcano, Arica y Parinacota Region, northern Chile |journal=Journal of South American Earth Sciences |date=April 2021 |volume=107 |page=4 |doi=10.1016/j.jsames.2020.103117 |bibcode=2021JSAES.10703117S |s2cid=233072322 |language=en |issn=0895-9811|doi-access= }} Glacial activity has exposed parts of the inner volcano, which is hydrothermally altered.{{cite journal |last1=Watts |first1=Robert B. |last2=Clavero Ribes |first2=Jorge |last3=Sparks |first3=R. Stephen J. |title=Origen y emplazamiento del Domo Tinto, volcán Guallatiri, Norte de Chile |trans-title=The origin and emplacement of Domo Tinto, Guallatiri volcano, Northern Chile |language=Spanish |journal=Andean Geology |date=30 September 2014 |volume=41 |issue=3 |pages=558–588 |doi=10.5027/andgeoV41n3-a04 |doi-access=free |bibcode=2014AndGe..41c...4W }} Glacial moraines lie at an altitude of {{convert|4200|m}} but a present ice cap is only found past {{convert|6000|m}} of altitude.{{cite journal |last1=Ochsenius |first1=Claudio |title=La Glaciación Puna durante el Wisconsin, Desglaciación y Máximo Lacustre en la Transición Wisconsin-Holoceno y Refugios de Megafauna Postglaciales en la Puna y Desierto de Atacama |trans-title=Late Pleistocene Puna Glaciation, Deglaciation and High Lake-Levels during the Transition Wisconsin-Holocene, and Postglacial Megafauna Refuges in the Atacama Desert and Puna Regions |language=Spanish |journal=Revista de Geografía Norte Grande|date=1986|volume=13|pages=29–58 |url=http://revistanortegrande.cl/archivos/13/03_13_1986.pdf |accessdate=10 April 2016 |archive-url=https://web.archive.org/web/20160304083347/http://revistanortegrande.cl/archivos/13/03_13_1986.pdf|archive-date=2016-03-04 |url-status=dead}}

The volcano is a popular hiking route in the Sajama National Park and Lauca National Park. It is on the border of two provinces: Chilean province of Parinacota and Bolivian province of Sajama. Its slopes are within the administrative boundaries of two cities: Chilean commune of Putre and Bolivian commune of Turco.

To climb the summit from the Chilean side is dangerous due to land mines,{{Citation|chapter=65/48. Aplicación de la Convención sobre la prohibición del empleo, almacenamiento, producción y transferencia de minas antipersonal y sobre su destrucción|date=2010-12-31|chapter-url=http://dx.doi.org/10.18356/bf323eee-es|pages=30–33|publisher=UN|doi=10.18356/bf323eee-es |isbn=978-92-1-058036-6|access-date=2021-08-12 |title=Anuario de las Naciones Unidas Sobre Desarme 2010: Parte I }} however it is relatively safe to climb the summit from the Bolivian side.Andean Summits 2013 Acotango;One of the triplets {{cite web|url=http://www.andeansummits.com/content/acotango-one-tripplets |title=Acotango; one of the tripplets | |accessdate=2013-08-23 |url-status=dead |archiveurl=https://web.archive.org/web/20130723042534/http://andeansummits.com/content/acotango-one-tripplets |archivedate=2013-07-23 }} The southern ascent starts over a glacier and passes an abandoned copper mine.