Sara Sara is a 5,505-metre-high (18,061 ft) volcano lying betweenLake Parinacochas and theOcoña River inPeru.[3] It is situated in the provinces ofParinacochas andPaucar del Sara Sara. The volcano formed during thePleistocene during four different stages of volcanic activity, which constructed a volcanic edifice with an oval outline consisting oflava flows andlava domes. The volcano was glaciated during thelast glacial maximum; it may still feature glaciers. The last eruption was about 14,000 years ago and future eruptions are possible. The volcano was worshipped by the local population, and anIncamummy of a 15-year old girl was found on the summit by archaeologists.
Sara Sara lies within theCordillera Ampato [es] sub-range of theAndes.[4] Administratively, it is located in theParinacochas andPaucar del Sara Sara provinces of theAyacucho Region,Peru.[5] The town ofPausa lies 12 kilometres (7.5 mi) away from the volcano, andagriculture occurs in the valleys of the area.[6] A disused road passes over the southern flank of the volcano and reaches an elevation of 4,600 metres (15,100 ft).[7]
The volcano is 5,505 metres (18,061 ft) high[8] and has an oval outline;[9] the summit lies at the southern end of a north-northwest-south-southeast trending summit ridge.[7] It consists of a complex oflava domes and lava flows superposed on olderstratovolcanoes[10] and has a total volume of 20–25 cubic kilometres (4.8–6.0 cu mi), with the edifice rising about 1 kilometre (0.62 mi) above the surrounding terrain.[11] The vents are aligned in north-northeast-south-southwest direction and are accompanied by lateral lava domes. These vents were the source of lava flows and block-and-ash flows generated by the collapse of lava domes.[12] Thick ash deposits underlie viscouslava flows that define the "Mollebamba Volcanics"[7] and reach lengths of 15 kilometres (9.3 mi).[13] Apyroclastic cone of recent age is found on the mountain[14] and a recent lava flow descends the eastern flank.[3] The western flank is heavily eroded.[9] West of the volcano isLake Parinacochas to its east is theOcoña River.[3]
Glacialcirques,[15]glacial valleys[16] and numerousmoraines surround the volcano.[17] Two past glaciations have been described, "Sara Sara II" which descended to about 4,500 metres (14,800 ft) elevation and also encompassed several peaks south of Sara Sara such as the 4,703 metres (15,430 ft) high Cerro Puca Puca, and "Sara Sara I" which has left moraine networks at lower elevations especially on the southwestern flank. The lowest moraines on the western flank occur at 4,000–4,100 metres (13,100–13,500 ft) while these on the eastern flank only reach 4,300 metres (14,100 ft), presumably because of the effects of later volcanism that erased other moraines.[18] Some of these encompass closed depressions.[19] A third set of moraines at higher elevations appears to correspond to theneoglacial.[20]Pleistocene moraines occur mostly on the western side of the volcano andHolocene ones on the eastern.[21] Thelast glacial maximum at Sara Sara occurred between 24,000 and 17,000 years ago[22] and theequilibrium line altitude descended to 4,500–4,800 metres (14,800–15,700 ft).[4]
Presently, it reaches 5,200 metres (17,100 ft) elevation at Sara Sara.[23] The mountain has been calledglaciated,[24] with an ice cap covering approximately 20 square kilometres (7.7 sq mi),[3] and alternatively, it has been stated that it only has a temporary snow cover.[15] Activerock glaciers extend below the snowline on the western and northern flanks, and inactive rock glaciers are found at lower elevations.[7] Water used forirrigation originates at Sara Sara's foot.[25]
Thebasement is formed byPrecambrian andPaleozoic rocks, which are covered byMesozoic andCenozoic sediments and volcanites.[10] The volcano is part of a 30 kilometres (19 mi) long,fault-controlled chain of volcanoes, which includes Cerro Grande, Yarihuato, Puca Ccasa, Sara Sara, Puca Puca and Cerro Queñuapunco.[10] A major geologicallineament known as the Sara Sara lineament[30] runs across the volcano in northwest-southeast direction.[31] Several faults cross the edifice in the same direction,[21] and some were active during the Holocene.[32]
A depression west of Sara Sara which contains theLaguna Parinacochas[33] may be the source of the regional Caraveliignimbrite[34] that was emplaced 8-9 million years ago.[35] This depression constitutes the 25 by 35 kilometres (16 mi × 22 mi) wide Incahuasicaldera, which may be connected to the magmatic system of Sara Sara.[36]
The climate showsaltitudinal zonation, with temperatures ranging from 20–6 °C (68–43 °F) in the valleys to freezing temperatures above 5,200 metres (17,100 ft). Precipitation is seasonal and mostly falls during summer, at higher elevations in the form of hail and snow[42] which covers the ground for months. There are no closeweather stations, but above 4,500 metres (14,800 ft) elevation the climate is always cold with temperatures never rising above 5 °C (41 °F).[43]
Trees grow at lower elevations, while onlyichu andquinua are present above 4,000 metres (13,000 ft).Alfalfa andmaize are cultivated at lower altitudes.[42] Animal husbandry, small commerce and tourism complete the economic activities of the region.[43]
Sara Sara was active during the last 2 million years[3] and produced the lower Barroso and Lampa Volcanics.[5] Fresh lava and pyroclastic flows imply recent activity.[6] The volcanic activity has been subdivided into four stages:[44]
Some publications define a first stage featuring lava flow and lava dome emissions.[45]
During the second stagelava domes grew and collapsed on the volcano, one such event occurred 162,000±20,000 years ago on the eastern flank.[46]
The third stage consisted ofdacitic lava flows that built the actual cone of the volcano, beginning 63,000-58,000 years ago.[46]
Sometimes considered part of the third stage,[48] the fourth stage is subdivided into two sub-stages before and after 64,000 years ago.[41] The last stage produced 14 kilometres (8.7 mi) longlava flows from[44] a cone named Yana Ranra on the eastern flank.[49] This flow is dated to 14,000±4,000 years ago.[37]
Two pyroclastic flows were dated to 44,500 and 49,200 years before present[50] and lava flows with ages of 340,000±60,000 to 50,000±10,000 years ago.[51] Sara Sara is currently classified as adormant volcano[5] and there isseismic activity.[52] The occurrence offumarolic activity was reported in 1963.[3]Hot springs are found northeast of Sara Sara in the Quilcata valley and close to the town of Chacaraya, implying the presence of a shallowmagma chamber.[6]
The volcano is considered to be "moderately dangerous" by the Peruvian Geological Service.[53][54] Future eruptions may endanger a population of 12,000[22]-8,000 around the volcano, which would be threatened bylahars,pyroclastic flows andtephra fallout.[3] Aside from Pausa, other towns andLake Parinacochas (an important source of water for the region) are located close to the volcano.[6]Volcanic hazard maps have been published.[55] Since 2018, the volcano is monitored by the Peruvian Geological Service;[56] Macedo Sánchez 2016 recommendedseismic and other monitoring techniques for Sara Sara.[57]
Sara Sara and Lake Parinacochas (foreground) as seen fromInka Wasi
The mountain was worshipped by local populations in and beforeInca time, and the Inca performedhuman sacrifices on it.[58] DuringInca times it was part of theKuntisuyu province.[59]
According to the writings of a cleric Cristóbal de Albornoz, who beginning in 1570 wrote about local religious practices, the local population considered Sara Sara a sacred mountain and offered gold, silver, animals and servants to it.[58] In 1996, archaeologists discovered a burial in a collapsed structure just northeast of the summit and recovered a body.[60] Thismummy was nicknamed "Sarita" and appears to be a 15-year old girl.[61] It was accompanied by the remnants of offerings and the ice surrounding the body had melted. Additional offerings such as allama and asilver object were also recovered from the summit.[60]
Stone walls are found on the ridge at the summit of Sara Sara.[62] They were initially described in 1982 by the archeologist Johan Reinhard, who described them on the northern summit.[60] In 1941,copper objects were found on its flanks.[62] The Yanapunkucave at 5,000 metres (16,000 ft) elevation features bones andceramics from theInca andWari cultures. Incaptiana is a site at the top of a hill at 4,565 metres (14,977 ft) elevation where Inca buildings were identified.[60]
^abSmith, Jacqueline A.; Seltzer, Geoffrey O.; Rodbell, Donald T.; Klein, Andrew G. (September 2005). "Regional synthesis of last glacial maximum snowlines in the tropical Andes, South America".Quaternary International.138–139:151–152.Bibcode:2005QuInt.138..145S.doi:10.1016/j.quaint.2005.02.011.ISSN1040-6182.
^Goss, A.R.; Kay, S.M.; Mpodozis, C.; Singer, B.S. (July 2009). "The Incapillo Caldera and Dome Complex (~28° S, Central Andes): A stranded magma chamber over a dying arc".Journal of Volcanology and Geothermal Research.184 (3–4): 391.Bibcode:2009JVGR..184..389G.doi:10.1016/j.jvolgeores.2009.05.005.ISSN0377-0273.
^Martin, A Keith (January 2024). "Opposite rotations in the Central Andes Bend: Tectonic scenario compared to other cases of opposite rotations and implications for long-term subduction at continental arcs".Journal of South American Earth Sciences.133: 2.doi:10.1016/j.jsames.2023.104698.
^abSchreiber, Katharina (1 January 2004). "Sacred Landscapes and Imperial Ideologies: The Wari Empire in Sondondo, Peru".Archeological Papers of the American Anthropological Association.14 (1): 137.doi:10.1525/ap3a.2004.14.131.ISSN1551-8248.
Dornbusch, Uwe (2000). "Pleistocene glaciation of the dry western Cordillera in southern Peru (14-25 (–15-30 (South)".Glacial Geology and Geomorphology – viaResearchGate.
