Quimsachata (possibly from Aymara and Quechua ''kimsa'' three, Pukina ''chata'' mountainTeofilo Laime Ajacopa, Lengua Pukina en Jesús de Machaca, referring to

Alfredo Torero Alfredo Augusto Torero Fernández de Córdova (September 10, 1930 in Huacho, Lima Region, Peru – June 19, 2004 in Valencia, Spain) was a Peruvian anthropologist and linguist. He was a student at the National University of San Marcos, from wh ...

("Reflexión acerca del pukina escrito por Alfredo Torero ... Pukina '''' – Castellano ''Cerro'' – Palabras relacionadas en aymara ''Qullu''") (English: mountain). ... Existencia de palabras pukinas en Jesús de Machaca: Qullunaka (cerros): ''Kimsa Chata'') is an extinct volcano in the Andes of Peru. It is located in the

Cusco Region Cusco, also spelled Cuzco (; qu, Qusqu suyu ), is a department and region in Peru and is the fourth largest department in the country, after Madre de Dios, Ucayali, and Loreto. It borders the departments of Ucayali on the north; Madre de D ...

, Canchis Province at about northwest of the town of Sicuani. This volcano is constructed from two separate centres, one active 11,500 years ago which formed a

scoria cone Scoria is a pyroclastic, highly vesicular, dark-colored volcanic rock that was ejected from a volcano as a molten blob and cooled in the air to form discrete grains or clasts.Neuendorf, K.K.E., J.P. Mehl, Jr., and J.A. Jackson, eds. (2005) ''G ...

and a lava field and another active 4450 BCE which formed two lava flows and a

lava dome In volcanology, a lava dome is a circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. Dome-building eruptions are common, particularly in convergent plate boundary settings. Around 6% of eruptions on ...

Geological context

Volcanism in southern Peru occurs as part of two distinct volcanic systems, the

stratovolcano A stratovolcano, also known as a composite volcano, is a conical volcano built up by many layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with a summit crater and per ...

es of the Western Cordillera and the Altiplano volcanoes which are typically small systems with surface areas of less than . Of these Altiplano volcanoes, a number of them are potassium enriched or

ultrapotassic Ultrapotassic igneous rocks are a class of rare, volumetrically minor and generally ultramafic or mafic silica-depleted igneous rocks. Ultrapotassic rocks are defined by molar K2 O/ Na2O >3 in much of the scientific literature. In other papers wr ...

rocks and are arranged along various lineaments. One of these lineaments is associated with the Cusco and Vilcanota faults which separate the Altiplano into a western and eastern portion. Quimsachata is located along this central and still active lineament, whereas the other two lineaments on each side of the fault system were active in the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

and Miocene. A variety of rock types occur in association with these lineaments.

Geology

The Quimsachata group consists of two volcanoes, Quimsachata itself and Oroscocha. Situated along the foot of the Eastern Cordillera, they are the northernmost young Peruvian volcanoes and lie far away from the principal volcanic arc. Local Inka myths may refer to volcanic activity at Quimsachata, and they may have included the event into their creation myths and religious practices despite the eruption occurring long before their civilization. the Quimsachata volcano is unmonitored but plans to install a monitoring network exist. It is considered a "very low hazard" volcano. The area is frequented by both national and international tourists and features

archeological site An archaeological site is a place (or group of physical sites) in which evidence of past activity is preserved (either prehistoric or historic or contemporary), and which has been, or may be, investigated using the discipline of archaeology and ...

s. Quimsachata was formed by a

and a lava field, next to the Vilcanota valley. It erupted about 11,500 years ago. Oroscocha () is a

dome A dome () is an architectural element similar to the hollow upper half of a sphere. There is significant overlap with the term cupola, which may also refer to a dome or a structure on top of a dome. The precise definition of a dome has been a m ...

with two associated

lava flows Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a moon onto its surface. Lava may be erupted at a volcano or through a fracture in the crust, on land or un ...

that reach thicknesses of . The volcano covers a surface area of . Oroscocha was erupted from a fissure about 4450 BCE, and the flow modified the course of the Vilcanota river. Oroscocha is formed by phenocryst-rich,

felsic In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, whi ...

porphyritic Porphyritic is an adjective used in geology to describe igneous rocks with a distinct difference in the size of mineral crystals, with the larger crystals known as phenocrysts. Both extrusive and intrusive rocks can be porphyritic, meaning all ...

rocks with a composition of peraluminous

rhyolite Rhyolite ( ) is the most silica-rich of volcanic rocks. It is generally glassy or fine-grained (aphanitic) in texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained groundmass. The mineral ...

in the flows and trachydacite in the dome, of which the dome is darker than the lava flows. Mafic inclusions with sizes larger in the lava flows than in the dome are also found. The magma that gave rise to the rocks was probably modified by the injection of lamprophyres while still in the magma chamber. Quimsachata is formed by potassium-rich andesite.

References

{{DEFAULTSORT:Quimsachata (Canchis) Volcanoes of Peru Mountains of Cusco Region Mountains of Peru Landforms of Cusco Region