Guallatiri is a high

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

. It is located southwest of the

Nevados de Quimsachata Kimsa Chata or Kimsachata (Aymara and Quechua ''kimsa'' three, Pukina ''chata'' mountain,Teofilo Laime Ajacopa, Lengua Pukina en Jesús de Machaca, referring to Alfredo Torero ("Reflexión acerca del pukina escrito por Alfredo Torero ... Pukina ...

volcanic group and is sometimes considered to be part of that group. It is a

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 ...

with numerous

fumarole A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

s around the summit. The summit may be composed of either 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 ...

or a pyroclastic cone, while the lower flanks of the volcano are covered by

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 ...

and lava domes. The volcano's eruptions have produced mostly

dacite Dacite () is a volcanic rock formed by rapid solidification of lava that is high in silica and low in alkali metal oxides. It has a fine-grained (aphanitic) to porphyritic texture and is intermediate in composition between andesite and rhyolite. ...

along with

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomi ...

and

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 ...

. Guallatiri has been active in historical times with a number of eruptions, the latest in 1960 but a large prehistorical eruption took place 2,600 years ago. Fumarolic and seismic activity is ongoing and has resulted in the deposition of

sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

and other minerals on the volcano. The volcano is covered by an

ice cap In glaciology, an ice cap is a mass of ice that covers less than of land area (usually covering a highland area). Larger ice masses covering more than are termed ice sheets. Description Ice caps are not constrained by topographical features ...

above elevation that has shrunk and fragmented during the course of the 20th-21st century. Guallatiri, along with several other volcanoes, is part of

Lauca National Park Lauca National Park is located in Chile's far north, in the Andean range. It encompasses an area of 1,379 km2 of altiplano and mountains, the latter consisting mainly of enormous volcanoes. Las Vicuñas National Reserve is its neighbour to ...

and is monitored by

SERNAGEOMIN 250px, Sernageomin building in Providencia, Santiago. The National Geology and Mining Service ( es, Servicio Nacional de Geología y Minería; SERNAGEOMIN) is a Chilean government agency. Its function is to provide geological information and adv ...

Name and first ascent

The term means "abundance of the

Andean goose The Andean goose (''Chloephaga melanoptera'') is a species of waterfowl in tribe Tadornini of subfamily Anserinae.HBW and BirdLife International (2021) Handbook of the Birds of the World and BirdLife International digital checklist of the birds ...

" in

Aymara Aymara may refer to: Languages and people * Aymaran languages, the second most widespread Andean language ** Aymara language, the main language within that family ** Central Aymara, the other surviving branch of the Aymara(n) family, which today ...

and refers to its frequent occurrence in the area. Other names are Punata which is also Aymara, Huallatiri and Huallatire. It was first climbed by the German-Bolivian geologist in 1926.

Geography and geomorphology

The volcano lies in the Putre

municipality A municipality is usually a single administrative division having corporate status and powers of self-government or jurisdiction as granted by national and regional laws to which it is subordinate. The term ''municipality'' may also mean the go ...

in the

Arica and Parinacota Region The Arica y Parinacota Region ( es, link=no, Región de Arica y Parinacota ) is one of Chile's 16 first order administrative divisions. It comprises two provinces, Arica and Parinacota. It borders Peru's Department of Tacna to the north, Bolivia ...

. It is located south of

Lake Chungara A lake is an area filled with water, localized in a basin, surrounded by land, and distinct from any river or other outlet that serves to feed or drain the lake. Lakes lie on land and are not part of the ocean, although, like the much larger ...

and west of

Cerro Capurata Cerro Capurata, also known as ''Elena Capurata'' or ''Quimsachatas'' is a stratovolcano in the Andes of Bolivia and Chile. To the south of Capurata lies Cerro Casparata and straight west Guallatiri. Geography and geomorphology It is on the b ...

. The latter is part of the

volcano chain which also includes Humurata and

Acotango Acotango is the central and highest of a group of stratovolcanoes straddling the border of Bolivia and Chile. It is high. The group is known as Kimsa Chata and consists of three mountains: Acotango, Umurata () north of it and Capurata () south ...

; sometimes Guallatiri is considered to be part of the Nevados de Quimsachata. Guallatiri is part of the larger Western Cordillera which is the western boundary of the

Altiplano The Altiplano (Spanish for "high plain"), Collao (Quechua and Aymara: Qullaw, meaning "place of the Qulla") or Andean Plateau, in west-central South America, is the most extensive high plateau on Earth outside Tibet. The plateau is located at the ...

high plateau In geology and physical geography, a plateau (; ; ), also called a high plain or a tableland, is an area of a highland consisting of flat terrain that is raised sharply above the surrounding area on at least one side. Often one or more sides ha ...

. The small town of Guallatiri is southwest of the volcano and is the settlement closest to it; it features a cemetery, a 17th-century church and a refuge of the National Forest Corporation. Other towns include Ancuta, Carbonire and Churiguaya. each had a population of less than 25 people. The provincial capital

Putre Putre is a Chilean town and commune, capital of the Parinacota Province in the Arica-Parinacota Region. It is located east of Arica, at an altitude of . The town is backdropped by Taapaca volcanic complex. Putre is on the edge of the Lauca Nati ...

is north of the volcano, and farther west

Arica Arica ( ; ) is a Communes of Chile, commune and a port city with a population of 222,619 in the Arica Province of northern Chile's Arica y Parinacota Region. It is Chile's northernmost city, being located only south of the border with Peru. The ...

lies on the Pacific Ocean. Economic activity in the area include the

Tambo Quemado Tambo may refer to: People * Adelaide Tambo (1929–2007), South African anti-apartheid activist * Dali Tambo (born 1959), South African anti-apartheid activist, TV presenter and also son of Oliver Tambo and Adelaide Tambo * Oliver Tambo (1917� ...

border crossing Border control refers to measures taken by governments to monitor and regulate the movement of people, animals, and goods across land, air, and maritime borders. While border control is typically associated with international borders, it a ...

, agriculture, animal husbandry as well as tourism and mountaineering, including ascents to the summit of Guallatiri. The frontier between Bolivia and Chile runs along the Nevados de Quimsachata northeast of Guallatiri and is not far from the volcano. The volcano is remote and thus poorly known.

The volcano

Guallatiri is , or high. It is a

composite volcano 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 ...

with a symmetric cone surmounted by a

or lava complex and a vent just south of it. The summit area has also been interpreted as an eroded

volcanic plug A volcanic plug, also called a volcanic neck or lava neck, is a volcanic object created when magma hardens within a vent on an active volcano. When present, a plug can cause an extreme build-up of high gas pressure if rising volatile-charged mag ...

or as a

. Lava domes, lava flows,

tephra Tephra is fragmental material produced by a volcanic eruption regardless of composition, fragment size, or emplacement mechanism. Volcanologists also refer to airborne fragments as pyroclasts. Once clasts have fallen to the ground, they rem ...

and

volcanic ash Volcanic ash consists of fragments of rock, mineral crystals, and volcanic glass, created during volcano, volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter. The term volcanic ash is also often loosely used t ...

make up the volcano. Guallatiri rises about above the surrounding terrain and covers a surface of about ; the total volume is about . Thick lava flows emanate in all directions but are primarily noted on the northern and western flanks and reach lengths of . The lava flows have a lobate appearance even when they are heavily eroded, and displays levees, ogives, polygonal cracks and blocky surfaces. Older flows have been eroded into hills. They reach thicknesses of . Fans of block-and-ash flows occur on the southern and southwestern flanks. Tephra deposits are mainly located on the eastern and southern side of Guallatiri.

Tuff Tuff is a type of rock made of volcanic ash ejected from a vent during a volcanic eruption. Following ejection and deposition, the ash is lithified into a solid rock. Rock that contains greater than 75% ash is considered tuff, while rock cont ...

s and

pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of bu ...

deposits occur both in the summit region and in radial valleys that emanate from Guallatiri although some of the latter have been reinterpreted as being reworked sediments. Apart from volcanic rocks,

glacial deposit image:Geschiebemergel.JPG, Closeup of glacial till. Note that the larger grains (pebbles and gravel) in the till are completely surrounded by the matrix of finer material (silt and sand), and this characteristic, known as ''matrix support'', is d ...

s cover large parts of the volcano and there are traces of mass failures. On the southern flank, there are two

s named Domo Tinto and Domo Sur; other than these Guallatiri has no lateral vents. These domes form a northwest–southeast line and are apart. Domo Tinto is wide and high while Domo Sur is thick and wide. Domo Tinto has a hummocky surface and resembles a pancake. There are both cold springs and

hot spring A hot spring, hydrothermal spring, or geothermal spring is a spring produced by the emergence of geothermally heated groundwater onto the surface of the Earth. The groundwater is heated either by shallow bodies of magma (molten rock) or by circ ...

s on Guallatiri, indicating that

groundwater Groundwater is the water present beneath Earth's surface in rock and soil pore spaces and in the fractures of rock formations. About 30 percent of all readily available freshwater in the world is groundwater. A unit of rock or an unconsolidate ...

interacts with the magmatic system. One hot spring is located at Chiriguaya on the northwestern foot of Guallatiri, where temperatures of were measured in bubbling pools and sinter deposition takes place. Several

stream A stream is a continuous body of water, body of surface water Current (stream), flowing within the stream bed, bed and bank (geography), banks of a channel (geography), channel. Depending on its location or certain characteristics, a stream ...

s run off the mountain; they eventually enter

and the Rio Lauca.

Ice

Above - elevation the volcano is covered with ice. , a small

on Guallatiri covered an area of with of ice. Ice area has been retreating at a rate of , leading to the breakup of the ice cap in several separate ice bodies. Heat emitted by

s may have contributed to the enhanced melting of the ice. Glacial deposits on Guallatiri cover an area of about above elevation, with lateral moraines reaching lengths of and thicknesses of . Unlike the global

last glacial maximum The Last Glacial Maximum (LGM), also referred to as the Late Glacial Maximum, was the most recent time during the Last Glacial Period that ice sheets were at their greatest extent. Ice sheets covered much of Northern North America, Northern Eur ...

which peaked between 21,000 and 19,000 years ago, in the area of Guallatiri glaciers reached their maximum extent between 13,500 and 8,900 years ago. This is a consequence of the climate in the region, where glacier extent was more sensitive to increased moisture supply than to decreasing temperatures. Some glaciers were still present during the Holocene, as the Domo Tinto lava dome bears traces of glacial erosion and is partially covered by moraines. Volcanic units overlie glacial deposits, or inversely glacial deposits such as various types of

moraine A moraine is any accumulation of unconsolidated debris (regolith and rock), sometimes referred to as glacial till, that occurs in both currently and formerly glaciated regions, and that has been previously carried along by a glacier or ice shee ...

s overlie older volcanic rocks. Older volcanic rocks bear

glacial striation Glacial striations or striae are scratches or gouges cut into bedrock by glacial abrasion. These scratches and gouges were first recognized as the result of a moving glacier in the late 18th century when Swiss alpinists first associated them w ...

s and

volcanic bomb A volcanic bomb or lava bomb is a mass of partially molten rock (tephra) larger than 64 mm (2.5 inches) in diameter, formed when a volcano ejects viscous fragments of lava during an eruption. Because volcanic bombs cool after they l ...

s on the lower flanks may have been transported there by glaciers.

Geology

Off the western coast of South America, the

Nazca Plate The Nazca Plate or Nasca Plate, named after the Nazca region of southern Peru, is an oceanic tectonic plate in the eastern Pacific Ocean basin off the west coast of South America. The ongoing subduction, along the Peru–Chile Trench, of the Na ...

subduct Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

s beneath the

South America Plate The South American Plate is a major tectonic plate which includes the continent of South America as well as a sizable region of the Atlantic Ocean seabed extending eastward to the African Plate, with which it forms the southern part of the Mid-A ...

at a rate of about . The subduction process is responsible for the volcanism of the

Northern Volcanic Zone The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South Ame ...

(NVZ),

Central Volcanic Zone The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South Americ ...

(CVZ) and

Southern Volcanic Zone The Andean Volcanic Belt is a major volcanic belt along the Andean cordillera in Argentina, Bolivia, Chile, Colombia, Ecuador, and Peru. It is formed as a result of subduction of the Nazca Plate and Antarctic Plate underneath the South American ...

(SVZ) and has also driven the formation of the Altiplano during the last 25 million years. The CVZ is a long chain of volcanoes spanning southern Peru, northern Chile, western Bolivia and northwestern Argentina. It contains about 58 volcanoes which are potentially active or active, 33 of which are located within Chile. The most active of these is

Lascar A lascar was a sailor or militiaman from the Indian subcontinent, Southeast Asia, the Arab world, British Somaliland, or other land east of the Cape of Good Hope, who was employed on European ships from the 16th century until the middle of the 2 ...

, which in 1993 produced the largest historical eruption of northern Chile. Guallatiri rises above

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 ...

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Formations. The Lupica Formation is older and consists mainly of volcanic rocks, while the Lauca Formation is formed by volcanic and sedimentary rocks that were deposited within the basin and in part glacially overprinted. The

basement A basement or cellar is one or more floors of a building that are completely or partly below the ground floor. It generally is used as a utility space for a building, where such items as the furnace, water heater, breaker panel or fuse box, ...

consists of

Archean The Archean Eon ( , also spelled Archaean or Archæan) is the second of four geologic eons of Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozoic. The Earth Earth ...

Precambrian The Precambrian (or Pre-Cambrian, sometimes abbreviated pꞒ, or Cryptozoic) is the earliest part of Earth's history, set before the current Phanerozoic Eon. The Precambrian is so named because it preceded the Cambrian, the first period of the ...

Paleozoic The Paleozoic (or Palaeozoic) Era is the earliest of three geologic eras of the Phanerozoic Eon. The name ''Paleozoic'' ( ;) was coined by the British geologist Adam Sedgwick in 1838 by combining the Greek words ''palaiós'' (, "old") and ' ...

rocks. There is evidence that the terrain was tectonically active during the

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million years ...

Composition

The composition of volcanic rocks ranges from

; with dacites being predominant. The summit dome is formed by

and most outcrops are

trachyandesite Trachyandesite is an extrusive igneous Rock (geology), rock with a composition between trachyte and andesite. It has little or no free quartz, but is dominated by Sodium, sodic plagioclase and alkali feldspar. It is formed from the cooling of ...

and

trachydacite Trachyte () is an extrusive igneous rock composed mostly of alkali feldspar. It is usually light-colored and aphanitic (fine-grained), with minor amounts of mafic minerals, and is formed by the rapid cooling of lava enriched with silica and alk ...

. The rocks define a

potassium Potassium is the chemical element with the symbol K (from Neo-Latin ''kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmosphe ...

-rich

calc-alkaline The calc-alkaline magma series is one of two main subdivisions of the subalkaline magma series, the other subalkaline magma series being the tholeiitic series. A magma series is a series of compositions that describes the evolution of a mafic mag ...

suite and contain

amphibole Amphibole () is a group of inosilicate minerals, forming prism or needlelike crystals, composed of double chain tetrahedra, linked at the vertices and generally containing ions of iron and/or magnesium in their structures. Its IMA symbol is A ...

apatite Apatite is a group of phosphate minerals, usually hydroxyapatite, fluorapatite and chlorapatite, with high concentrations of OH−, F− and Cl− ions, respectively, in the crystal. The formula of the admixture of the three most common e ...

biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron-endmember annite, and the magnesium-endmember phlogopite; more alumino ...

clinopyroxene The pyroxenes (commonly abbreviated to ''Px'') are a group of important rock-forming inosilicate minerals found in many igneous and metamorphic rocks. Pyroxenes have the general formula , where X represents calcium (Ca), sodium (Na), iron (Fe II) ...

olivine The mineral olivine () is a magnesium iron silicate with the chemical formula . It is a type of nesosilicate or orthosilicate. The primary component of the Earth's upper mantle, it is a common mineral in Earth's subsurface, but weathers quickl ...

and

plagioclase Plagioclase is a series of tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continuous solid solution series, more prope ...

phenocryst 300px, feldspathic phenocrysts. This granite, from the Switzerland">Swiss side of the Mont Blanc massif, has large white plagioclase phenocrysts, triclinic minerals that give trapezoid shapes when cut through). 1 euro coins, 1 euro coin (diameter ...

s, similar to other volcanoes in the region. The occurrence of

obsidian Obsidian () is a naturally occurring volcanic glass formed when lava extrusive rock, extruded from a volcano cools rapidly with minimal crystal growth. It is an igneous rock. Obsidian is produced from felsic lava, rich in the lighter elements s ...

has been reported.

Mafic A mafic mineral or rock is a silicate mineral or igneous rock rich in magnesium and iron. Most mafic minerals are dark in color, and common rock-forming mafic minerals include olivine, pyroxene, amphibole, and biotite. Common mafic rocks include ...

rock enclaves have been observed in Domo Tinto rocks, which indicate that mafic magmas were injected into the

magma chamber A magma chamber is a large pool of liquid rock beneath the surface of the Earth. The molten rock, or magma, in such a chamber is less dense than the surrounding country rock, which produces buoyant forces on the magma that tend to drive it upw ...

and mixed with already present magma. Fractional crystallization and magma mixing processes gave rise to Guallatiri's magmas. Fumaroles have deposited minerals such as

anhydrite Anhydrite, or anhydrous calcium sulfate, is a mineral with the chemical formula CaSO4. It is in the orthorhombic crystal system, with three directions of perfect cleavage parallel to the three planes of symmetry. It is not isomorphous with the ...

baryte Baryte, barite or barytes ( or ) is a mineral consisting of barium sulfate ( Ba S O4). Baryte is generally white or colorless, and is the main source of the element barium. The ''baryte group'' consists of baryte, celestine (strontium sulfate), ...

cristobalite Cristobalite is a mineral polymorph of silica that is formed at very high temperatures. It has the same chemical formula as quartz, SiO2, but a distinct crystal structure. Both quartz and cristobalite are polymorphs with all the members of the ...

gypsum Gypsum is a soft sulfate mineral composed of calcium sulfate dihydrate, with the chemical formula . It is widely mined and is used as a fertilizer and as the main constituent in many forms of plaster, blackboard or sidewalk chalk, and drywall. ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon-oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical form ...

sassolite Sassolite is a borate mineral, specifically the mineral form of boric acid. It is usually white to gray, and colourless in transmitted light. It can also take on a yellow colour from sulfur impurities, or brown from iron oxides. History and occ ...

and

. Less common are

galena Galena, also called lead glance, is the natural mineral form of lead(II) sulfide (PbS). It is the most important ore of lead and an important source of silver. Galena is one of the most abundant and widely distributed sulfide minerals. It cryst ...

orpiment Orpiment is a deep-colored, orange-yellow arsenic sulfide mineral with formula . It is found in volcanic fumaroles, low-temperature hydrothermal veins, and hot springs and is formed both by sublimation and as a byproduct of the decay of another a ...

and

pyrite The mineral pyrite (), or iron pyrite, also known as fool's gold, is an iron sulfide with the chemical formula Iron, FeSulfur, S2 (iron (II) disulfide). Pyrite is the most abundant sulfide mineral. Pyrite's metallic Luster (mineralogy), lust ...

. Sulfur deposits have yellow, orange or red colours and are sometimes accompanied by

arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...

-sulfur compounds that also contain

iodine Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a vi ...

mercury Mercury commonly refers to: * Mercury (planet), the nearest planet to the Sun * Mercury (element), a metallic chemical element with the symbol Hg * Mercury (mythology), a Roman god Mercury or The Mercury may also refer to: Companies * Merc ...

selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ...

and

tellurium Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally fou ...

Sulfur Sulfur (or sulphur in British English) is a chemical element with the symbol S and atomic number 16. It is abundant, multivalent and nonmetallic. Under normal conditions, sulfur atoms form cyclic octatomic molecules with a chemical formula ...

deposits are reported from its southern flank, and according to the first Panamerican Congress on Mine Engineering and Geology, in 1942 the volcano featured about 800,000 tonnes sulfur

ore Ore is natural rock or sediment that contains one or more valuable minerals, typically containing metals, that can be mined, treated and sold at a profit.Encyclopædia Britannica. "Ore". Encyclopædia Britannica Online. Retrieved 7 Apr ...

with a grade of about 55% sulfur. The volcano may be an important source of

pollution in the region.

Flora, fauna and climate

The volcano is inside the

and the

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

s - '' bofedales'' - in the area of Guallatiri have regional importance. Vegetation there include '' Arenaria rivularis'', '' Calandrinia compacta'', '' Deyeuxia curvula'', '' Distichlis humilis'', '' Lobelia oligophylla'' and '' Oxychloe andina''. Animal species include birds such as the

Andean flamingo The Andean flamingo (''Phoenicoparrus andinus'') is a species of flamingo native to the Andes mountains of South America. Until 2014, it was classified in genus ''Phoenicopterus''. It is closely related to James's flamingo, and the two make up th ...

Andean gull The Andean gull (''Chroicocephalus serranus'') is a species of gull in the family Laridae. As is the case with many gulls, it has traditionally been placed in the genus ''Larus''. It is found in the Andes in mountainous regions of Argentina, Bol ...

, Andean goose, buff-winged cinclodes,

Chilean flamingo The Chilean flamingo (''Phoenicopterus chilensis'') is a species of large flamingo at closely related to the American flamingo and the greater flamingo, with which it was sometimes considered conspecific. The species is listed as near threatened ...

condor Condor is the common name for two species of New World vultures, each in a monotypic genus. The name derives from the Quechua ''kuntur''. They are the largest flying land birds in the Western Hemisphere. They are: * The Andean condor (''Vult ...

giant coot The giant coot (''Fulica gigantea'') is a species of bird in subfamily Rallinae of family Rallidae, the rails, gallinules, and coots. It is found in Argentina, Bolivia, Chile, and Peru.HBW and BirdLife International (2021) Handbook of the Birds ...

James's flamingo James's flamingo (''Phoenicoparrus jamesi''), also known as the puna flamingo, is a species of flamingo that lives at high altitudes in the Andean plateaus of Peru, Chile, Bolivia, and northwest Argentina. It is named for Harry Berkeley James, a ...

, mountain parakeet,

Puna ibis The Puna ibis (''Plegadis ridgwayi'') is a species of bird in the family Threskiornithidae. It is found in Argentina, Bolivia, Chile, and Peru. Its natural habitats are swamps, marshes and lakes, and most of its range is in the Andean highlands, ...

Puna tinamou The puna tinamou (''Tinamotis pentlandii'') also known as Pentland's tinamou, is a member of the most ancient groups of bird families, the tinamous. This species is native to southern South America.Clements, J. (2007) The binomial name of the spec ...

and

torrent duck The torrent duck (''Merganetta armata'') is a member of the duck, goose and swan family (biology), family Anatidae. It is the only member of the genus ''Merganetta''. It is placed in the shelduck subfamily Tadorninae after the "perching duck" ass ...

. Among the mammals are the

alpaca The alpaca (''Lama pacos'') is a species of South American camelid mammal. It is similar to, and often confused with, the llama. However, alpacas are often noticeably smaller than llamas. The two animals are closely related and can successfu ...

Altiplano chinchilla mouse The Altiplano chinchilla mouse or achallo (''Chinchillula sahamae'') is a species of rodent in the family Cricetidae. It is the only species in the genus ''Chinchillula''. It is found in Argentina, Bolivia, Chile, and Peru. References

*Mus ...

, Andean swamp rat,

lesser grison The lesser grison (''Galictis cuja'') is a species of mustelid from South America. Description Lesser grisons have a long, slender body, short legs, and a bushy tail. They have a long neck and a small head with a flattened forehead and rounded ea ...

llama The llama (; ) (''Lama glama'') is a domesticated South American camelid, widely used as a List of meat animals, meat and pack animal by Inca empire, Andean cultures since the Pre-Columbian era. Llamas are social animals and live with othe ...

, mountain degu, Osgood's leaf-eared mouse, short-tailed chinchilla and

vicuña The vicuña (''Lama vicugna'') or vicuna (both , very rarely spelled ''vicugna'', its former genus name) is one of the two wild South American camelids, which live in the high alpine areas of the Andes, the other being the guanaco, which live ...

Woodland A woodland () is, in the broad sense, land covered with trees, or in a narrow sense, synonymous with wood (or in the U.S., the ''plurale tantum'' woods), a low-density forest forming open habitats with plenty of sunlight and limited shade (see ...

s formed by the tree '' Polylepis tarapacana'' occur on Guallatiri; this tree forms the world's highest woodlands. The region features a

tundra In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless moun ...

climate. Most precipitation falls during the summer months and amounts to about .

Moisture Moisture is the presence of a liquid, especially water, often in trace amounts. Small amounts of water may be found, for example, in the air (humidity), in foods, and in some commercial products. Moisture also refers to the amount of water vapo ...

mainly originates in the

Atlantic Ocean The Atlantic Ocean is the second-largest of the world's five oceans, with an area of about . It covers approximately 20% of Earth's surface and about 29% of its water surface area. It is known to separate the " Old World" of Africa, Europe ...

and the

Amazon Amazon most often refers to: * Amazons, a tribe of female warriors in Greek mythology * Amazon rainforest, a rainforest covering most of the Amazon basin * Amazon River, in South America * Amazon (company), an American multinational technology c ...

and arrives on the Altiplano mainly during the summer months, especially during cold events of the

El Niño-Southern Oscillation EL, El or el may refer to: Religion * El (deity), a Semitic word for "God" People * EL (rapper) (born 1983), stage name of Elorm Adablah, a Ghanaian rapper and sound engineer * El DeBarge, music artist * El Franco Lee (1949–2016), American po ...

when moisture supply increases.

Tree ring Dendrochronology (or tree-ring dating) is the scientific method of dating tree rings (also called growth rings) to the exact year they were formed. As well as dating them, this can give data for dendroclimatology, the study of climate and atmos ...

chronologies from '' Polylepis tarapacana'' trees growing at Guallatiri have been used for climate reconstructions.

Eruptive history

Volcanic activity at Guallatiri commenced about 710,000 or 262,000-130,000 years ago and the volcano subsequently grew during the

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

and

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togethe ...

. The older Humurata and Acotango volcanoes are heavily eroded while Capurata is better preserved. Total magma supply at Guallatiri amounts to , less than at

Parinacota Parinacota (in hispanicized spelling), Parina Quta or Parinaquta (Aymara, ''parina'' flamingo, ''quta'' lake, "flamingo lake", other hispanicized spellings ''Parinaccota, Parinajota'') may refer to: Lakes * Parinaquta (Carabaya), in Peru, Puno R ...

but higher than Lascar. During an initial stage, "Guallatiri I" grew in the form of andesitic and dacitic lava flows as well as heavily eroded pyroclastic deposits, which crop out around the volcano. Then the dacitic "Guallatiri II" developed in close proximity to the central vent; unlike "Guallatiri I" units it has not been eroded by glaciation and flows preserve flow structures. The central sector of the volcano is mainly of Holocene age while the peripheral parts date to the Pleistocene. Later research subdivided the growth of the volcano into seven separate stages, of which 1-4 crop out mainly at the periphery of the volcano and 5-6 in its central sector. All these units were erupted by the central vent of Guallatiri. Some lava flows are well preserved, others have been glaciated. Evidence indicates that large eruptions similar to the one of Lascar in 1993 may have occurred at Guallatiri. The largest Holocene event at the volcano was a Plinian or sub-Plinian eruption that deposited tephra and pumice southwest of the volcano, reaching thicknesses of at distance, approximately 2,600 years ago. Non-explosive eruptions also took place, such as the Domo Tinto eruption 5,000±3,000 years ago. The eruption emplaced lobes of lava over a flat surface.

Pyroclastic flow A pyroclastic flow (also known as a pyroclastic density current or a pyroclastic cloud) is a fast-moving current of hot gas and volcanic matter (collectively known as tephra) that flows along the ground away from a volcano at average speeds of bu ...

deposits extend to distance from Guallatiri.

Radiocarbon dating Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was dev ...

has yielded ages ranging between 6,255±41-140±30 years

before present Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Becaus ...

. These flows are unrelated to the lava domes, which show no evidence of collapses that could have formed pyroclastic flows.

Lahar A lahar (, from jv, ꦮ꧀ꦭꦲꦂ) is a violent type of mudflow or debris flow composed of a slurry of pyroclastic material, rocky debris and water. The material flows down from a volcano, typically along a river valley. Lahars are extreme ...

deposits are found on the southern flanks of the volcano and do not exceed thickness. They form when volcanic material interacts with water, produced either by the melting of ice or through intense rainfall. Holocene lahar deposits have been found in river valleys.

Historical and seismic activity

Guallatiri is after

the second-most active volcano in northern Chile, with numerous small

explosive eruption In volcanology, an explosive eruption is a volcanic eruption of the most violent type. A notable example is the 1980 eruption of Mount St. Helens. Such eruptions result when sufficient gas has dissolved under pressure within a viscous magma such ...

s since the 19th century which produced thin

layers. The eruption history of Guallatiri is poorly known and historical eruptions are poorly documented. Eruptions with a volcanic explosivity index of 2 took place in 1825 ± 25, 1913, July 1959 and December 1960. A further uncertain eruption took place in 1908 and additional poorly documented eruptions are reported from 1862, 1864, 1870, 1902, 1904 and 1987. Radiocarbon dating has yielded evidence of at least one eruption during the past 200 years. Increased steam emission was observed in December 1985 and initially attributed to Acotango volcano, before it was linked to Guallatiri; it may have been an eruption of the latter. In May 2015

raised the volcano alert level when seismic activity increased and a high plume appeared over the volcano, only to lower it again in July when activity decreased. Shallow

earthquake An earthquake (also known as a quake, tremor or temblor) is the shaking of the surface of the Earth resulting from a sudden release of energy in the Earth's lithosphere that creates seismic waves. Earthquakes can range in intensity, from ...

s and sporadic seismic swarms are recorded at Guallatiri; one such swarm was induced by the 2001 Peru earthquake. Satellite imaging has not shown any evidence of ongoing deformation of the volcanic edifice.

Fumarolic activity

Guallatiri features

s and

solfatara A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcani ...

s, and

mud pool A mudpot, or mud pool, is a sort of acidic hot spring, or fumarole, with limited water. It usually takes the form of a pool of bubbling mud. The acid and microorganisms decompose surrounding rock into clay and mud. Description The mud of a mud ...

s have been reported as well. There are two main areas, one on the western flank below the summit and another on the south-southwestern flank. Fumaroles form alignments, and a long fracture lies in the southern area. Some sources also identify a third area on the upper western flank. The vents of individual fumaroles sometimes form cones that reach heights of and widths of , and there are small explosion craters with widths of in the summit region. Liquid

has formed

pahoehoe 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 und ...

-like flows which reach lengths of . Other minerals deposited by the fumaroles are

sulfate The sulfate or sulphate ion is a polyatomic anion with the empirical formula . Salts, acid derivatives, and peroxides of sulfate are widely used in industry. Sulfates occur widely in everyday life. Sulfates are salts of sulfuric acid and many ar ...

s such as

and

sulfide Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to chemical compounds lar ...

s, including

cinnabar Cinnabar (), or cinnabarite (), from the grc, κιννάβαρι (), is the bright scarlet to brick-red form of Mercury sulfide, mercury(II) sulfide (HgS). It is the most common source ore for refining mercury (element), elemental mercury and ...

antimony Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient time ...

sulfides and

sulfides. The temperatures of the fumaroles range between . Guallatiri produces gases consisting of

carbon dioxide Carbon dioxide (chemical formula ) is a chemical compound made up of molecules that each have one carbon atom covalently double bonded to two oxygen atoms. It is found in the gas state at room temperature. In the air, carbon dioxide is transpar ...

and

water vapour (99.9839 °C) , - , Boiling point , , - , specific gas constant , 461.5 J/( kg·K) , - , Heat of vaporization , 2.27 MJ/kg , - , Heat capacity , 1.864 kJ/(kg·K) Water vapor, water vapour or aqueous vapor is the gaseous pha ...

, with

hydrogen chloride The compound hydrogen chloride has the chemical formula and as such is a hydrogen halide. At room temperature, it is a colourless gas, which forms white fumes of hydrochloric acid upon contact with atmospheric water vapor. Hydrogen chloride ga ...

hydrogen fluoride Hydrogen fluoride (fluorane) is an inorganic compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock i ...

hydrogen sulfide Hydrogen sulfide is a chemical compound with the formula . It is a colorless chalcogen-hydride gas, and is poisonous, corrosive, and flammable, with trace amounts in ambient atmosphere having a characteristic foul odor of rotten eggs. The unde ...

methane Methane ( , ) is a chemical compound with the chemical formula (one carbon atom bonded to four hydrogen atoms). It is a group-14 hydride, the simplest alkane, and the main constituent of natural gas. The relative abundance of methane on Eart ...

and

sulfur dioxide Sulfur dioxide (IUPAC-recommended spelling) or sulphur dioxide (traditional Commonwealth English) is the chemical compound with the formula . It is a toxic gas responsible for the odor of burnt matches. It is released naturally by volcanic activ ...

as additional components. They appear to originate from a

hydrothermal Hydrothermal circulation in its most general sense is the circulation of hot water (Ancient Greek ὕδωρ, ''water'',Liddell, H.G. & Scott, R. (1940). ''A Greek-English Lexicon. revised and augmented throughout by Sir Henry Stuart Jones. with th ...

system where intense rock-gas interaction takes place. The water originates in part from the magma and in part from precipitation. Different degrees of interaction with precipitation water may explain why the south-southwestern flank fumarole gases have a different composition than these released in the summit region. The fumarolic activity has produced intense

alteration of Guallatiri's rocks east-northeast of the summit and at a lower elevation northwest of it.

Fumarole plume

The fumarole clouds emanating mainly from the summit fumarole are visible from more than distance and also from

infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to the human eye. IR is generally understood to encompass wavelengths from around ...

satellite A satellite or artificial satellite is an object intentionally placed into orbit in outer space. Except for passive satellites, most satellites have an electricity generation system for equipment on board, such as solar panels or radioisotope ...

images. The fumarole cloud influences the perception of volcanic activity by the local population. Puffing behaviour was noted in 1996 and emissions every half-hour in November 1987, which gave rise to yellow-white plumes up to high. Jet-like noises are heard from the fumaroles. According to a report by mountaineers in 1966, fire emanated from the fumarole vents.

Hazards and monitoring

Future eruptions may consist of the emission of lava domes or lava flows, preceded by explosive activity that could impact the settlements of Ancuta and Guallatiri on the southern and western flanks. Large explosive eruptions could deposit

pyroclastic Pyroclastic rocks (derived from the el, πῦρ, links=no, meaning fire; and , meaning broken) are clastic rocks composed of rock fragments produced and ejected by explosive volcanic eruptions. The individual rock fragments are known as pyroc ...

s over hundreds of kilometres, with the direction depending on the wind direction at the time of the eruption.

s would mainly impact the western and southwestern sectors of the volcano, as the snow cover is concentrated there.

Lava flow 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 und ...

s would also primarily impact this sector of the volcano.

s may impact areas within from Guallatiri, including the settlements Ancuta and Guallatiri. Apart from Ancuta and Guallatiri in Chile, the volcano may threaten towns in Bolivia and ash clouds from Guallatiri could impact

airport An airport is an aerodrome with extended facilities, mostly for commercial air transport. Airports usually consists of a landing area, which comprises an aerially accessible open space including at least one operationally active surface ...

s in the wider region as far as

Paraguay Paraguay (; ), officially the Republic of Paraguay ( es, República del Paraguay, links=no; gn, Tavakuairetã Paraguái, links=si), is a landlocked country in South America. It is bordered by Argentina to the south and southwest, Brazil to th ...

. The vulnerability of the local population reflects both the widespread poverty and marginalization on the one hand, and the low population density on the other hand. Significant eruptions are expected to reoccur on century timescales. Guallatiri is ranked second in the Chilean scale of dangerous volcanoes and the 30th most dangerous in the country. In 2013, the

Southern Andean Volcano Observatory The Southern Andean Volcano Observatory (Spanish: ''Observatorio Volcanológico de los Andes del Sur''), also known by its acronyms as OVDAS, is part of ''Red Nacional de Vigilancia Volcánica'', a program of the Chilean National Geology and Minin ...

began to monitor the volcano with video surveillance, measurements of seismic activity and deformations of the volcanic edifice. Volcano hazard maps have been published.

Mythology and religious importance

In the

oral tradition Oral tradition, or oral lore, is a form of human communication wherein knowledge, art, ideas and cultural material is received, preserved, and transmitted orally from one generation to another. Vansina, Jan: ''Oral Tradition as History'' (1985 ...

of Chipaya, cold winds called blow from the

Pacific Ocean The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...

to the

and towards Guallatiri. The volcano there is linked with

hell In religion and folklore, hell is a location in the afterlife in which evil souls are subjected to punitive suffering, most often through torture, as eternal punishment after death. Religions with a linear divine history often depict hell ...

. They believed that the waters of the Lauca River originate on Guallatiri and directly from hell. On the contrary, Guallatiri was also considered to be an ''

apu APU or Apu may refer to: Film and television * ''The Apu Trilogy'', a series of three Bengali films, directed by Satyajit Ray, with the fictional character Apu Roy, comprising: ** ''Pather Panchali'' (''Song of the Little Road'') (1955), the first ...

'', a protective mountain spirit. The mountain was and still is worshipped by local inhabitants, and the church in the town of Guallatiri is constructed in a way that it points to the volcano. There are no known archeological sites on the summit of Guallatiri, unlike several other mountains in the region. Either the continuous ice cover or the constant volcanic activity may be the reason.

Notes

References

Sources

* * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * {{Andean volcanoes Active volcanoes Volcanoes of Arica y Parinacota Region Stratovolcanoes of Chile Mountains of Chile Six-thousanders of the Andes Pleistocene stratovolcanoes Holocene stratovolcanoes

Name and first ascent

Geography and geomorphology

The volcano

Ice

Geology

Composition

Flora, fauna and climate

Eruptive history

Historical and seismic activity

Fumarolic activity

Fumarole plume

Hazards and monitoring

Mythology and religious importance

See also

Notes

References

Sources