Licancabur () is a stratovolcano on the border between Bolivia and

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 ...

, south of the Sairecabur volcano and west of Juriques. Part of the

Andean The Andes, Andes Mountains or Andean Mountains (; ) are the longest continental mountain range in the world, forming a continuous highland along the western edge of South America. The range is long, wide (widest between 18°S – 20°S l ...

Central Volcanic Zone, it has a prominent, -high

cone A cone is a three-dimensional geometric shape that tapers smoothly from a flat base (frequently, though not necessarily, circular) to a point called the apex or vertex. A cone is formed by a set of line segments, half-lines, or lines con ...

. A summit crater containing Licancabur Lake, a

crater lake Crater Lake ( Klamath: ''Giiwas'') is a volcanic crater lake in south-central Oregon in the western United States. It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity. The lake partly fill ...

which is among the highest lakes in the world, caps the volcano. Three stages of lava flows emanate from the edifice. Licancabur formed atop of

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological 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 finally confirmed in ...

ignimbrite Ignimbrite is a type of volcanic rock, consisting of hardened tuff. Ignimbrites form from the deposits of pyroclastic flows, which are a hot suspension of particles and gases flowing rapidly from a volcano, driven by being denser than the surro ...

s and has been active during the

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 togeth ...

, after the

ice age An ice age is a long period of reduction in the temperature of Earth's surface and atmosphere, resulting in the presence or expansion of continental and polar ice sheets and alpine glaciers. Earth's climate alternates between ice ages and gre ...

s. Although no historic eruptions of the volcano are known, lava flows extending into Laguna Verde have been dated to 13,240 ± 100 BP. The volcano has primarily erupted

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 predo ...

, with small amounts of

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 ...

and

basaltic andesite Basaltic andesite is a volcanic rock that is intermediate in composition between basalt and andesite. It is composed predominantly of augite and plagioclase. Basaltic andesite can be found in volcanoes around the world, including in Central Amer ...

. Its climate is cold, dry and very sunny, with high levels of

ultraviolet radiation Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...

. Licancabur is not covered by

glacier A glacier (; ) is a persistent body of dense ice that is constantly moving under its own weight. A glacier forms where the accumulation of snow exceeds its ablation over many years, often centuries. It acquires distinguishing features, such as ...

Cushion plant A cushion plant is a compact, low-growing, mat-forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world. The term "cushion" is usually applied to woody plants that grow as spreading mats, are limited in ...

s and shrubs form the vegetation lower on its slopes. Chinchillas were formerly hunted on the volcano. Licancabur is considered a holy mountain by the Atacameno people, which consider it a relative of Cerro Quimal mountain in northern Chile.

Archeological sites 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 ...

have been found on its slopes and in the summit crater, which was possibly a prehistoric

watchtower A watchtower or watch tower is a type of fortification used in many parts of the world. It differs from a regular tower in that its primary use is military and from a turret in that it is usually a freestanding structure. Its main purpose is to ...

Name

"Licancabur" derives from the Kunza words used by the

Atacameño The Atacama people, also called Atacameño, are indigenous people from the Atacama Desert and altiplano region in the north of Chile and Argentina and southern Bolivia, mainly Antofagasta Region. According to the Argentinean Census in 2010, 13,9 ...

people to refer to the volcano: ("people", or ''

pueblo In the Southwestern United States, Pueblo (capitalized) refers to the Native tribes of Puebloans having fixed-location communities with permanent buildings which also are called pueblos (lowercased). The Spanish explorers of northern New Spain ...

'') and ("mountain"); thus, "mountain of the people". It is also known as "Volcan de Atacama" and "Licancaur". The border between Bolivia and Chile, defined by the 1904 Treaty of Peace and Friendship, crosses the volcano.

Geography and geology

General setting

Off the western coast of South America, the Nazca Plate subducts into the Peru-Chile Trench beneath the South American Plate. The

Andean Volcanic Belt 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 ...

consists of three main volcanic zones: the Northern Volcanic Zone (from 2° N to 5° S), the Central Volcanic Zone (16° to 28° S) and the Southern Volcanic Zone (33° to 46° S). These volcanic zones are separated by gaps without volcanic activity, where the subducting plate is shallower. These shallower zones have been attributed to the high speed of the plate collision, the young age of the subducting oceanic lithosphere and the curvature of the subducting plate. The most plausible theory is that variations in

buoyancy Buoyancy (), or upthrust, is an upward force exerted by a fluid that opposes the weight of a partially or fully immersed object. In a column of fluid, pressure increases with depth as a result of the weight of the overlying fluid. Thus the ...

of a subducting plate creates a flat subduction zone. The Cocos, Juan Fernandez and Nazca Ridges are associated with such volcanic gaps where they collide with the

oceanic trench Oceanic trenches are prominent long, narrow topographic depressions of the ocean floor. They are typically wide and below the level of the surrounding oceanic floor, but can be thousands of kilometers in length. There are about of oceanic tren ...

. The subduction of

spreading ridge A mid-ocean ridge (MOR) is a seafloor mountain system formed by plate tectonics. It typically has a depth of about and rises about above the deepest portion of an ocean basin. This feature is where seafloor spreading takes place along a diver ...

s can also diminish volcanism, as observed at the Chile Rise further south. The buoyancy of these crustal structures may hinder subduction, reducing water supply to the mantle and inducing the formation of melts. Not all volcanism in Chile is relative to subduction of the Nazca Plate; the

Chile Ridge The Chile Ridge, also known as the Chile Rise, is a submarine oceanic ridge formed by the divergent plate boundary between the Nazca Plate and the Antarctic Plate. It extends from the triple junction of the Nazca, Pacific, and Antarctic plates ...

exhibits submarine volcanism, and volcanism in the Austral Volcanic Zone is triggered by the

Antarctic Plate The Antarctic Plate is a tectonic plate containing the continent of Antarctica, the Kerguelen Plateau, and some remote islands in the Southern Ocean and other surrounding oceans. After breakup from Gondwana (the southern part of the superconti ...

subducting beneath the South American Plate. , one hundred ninety-eight South American volcanoes were on the

Global Volcanism Program The Smithsonian Institution's Global Volcanism Program (GVP) documents Earth's volcanoes and their eruptive history over the past 10,000 years. The mission of the GVP is to document, understand, and disseminate information about global volcanic a ...

's list of volcanoes with Holocene activity.

Local setting

Licancabur is part of the Central Volcanic Zone and is situated at the western edge 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 ...

. Among the active volcanoes of the region are

Putana In Hinduism, Pūtanā () is a rakshasi (demoness), who was killed by the infant-god Krishna. Putana disguises as a young, beautiful woman and tries to kill the god by breast-feeding poisoned milk; however Krishna sucks her milk as well as her l ...

(erupted at the end of the 19th century),

Llullaillaco Llullaillaco () is a dormant stratovolcano at the border of Argentina (Salta Province) and Chile (Antofagasta Region). It lies in the Puna de Atacama, a region of tall volcanic peaks on a high plateau close to the Atacama Desert, one of the dri ...

(1868) and

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 ...

(1993). Other

stratovolcanoes 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 peri ...

are Tacora, Nevados de Payachata, Isluga, Tata Sabaya, Ollague,

Tocorpuri Tocorpuri is a volcano in Chile, close to the border with Bolivia. Its peak height is most recently given as and it features a wide summit crater. The volcano consists mainly of lava flows and pyroclastic deposits and is subdivided into two se ...

, Sairecabur and

Socompa Socompa is a large stratovolcano at the border of Argentina and Chile with an elevation of metres. Part of the Chilean and Argentine Andean Volcanic Belt (AVB), it is part of the Central Volcanic Zone, one of the various segments of the AVB. Th ...

. The Central Volcanic Zone has more than 1,100 volcanic centres—many older than the Pleistocene, since the area's prevailing arid climate prevented substantial erosion. During the

Miocene The Miocene ( ) is the first epoch (geology), geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and mea ...

, the area around Licancabur was the site of major ignimbrite-forming eruptions. Llano de Chajnantor (southeast of Licancabur) is the site of several observatories, including the

Llano de Chajnantor Observatory Llano de Chajnantor Observatory is the name for a group of astronomical observatories located at an altitude of over 4,800 m (15,700 ft) in the Atacama Desert of northern Chile. The site is in the Antofagasta Region approximately 50 ki ...

. Licancabur is a -high symmetrical cone. The cone rises above the surrounding terrain, covering a base diameter of . The volcano has a total volume of , with mean slopes of the cone being about 30°. The volcano has erupted blocky lava flows, with thicknesses ranging from ; younger lava flows are thinner. Young lava flows on the western sides of the volcano are long; older flows extend . Some old lava flows reach Laguna Verde, and -long

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 b ...

deposits have been found. There are no glacial cirques on the volcano. The volcano's eastern and western flanks have distinct appearances, since it formed on a basement which dips towards the Salar de Atacama. West of Licancabur are deposits stemming from debris avalanche activity, including blocks wide.

Crater and lake

The top of the mountain features a -wide crater which contains an elliptical lake. The lake is below the crater rim, it has a length of and a depth of . Fed by snowfall, it is one of the highest lakes in the world. Based on its relative lack of salt deposits, in 1955 researchers postulated that the lake spilled through a notch in the crater's southwestern rim when the climate was wetter. Excess water now leaves through seepage, keeping salt levels low. There are other lakes (usually frozen) at similar altitudes in the Andes.

Neighbouring volcanoes

Licancabur is just south of Sairecabur, a group of volcanoes which rises to and is an apparent source of recent volcanic activity. East of Licancabur is its companion volcano, Juriques. It is high and has a large——deep crater. West–east alignments of volcanoes like Licancabur and Juriques are common in the region, due to tectonic influences. Araral, Cerro Cabana, Cerro Canapa, Cerros de Tocorpuri, Cerro Linzor, Inacaliri, Inca, Jardin, Putana, Volcan Tatio and Zapaleri are other volcanoes in the neighbourhood of Licancabur. southeast, volcanoes continue with Tocol, the Purico Complex and the -high Llullaillaco. Volcanoes in the

Puna de Atacama The Puna de Atacama or Atacama Plateau''Atacama Plateau''
article at the ''

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Tertiary Tertiary ( ) is a widely used but obsolete term for the geologic period from 66 million to 2.6 million years ago. The period began with the demise of the non-avian dinosaurs in the Cretaceous–Paleogene extinction event, at the start ...

dacitic, liparitic and

rhyolitic 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 ...

ignimbrites. These rocks have a light colour, due to the rhyolite. Licancabur grew over the 1.35-million-year-old Purico, the

La Pacana La Pacana is a Miocene age caldera in northern Chile's Antofagasta Region. Part of the Central Volcanic Zone of the Andes, it is part of the Altiplano-Puna volcanic complex, a major caldera and silicic ignimbrite volcanic field. This volcanic f ...

and 1.09±0.56-million-year-old Chaxas ignimbrites.

Composition

Licancabur has erupted primarily andesite, but basaltic andesite and dacite have also been found. The rocks are dark and grey-coloured. Basaltic andesite is present in the older lavas, and dacite in the more-recent ones. Although the rocks have a seriate texture, the

groundmass The matrix or groundmass of a rock is the finer-grained mass of material in which larger grains, crystals, or clasts are embedded. The matrix of an igneous rock consists of finer-grained, often microscopic, crystals in which larger crystals, ...

hyalopilitic Hyalopilitic is a textural term used in petrographic classification of volcanic rocks. Specifically, hyalopilitic refers to a volcanic rock groundmass, which is visible only under magnification with a petrographic microscope, that contains a mix ...

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 include amphibole,

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 I ...

hornblende Hornblende is a complex inosilicate series of minerals. It is not a recognized mineral in its own right, but the name is used as a general or field term, to refer to a dark amphibole. Hornblende minerals are common in igneous and metamorphic rock ...

, orthopyroxene,

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 pro ...

and titanomagnetite;

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 ...

is found in andesite, and biotite in dacites. Plagioclase is the most common. The amount of phenocrysts in Licancabur's rocks is smaller than that in other Central Volcanic Zone volcanoes, such as

. Clots of crystals with diameters of or larger have also been found. They contain glass,

microlith A microlith is a small stone tool usually made of flint or chert and typically a centimetre or so in length and half a centimetre wide. They were made by humans from around 35,000 to 3,000 years ago, across Europe, Africa, Asia and Australia. Th ...

s and phenocrysts, and have a composition similar to phenocrysts. The clots probably formed from the aggregation of phenocrysts and their subsequent growth; some phenocrysts in the rocks formed when the clots broke apart. The temperature of Licancabur's pre-eruption magma determined the composition of the rocks; it ranges from for dacite to for andesite.

Isotope Isotopes are two or more types of atoms that have the same atomic number (number of protons in their nuclei) and position in the periodic table (and hence belong to the same chemical element), and that differ in nucleon numbers (mass numb ...

ratios are typical of Central Volcanic Zone volcanoes. There are differences in the elemental composition of andesites and dacites, with the latter resembling

adakite Adakites are volcanic rocks of intermediate to felsic composition that have geochemical characteristics of magma originally thought to have formed by partial melting of altered basalt that is subducted below volcanic arcs. Most magmas derived ...

s more than the former.

Antisana Antisana is a stratovolcano of the northern Andes, in Ecuador. It is the fourth highest volcano in Ecuador, at , and is located SE of the capital city of Quito. Antisana presents one of the most challenging technical climbs in the Ecuadorian ...

(in the Northern Volcanic Zone) and El Negrillar (in the Central Volcanic Zone) are two other volcanoes which have erupted adakites or adakite-like lavas. Based on its composition, it is assumed that the magma at Licancabur formed from the

partial melting Partial melting occurs when only a portion of a solid is melted. For mixed substances, such as a rock containing several different minerals or a mineral that displays solid solution, this melt can be different from the bulk composition of the soli ...

of the

oceanic crust Oceanic crust is the uppermost layer of the oceanic portion of the tectonic plates. It is composed of the upper oceanic crust, with pillow lavas and a dike complex, and the lower oceanic crust, composed of troctolite, gabbro and ultramafic ...

subducted at the Peru-Chile Trench after metamorphosis. This magma melted part of the

mantle wedge A mantle wedge is a triangular shaped piece of mantle that lies above a subducting tectonic plate and below the overriding plate. This piece of mantle can be identified using seismic velocity imaging as well as earthquake maps. Subducting oceanic ...

above the subducting plate, mixing with the melt products. Further contamination by crustal Tonalite-Trondhjemite-Granodiorite-like rocks from the

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 during the Arc ...

, crystal fractionation and magma mixing further up in the crust then yielded the Licancabur magmas. The younger lavas may have formed from the mixing of dacite with the magmas forming the older lavas. Some inclusions in Licancabur rocks seem to be have originated as wall rocks of 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 up ...

Xenolith A xenolith ("foreign rock") is a rock fragment ( country rock) that becomes enveloped in a larger rock during the latter's development and solidification. In geology, the term ''xenolith'' is almost exclusively used to describe inclusions in ig ...

s containing

gabbro Gabbro () is a phaneritic (coarse-grained), mafic intrusive igneous rock formed from the slow cooling of magnesium-rich and iron-rich magma into a holocrystalline mass deep beneath the Earth's surface. Slow-cooling, coarse-grained gabbro is ch ...

are also found. Unlike neighbouring volcanoes, such as Saciel at Sairecabur (further north) and Tocol (further south), there appear to be no sulfur deposits on Licancabur.

Climate and ecosystem

Llamas, volcan Licancabur, Atacama, Chile

The region's climate has been dry since the Tertiary. The area around Licancabur is dominated by year-round

high pressure In science and engineering the study of high pressure examines its effects on materials and the design and construction of devices, such as a diamond anvil cell, which can create high pressure. By ''high pressure'' is usually meant pressures of th ...

caused by the South Pacific High, giving it a very sunny climate. Because of the lack of

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 ...

, the energy from solar radiation is dissipated primarily by

wind Wind is the natural movement of air or other gases relative to a planet's surface. Winds occur on a range of scales, from thunderstorm flows lasting tens of minutes, to local breezes generated by heating of land surfaces and lasting a few ho ...

. In the Llano de Chajnantor area, wind generally reaches its maximum strength during the day. Its prevailing direction is from the west, except in summer when winds are more variable. Because of the area's tropical location (where the ozone layer is thinner) and high altitude, it receives a large amount of ultraviolet (UV) radiation. The world's highest level of UV radiation (

UV index The ultraviolet index, or UV index, is an international standard measurement of the strength of the sunburn-producing ultraviolet (UV) radiation at a particular place and time. It is primarily used in daily and hourly forecasts aimed at the general ...

of 43.3>) was reported from Licancabur, although the high irradiation might have caused measurement artifacts. Air temperatures obtained at the lake in Licancabur's crater range from . According to observers in 1955, temperatures at the Licancabur summit were always below freezing, sometimes falling below . At Llano de Chajnantor, southeast of Licancabur, weather records indicate that maximum temperatures range from . Average precipitation on Licancabur is estimated at per year, but snowfall probably exceeded in 1955. Snow has been recorded at Llano de Chajnantor when in summer easterly winds transport moisture from 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 technolog ...

to the area. Licancabur has no persistent

snow Snow comprises individual ice crystals that grow while suspended in the atmosphere—usually within clouds—and then fall, accumulating on the ground where they undergo further changes. It consists of frozen crystalline water throughout ...

pack; snow deposited by storms usually disappears within a few days. In sheltered areas, however, it can persist for months, and a 1985 map shows a persistent snow/ice cover at the summit. The elevation of the snow line at Licancabur is estimated to be . ALMA Dwarfed by Mountain Peaks

Licancabur is part of the

Eduardo Avaroa Andean Fauna National Reserve The Eduardo Avaroa Andean Fauna National Reserve (''Reserva Nacional de Fauna Andina Eduardo Avaroa''; Spanish acronym: REA) is located in Sur Lípez Province. Situated in the far southwestern region of Bolivia, it is the country's most visit ...

. Vegetation at lower altitudes is typical of a high tropical desert climate. Three

biozone In biostratigraphy, biostratigraphic units or biozones are intervals of geological strata that are defined on the basis of their characteristic fossil taxa, as opposed to a lithostratigraphic unit which is defined by the lithological properties ...

s have been described in the region: an Andean zone from , with

cushion plant A cushion plant is a compact, low-growing, mat-forming plant that is found in alpine, subalpine, arctic, or subarctic environments around the world. The term "cushion" is usually applied to woody plants that grow as spreading mats, are limited in ...

s and

tussock grass Tussock grasses or bunch grasses are a group of grass species in the family Poaceae. They usually grow as singular plants in clumps, tufts, hummocks, or bunches, rather than forming a sod or lawn, in meadows, grasslands, and prairies. As perenni ...

; a Puna zone from , and a pre-Puna zone from with thorny shrubs. In oases and

river valley A valley is an elongated low area often running between hills or mountains, which will typically contain a river or stream running from one end to the other. Most valleys are formed by erosion of the land surface by rivers or streams ...

s of the depression between the pre-Cordillera and the Andes, shrubs such as '' Atriplex'' grow; however, the surrounding

Atacama Desert The Atacama Desert ( es, Desierto de Atacama) is a desert plateau in South America covering a 1,600 km (990 mi) strip of land on the Pacific coast, west of the Andes Mountains. The Atacama Desert is the driest nonpolar desert in th ...

is mostly devoid of plant life. At higher altitudes, meltwater from snow supports more life on Licancabur than on similar mountains. Chinchillas (in 1955),

grass Poaceae () or Gramineae () is a large and nearly ubiquitous family of monocotyledonous flowering plants commonly known as grasses. It includes the cereal grasses, bamboos and the grasses of natural grassland and species cultivated in lawns a ...

es, tola bushes, butterflies,

flies Flies are insects of the order Diptera, the name being derived from the Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwings having evolved into advanced m ...

and lizards are found at elevations reaching above sea level. Life further down the mountain could be supported by the fertilizing effect of dust from volcanic rocks. '' Polylepis incana'' might have been more prevalent at Licancabur during wetter times, and is now more common in Bolivia. The upper parts of the mountain had been avoided by hunters, and after some attempts at high elevations during the 1920s chinchilla hunting disappeared from the area.

Eruptive history

Licancabur formed as three units, all of which feature lava flows; the last one also includes pyroclastic deposits. The bulk of the cone was formed by the second unit. The emplacement of the second unit was preceded by the injection of basic

magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma is found beneath the surface of the Earth, and evidence of magmatism has also been discovered on other terrestrial planets and some natural sa ...

into the magma chamber. The oldest flows crop out on the western and northern sides of the volcano and are partially covered by more-recent flows from Licancabur and flows from Sairecabur. The neighbouring Juriques dates to the Pleistocene. Flows from both volcanoes appear to be pre-glacial. The older lavas have compositions similar to

shoshonite Shoshonite is a type of igneous rock. More specifically, it is a potassium-rich variety of basaltic trachyandesite, composed of olivine, augite and plagioclase phenocrysts in a groundmass with calcic plagioclase and sanidine and some dark-colored v ...

and to old Sairecabur lavas, and tend to be more basic than recent lavas. Weak explosive activity left pyroclastic deposits on the volcano. Laguna Verde, Bolivia, 2016-02-02, DD 74

Laguna Verde, Bolivia, 2016-02-02, DD 74

Licancabur formed primarily after the late

glacial A glacial period (alternatively glacial or glaciation) is an interval of time (thousands of years) within an ice age that is marked by colder temperatures and glacier advances. Interglacials, on the other hand, are periods of warmer climate betwe ...

period, between 12,000 and 10,000 years ago. Flank lava flows are its youngest feature: They were not affected by glaciation, and some have levees and ridges. Lava flows reaching Laguna Verde have been

radiocarbon Carbon-14, C-14, or radiocarbon, is a radioactive isotope of carbon with an atomic nucleus containing 6 protons and 8 neutrons. Its presence in organic materials is the basis of the radiocarbon dating method pioneered by Willard Libby and c ...

dated to 13,240 ± 100 BP, and 13,270 ± 100 years old lacustrine sediments have been buried by flows. The volcano has not erupted during

recorded history Recorded history or written history describes the historical events that have been recorded in a written form or other documented communication which are subsequently evaluated by historians using the historical method. For broader world his ...

, and the state of Inca ruins indicates that eruptions during the last millennium are improbable, Bubbling and water temperatures of have been observed in the crater lake of Licancabur, which may remain liquid due to geothermal heating. Renewed activity would most likely consist of the emission of lava and pyroclastic flows either from the crater or the flanks.

Human settlement

Ruinas Incas a los pies del volcán Licancabur Bolivia

Despite being lower than many neighbouring mountains, Licancabur stands out from other volcanoes in the region and is well-known. The Atacameno people worshiped it, and other high mountains are still considered sacred. Licancabur was considered divine, and attempts to climb it were discouraged and sometimes met by force; climbing it supposedly brought misfortune. It is said that Licancabur would punish people who climbed it, and the was considered divine retribution for an attempt to climb the mountain that year. The volcano is the mate of Quimal in the Cordillera Domeyko; at the

solstice A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countr ...

s, the mountains overshadow one another. According to local myth, this

copulation Sexual intercourse (or coitus or copulation) is a sexual activity typically involving the insertion and thrusting of the penis into the vagina for sexual pleasure or reproduction.Sexual intercourse most commonly means penile–vaginal penetra ...

fertilizes the earth. Another legend mentions that a legless Inka king lived on Licancabur's summit; he was carried around in a litter and sometimes the carriers died from exhaustion and were buried with treasures. There is a story about Inkas hiding

gold Gold is a chemical element with the symbol Au (from la, aurum) and atomic number 79. This makes it one of the higher atomic number elements that occur naturally. It is a bright, slightly orange-yellow, dense, soft, malleable, and ductile me ...

and

silver Silver is a chemical element with the symbol Ag (from the Latin ', derived from the Proto-Indo-European ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, white, lustrous transition metal, it exhibits the highest electrical ...

in the crater lake; the wares disappeared and supposedly turned the lake bitter and emerald-green. Licancabur is considered "male" and a mountain of fire, in contrast to San Pedro (considered a mountain of water). According to legend, a

en object (most commonly a

guanaco The guanaco (; ''Lama guanicoe'') is a camelid native to South America, closely related to the llama. Guanacos are one of two wild South American camelids, the other being the vicuña, which lives at higher elevations. Etymology The guanaco ...

) was offered as tribute in the summit crater;

human sacrifice Human sacrifice is the act of killing one or more humans as part of a ritual, which is usually intended to please or appease gods, a human ruler, an authoritative/priestly figure or spirits of dead ancestors or as a retainer sacrifice, wherein ...

s have been reported on the volcano. Between 1,500 and 1,000 years ago, people were buried in

San Pedro de Atacama San Pedro de Atacama is a Chilean town and commune in El Loa Province, Antofagasta Region. It is located east of Antofagasta, some 106 km (60 mi) southeast of Calama and the Chuquicamata copper mine, overlooking the Licancabur volcano. ...

in a posture facing the volcano and the Pukará de Quitor fortress in Chile is also oriented towards the mountain. In 1953, climbers found three buildings on one side on Licancabur. They were built in the '' pirca'' style, where stones are fitted together without mortar. A woodpile was found between two of the buildings, which were described as two dwellings and a fireplace. There is a ceremonial platform on the top of Licancabur. Wood was also scattered around its crater. With the summit's panoramic view, which includes Calama and pass routes from

Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...

, Licancabur may have been a watchtower for the Atacamenos. Its watchtower function may have been coordinated with fortresses in the area such as

Lasana Lasana is a small village located northeast of the city of Calama in the Calama province of Chile's northern Antofagasta Region. It sits along the banks of the Loa River. Pukará de Lasana, (Quechua ''pukara'' fortress), a pre-Columbian In the ...

, Turi and a settlement identified in 1955 at Quebrada de Chaxas (northwest of the volcano). The settlement at Licancabur had a central courtyard, surrounded by buildings, and ceramics found there resemble these of Pukará de Quitor and Toconao Oriente. A '' tambo'' reportedly existed at the volcano, and its construction is indicative of the influence the Inca state had over the region. 325 Pueblo de San Pedro

Other archeological findings on Andean mountains were made on

Acamarachi __NOTOC__ Acamarachi (also known as ''Pili'') is a high volcano in northern Chile. In this part of Chile, it is the highest volcano. Its name means "black moon". It is a volcano in the Central Volcanic Zone of the Andes, a zone of strong volcani ...

and Pular (where ceremonial platforms were found), Cerro Colorado, Juriques, Llullaillaco, Miniques and Quimal. Sites had ''pirca'' structures and firewood, and some may have been part of a signaling system. Many were in use during the

Inca civilization The Incas were most notable for establishing the Inca Empire in Pre-Columbian America, which was centered in modern day South America in Peru and Chile. It was about 2,500 miles from the northern to southern tip. The civilization lasted from 1 ...

, and on Quimal artifacts correlative to the Spanish period have been found.

Aconcagua Aconcagua () is a mountain in the Principal Cordillera of the Andes mountain range, in Mendoza Province, Argentina. It is the highest mountain in the Americas, the highest outside Asia, and the highest in the Southern Hemisphere with a summi ...

Coropuna Coropuna is a dormant compound volcano located in the Andes mountains of southeast-central Peru. The upper reaches of Coropuna consist of several perennially snowbound conical summits, lending it the name Nevado Coropuna in Spanish. The compl ...

Chachani Chachani is a volcanic group in southern Peru, northwest of the city of Arequipa. Part of the Central Volcanic Zone of the Andes, it is above sea level. It consists of several lava domes and individual volcanoes such as Nocarane, along with ...

, El Plomo, El Toro, Llullaillaco, Mercedario and Picchu Picchu are other mountains with Inca sanctuaries. The area around Licancabur was first settled by the Atacameno people, presumably because of the water in local canyons. The Incas, under

Yawar Waqaq Yawar Waqaq (Hispanicized spellings ''Yahuar Huacac, Yáhuar Huácac'') or Yawar Waqaq Inka was the seventh Sapa Inca of the Kingdom of Cusco (beginning around CE 1380) and the second of the Hanan dynasty. His father was Inca Roca Inca Roca (Qu ...

, were followed by the Spanish during the early 16th century in the region; both were looking for ''

yareta __NOTOC__ Yareta or llareta (''Azorella compacta'', known historically as ''Azorella yareta'', from ''yarita'' in the Quechua language) is a velvety, chartreuse cushion plant in the family Apiaceae which is native to South America. It grows in th ...

'' and chinchillas.

Climbing

Unlike neighbouring mountains, Licancabur is difficult to climb; its upper part slopes steeply, and the ground is loose and prone to landslides. Some of the instability may be due to

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, fr ...

s, snow, wind or geothermal effects (resulting in

thermal stress In mechanics and thermodynamics, thermal stress is mechanical stress created by any change in temperature of a material. These stresses can lead to fracturing or plastic deformation depending on the other variables of heating, which include mat ...

), and it frustrated an attempt of an engineer at

Chuquicamata Chuquicamata ( ; referred to as Chuqui for short) is the largest open pit copper mine in terms of excavated volume in the world. It is located in the north of Chile, just outside Calama, at above sea level. It is northeast of Antofagasta and ...

to climb the mountain in the 1920s. Ascent from the Bolivian side takes six hours plus half that time for the descent and requires caution during winter, although the mountain can be climbed during any month. Rumours about a "staircase", later probably obliterated by landslides and rockfalls, were reported in 1955. In 1953, a road climbed to . The first recorded ascent of the volcano was in 1884 by Severo Titicocha, who was accompanied by Juan Santelices (a delegate of the Chilean government) in an 1886 ascent.

Landmine A land mine is an explosive weapon, explosive device concealed under or on the ground and designed to destroy or disable enemy targets, ranging from combatants to vehicles and tanks, as they pass over or near it. Such a device is typically d ...

s have been reported from the Chilean side.

Notes

References

Sources

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General sources

* *
NASA Licancabur Expedition: Exploring the Highest Lakes on Earth
*

External links

Lake Licancabur

– (In Spanish). {{authority control Volcanoes of Antofagasta Region Volcanoes of Potosí Department Andean Volcanic Belt Stratovolcanoes of Bolivia Stratovolcanoes of Chile Subduction volcanoes Bolivia–Chile border International mountains of South America Mountains of Chile Volcanic crater lakes Polygenetic volcanoes Holocene stratovolcanoes Quaternary South America Five-thousanders of the Andes