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 p ...
on the border between
Bolivia
, image_flag = Bandera de Bolivia (Estado).svg
, flag_alt = Horizontal tricolor (red, yellow, and green from top to bottom) with the coat of arms of Bolivia in the center
, flag_alt2 = 7 × 7 square p ...
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 eas ...
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 ...
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 fills ...
which is among the highest lakes in the world, caps the volcano. Three stages of
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 un ...
s 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 ...
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 Laguna Verde, the Spanish-language form of ''green lagoon'' or ''green lake'', may refer to:
Bolivia
*Laguna Verde (Bolivia), a salt lake in Potosi Department
*Laguna Verde (Beni), a lake in Beni Department
*Laguna Verde (Comarapa), a lake in Comar ...
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 predomina ...
, 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 rhy ...
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 Ameri ...
.
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 nanometer, nm (with a corresponding frequency around 30 Hertz, PHz) to 400 nm (750 Hertz, THz), shorter than that of visible light, but longer than ...
. 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 a ...
Chinchilla
Chinchillas are either of two species ('' Chinchilla chinchilla'' and '' Chinchilla lanigera'') of crepuscular rodents of the parvorder Caviomorpha. They are slightly larger and more robust than ground squirrels, and are native to the Andes m ...
s 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 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 t ...
.
Name
"Licancabur" derives from the Kunza words used by the Atacameño 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
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 ...
subducts
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 ...
South American 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 Mi ...
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 American ...
(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
A lithosphere () is the rigid, outermost rocky shell of a terrestrial planet or natural satellite. On Earth, it is composed of the crust and the portion of the upper mantle that behaves elastically on time scales of up to thousands of years ...
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 p ...
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 ridges 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
A mantle is a piece of clothing, a type of cloak. Several other meanings are derived from that.
Mantle may refer to:
*Mantle (clothing), a cloak-like garment worn mainly by women as fashionable outerwear
**Mantle (vesture), an Eastern Orthodox ve ...
and inducing the formation of melts.
Not all volcanism in Chile is relative to subduction of the Nazca Plate; the Chile Ridge exhibits
submarine volcanism
A submarine (or sub) is a watercraft capable of independent operation underwater. It differs from a submersible, which has more limited underwater capability. The term is also sometimes used historically or colloquially to refer to remotely op ...
, and volcanism in the Austral Volcanic Zone is triggered by the Antarctic Plate 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 act ...
'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 a ...
. Among the active volcanoes of the region are Putana (erupted at the end of the 19th century), Llullaillaco (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 t ...
Tacora
Tacora is a stratovolcano located in the Andes of the Arica y Parinacota Region of Chile. Near the border with Peru, it is one of the northernmost volcanoes of Chile. It is part of the Central Volcanic Zone in Chile, one of the four volcanic b ...
, Nevados de Payachata, Isluga, Tata Sabaya, Ollague, Tocorpuri, Sairecabur and Socompa. 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 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 means "less recent" ...
, 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.
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 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 un ...
s, 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
cirque
A (; from the Latin word ') is an amphitheatre-like valley formed by glacial erosion. Alternative names for this landform are corrie (from Scottish Gaelic , meaning a pot or cauldron) and (; ). A cirque may also be a similarly shaped landf ...
s 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 Araral is an extinct volcano located in the Andes on the border between Chile and Bolivia in the Potosí Department and in the Antofagasta Region. It has a height of 5647 metres, rising over a base of 3900 metres and covers an area of . ...
,
Cerro Cabana
Cerro is Spanish for "hill" or "mountain".
Toponyms
;Bolivia:
* Cerro Rico, the "Rich Mountain" containing silver ore near Potosi, Bolivia
;Brazil:
*Cerro Branco, a municipality of Rio Grande do Sul
*Cerro Grande, Rio Grande do Sul, a municip ...
Cerros de 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 s ...
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 ignimbrites. These rocks have a light colour, due to the rhyolite. Licancabur grew over the 1.35-million-year-old Purico, the La Pacana 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
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, c ...
Phenocryst
300px, 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 2.3 cm) for scale.
A phenocryst is an early forming, relati ...
s include
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 ...
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 ro ...
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 ...
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 qui ...
is found in andesite, and
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 alum ...
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
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 t ...
.
Clots of crystals with diameters of or larger have also been found. They contain glass, microliths 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 number ...
ratios are typical of Central Volcanic Zone volcanoes. There are differences in the elemental composition of andesites and dacites, with the latter resembling adakites 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 And ...
(in the Northern Volcanic Zone) and
El Negrillar
El Negrillar is a volcanic field in the Andes. Located south of the Salar de Atacama and west of the Cordón de Púlar, it generated cinder cones and lava flows. Covering a surface area of , it is the largest volcanic field in northern Chile, wit ...
(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 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 ultramafi ...
Archean
The Archean Eon ( , also spelled Archaean or Archæan) is the second of four eon (geology), geologic eons of History of Earth, Earth's history, representing the time from . The Archean was preceded by the Hadean Eon and followed by the Proterozo ...
, 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 i ...
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 ...
are also found. Unlike neighbouring volcanoes, such as Saciel at Sairecabur (further north) and Tocol (further south), there appear to be no
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 formul ...
deposits on Licancabur.
Climate and ecosystem
The region's climate has been dry since the Tertiary. The area around Licancabur is dominated by year-round high pressure 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 ...
. 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
The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in rel ...
is thinner) and high altitude, it receives a large amount of ultraviolet (UV) radiation. The world's highest level of UV radiation ( UV index 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
An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet ...
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
The climatic snow line is the boundary between a snow-covered and snow-free surface. The actual snow line may adjust seasonally, and be either significantly higher in elevation, or lower. The permanent snow line is the level above which snow wil ...
at Licancabur is estimated to be .
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 visited ...
. 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 plants 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
In ecology, an oasis (; ) is a fertile area of a desert or semi-desert environmentriver 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 ov ...
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 the ...
is mostly devoid of plant life.
At higher altitudes, meltwater from snow supports more life on Licancabur than on similar mountains.
Chinchilla
Chinchillas are either of two species ('' Chinchilla chinchilla'' and '' Chinchilla lanigera'') of crepuscular rodents of the parvorder Caviomorpha. They are slightly larger and more robust than ground squirrels, and are native to the Andes m ...
s (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 law ...
butterflies
Butterflies are insects in the macrolepidopteran clade Rhopalocera from the order Lepidoptera, which also includes moths. Adult butterflies have large, often brightly coloured wings, and conspicuous, fluttering flight. The group comprises t ...
,
flies
Flies are insects of the Order (biology), order Diptera, the name being derived from the Ancient Greek, Greek δι- ''di-'' "two", and πτερόν ''pteron'' "wing". Insects of this order use only a single pair of wings to fly, the hindwing ...
and
lizard
Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia al ...
s 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
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 ...
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
BASIC (Beginners' All-purpose Symbolic Instruction Code) is a family of general-purpose, high-level programming languages designed for ease of use. The original version was created by John G. Kemeny and Thomas E. Kurtz at Dartmouth College ...
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 natura ...
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 and to old Sairecabur lavas, and tend to be more basic than recent lavas. Weak explosive activity left pyroclastic deposits on the volcano.
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
levee
A levee (), dike (American English), dyke (Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually earthen and that often runs parallel to the course of a river in its floodplain or along low-lying coastl ...
s and
ridge
A ridge or a mountain ridge is a geographical feature consisting of a chain of mountains or hills that form a continuous elevated crest for an extended distance. The sides of the ridge slope away from the narrow top on either side. The line ...
s. 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 co ...
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 hi ...
, 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
Despite being lower than many neighbouring mountains, Licancabur stands out from other volcanoes in the region and is well-known. The
Atacameno
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, 13,93 ...
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
The Cordillera Domeyko is a mountain range of the Andes located in northern Chile, west of Salar de Atacama. It runs north-south for approximately 600 km, parallel to the main chain. The mountain range marks the eastern border of the fla ...
; 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 count ...
s, the mountains overshadow one another. According to local myth, this copulation 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 ...
and
silver
Silver is a chemical element with the Symbol (chemistry), symbol Ag (from the Latin ', derived from the Proto-Indo-European wikt:Reconstruction:Proto-Indo-European/h₂erǵ-, ''h₂erǵ'': "shiny" or "white") and atomic number 47. A soft, whi ...
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
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 ...
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, wherei ...
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 volca ...
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, t ...
, Licancabur may have been a watchtower for the Atacamenos. Its watchtower function may have been coordinated with fortresses in the area such as Lasana, 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.
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 volcan ...
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
Signalling System No. 7 (SS7) is a set of telephony signaling protocols developed in 1975, which is used to set up and tear down telephone calls in most parts of the world-wide public switched telephone network (PSTN). The protocol also perform ...
. 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, Chachani, 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
canyon
A canyon (from ; archaic British English spelling: ''cañon''), or gorge, is a deep cleft between escarpments or cliffs resulting from weathering and the erosive activity of a river over geologic time scales. Rivers have a natural tendency to cut ...
s. The Incas, under Yawar Waqaq, were followed by the Spanish during the early 16th century in the region; both were looking for '' yareta'' and chinchillas.
Climbing
Unlike neighbouring mountains, Licancabur is difficult to climb; its upper part slopes steeply, and the ground is loose and prone to
landslide
Landslides, also known as landslips, are several forms of mass wasting that may include a wide range of ground movements, such as rockfalls, deep-seated slope failures, mudflows, and debris flows. Landslides occur in a variety of environments, ...
s. 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, from ...
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 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 detonated automati ...