Paniri (

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 ...

for "he who comes, visits") 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 ...

located in

El Loa Province El Loa Province ( es, Provincia El Loa) is one of three provinces of the northern Chilean region of Antofagasta (II). It is named after the longest of rivers in Chile, the Loa River. The provincial capital is Calama. Geography and demography A ...

Antofagasta Region The Antofagasta Region ( es, Región de Antofagasta, ) is one of Chile's sixteen first-order administrative divisions. The second-largest region of Chile in area, it comprises three provinces, Antofagasta, El Loa and Tocopilla. It is bordered t ...

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 ...

, and near the border with

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 ...

. To its northwest lie the twin volcanoes San Pedro and San Pablo, and to its southeast lies

Cerro del León Cerro del León is a stratovolcano located in El Loa province, Antofagasta Region, Chile. It is part of the Chilean Central Volcanic Zone and forms a volcanic lineament with neighbouring Paniri and Toconce that was active into the Holocene. Cer ...

, from which it is separated by the huge '' Chao''

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 ...

. The volcano features lava flows, which are well preserved on the south-southwest flanks, and a

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

on its summit. The volcano has three craters. Paniri also shows evidence of

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#Glaciology, ablation over many years, often Century, centuries. It acquires dis ...

activity on its southeastern slope. The volcano developed in several different stages with substages; the first stage formed a shield like volcano with most of its volume, the later ones formed the cone and "main edifice". One date obtained from the youngest stage is 150,000 years ago, with an uncertainty of 6,000 years. Once considered of

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 ...

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 ...

age, Paniri was later determined that to be of Pleistocene age. Paniri is part of the San Pedro-Linzor volcanic chain, a chain of volcanoes formed by

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 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 ...

s. Composition of the rocks erupted by Paniri ranges from

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 ...

and

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. ...

Geography and geomorphology

Paniri lies in the

Antofagasta Province Antofagasta Province ( es, Provincia de Antofagasta) is one of three provinces in the northern Chilean region of Antofagasta (II). The capital is the port city of Antofagasta. Located within the Atacama Desert, it borders the El Loa and Tocopil ...

.Hegna and Lazo-Wasem 2010, p.446 The volcano rises between Cerro Carcanal in the west and

Cerro del Leon 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 ...

in the east.

Road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...

s lead around the northern and western flanks of the volcano.Godoy ''et al.'' 2018, p.188 The large lava flow

Cerro Chao Cerro Chao is a lava flow complex associated with the Cerro del León volcano in the Andes. It is the largest known Quaternary silicic volcano body and part of the most recent phase of activity in the Altiplano–Puna volcanic complex. Cerro Cha ...

borders Paniri to the southeast and separates it from Cerro del Leon. The towns of Cupo and Turi lie west-southwest and south-southwest of Paniri, respectively. Paniri is part of the

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 ...

, a volcanic belt in the Andes. Other than Paniri, other volcanoes in the Central Volcanic Zone are

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 ...

Sabancaya Sabancaya is an active stratovolcano in the Andes of southern Peru, about northwest of Arequipa. It is considered part of the Central Volcanic Zone of the Andes, one of the three distinct volcanic belts of the Andes. The Central Volcanic Zone i ...

and

Ubinas Ubinas is an active stratovolcano in the Moquegua Region of southern Peru, approximately east of the city of Arequipa. Part of the Central Volcanic Zone of the Andes, it rises above sea level. The volcano's summit is cut by a and caldera, wh ...

, as well as geothermal fields such as

El Tatio El Tatio is a geothermal field with many geysers located in the Andes Mountains of northern Chile at above mean sea level. It is the third-largest geyser field in the world and the largest in the Southern Hemisphere. Various meanings have bee ...

.Godoy ''et al.'' 2018, p.185 The volcano is formed by about two units and contains three summit craters and one vent; one of the craters contains a

crater lake Crater Lake (Klamath language, 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 ...

Godoy ''et al.'' 2018, p.187 with dimensions of . The volcano is topped off with a

. Thick

s extend from the summit and form the foot of Paniri.

Gullies A gully is a landform created by running water, mass movement, or commonly a combination of both eroding sharply into soil or other relatively erodible material, typically on a hillside or in river floodplains or terraces. Gullies resemble lar ...

cut into its slopes and

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 have developed around its summit.

Geology

Since the

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately Mya. The J ...

, 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 ...

has been

subducting 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 ...

beneath the western margin of South America. This subduction process is responsible for the volcanism in the

of the Andes, one of four

volcanic arc A volcanic arc (also known as a magmatic arc) is a belt of volcanoes formed above a subducting oceanic tectonic plate, with the belt arranged in an arc shape as seen from above. Volcanic arcs typically parallel an oceanic trench, with the arc lo ...

s in the Andes. The volcano is mainly of

age, but well preserved surface features indicate it may be still active. Other parts of the volcano have been subject to

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 betw ...

erosion and

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 ...

alteration, and

evaporite An evaporite () is a water-soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocea ...

deposits have formed on its feet. The basement that Paniri is constructed on consists of both

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 ...

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 recen ...

sediments of the San Pedro formation and

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 surrou ...

s of

age which are formed by

rhyodacitic Rhyodacite is a volcanic rock intermediate in composition between dacite and rhyolite. It is the extrusive equivalent of those plutonic rocks that are intermediate in composition between monzogranite and granodiorite. Rhyodacites form from rapid ...

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 ...

material. Atop this basement Paniri developed together with other volcanoes such as

in a linear volcanic chain, the San Pedro-Linzor complex which is formed 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

s and whose existence may be due to a tectonic

lineament ''See also Line (geometry)'' A lineament is a linear feature in a landscape which is an expression of an underlying geological structure such as a fault. Typically a lineament will appear as a fault-aligned valley, a series of fault or fold-aligne ...

. Paniri has erupted rocks ranging from

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 ...

, which mainly 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 ...

volcanic suite.Godoy ''et al.'' 2018, p.192

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

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) ...

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 rocks ...

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 ...

, opaque minerals,

orthopyroxene 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) ...

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 ...

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 ...

and

rutile Rutile is an oxide mineral composed of titanium dioxide (TiO2), the most common natural form of TiO2. Rarer Polymorphism (materials science), polymorphs of TiO2 are known, including anatase, akaogiite, and brookite. Rutile has one of the highest ...

; the exact composition varies between various units. Alteration of the erupted rocks has given rise to

clay Clay is a type of fine-grained natural soil material containing clay minerals (hydrous aluminium phyllosilicates, e.g. kaolin, Al2 Si2 O5( OH)4). Clays develop plasticity when wet, due to a molecular film of water surrounding the clay par ...

chlorite The chlorite ion, or chlorine dioxide anion, is the halite with the chemical formula of . A chlorite (compound) is a compound that contains this group, with chlorine in the oxidation state of +3. Chlorites are also known as salts of chlorous ac ...

epidote Epidote is a calcium aluminium iron sorosilicate mineral. Description Well developed crystals of epidote, Ca2Al2(Fe3+;Al)(SiO4)(Si2O7)O(OH), crystallizing in the monoclinic system, are of frequent occurrence: they are commonly prismatic in habi ...

and

illite Illite is a group of closely related non-expanding clay minerals. Illite is a secondary mineral precipitate, and an example of a phyllosilicate, or layered alumino-silicate. Its structure is a 2:1 sandwich of silica tetrahedron (T) – alumina ...

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 ...

genesis at Paniri appears to involve both the assimilation of crustal rocks in the Altiplano-Puna volcanic complex and

fractional crystallization Fractional crystallization may refer to: * Fractional crystallization (chemistry), a process to separate different solutes from a solution * Fractional crystallization (geology) Fractional crystallization, or crystal fractionation, is one of the ...

processes in shallow

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 ...

Life and human history

The

fairy shrimp Anostraca is one of the four orders of crustaceans in the class Branchiopoda; its members are referred to as fairy shrimp. They live in vernal pools and hypersaline lakes across the world, and they have even been found in deserts, ice-covered mou ...

'' Branchinecta brushi'' was discovered in 2009 in the crater lake of Paniri. The occurrence of this shrimp at Paniri made it the highest finding of

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group ...

s known. Native people, considered to be Inka, made the first ascents of this mountain. Claudio Lucero and Nelson Muñoz made the first recorded ascent of Paniri in 1972. They found archaeological remains on its summit,Humberto Barrera, "Paniri", ''

American Alpine Journal The ''American Alpine Journal'' is an annual magazine published by the American Alpine Club. Its mission is "to document and communicate mountain exploration." The headquarters is in Golden, Colorado. Subtitled as a compilation of "The World's M ...

'', 1974, p. 194. Available a
AAJ Online
(PDF). which along with similar sanctuaries at Licancabur and other mountains are considered to be of Inka origin. Paniri is the sacred mountain for the village of Ayquina, and was also used as a source of

dacitic 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 ...

rocks.

Eruptive history

The first units erupted by Paniri are the mainly lavic (plus one

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 ...

deposit) Malku unit which crops out in the northwestern sector of the volcano and the Los Gordos unit. The Los Gordos unit consists of pyroclastics and

brecciated Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

lava flows which are much thicker than these of the Malku unit; they crop out north and northwest of Paniri and one date obtained from this unit is 1.39 ± 0.28 million years ago. These two units define the "shield" stage of Paniri, the longest lasting and most voluminous phase of volcanic activity at this volcano.Godoy ''et al.'' 2018, p.196 Afterwards, the widespread Las Lenguas unit was emplaced which consists of blocky lava flows with some thin pyroclastic deposits. Ages of 640,000 ± 140,000 to 400,000 ± 100,000 have been obtained by

radiometric dating Radiometric dating, radioactive dating or radioisotope dating is a technique which is used to date materials such as rocks or carbon, in which trace radioactive impurities were selectively incorporated when they were formed. The method compares t ...

. More restricted in exposure is the Las Negras unit, which forms

basalt Basalt (; ) is an aphanite, aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the planetary surface, surface of a terrestrial ...

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 ...

lava flows with prominent

levee A levee (), dike (American English), dyke (English in the Commonwealth of Nations, Commonwealth English), embankment, floodbank, or stop bank is a structure that is usually soil, earthen and that often runs parallel (geometry), parallel to ...

s on the northwestern flank of Paniri (one of these is dated to 402,000 ± 46,000 years ago).Godoy ''et al.'' 2018, p.190 This is considered to be the "main edifice" stage of volcano growth at Paniri. The last three units of Paniri are the Viscachas, Laguna and Llareta units. The former consists of lava flows on the southeastern flank, with dates of 325,000 ± 8,000 and 300,000 ± 100,000 years before present. The Laguna unit again features lava flows but also

breccia Breccia () is a rock composed of large angular broken fragments of minerals or rocks cemented together by a fine-grained matrix. The word has its origins in the Italian language, in which it means "rubble". A breccia may have a variety of di ...

and

material, and one age of 169,000 ± 5,000 was obtained on its rocks. The last unit, Llareta, was erupted by the summit vent which generated lava flows on the northeastern and southwestern sectors of the volcano, plus large pyroclastic bombs. Its age ranges 264,000 ± 99,000 to 150,000 ± 6,000 years before present. These are considered to be the Old Cone and New Cone stages of volcano growth. The volcano was formerly considered to be of Holocene age.

References

* * *

External links

*
South American Summits Ranked By Re-Ascent
Chao dacite domes

{{DEFAULTSORT:Paniri Volcanoes of Antofagasta Region Mountains of Chile Stratovolcanoes of Chile Five-thousanders of the Andes Pleistocene stratovolcanoes