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 typically conical volcano built up by many alternating layers (strata) of hardened lava and tephra. Unlike shield volcanoes, stratovolcanoes are characterized by a steep profile with ...

located in

El Loa Province El Loa Province () 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 According to the 2012 ...

Antofagasta Region The Antofagasta Region (, ) is one of Chile's Administrative divisions of Chile, sixteen first-order administrative divisions. Being the second-largest region of Chile in area, it comprises three provinces, Antofagasta Province, Antofagasta, El ...

Chile Chile, officially the Republic of Chile, is a country in western South America. It is the southernmost country in the world and the closest to Antarctica, stretching along a narrow strip of land between the Andes, Andes Mountains and the Paci ...

, and near the border with

Bolivia Bolivia, officially the Plurinational State of Bolivia, is a landlocked country located in central South America. The country features diverse geography, including vast Amazonian plains, tropical lowlands, mountains, the Gran Chaco Province, w ...

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

Cerro del León Cerro is Spanish for "hill" or "mountain". People * Francisco Cerro (born 1988), Argentine footballer * Francisco Cerro Chaves (born 1957), Spanish prelate, theologian, and philosopher of the Catholic Church * Ian Cerro (born 1996), American ...

, 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 ...

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

scoria cone A cinder cone or scoria cone is a steep, conical landform of loose pyroclastic fragments, such as volcanic ash, clinkers, or scoria that has been built around a volcanic vent. The pyroclastic fragments are formed by explosive eruptions or l ...

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

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

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 geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...

Pleistocene The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...

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 Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...

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 b ...

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 () 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 Tocopilla provinces to the north, t ...

.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". People * Francisco Cerro (born 1988), Argentine footballer * Francisco Cerro Chaves (born 1957), Spanish prelate, theologian, and philosopher of the Catholic Church * Ian Cerro (born 1996), American f ...

in the east.

Road A road is a thoroughfare used primarily for movement of traffic. Roads differ from streets, whose primary use is local access. They also differ from stroads, which combine the features of streets and roads. Most modern roads are paved. Th ...

s lead around the northern and western flanks of the volcano.Godoy ''et al.'' 2018, p.188 The large lava flow Cerro Chao 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 lands east of the Cape of Good Hope who was employed on European ships from the 16th century until the mid-20th centur ...

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, w ...

, as well as

geothermal Geothermal is related to energy and may refer to: * Geothermal energy, useful energy generated and stored in the Earth * Geothermal activity, the range of natural phenomena at or near the surface, associated with release of the Earth's internal he ...

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: ) 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 a tourist attraction for its deep blue color and water clarity. T ...

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 both, which erodes soil to a sharp angle, typically on a hillside or in river floodplains or terraces. Gullies resemble large ditches or small valleys, but are metres to t ...

cut into its slopes and

moraine A moraine is any accumulation of unconsolidated debris (regolith and Rock (geology), 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 gla ...

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 143.1 Mya. ...

, the

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

has been

subducting Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second pla ...

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 ...

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

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 oce ...

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

Oligocene The Oligocene ( ) is a geologic epoch (geology), epoch of the Paleogene Geologic time scale, Period that extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that defin ...

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 ...

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 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 miner ...

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

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-align ...

. The chain is made up by San Pedro, San Pablo, Paniri, Cerro Chao, Cerro de Leon,

Toconce Toconce is a small Chilean village located on the south rim of the Toconce River Canyon at 3,350 m above sea level. To the north, the landscape is dominated by the volcanoes Cerro Paniri, Cerro del León Cerro is Spanish for "hill" or "mountain". ...

and Linzor. 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 (geology), texture, but may be porphyritic, containing larger mineral crystals (phenocrysts) in an otherwise fine-grained matri ...

, which mainly define a

potassium Potassium is a chemical element; it has Symbol (chemistry), symbol K (from Neo-Latin ) and atomic number19. It is a silvery white metal that is soft enough to easily cut with a knife. Potassium metal reacts rapidly with atmospheric oxygen to ...

-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 ...

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

Phenocryst image:montblanc granite phenocrysts.JPG, 300px, Granites often have large feldspar, feldspathic phenocrysts. This granite, from the Switzerland, Swiss side of the Mont Blanc massif, has large white phenocrysts of plagioclase (that have trapezoid sh ...

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 al ...

clinopyroxene The pyroxenes (commonly abbreviated 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 ions of calcium (Ca), sodium (Na), iron (Fe ...

hornblende Hornblende is a complex silicate minerals#Inosilicates, 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 ...

olivine The mineral olivine () is a magnesium iron Silicate minerals, silicate with the chemical formula . It is a type of Nesosilicates, nesosilicate or orthosilicate. The primary component of the Earth's upper mantle (Earth), upper mantle, it is a com ...

, opaque minerals,

orthopyroxene The pyroxenes (commonly abbreviated 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 ions of calcium (Ca), sodium (Na), iron (Fe( ...

plagioclase Plagioclase ( ) is a series of Silicate minerals#Tectosilicates, tectosilicate (framework silicate) minerals within the feldspar group. Rather than referring to a particular mineral with a specific chemical composition, plagioclase is a continu ...

quartz Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The Atom, atoms are linked in a continuous framework of SiO4 silicon–oxygen Tetrahedral molecular geometry, tetrahedra, with each oxygen being shared between two tet ...

and

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

; 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. kaolinite, ). Most pure clay minerals are white or light-coloured, but natural clays show a variety of colours from impuriti ...

chlorite The chlorite ion, or chlorine dioxide anion, is the halite (oxyanion), 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 s ...

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 ha ...

and

illite Illite, also called hydromica or hydromuscovite, 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 sandw ...

Magma Magma () is the molten or semi-molten natural material from which all igneous rocks are formed. Magma (sometimes colloquially but incorrectly referred to as ''lava'') is found beneath the surface of the Earth, and evidence of magmatism has also ...

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 u ...

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 (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

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 ...

'', 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 Pyroclast, Pyroclastic or Pyroclastics may refer to: Geology * Pyroclast, or airborne volcanic tephra fragments * Pyroclastic rock, rock fragments produced and ejected by explosive volcanic eruptions * Pyroclastic cone, landform of ejecta fro ...

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 varie ...

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 Chronological dating, date materials such as Rock (geology), rocks or carbon, in which trace radioactive impurity, impurities were selectively incorporat ...

. 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 predomina ...

lava flows with prominent

levee A levee ( or ), dike (American English), dyke (British English; see American and British English spelling differences#Miscellaneous spelling differences, spelling differences), embankment, floodbank, or stop bank is an elevated ridge, natural ...

s on the northwestern flank of Paniri (one of these is dated to 402,000 ± 46,000 years ago). 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 Rock (geology), rocks cementation (geology), cemented together by a fine-grained matrix (geology), matrix. The word has its origins in the Italian language ...

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.

Electric conductivity Electrical resistivity (also called volume resistivity or specific electrical resistance) is a fundamental specific property of a material that measures its electrical resistance or how strongly it resists electric current. A low resistivity in ...

anomalies imply that there is still a geothermal system under Paniri; a

may not be sufficiently visible.Mancini ''et al.'' 2019, p.4394

References

* * * *

External links

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

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