Lanín is an ice-clad, cone-shaped

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 ...

on the border of

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 ...

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 ...

. It forms part of two

national park A national park is a nature park, natural park in use for conservation (ethic), conservation purposes, created and protected by national governments. Often it is a reserve of natural, semi-natural, or developed land that a sovereign state dec ...

Lanín Lanín is an ice-clad, cone-shaped stratovolcano on the border of Argentina and Chile. It forms part of two national parks: Lanín in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of Neuquén, being part of its f ...

in Argentina and Villarrica in Chile. It is a symbol of the Argentine province of

Neuquén Neuquén (; arn, Nehuenken) is the capital city of the Argentine province of Neuquén and of the Confluencia Department, located in the east of the province. It occupies a strip of land west of the confluence of the Limay and Neuquén rivers w ...

, being part of its flag and its anthem. Although the date of its last eruption is not known, it is estimated to have occurred within the last 10,000 years. Following the

1906 Valparaíso earthquake The 1906 Valparaíso earthquake hit Valparaíso, Chile, on August 16 at 19:55 local time. Its epicenter was offshore from the Valparaíso Region, and its intensity was estimated at magnitude 8.2 . This earthquake occurred thirty minutes after the ...

a local newspaper reported the volcano to have erupted, but a work published in 1917 by Karl Sapper disputed this.Luis E. Lara, José A. Naranjo and Hugo Moreno, 2004
Lanín volcano (39.5°S), Southern Andes: geology and morphostructural evolution
'' Revista Geológica de Chile'' vol. 31. The ascent is regulated by the management of Argentine National Parks and the

Argentine National Gendarmerie The Argentine National Gendarmerie ( es, Gendarmería Nacional Argentina, GNA) is the national gendarmerie force and corps of border guards of the Argentine Republic. It has a strength of 70,000. The gendarmerie is primarily a frontier guard forc ...

and is technically relatively simple but has a much higher level of exposure than the neighbouring volcanoes. The nearest towns, usually employed as a base for climbers, are

Pucón Pucón (Mapudungun: "entrance to the cordillera") is a Chilean city and commune administered by the municipality of Pucón https://www.mipucon.com/ sitio web. It is located in the Province of Cautín, Araucanía Region, 100 km to the south ...

in Chile and

Junín de los Andes Junín de los Andes is a first category municipality and administrative center of the Huiliches Department in the province of Neuquén, Argentina. It is located in the south of the province, by the Chimehuin River, on National Route 234, about ...

in Argentina. There are two paths to the summit: one on the north, starting at 1,200 metres above mean sea level near Tromen Lake and the international

Mamuil Malal Pass Mamuil Malal Pass (Mapudungun for ''corral of wooden sticks'') is an international mountain pass in the Andes between Chile and Argentina. The pass connects Pucón and Curarrehue in Chile with Junín de los Andes in Argentina. The road passes j ...

, accessible via Neuquén's Provincial Route 60; and one on the south, starting beside

Huechulafquen Lake Huechulafquen Lake () is a lake in Neuquén Province, Patagonian Argentina. This glacial lake is located in the Andes, Andean mountains in Lanín National Park some 25 kilometres from Junín de los Andes and 60 kilometres from San Martín de los A ...

, accessible via Provincial Route 61.

Geography and geology

Lanín lies at the Atlantic-Pacific water divide of the Andes, being for that reason located on the Argentina-Chile border according to the 1881 border treaty between these countries. To the north and south lie the

Tromen Tromen is a stratovolcano in western Argentina. It rises above the older caldera of the Volcán Negro del Tromen. See also * List of volcanoes in Argentina This is a list of active and extinct volcanoes in Argentina. Volcanoes {, cla ...

and Paimun Lakes, respectively. Lanín is the easternmost volcano of a north-west south-east oriented chain of three large

es, Villarrica being the westernmost one and

Quetrupillán Quetrupillán ("blunted", "mutilated"; also known as Ketropillán) is a stratovolcano located in Los Ríos Region of Chile. It is situated between Villarrica and Lanín volcanoes, within Villarrica National Park. Geologically, Quetrupillán is ...

the one in the middle. This alignment is attributed to the existence of a fault beneath the volcanoes. In historical times, Lanín has been the least active of these volcanoes. Apart from Quetrupillán and Villarrica, there are a number of old eroded remains of stratovolcanoes in the alignment. The volcano itself rests on a basement of

gneiss Gneiss ( ) is a common and widely distributed type of metamorphic rock. It is formed by high-temperature and high-pressure metamorphic processes acting on formations composed of igneous or sedimentary rocks. Gneiss forms at higher temperatures an ...

es,

felsic In geology, felsic is a modifier describing igneous rocks that are relatively rich in elements that form feldspar and quartz.Marshak, Stephen, 2009, ''Essentials of Geology,'' W. W. Norton & Company, 3rd ed. It is contrasted with mafic rocks, whi ...

pluton In geology, an igneous intrusion (or intrusive body or simply intrusion) is a body of intrusive igneous rock that forms by crystallization of magma slowly cooling below the surface of the Earth. Intrusions have a wide variety of forms and com ...

s, and volcani

clast Clastic rocks are composed of fragments, or clasts, of pre-existing minerals and rock. A clast is a fragment of geological detritus,Essentials of Geology, 3rd Ed, Stephen Marshak, p. G-3 chunks, and smaller grains of rock broken off other rocks ...

ic sequences. The basement rocks constitute a tectonically elevated block limited in the west by the north–south

Reigolil-Pirihueico Fault The Reigolil-Pirihueico Fault (Spanish: ''Falla Reigolil-Pirihueico'') is a second-order geological fault located in the Chilean and Argentine Andes. As the name implies, it runs from Pirihueico Lake to Reigolil Valley. Reigolil-Pirihueico Fault ru ...

. Ages of ranging from Late

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58Pleistocene 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 ...

have been suggested for the oldest known parts of the volcano, which are

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 rhyol ...

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 with columnar joints.

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 ...

is the most common rock of the volcano. Lanín shows overall higher alkali (Na₂O plus K₂O) to silica ratio than Villarrica, which is interpreted as reflecting a lesser degree of

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 solid ...

underneath the volcano and showing that the volcanoes of the chain have distinct source regions in Earth's mantle. Another

petrologic Petrology () is the branch of geology that studies rocks and the conditions under which they form. Petrology has three subdivisions: igneous, metamorphic, and sedimentary petrology. Igneous and metamorphic petrology are commonly taught together ...

characteristic of Lanín is its

bimodal volcanism Bimodal volcanism is the eruption of both mafic and felsic lavas from a single volcanic centre with little or no lavas of intermediate composition. This type of volcanism is normally associated with areas of extensional tectonics, particularly r ...

References

External links

La estrella del Parque: el Volcán Lanín
- San Martín de los Andes municipal website.
"Volcán Lanín, Argentina/Chile" on Peakbagger
{{DEFAULTSORT:Lanin Stratovolcanoes of Chile Subduction volcanoes Stratovolcanoes of Argentina Villarrica National Park Volcanoes of Araucanía Region Volcanoes of Neuquén Province Argentina–Chile border International mountains of South America Three-thousanders of the Andes Pliocene stratovolcanoes Pleistocene stratovolcanoes Holocene stratovolcanoes