Nevado San Francisco, or Cerro San Francisco (), 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 ...

on the border between

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 ...

, located just southeast of

San Francisco Pass The San Francisco Pass is a pass over the Andes mountains which connects Argentina and Chile. The highest point of this pass is at AMSL. Location The pass is located at and connects the Argentine province of Catamarca with the Atacama Re ...

. It is considered extinct and is one of the several peaks in the area, of which the chief is the

Ojos del Salado Nevado Ojos del Salado is a dormant complex volcano in the Andes on the Argentina–Chile border. It is the highest volcano on Earth and the highest peak in Chile. The upper reaches of Ojos del Salado consist of several overlapping lava domes, ...

. It is on the border of 2 provinces: Argentinean province of Catamarca; Chilean province of Copiapo. The volcano 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 ...

of the Andes and reaches an elevation of .Difrol
It is composed from

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 ...

with the exception of basaltic cones and lava flows on the eastern side. These cones are part of the Peinado lineament and a sample was dated 200,000 years ago by argon chronology. They are noteworthy for their

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 ...

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. One lava flow less than one million years old reaches a length of . The western slopes contain

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 ...

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 ...

s. On the summit lie two circle-shaped constructs, of Inca or Formative period ages. San Francisco was first climbed by

Walther Penck Walther Penck (30 August 1888 – 29 September 1923) was a geologist and geomorphologist known for his theories on landscape evolution. Penck is noted for criticizing key elements of the Davisian cycle of erosion, concluding that the process ...

(Germany) on 16 December 1913.

Notes

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External links

Elevation information about San Francisco

Weather Forecast at San Francisco
Volcanoes of Atacama Region Stratovolcanoes of Argentina Andean Volcanic Belt Stratovolcanoes of Chile Mountains of Argentina Mountains of Chile Polygenetic volcanoes Mountains of Atacama Region Mountains of Catamarca Province Pleistocene stratovolcanoes {{Atacama-geo-stub

Notes

See also

References

External links