Cerro del León

Geology

The volcano has a diameter of 6 km and is constructed from andesites erupted through three stages of activity. Two nested craters lie on its summit and have diameters of 260 -. Volcán Lagunita is a neighbouring volcano and is more heavily eroded and hydrothermally altered.

Regional setting

Cerro del León is part of the Central Volcanic Zone, a volcanic belt in the Andes. Volcanic activity occurs since the Oligocene and includes dacitic–rhyolitic ignimbrites. On top of these the main volcanic arc, including andesitic-dacitic stratovolcanoes, has formed 300 - away from the Peru–Chile Trench on a crust 120 km thick. San Pedro and Lascar have historical activity, but only a few volcanoes have been studied, namely Lascar, Ollagüe and Parinacota.

The volcano is part of the San Pedro-Linzor lineament, a 65 km long volcanic chain that extends northwest-southeastward. It was constructed on top the Toconce and Sifon Ignimbrites. The alignment was active during the late Pleistocene–Holocene and contains San Pedro-San Pablo–Paniri–Cerro del León–Toconce–Linzor.

Eruption history

The volcano was constructed in various phases. The base of the volcano is constructed from andesitic lava flows that directly overlie the ignimbrite basement. These at first erupted in the west and east, subsequently northwest and southeast. Dacites and andesites form the last stage and the bulk of the edifice.

The volcano was subject to glaciation, leaving moraines down to 5200 m altitude, formed during the last glaciation 15,000–11,000 years ago. Glacial effects are noticeable on the north-northwest flanks.

Petrology

Lavas contain phenocrysts of plagioclase with variable amounts of biotite, clinopyroxene, opaque minerals, and orthopyroxene. The matrix is glassy and contains hornblende and plagioclase. The lavas have vesicular and minor proportions of amygdaloid, porphyric, trachytic and vitrophyric texture. Hydrothermal alteration has been reported.

Religious importance

Cerro del Leon is a holy mountain for the local territory. An Inca religious site is located on its summit.

References

References

1. (15 July 2017). "Sr- and Nd- isotope variations along the Pleistocene San Pedro – Linzor volcanic chain, N. Chile: Tracking the influence of the upper crustal Altiplano-Puna Magma Body". Journal of Volcanology and Geothermal Research.
2. (2012). "Evolución del sistema Volcánico Cerro el León (Región de Antofagasta, Chile), mediante interpretación fotogeológica, petrográfica y geoquímica". Actas XIII Congreso Geológico Chileno, Antofagasta, Chile.
3. (August 2012). "Geología de la cadena volcánica Paniri-Toconce, Zona Volcánica Central, Altiplano de la Región de Antofagasta, Chile". Congreso Geológico Chileno.
4. (July 2004). "Principios Orientadores y Metodología Para el Estudio del Qhapaqñan en Atacama: Desde el Portezuelo del Inka Hasta Río Grande". Chungará.