Cerro Cebollar is a 5,716-metre-high (18,753 ft) volcano including andesitic-dacitic irregular lava flows. They contain 61.7–61.8% SiO2; the volcano itself is a few million years old judging by its appearance. It is covered by a rhyolitic pumice coming from a neighbouring caldera. It is part of the Cerro de las Cuevas-Cerro Palpana volcanic chain.
Map of Cerro Cebollar, Ollague, Antofagasta Region, Chile
References
Cerro Cebollar Wikipedia(Text) CC BY-SA