DOI: http://dx.doi.org/10.5027/andgeoV38n2-a05

Geology, petrology and geochemistry of the dome complex of Huequi volcano, southern Chile.

Sebastian F.L. Watt, David M. Pyle, Tamsin A. Mather

Abstract


Huequi, a little-known volcano in the southern part of the Andean southern volcanic zone (SSVZ), shows a regionally unusual eruption style, mineralogy and geochemistry. The volcano comprises multiple highly-eroded lava domes. Past eruptions were accompanied by relatively minor explosive activity, most recently from 1890-1920. The rocks erupted by Huequi range from basaltic andesite to dacite, and are highly distinctive when compared to other volcanoes of the SSVZ, being K-poor and Al-rich, and containing euhedral hornblende phenocrysts. Overall compositions suggest a notably water-rich magma source, evolving through high levels of fractionation and subsequent degassing to produce highly porphyritic dome-forming andesites. The ultimate causes of water-rich magmas at this point in the arc remain unclear.

How to cite this article Watt, S., Pyle, D., and Mather, T., 2011, Geology, petrology and geochemistry of the dome complex of Huequi volcano, southern Chile.: Andean Geology, v. 38, no. 2, p. 335-348., doi:http://dx.doi.org/10.5027/andgeoV38n2-a05