Holocene volcanism at the Quetrupillán Volcanic Complex (39°30’ S, 71°43’ W), southern Chile

This paper provides the first detailed description of Holocene volcanism at the Quetrupillán Volcanic Complex. This little-known volcanic complex consists of a truncated stratocone plus numerous satellite vents on its lower flanks. The c.16 satellite vents are the products of c.10 eruptions, with seven erupting trachytes (a composition unusual in Chile), two erupting trachyandesites, and one erupting a basaltic andesite. Intense and atypical Holocene scouring of the stratocone by ice has removed evidence of its Holocene eruptions, and thus Holocene volcanism at the stratocone remains largely unknown. Geochemical analysis of tephra layers from three logged sections in nearby valleys provides evidence of only three explosive eruptions from Quetrupillán. No evidence of PDC deposits were identified at the logged sections. Our results suggest that the explosive volcanic hazards from Quetrupillán are less than current hazard maps indicate.