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

Abstract

This paper provides the first detailed description of Holocene volcanism at the Quetrupillán Volcanic Complex. This volcanic complex consists of a truncated and eroded stratocone plus sixteen well-preserved satellite vents on its lower flanks. Intense scouring of the stratocone’s flanks (presumably by ice) has removed much evidence of its Holocene eruptions, and thus the Holocene construction of the stratocone (i.e. number and volume of eruptions) cannot be determined. The sixteen satellite vents are the products of an uncertain number of eruptions, with trachyte comprising ~97% of the lava erupted. Geochemical analysis of tephra layers from three logged sections in nearby valleys provides evidence of three explosive eruptions from Quetrupillán. In these sections, no evidence of pyroclastic density current deposits was identified, which may suggest that explosive volcanic hazards from Quetrupillán are less than indicated on current hazard maps.

Keywords

• holocene
• volcanism
• chile
• trachyte
• glacial scouring
• glacier-volcano interactions