2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)
Paper No. 268-12
Presentation Time: 11:00 AM-11:15 AM

GLACIOVOLCANISM AT VOLCÁN QUETRUPILLÁN, CHILE

MCGARVIE, Dave, Faculty of Science, The Open University, Walton Hall, Milton Keynes, MK7 6AA, United Kingdom, dave.mcgarvie@open.ac.uk, PAVEZ, Andres, Department de Geofísica, Universidad de Chile, Santiago, Chile, CORTES, Caco, University of Edinburgh, Edinburgh, EH3 7QJ, United Kingdom, FAGGETTER, Luke, University of Leeds, Leeds, LS1 6ED, United Kingdom, BURGESS, Ray, University of Manchester, Manchester, M13 9PL, United Kingdom, and MCGARVIE, Dan, University of Exeter, Exeter, TR10 9EZ, United Kingdom

Volcán Quetrupillán is flanked by Volcán Villarrica and Volcán Lanín, and these three volcanoes form a chain oriented obliquely to the major N-S structure tectono-volcanic structure in this part of Chile - the Liquiñe-Ofqui Fault Zone (LOFZ).

During stratocone construction the products of earlier eruptions are often buried and/or destroyed by later eruptions, which is exemplified by the prominent stratocones of Villarrica and Lanín. Although Quetrupillán has also constructed a small Holocene stratocone, its closer proximity to the LOFZ has resulted in a more dispersed (fault-controlled) volcanic field, particularly around its southern flanks where the products of Holocene and Pleistocene fissure eruptions (dacite with minor basaltic andesite – Pavel et al., 2004) are well preserved. Fourteen lava-ice edifices of assumed varying ages are exposed here, and provide an opportunity to study longer term volcano-ice interactions at this volcano.

Lava-ice interactions at Quetrupillán include: ridges formed above erupting fissures, ridge-forming lavas with prominent flanking buttresses; and irregular sheet-like bodies with sinuous (esker-like) and lobate termini. One source of the latter reveals agglutinate mounds from which clastogenic lava sheets flowed beneath relatively thin ice and then plunged into an ice-filled trough to its base. This example illustrates how careful study of lava-ice interactions can reveal important palaeoenvironmental information.

Future work will include Ar-Ar dating and petrological characterisation of the lava-ice edifices to provide a timeline illustrating the development of volcanic field and its relation to ice thicknesses, as well activity on the Liquiñe-Ofqui Fault Zone through time.

Reference

Pavez, A., Lara, LE., Naranjo, JA., and Moreno, H. (2004). Quetrupillán Volcano (Southern Andes, Chile): Holocene explosive activity and morphostructural evolution. Poster presentation at IAVCEI 2004 General Assembly, Pucon, Chile.

2014 GSA Annual Meeting in Vancouver, British Columbia (19–22 October 2014)
General Information for this Meeting
Session No. 268
Recent Advances in Igneous Processes
Vancouver Convention Centre-West: 219
8:00 AM-12:00 PM, Wednesday, 22 October 2014


© Copyright 2014 The Geological Society of America (GSA), all rights reserved. Permission is hereby granted to the author(s) of this abstract to reproduce and distribute it freely, for noncommercial purposes. Permission is hereby granted to any individual scientist to download a single copy of this electronic file and reproduce up to 20 paper copies for noncommercial purposes advancing science and education, including classroom use, providing all reproductions include the complete content shown here, including the author information. All other forms of reproduction and/or transmittal are prohibited without written permission from GSA Copyright Permissions.