Glaciovolcanism at Volcán Sollipulli, southern Chile:lithofacies analysis and interpretation

Lachowycz, Stefan M. and Pyle, David and Gilbert, Jennifer Susan and Mather, Tamsin and Mee, Katy and Naranjo, José A. and Hobbs, Laura (2015) Glaciovolcanism at Volcán Sollipulli, southern Chile:lithofacies analysis and interpretation. Journal of Volcanology and Geothermal Research, 303. pp. 59-78. ISSN 0377-0273

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Abstract

Magma–ice–meltwater interactions produce diverse landforms and lithofacies, reflecting the multitude of factors that influence glaciovolcanism, including both magmatic (e.g., composition, eruption rate) and glacial (e.g., ice thickness, thermal regime) conditions. This is exemplified by the walls of the partly ice-filled summit caldera of Volcán Sollipulli, a stratovolcano in southern Chile, which include lithofacies from eruptions of a wide range of magma compositions beneath or in contact with ice. Here we analyse these lithofacies and hence propose new interpretations of the eruptive and glacial history of Sollipulli. The facies include a thick, laterally extensive sequence of fragmental glaciovolcanic deposits, comprising massive, mafic lava pillow-bearing hyaloclastite overlain by sills and then hyaloclastic debris flow deposits (similar to Dalsheidi-type sequences). The distribution and thickness of these units indicate an unusual abundance of magma–meltwater interaction for an arc stratovolcano in temperate latitudes, perhaps due to eruptions beneath a thick ice cap. Coherent lava coulées, domes, lobes, and stacks of basaltic andesite–trachydacite composition are present around the top of the caldera rim; these display morphologies and fracture patterns on caldera-facing margins that indicate that the caldera was filled with ice when these lavas were erupted. The lithofacies characterised in this study demonstrate the diversity of glaciovolcanism that is possible at arc stratovolcanoes capped by temperate ice or with ice-filled calderas, and the potential for uncertainties in inference of the palaeoenvironmental conditions of their emplacement.

Item Type:
Journal Article
Journal or Publication Title:
Journal of Volcanology and Geothermal Research
Additional Information:
© 2015 The Authors. Published by Elsevier B.V. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).
Uncontrolled Keywords:
/dk/atira/pure/subjectarea/aacsb/disciplinebasedresearch
Subjects:
ID Code:
76969
Deposited By:
Deposited On:
02 Dec 2015 11:06
Refereed?:
Yes
Published?:
Published
Last Modified:
05 Jul 2020 04:43