6533b86efe1ef96bd12cc9cb
RESEARCH PRODUCT
Halogen (Cl, F) release during explosive, effusive, and intrusive phases of the 2011 rhyolitic eruption at Cordón Caulle volcano (Chile)
Hugh TuffenBen KennedyC. Ian SchipperPablo ForteGilles SeropianBruce ChristensonBrent V. AllowayJonathan M. CastroAlessandro Aiuppasubject
Explosive materialLavaGeochemistryrhyolitevolatile budgetvolatileHydrothermal circulationGeochemistry and PetrologyRhyolitehalogensEarth and Planetary Sciences (miscellaneous)QE1-996.5geographygeography.geographical_feature_categoryChemistrydegassingGeologyhalogenFumarolevolatilesGeophysicsDevitrificationVolcanoCordón CaulleMagmaPuyehuedescription
We investigate sulphur, chlorine and fluorine release during explosive, effusive and intrusive phases of the 2011 Cordon Caulle eruption, with a focus on halogen devolatilization. Petrological analysis shows halogen release to have been promoted by isobaric crystallization in slowly-cooled magma that was emplaced in a lava flow and sub-vent intrusion. Fluorine in particular mobilized only after extensive groundmass crystallization and incipient devitrification. By 2017, the gas emitted from vent-proximal fumaroles had hydrothermal compositions, with HCl/HF ratios decreasing with decreasing temperature. We estimate that the eruption could eventually emit up to 0.84 Mt of SO2, 6.3 Mt of HCl, and 1.9 Mt of HF, but only ~7% and ~2% of total HCl and HF were emitted during explosive phases, and significant halogens are yet to be released from the intrusion. Halogen devolatilization and its associated hazards can persist long after the cessation of rhyolite eruptions with complex magma emplacement mechanisms.
year | journal | country | edition | language |
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2019-05-11 |