0000000000182441

AUTHOR

Bernard Pelletier

showing 2 related works from this author

Understanding volcanoes in the Vanuatu arc

2016

We report the first helium isotope survey of volcanic gases, hot springs and some olivine phenocrysts along the Vanuatu island arc, from Tanna in the south to Vanua Lava in the north. Low CO2 content and low He-3/He-4 ratios in thermal fluids of Epi (4.0 +/- 0.1 R-a), Efate (4.5 +/- 0.1 R-a) and Pentecost (5.3 +/- 0.5 R-a) islands coherently indicate reduced mantle gas leakage and crustal contamination by radiogenic helium on these extinct volcanic systems of the former (Pliocene) arc. Instead, presently active Vanuatu volcanoes display He-3/He-4 and C/He-3 ratios typical of subduction-related volcanic arcs: He-3/He-4 ratios range from 6.4 +/- 0.5 Ra in southernmost Tanna and 7.23 +/- 0.09 …

010504 meteorology & atmospheric sciencesLavaEarth scienceGeochemistryVanuatu arcHelium isotopes[SDU.STU]Sciences of the Universe [physics]/Earth Sciences010502 geochemistry & geophysics01 natural sciencesVolcanic fluidsVolcanic GasesGeochemistry and Petrologyevent0105 earth and related environmental sciencesBasaltevent.disaster_typegeographygeography.geographical_feature_categoryVolcanic arcHotspot contributionFumaroleExtinct and active volcanoesMantle sourceSettore GEO/08 - Geochimica E VulcanologiaGeophysicsVolcano13. Climate actionVanuatu arc Volcanic fluids Helium isotopes Extinct and active volcanoes Mantle source Hotspot contributionIsland arcPhenocrystGeology
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Prodigious emission rates and magma degassing budget of major, trace and radioactive volatile species from Ambrym basaltic volcano, Vanuatu island Arc

2016

Abstract Ambrym volcano, in the Vanuatu arc, is one of the most active volcanoes of the Southwest Pacific region, where persistent lava lake and/or Strombolian activity sustains voluminous gas plume emissions. Here we report on the first comprehensive budget for the discharge of major, minor, trace and radioactive volatile species from Ambrym volcano, as well as the first data for volatiles dissolved in its basaltic magma (olivine-hosted melt inclusions). In situ MultiGAS analysis of H 2 O, CO 2 , SO 2 and H 2 S in crater rim emissions, coupled with filter-pack determination of SO 2 , halogens, stable and radioactive metals demonstrates a common magmatic source for volcanic gases emitted by…

010504 meteorology & atmospheric sciencesLavaGeochemistryMineralogy[SDU.STU]Sciences of the Universe [physics]/Earth SciencesAmbrymVolatile fluxes010502 geochemistry & geophysics01 natural sciencesVolcanic GasesMagma reservoirVanuatuVolatile fluxeGeochemistry and PetrologyCalderaeventGeophysicComputingMilieux_MISCELLANEOUS0105 earth and related environmental sciencesMelt inclusionsBasaltevent.disaster_typegeographygeography.geographical_feature_categoryMagma degassing budgetStrombolian eruptionGeophysicsVolcano13. Climate actionIsland arcRadioactive disequilibriaGeology
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