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dc.contributor.authorPreece, Katie
dc.contributor.authorBarclay, Jenni
dc.contributor.authorBrown, Richard J.
dc.contributor.authorChamberlain, Katy
dc.contributor.authorMark, Darren F.
dc.date.accessioned2021-05-28T11:25:32Z
dc.date.available2021-05-28T11:25:32Z
dc.date.issued2021-05-19
dc.identifier.citationPreece, K., Barclay, J., Brown, R.J., Chamberlain, K.J. and Mark, D.F., 2021. Explosive felsic eruptions on ocean islands: A case study from Ascension Island (South Atlantic). Journal of Volcanology and Geothermal Research, pp. 1-19.en_US
dc.identifier.issn0377-0273
dc.identifier.doi10.1016/j.jvolgeores.2021.107284
dc.identifier.urihttp://hdl.handle.net/10545/625802
dc.description.abstractOcean island volcanism is generally considered to be dominated by basaltic eruptions, yet felsic products associated with more hazardous explosive eruptive events are also present in the geological record of many of these islands. Ascension Island, recently recognised as an active volcanic system, exhibits explosive felsic eruption deposits but their age, eruptive styles and stratigraphic association with mafic volcanism are thus far unclear. Here we present a felsic pyroclastic stratigraphy for Ascension Island, supplemented by 26 new 40Ar/39Ar ages and whole rock geochemical XRF data. More than 80 felsic pyroclastic eruptions have occurred over the last ~ 1 Myr, including subplinian and phreatomagmatic eruptions, which produced pumice fall and pyroclastic density current deposits. Detailed sampling suggests felsic events are unevenly distributed in space and time. Subaerial activity can be divided into four Periods: Period 1 (~1000 – 500 ka) felsic and mafic eruptions, with felsic explosive eruptions, linked to a Central Felsic Complex; Period 2 (~ 500 – 100 ka) mafic period; Period 3 (~ 100 – 50 ka) felsic eruptions associated with the Eastern Felsic Complex; Period 4 (< 50 ka) mafic eruptions. The last explosive eruption occurred at ~ 60 ka. This work highlights the cyclical nature of ocean island volcanism and the timescales over which changes between predominantly mafic and felsic volcanism occur. The prevalence of past felsic explosive eruptions on Ascension highlights the need to consider the possibility of future subplinian or phreatomagmatic events in hazard management plans, with any potential risk compounded by Ascension’s small size 41 and remote location.en_US
dc.description.sponsorshipThis work was funded by a Leverhulme Trust Research Project 721 Grant (RPG-2013-042), with support from a Gloyne Outdoor Geological Research award from the Geological Society of London.en_US
dc.language.isoenen_US
dc.publisherElsevieren_US
dc.relation.urlhttps://www.sciencedirect.com/science/article/abs/pii/S037702732100113Xen_US
dc.subjectAscension Islanden_US
dc.subjectpyroclastic eruptionen_US
dc.subjectvolcanic stratigraphyen_US
dc.subject40Ar/39Ar geochronologyen_US
dc.subjectvolcanic hazardsen_US
dc.titleExplosive felsic eruptions on ocean islands: a case study from Ascension Island (South Atlantic)en_US
dc.typeArticleen_US
dc.contributor.departmentSwansea Universityen_US
dc.contributor.departmentUniversity of East Angliaen_US
dc.contributor.departmentDurham Universityen_US
dc.contributor.departmentUniversity of Derbyen_US
dc.contributor.departmentScottish Universities Environmental Research Centre, East Kilbrideen_US
dc.contributor.departmentUniversity of St Andrewsen_US
dc.identifier.journalJournal of Volcanology and Geothermal Researchen_US
dcterms.dateAccepted2021-05-16
dc.author.detail786068en_US


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