Deep and disturbed: conditions for formation and eruption of a mingled rhyolite at Ascension Island, south Atlantic
Journal article
Authors | Chamberlain, Katy J., Barclay, Jenni, Preece, Katie, Brown, Richard J., McIntosh, Iona and EIMF |
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Abstract | The generation of felsic melts (through open or closed system processes) within ocean island volcanoes has been a key area of study since their identification. At Ascension Island in the south Atlantic, explosively erupted felsic melts have, to date, demonstrated a marked absence of signs of magma mixing and crustal assimilation. Here we present the first observations of a fall deposit from Ascension Island recording both macro- and micro-scale evidence for magma mingling. Geochemical analyses of mineral and glass phases, coupled with volatile concentrations of melt inclusions highlight the role of lower-crustal partial melting to produce rhyolitic magmas. Glass textures and the lack of zoning in major mineral phases indicate that mingling with a mafic melt occurred shortly prior to eruption. These inferences of a deep rhyolite production zone, coupled with rapid ascent rates highlight the challenges in forecasting a similar style of eruption at Ascension Island in the future. |
Keywords | Magma mingling; Ascension Island; Crustal melting; Magma genesis |
Year | 2020 |
Journal | Volcanica |
Publisher | Presses universitaires de Strasbourg |
ISSN | 2610-3540 |
Digital Object Identifier (DOI) | https://doi.org/10.30909/vol.03.01.139153 |
Web address (URL) | http://hdl.handle.net/10545/624811 |
hdl:10545/624811 | |
Publication dates | 05 May 2020 |
Publication process dates | |
Deposited | 22 May 2020, 16:02 |
Accepted | 17 Mar 2020 |
Contributors | University of Derby, University of East Anglia, Swansea University, Durham University, JAMSTEC and University of Edinburgh |
File | File Access Level Open |
File | File Access Level Open |
File | File Access Level Open |
https://repository.derby.ac.uk/item/93q74/deep-and-disturbed-conditions-for-formation-and-eruption-of-a-mingled-rhyolite-at-ascension-island-south-atlantic
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