Deep and disturbed: conditions for formation and eruption of a mingled rhyolite at Ascension Island, south Atlantic
Affiliation
University of DerbyUniversity of East Anglia
Swansea University
Durham University
JAMSTEC
University of Edinburgh
Issue Date
2020-05-05
Metadata
Show full item recordAbstract
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.Citation
Chamberlain, K. (2020). 'Deep and disturbed: conditions for formation and eruption of a mingled rhyolite at Ascension Island, south Atlantic'. Volcanica, 3(1), pp. 139 – 153Publisher
Presses universitaires de StrasbourgJournal
VolcanicaDOI
10.30909/vol.03.01.139153Additional Links
https://www.jvolcanica.org/ojs/index.php/volcanica/indexhttp://www.jvolcanica.org/ojs/index.php/volcanica/article/view/59
Type
ArticleDataset
Language
enEISSN
2610-3540ae974a485f413a2113503eed53cd6c53
10.30909/vol.03.01.139153