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Melt movement through the Icelandic crust.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

White, Robert S 
Greenfield, Timothy  ORCID logo  https://orcid.org/0000-0002-4370-7298
Agustsdottir, Thorbjorg 

Abstract

We use both seismology and geobarometry to investigate the movement of melt through the volcanic crust of Iceland. We have captured melt in the act of moving within or through a series of sills ranging from the upper mantle to the shallow crust by the clusters of small earthquakes it produces as it forces its way upward. The melt is injected not just beneath the central volcanoes, but also at discrete locations along the rift zones and above the centre of the underlying mantle plume. We suggest that the high strain rates required to produce seismicity at depths of 10-25 km in a normally ductile part of the Icelandic crust are linked to the exsolution of carbon dioxide from the basaltic melts. The seismicity and geobarometry provide complementary information on the way that the melt moves through the crust, stalling and fractionating, and often freezing in one or more melt lenses on its way upwards: the seismicity shows what is happening instantaneously today, while the geobarometry gives constraints averaged over longer time scales on the depths of residence in the crust of melts prior to their eruption. This article is part of the Theo Murphy meeting issue 'Magma reservoir architecture and dynamics'.

Description

Keywords

Iceland, basaltic melt, carbon dioxide, geobarometry, rifts, seismology

Journal Title

Philos Trans A Math Phys Eng Sci

Conference Name

Journal ISSN

1364-503X
1471-2962

Volume Title

377

Publisher

The Royal Society
Sponsorship
Natural Environment Research Council (NE/F011407/1)
Natural Environment Research Council (NE/H025006/1)
Natural Environment Research Council (NE/I018263/1)
Natural Environment Research Council (NE/M017427/1)
European Commission (308377)
Natural Environment Research Council (NE/I012508/1)
Royal Society (IE50300)
NERC (via British Geological Survey (BGS)) (GA/14S/021/)