Ice sheet extension to the Celtic Sea shelf edge at the Last Glacial Maximum

Praeg, D.; McCarron, S.; Dove, D.; Ó Cofaigh, C.; Scott, G.; Monteys, X.; Facchin, L.; Romeo, R.; Coxon, P.

doi:10.1016/j.quascirev.2014.12.010

Ice sheet extension to the Celtic Sea shelf edge at the Last Glacial Maximum

Praeg, D.; McCarron, S.; Dove, D.; Ó Cofaigh, C.; Scott, G.; Monteys, X.; Facchin, L.; Romeo, R.; Coxon, P.

Authors

D. Praeg

S. McCarron

D. Dove

Professor Colm O'Cofaigh colm.ocofaigh@durham.ac.uk
Head Of Department

G. Scott

X. Monteys

L. Facchin

R. Romeo

P. Coxon

Abstract

Previous reconstructions of the British–Irish Ice Sheet (BIIS) envisage ice streaming from the Irish Sea to the Celtic Sea at the Last Glacial Maximum, to a limit on the mid-shelf of the Irish-UK sectors. We present evidence from sediment cores and geophysical profiles that the BIIS extended 150 km farther seaward to reach the continental shelf edge. Three cores recently acquired from the flank of outer Cockburn Bank, a shelf-crossing sediment ridge, terminated in an eroded glacigenic layer including two facies: overconsolidated stratified diamicts; and finely-bedded muddy sand containing micro- and macrofossil species of cold water affinities. We interpret these facies to result from subglacial deformation and glacimarine deposition from turbid meltwater plumes. A date of 24,265 ± 195 cal BP on a chipped but unabraded mollusc valve in the glacimarine sediments indicates withdrawal of a tidewater ice sheet margin from the shelf edge by this time, consistent with evidence from deep-sea cores for ice-rafted debris peaks of Celtic Sea provenance between 25.5 and 23.4 ka BP. Together with terrestrial evidence, this supports rapid (ca 2 ka) purging of the BIIS by an ice stream that advanced from the Irish Sea to the shelf edge and collapsed back during Heinrich event 2.

Citation

Praeg, D., McCarron, S., Dove, D., Ó Cofaigh, C., Scott, G., Monteys, X., …Coxon, P. (2015). Ice sheet extension to the Celtic Sea shelf edge at the Last Glacial Maximum. Quaternary Science Reviews, 111, 107-112. https://doi.org/10.1016/j.quascirev.2014.12.010

Journal Article Type	Article
Acceptance Date	Dec 11, 2014
Publication Date	Mar 1, 2015
Deposit Date	Feb 6, 2015
Publicly Available Date	Feb 11, 2015
Journal	Quaternary Science Reviews
Print ISSN	0277-3791
Publisher	Elsevier
Peer Reviewed	Peer Reviewed
Volume	111
Pages	107-112
DOI	https://doi.org/10.1016/j.quascirev.2014.12.010
Keywords	British–Irish Ice Sheet, Last Glacial Maximum, Celtic Sea, Cockburn Bank, Glacigenic sediments, Heinrich Event 2.
Public URL	https://durham-repository.worktribe.com/output/1437020

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Copyright Statement
NOTICE: this is the author’s version of a work that was accepted for publication in Quaternary Science Reviews. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Quaternary Science Reviews, 111, 1 March 2015, 10.1016/j.quascirev.2014.12.010.