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


    Praeg, Daniel and McCarron, Stephen and Dove, Dayton and Ó Cofaigh, Colm and Scott, Gill and Monteys, Xavier and Facchin, Lorenzo and Romeo, Roberto and Coxon, Peter (2015) Ice sheet extension to the Celtic Sea shelf edge at the Last Glacial Maximum. Quaternary Science Reviews, 111. pp. 107-112. ISSN 0277-3791

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    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: over- consolidated 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

    Item Type: Article
    Keywords: British-Irish Ice Sheet; Last Glacial Maximum; Celtic Sea; Cockburn Bank; Glacigenic sediments; Heinrich Event 2;
    Academic Unit: Faculty of Social Sciences > Geography
    Faculty of Social Sciences > Research Institutes > Irish Climate Analysis and Research Units, ICARUS
    Item ID: 8868
    Identification Number: https://doi.org/10.1016/j.quascirev.2014.12.010
    Depositing User: Dr. Stephen McCarron
    Date Deposited: 03 Oct 2017 15:51
    Journal or Publication Title: Quaternary Science Reviews
    Publisher: Elsevier
    Refereed: Yes
    URI:

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