Oscillating retreat of the last British-Irish Ice Sheet on the continental shelf offshore Galway Bay, western Ireland

Callard, S Louise, Ó Cofaigh, Colm, Benetti, Sara, Chiverrell, Richard C ORCID: 0000-0002-7307-2756, Van Landeghem, Katrien JJ, Saher, Margot H, Livingstone, Stephen J, Clark, Chris D, Small, David, Fabel, Derek
et al (show 1 more authors) (2020) Oscillating retreat of the last British-Irish Ice Sheet on the continental shelf offshore Galway Bay, western Ireland. Marine Geology, 420. p. 106087.

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During the Last Glacial Maximum, the British-Irish Ice Sheet extended across the continental shelf offshore of Galway Bay, western Ireland, and reached a maximum westward extent on the Porcupine Bank. New marine geophysical data, sediment cores and radiocarbon dates are used to constrain the style and timing of ice-sheet retreat across the mid to inner-shelf. Radiocarbon dated shell fragments in subglacial till on the mid-shelf constrains ice advance to after 26.4 ka BP. Initial retreat was underway before 24.4 ka BP, significantly earlier than previous reconstructions. Grounding-line retreat was accompanied by stillstands and/or localised readvances of the grounding-line. A large composite Mid-Shelf Grounding Zone Complex marks a major grounding-line position, with the ice grounded and the margin oscillating at this position by, and probably after, 23 ka BP. The continental shelf was ice-free by 17.1 cal. ka BP, but the ice sheet may have retained a marine margin until c. 15.3 ka BP. Retreat occurred in a glacimarine setting and the ice sheet was fringed by a floating ice-shelf. Collectively, this evidence indicates a dynamic and oscillatory marine-terminating ice sheet offshore of western Ireland during the last deglaciation.

Item Type: Article
Uncontrolled Keywords: Grounding zone wedges, British-Irish Ice Sheet, Ice shelf, Glacimarine, Last Glacial Maximum, Ice-sheet retreat, Continental shelf
Depositing User: Symplectic Admin
Date Deposited: 04 Feb 2020 10:27
Last Modified: 19 Jan 2023 00:05
DOI: 10.1016/j.margeo.2019.106087
Related URLs:
URI: https://livrepository.liverpool.ac.uk/id/eprint/3073379