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Exploring controls of the early and stepped deglaciation on the western margin of the British Irish Ice Sheet

Benetti, Sara; Chiverrell, Richard C.; Cofaigh, Colm Ó; Burke, Matt; Medialdea, Alicia; Small, David; Ballantyne, Colin; Bateman, Mark D.; Callard, S. Louise; Wilson, Peter; Fabel, Derek; Clark, Chris D.; Arosio, Riccardo; Bradley, Sarah; Dunlop, Paul; Ely, Jeremy C.; Gales, Jenny; Livingstone, Stephen J.; Moreton, Steven G.; Purcell, Catriona; Saher, Margot; Schiele, Kevin; Van Landeghem, Katrien; Weilbach, Kasper

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Sara Benetti

Richard C. Chiverrell

Matt Burke

Alicia Medialdea

Colin Ballantyne

Mark D. Bateman

S. Louise Callard

Peter Wilson

Derek Fabel

Chris D. Clark

Riccardo Arosio

Sarah Bradley

Paul Dunlop

Jeremy C. Ely

Jenny Gales

Stephen J. Livingstone

Steven G. Moreton

Catriona Purcell

Margot Saher

Kevin Schiele

Katrien Van Landeghem

Kasper Weilbach


New optically stimulated luminescence dating and Bayesian models integrating all legacy and BRITICE-CHRONO geochronology facilitated exploration of the controls on the deglaciation of two former sectors of the British–Irish Ice Sheet, the Donegal Bay (DBIS) and Malin Sea ice-streams (MSIS). Shelf-edge glaciation occurred ~27 ka, before the global Last Glacial Maximum, and shelf-wide retreat began 26–26.5 ka at a rate of ~18.7–20.7 m a–1. MSIS grounding zone wedges and DBIS recessional moraines show episodic retreat punctuated by prolonged still-stands. By ~23–22 ka the outer shelf (~25 000 km2) was free of grounded ice. After this time, MSIS retreat was faster (~20 m a–1 vs. ~2–6 m a–1 of DBIS). Separation of Irish and Scottish ice sources occurred ~20–19.5 ka, leaving an autonomous Donegal ice dome. Inner Malin shelf deglaciation followed the submarine troughs reaching the Hebridean coast ~19 ka. DBIS retreat formed the extensive complex of moraines in outer Donegal Bay at 20.5–19 ka. DBIS retreated on land by ~17–16 ka. Isolated ice caps in Scotland and Ireland persisted until ~14.5 ka. Early retreat of this marine-terminating margin is best explained by local ice loading increasing water depths and promoting calving ice losses rather than by changes in global temperatures. Topographical controls governed the differences between the ice-stream retreat from mid-shelf to the coast.


Benetti, S., Chiverrell, R. C., Cofaigh, C. Ó., Burke, M., Medialdea, A., Small, D., …Weilbach, K. (2021). Exploring controls of the early and stepped deglaciation on the western margin of the British Irish Ice Sheet. Journal of Quaternary Science, 36(5), 833 - 870.

Journal Article Type Article
Acceptance Date Mar 18, 2021
Online Publication Date Jun 2, 2021
Publication Date 2021-07
Deposit Date Jul 30, 2021
Publicly Available Date Jul 30, 2021
Journal Journal of Quaternary Science
Print ISSN 0267-8179
Electronic ISSN 1099-1417
Publisher Wiley
Peer Reviewed Peer Reviewed
Volume 36
Issue 5
Pages 833 - 870
Public URL


Published Journal Article (Advance online version) (20.8 Mb)

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Copyright Statement
Advance online version This is an open access article under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited.

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