TY - JOUR

T1 - Exploring controls of the early and stepped deglaciation on the western margin of the British Irish Ice Sheet.

AU - Benetti, Sara

AU - Chiverrell, Richard C.

AU - Ó Cofaigh, Colm

AU - Burke, Matthew

AU - Medialdea, Alicia

AU - Small, David

AU - Ballantyne, Colin

AU - Bateman, Mark

AU - Callard, Sarah Louise

AU - Wilson, Peter

AU - Fabel, Derek

AU - Clark, Chris

AU - Arosio, Riccardo

AU - Bradley, Sarah L.

AU - Dunlop, Paul

AU - Ely, Jeremy C.

AU - Gales, Jenny

AU - Livingstone, Stephen J.

AU - Moreton, Steven

AU - Purcell, Catriona

AU - Saher, Margot

AU - Schiele, Kevin

AU - Van Landeghem, Katrien

AU - Weilbach, Kasper

PY - 2021/7

Y1 - 2021/7

N2 - 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 ~27ka, prior to the global Last Glacial Maximum, and shelf-wide retreat began 26-26.5ka at a rate of ~18.7- 20.7m/a. MSIS grounding zone wedges and DBIS recessional moraines show episodic retreat punctuated by prolonged still-stands. By ~23-22ka the outer shelf (~25,000 km2) was free of grounded ice. After this time, MSIS retreat was faster (~20m/a vs. ~2-6m/a of DBIS). Separation of Irish and Scottish ice sources occurred ~20-19.5ka, leaving an autonomous Donegal ice dome. Inner Malin shelf deglaciation followed the submarine troughs reaching the Hebridean coast ~19ka. DBIS retreat formed the extensive complex of moraines in outer Donegal Bay at 20.5-19ka. DBIS retreated on land by ~17-16ka. Isolated ice caps in Scotland and Ireland persisted until ~14.5ka. Early retreat of this marine terminating margin margins 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 midshelf to the coast.

AB - 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 ~27ka, prior to the global Last Glacial Maximum, and shelf-wide retreat began 26-26.5ka at a rate of ~18.7- 20.7m/a. MSIS grounding zone wedges and DBIS recessional moraines show episodic retreat punctuated by prolonged still-stands. By ~23-22ka the outer shelf (~25,000 km2) was free of grounded ice. After this time, MSIS retreat was faster (~20m/a vs. ~2-6m/a of DBIS). Separation of Irish and Scottish ice sources occurred ~20-19.5ka, leaving an autonomous Donegal ice dome. Inner Malin shelf deglaciation followed the submarine troughs reaching the Hebridean coast ~19ka. DBIS retreat formed the extensive complex of moraines in outer Donegal Bay at 20.5-19ka. DBIS retreated on land by ~17-16ka. Isolated ice caps in Scotland and Ireland persisted until ~14.5ka. Early retreat of this marine terminating margin margins 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 midshelf to the coast.

KW - Malin Sea

KW - Donegal

KW - ice streams

KW - deglaciations

KW - retreat rate

U2 - 10.1002/jqs.3315

DO - 10.1002/jqs.3315

M3 - Article

VL - 36

SP - 833

EP - 870

JO - Journal of Quaternary Science

JF - Journal of Quaternary Science

SN - 1099-1417

IS - 5

ER -