Marine Isotope Stage 4 (71–57 ka) on the Western European margin: Insights to the drainage and dynamics of the Western European Ice Sheet

• Published in: Global and Planetary Change
• Main Authors: Toucanne, Samuel, Rodrigues, Teresa, Menot, Guillemette, Soulet, Guillaume, Cheron, Sandrine, Billy, Isabelle, Eynaud, Frederique, Antoine, Pierre, Sinninghe Damste, Jaap, Bard, Edouard, Sanchez Goñi, Maria-Fernanda
• Other Authors: Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER), Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Durham University, Laboratoire Géosciences Océan (LGO), Université de Bretagne Sud (UBS)-Institut Français de Recherche pour l'Exploitation de la Mer (IFREMER)-Université de Brest (UBO)-Centre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris Sciences et Lettres (PSL)-Université Paris Sciences et Lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Université de Bordeaux - Sciences Technologies (U. Bordeaux ), Laboratoire de géographie physique : Environnements Quaternaires et Actuels (LGP), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris-Est Créteil Val-de-Marne - Paris 12 (UPEC UP12)-Centre National de la Recherche Scientifique (CNRS), Centre Européen de Recherche et d'Enseignement des Géosciences de l'Environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Aix Marseille Université (AMU)-Collège de France (CdF (institution))-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2023
• Subjects: [SDU.STU]Sciences of the Universe [physics]/Earth Sciences; Fennoscandian; Ice Sheet; Sea ice
• Online Access: https://hal.science/hal-04202407; https://doi.org/10.1016/j.gloplacha.2023.104221

International audience Marine Isotope Stage (MIS) 4 (ca. 71-57 ka; within the Middle Weichselian Substage) is considered a significant Pleistocene glaciation, but it remains poorly constrained in comparison to that of the Late Weichselian Last Glacial Maximum (LGM; ca. 29-19 ka, during MIS 2), or even the Late Saalian MIS 6 (ca. 190-130 ka). Most MIS 4 glacial landforms in Europe were erased by the more extensive LGM ice advance, precluding a robust reconstruction of its extent and dynamic through time. Marine sedimentary archives, in preserving the source-to-sink sediment transfer signals of ice-sheet and glacier processes, help to bridge this gap. Here, the signals west of the European Ice Sheet (EIS) are tracked for MIS 4 from the deep Bay of Biscay (NE Atlantic), which was the outlet for Fennoscandian Ice Sheet (FIS) sediment-laden meltwater during extensive glaciations, specifically when the British-Irish Ice Sheet (BIIS) and the FIS coalesced into the North Sea (as during MIS 6 and the LGM). Sedimentological, geochemical, and mineralogical proxies reveal the absence of FIS-derived material in Bay of Biscay sediment throughout MIS 4, which indicates that FIS meltwater and huge river systems from the North European Plain never drained into the Bay of Biscay at that time. This suggests that contrary to MIS 6 and the LGM, the BIIS and FIS were not likely large enough to coalesce and form a (grounded) ice bridge onto the North Sea, thus confirming geomorphic evidence for a significant, but relatively limited, glaciation in Europe during MIS 4. Closer to the Bay of Biscay, ice-marginal fluctuations of the BIIS are identified in the Celtic-Irish Sea region from the deep-sea record. More specifically, our findings suggest an early retreat of the Irish Sea Ice Stream as soon as ca. 68-65 ka, a few millennia before the demise of the EIS, and the Northern Hemisphere ice sheets as a whole, during Heinrich Stadial (HS) 6. This pattern is similar to that already recorded during MIS 2. Finally, this study reveals that ...