The Last Glacial Maximum extent of the Scandinavian Ice Sheet in the Valday Heights, western Russia: Evidence from cosmogenic surface exposure dating using 10Be

• Published in: Quaternary Science Reviews
• Main Authors: Rinterknecht, Vincent, Hang, Tiit, Gorlach, Aleksandr, Kohv, Marko, Kalla, Katrin, Subetto, Dmitry, Bourlès, Didier, Leanni, Laëtitia, Guillou, Valery, Aster, Team
• Other Authors: 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), Institute of Ecology and Earth Sciences, University of Tartu, Tartu, Estonia, University of Tartu, Centre européen de recherche et d'enseignement des géosciences de l'environnement (CEREGE), Institut de Recherche pour le Développement (IRD)-Institut National de la Recherche Agronomique (INRA)-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)
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2018
• Subjects: heights; Cosmogenic 10Be; Russia Valday; Scandinavian ice sheet; Late weichselian; LGM NW; [SDU]Sciences of the Universe [physics]; [SDU.STU.GL]Sciences of the Universe [physics]/Earth Sciences/Glaciology; Valday; Ice Sheet
• Online Access: https://hal.science/hal-02051718; https://doi.org/10.1016/j.quascirev.2018.09.032

International audience Recent synoptic studies have summarized the former spatial extent and chronology of the last Scandinavian Ice Sheet (SIS) and provide exceptional compilations of empirical datasets. The latter represent the primary source of information for the modelling community to test and develop thermomechanical ice sheet model, which are then further embedded into climatic and general circulation models. The Last Glacial Maximum (LGM) extent and chronology of the SIS across continental Europe were highlighted as being the least well-known thus generating the biggest uncertainties in the reconstruction of the ice sheet. While early geomorphological studies of the ice sheet marginal belts are numerous and detailed in western Russia, geochronological data are virtually inexistent. In an attempt to fill in this gap, we conducted a series of sampling campaigns for surface exposure dating using 10Be in the western and northwestern regions of Russia. We present here the first results from the Valday Heights where glacial deposits constitute well-preserved margins of the SIS. A total of 16 samples firmly establish the timing of the LGM in the Valday Heights at 20.1 ± 0.4 ka. The Valday Heights acted as a natural wall for the last maximum advance of the SIS during MIS2, constraining the eastern flank of the Ladoga-Ilmen-Lovat ice stream to the west of the hills. The Valday Heights were only overran by previously more extensive glacial advances as suggested by older exposure ages obtain on erratic boulders (31.2 ± 1.4 to 47.1 ± 1.5 ka) located east of the LGM limit.