Late Pleistocene glaciation in the Cantal Mountains and on the Cézallier Plateau (western Massif Central, France): Insights from glacial geomorphology and surface exposure dating

Abstract

The aim of this work is to build a new chronology of the Late Pleistocene glacial fluctuations in the Cantal Mountains and on the Cézallier Plateau (western Massif Central, France). The study of glacial landform-sediment assemblages is supported by the production of new exposure ages (n = 48) from (i) forty-three erratic boulders (36Cl and 10Be) spread over twelve glacial landforms, (ii) two ages from polished bedrocks (10Be) and (iii) three ages from depth profiles (10Be and 26Al) in tills. The results indicate that the majority of glacial deposits are attributed to Marine Isotopic Stage 2 (29 to 11 ka). From this dataset, four glacial stadials are discriminated: the Early-Local Last Glacial Maximum at 29–24 ka, (ii) Late-Last Glacial Maximum at 24–20 ka, (iii) a glacial still stand at approximately 17 ka, during a general deglaciation phase between 20 and 16 ka and finally (iv) a cirque stadial localized only in the Cantal Mountains at <16 ka. This new chronology strengthens the chronostratigraphy of the western Massif Central and highlights the sensitivity of the area to atmospheric circulation changes.