LATE QUATERNARY CHRONOLOGY OF THE ALLIER TERRACE SEDIMENTS (MASSIF-CENTRAL, FRANCE)

The Late Quaternary terrace chronology of the middle Allier basin (Lim agne, Massif Central, France) has been reconstructed by means of terra ce (chemo)lithostratigraphy and with Th/U disequilibrium and C-14 dati ngs. The 25 m terrace level (Wb) has a Late Saalian age. The Weichseli an terrace levels Xa and Xb (20 and 10 m) contain at least four differ ent lithostratigraphical units: one Middle Pleniglacial, two Late Plen iglacial and one Younger Dryas. The oldest Holocene ZY terrace sedimen ts have Atlanticum ages. Timing of Allier incision and sedimentation d uring the Late Pleniglacial and Late Glacial appears to be mainly clim ate-related. Major fluvioglacial sediment fluxes from melting glaciers on the Mt. Dore and Cantal at the end of the Late Pleniglacial caused a strong rise of the Allier river bed level. This rise of approximate ly 20 m in the Limagne seems to have contributed to the formation of l akes like Marais de Ravel and the Grand Marais. Fluvial dynamics in th e Allier basin seem to be mainly climate controlled.