Middle and Upper Pleistocene evolution of the River Yonne Valley (France) -First results.
Résumé
The Yonne terrace system, in the South-East of the Paris Basin (France) is composed of eleven alluvial sheets older than the modern fluvial deposits. These deposits cover distinct incision surfaces, which are parallel and regularly stepped along their longitudinal profile. The last six alluvial formations have fossilized several palaeolithic sites. This study describes a cyclic morphosedimentary pattern driven by the climatic changes of glacial- mterglacial or glacial-interstadial cycles. The chronostratigraphical interpretation is based on both ESR and U-Th dates and on lithopedostratigraphical observation Interpretation of this information allows the evolution of the Yonne terrace system since the Middle Pleistocene to be discussed and provides the context for several palaeolithic levels.