ESR DATING OF PLEISTOCENE ALLUVIAL TERRACES OF THE AUBE RIVER VALLEY: FIRST RESULTS.

摘要

Four stepped fluvial terraces along the Aube River Valley have been dated using the Electron Spin Resonance (ESR) method applied on optically bleached quartz. The obtained chronology indicates that the deposition of the terraces system was initiated during the Middle Pleistocene, i.e. later that in other valleys of Parisian Basin area (Cher, Creuse, Somme), in which the oldest fluvial sheets are coeval of Lower Pleistocene times. This pattern raises the question of the preservation of the alluvial sheets, of the Aube river course at that time or even of its existence. On the other hand, the evolution of the system follows the general model proposed for several rivers of the northern Parisian Basin (Seine, Somme, Yonne), each sheet corresponding to the depositional balance of a Glacial/Interglacial cycle.