Nouvelles données sur le Pléistocène du nord du Bassin parisien: les séquences loessiques de Villiers-Adam (Val d'Oise, France) [New data on the Pleistocene of the north of the Paris hasin : the hess-palacosols sequences of Villiers-Adam (lal d'Oise. France).]

The excavation linked to the building of a new high way at Villiers-Adam (Val d'Oise France) allowed discovering of very important Pleistocene loess and palaeosols pedosedimentary sequences, and a Palaeolithic level attributable to the young phase of the Middle Palaeolithic (±100 ka BP). The very important interdisciplinary work that has been overtaken (stratigraphy, sedimentology, micromorphology, malacology, palynology and TL-IRSL dating) has led to the detailed characterisation of three overlapping Glacial-interglacial sequences (cumulative thickness* 19 m), dating from the Younger Middle Pleistocene (MIS 8/7 and 7/6), to the Upper Pleistocene (MIS 5 to 2) (± 300 to 15 ka BP). In addition this study has provided a very complete record of the Weichselian Early-Glacial period (± 112-70 ka BP), and an exceptionally developed mterstadial soil complex corresponding to the Weichselian Middle Pleniglacial (± 55-30 ka BP). In an area where the data concerning loess, and especially Middle Pleistocene loess, were very poor, these research provide a regional type sequence including a lot of new elements to the stratigraphical scheme of the bordering area, and the first reference analytical data base for northern France.