Résumé
The excavation linked to the building of a new highway at Villiers-Adam (Val d'Oise France) led to the discovery of very important Pleistocene loess and palaeosols pedosedimentary sequences, and a Palaeolithic level attributable to the young phase of the Middle Palaeolithic (+ or -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) (+ or -300 to 15 ka BP). In addition this study has provided a very complete record of the Weichselian Early-Glacial period (+ or -112-70 ka BP), and an exceptionally developed interstadial soil complex corresponding to the Weichselian Middle Pleniglacial (+ or -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.