文摘
Research undertaken for more than 15 years on both fluvial and loess sequences of the main river valleys in Northern France (Somme, Seine and Yonne) is based on an interdisciplinary approach combining stratigraphy, sedimentology, bioclimate studies and geochronology using the following methods: U-series, ESR, OSL, and ESR/U-series. The investigations of the bottom valley fluvial sequences (Lateglacial and Holocene) allowed development of a model concerning the response of the fluvial systems to climate changes, which can be applied to the entire dataset from the Middle Pleistocene. Results obtained from modern archaeological excavations were also integrated within the chrono-climate reference system of Northern France. The complete data set indicates that human occupation of this area has been likely discontinuous and highly influenced by climate and environmental factors. In the Somme basin, the oldest in situ human occupations recently excavated are dated at 450–500 ka maximum (Early MIS 12), but handaxes have been found up to 500–550 ka within the Fréville formation (MIS 13–14). In the Seine basin, the oldest in situ Acheulean archaeological level has been recognized within a tufa sequence attributed to MIS 11 at La Celle. Between 450 and 200 ka, data are relatively rare and less accurate, but the archaeological sites seem nevertheless to be mainly associated with interglacial periods or climate transitions such as Early or Lateglacial, as demonstrated for the Last climate cycle. Taking into account all data and especially the available dating results of the oldest levels, there is as yet no clear evidence of an Acheulean settlement in Northern France before 500–550 ka.