Neandertal’s Presence during the Eemian Interglacial in North-western Europe: a New Site at Waziers (Northern France)

International audience; At the end of the 1980’s, C. Gamble launched a debate on the ability of Early hominids to colonize northern latitudes of Europeduring Middle and Late Pleistocene Interglacial periods. At that time, the Eemian (MIS 5e) was characterised by a total absence ofhuman occupation in Northern France, Belgium, Netherlands, Germany and Great Britain. Since the 1990’s, a few sites with humanoccupation attributed to the Eemian have been discovered and excavated in north-west Europe, particularly in Germany. Afterthese discoveries some authors like Roebroeks et al. [2, 3] rejected Gamble’s model. In northern France, several Middle Palaeolithiclevels were discovered at the base of the Eemian tufa of Caours (Somme basin) in 2006. They represent the first record of Humanoccupation during the Last Interglacial in the area.Recently, in 2012 an archaeological diagnostic conducted at Waziers (North, France) before the building of a Do-it-Yourselfshop, led to the discovery of a peat layer at 3,2 metres deep in some test pits, overlying fluvial silts and sands. Complementaryobservations made in 2013 allowed to propose an Eemian age for the fluvial sequence. This interpretation relies on geomorphologicaland palaeontological observations: (1) the presence of loess covering the fluvial deposits and the peat, and (2) the occurrenceof both Interglacial Pleistocene mammals (aurochs and red deer) and Pleistocene aquatic mollusc species (Belgrandia marginata,Anisus septemgyratus) that no longer exist in this area, in the fluvial deposits and in the peat. Moreover, a minimum age of 103+3.5/-3.4 ka was obtained by U/Th dating of small CacO3 nodules (oogons of characeae) extracted from a fine grained tufa layerdirectly underlying the peat (GEOTOP Montreal). This result reinforces the allocation of the the Waziers interglacial sequence tothe Eemian (a radiocarbon measurement undertaken earlier on the peat logically gave an age prior to 43 500 BP). The presence oflithic artefacts and aurochs bones with anthropic fractures lead to design an extended archaeological excavation in order to confirmthe existence of a second site with Eemian human occupation in Northern France.In 2013, a complete overview of the geomorphology of the valley has been carried out by geophysical research using two differentmethods. An EM31 connected to a GPS was used to record the mean electrical conductivity of soils (continuous, 4-6 m deep)and to obtain a map with the location of the Eemian channel. Two electric panels were made perpendicularly to the palaeochannelin order to observe the morphology of the valley and the fluvial deposits. Based on this information, a series of core drillings allowedto build five transects.In 2014, during a first campaign, 41 m2 were excavated. The geomorphology of the site was investigated and continuous samplingcolumns of the stratigraphical sequence were undertaken for paleontological studies on mollusc, pollen and mammal assemblages(presently in progress). The palaeoenvironmental reconstruction will be completed by the study of the rich corpus of woodand other organic remains such as hazelnuts or insects preserved in the peat. Thanks to the discovery of some lithic artefacts andhuman activity traces on faunal remains (cut maks on beaver tibia, burnt bones, aurochs bones typical breakage patterns) found insitu in fluvial deposit, the presence of human occupation during the Eemian at Waziers has been definitively demonstrated. Datings(OSL) are in progress and a second field campaign will take place this summer.References: [1] Gamble, C., 1986. The Palaeolithic Settlement of Europe. Cambridge University Press.[2] Roebroeks, W.,Conard, N. J., Van Kolfschoten, T., 1992. Dense forests, cold steppes, and the palaeolithic settlement of northern europe [andcomments and replies]. Current Anthropology, 33, 551-586.[3] Roebroeks, J.W.M., Tuffreau, A., 1999. Palaeoenvironment andsettlement patterns of the Northwest European Middle Palaeolithic. In: Roebroeks, W., Gamble, C. (red.), The MiddlePalaeolithic Occupation of Europe, pp. 121-138.[4] Antoine, P., Limondin-Lozouet, N., Auguste, P., Locht, J.-L., Galheb, Reyss,J.-L., Escude, É., Carbonel, P., Mercier, N., Bahain, J.-J., Falguères, C., Voinchet, P., 2006. Le tuf de Caours (Somme, France miseen évidence d’une séquence eemienne et d’un site paléolithique associé. Quaternaire, 17,4, 281-320.