International audienceNorthwestern France is characterized by a relatively high number of open-air sites attributed to the Late Middle Pleistocene. During this period, the biological evolution of Homo heidelbergensis that will lead to the emergence of the Neanderthal lineage, is the cause of many societal, cultural and technical changes. From a cultural point of view, the Middle Pleistocene covers the end of the Acheulean and the early Middle Paleolithic. This phase of transition is contemporary with the emergence and mostly the rapid generalization of the use of Levallois production. On a more general point of view, the Late Middle Pleistocene appears as a phase of complex maturation of human societies, at the origin of the specificity of ...