Acheulean of the Somme basin (France): Assessment of lithic changes during MIS 12 to 9

Several Acheulean sites dated between stages MIS 12 to 9 are located around the town of Amiens in the Somme Valley. These include: Cagny-la-Garenne I, Cagny-la-Garenne II, Cagny-la-Ferme de l'Epinette, Cagny-l'Epinette, Revelles and Gentelles. The aim of this paper is to present the chronological situation and context of each of these sites and to ascertain the continuity or the discontinuity of the main behavioral aspects of the raw material procurement patterns, the core types and the biface and tool-flake status. We also examine numerous aspects of shaping and knapping, such as the presence of hammerstones or specialized classes of lithics. A synthesis of data underlines changes in the main categories of lithic artifacts and variability or convergence in the production systems.