Innovations in Acheulean biface production at la Noira (France) during Middle Pleistocene in Western Europe

Abstract

The archaeological sequence of la Noira (Centre region, France) yielded two phases of occupation: ca 700 ka (stratum a) and ca 450 ka (stratum c). No site between these two dates has yet been discovered in the area, and this chronological period has thus been interpreted as a gap in settlement from MIS 16 to MIS 12, two crucial phases of occupation in Western Europe. The record before the long glacial event MIS 12 has been traditionally associated with the onset of the Acheulean in Europe. From MIS 12, the record represents the earliest evidence of innovations, a clear shift in human evolution. Here, we compare these two levels (strata a and c), tracking the technological innovations during this time and combining technological analysis with geometric morphometrics with the use of 3D models comparison of the large cutting tools (LCTs). Stratum a yielded an Early Acheulean, one of the few evidences in Europe presents tools with mainly short shaping sequences on local millstone slabs, with special attention to tips, but with clear management of tool volume. Stratum c, dated to the MIS 11, differs in that both local millstone and flints from distant sources show longer shaping sequences, the use of soft hammers for several series of removals on tools, combined with final regularizing retouch on entire edges. The morphometric approach shows a morphological transition from oval to teardrop shapes for the thinnest tools. Our data suggest a clear technological filiation between strata a and c and in la Noira populations from MIS 16 and MIS 12, as suggested for innovations of core technologies and land-use patterns, and raise question on local human behavioural evolution over the Middle Pleistocene in Western Europe.