A Hierarchical Bayesian Examination of the Chronological Relationship between the Noaillian and Rayssian Phases of the French Middle Gravettian

Issues of chronology are central to inferences pertaining to relationships between both contemporaneous and successive prehistoric typo-technological entities (i.e., archaeological cultures), culture-environment relationships, and ultimately the mechanisms at play behind cultural changes observed through time in the archaeological record. We refine the chronology of Upper Paleolithic archaeological cultures between 35-18 calibrated kiloanni before the present in present-day France by incorporating recently published radiocarbon data along with new 14C ages that we obtained from several Gravettian archaeological contexts. We present the results of a Bayesian age model that includes these new radiometric data and that, more importantly, separates Gravettian contexts in regions north of the Garonne River into two successive cultural phases: The Northern Noaillian and the Rayssian, respectively. This new age model places the beginning of the Noaillian during Greenland Stadial 5.2. The appearance of contexts containing assemblages associated with the Rayssian lithic technical system occurs immediately prior to the termination of Greenland Interstadial 5.1, and it is present throughout Heinrich Event 3 (GS-5.1) and into the following GI-4 climatic amelioration. Despite the Rayssian's initial appearance during the brief and relatively weakly expressed Greenland Interstadial 5.1, its duration suggests that Rayssian lithic technology was well-suited to the environmental conditions of Greenland Stadial 5.1.