Determining the impact of climatic variations on past human cultural changes is a difficult task due to the chronological uncertainties inherent to the dating methods applied to archaeological and paleoclimatic archives, and by the different temporal resolution of both archives.
Here, we present two high-resolution pollen-based palaeoenvironmental sequences from the Bay of Biscay (45°21'N, 5°13'W) and the Gulf of Lion (40°29'N, 4°01'E) plotted against up-to-date chronologies. These sequences unambiguously identify millennial-scale vegetation and climatic changes in southern France in response to Greenland warming and cooling events, i.e. Dansgaard-Oeschger (D-O) cycles, and to the North Atlantic major iceberg discharges called Heinrich events (HEs). The chronologies are well constrained by numerical dating (new IRSL ages for the Bay of Biscay deep-sea core) and new age-depth models, based on Bayesian statistics and stratigraphic constrains using ChronoModel software and R-package ArchaeoPhases.
The construction and updating of archaeological databases for the Middle-to-Upper Palaeolithic transition in southwestern and southeastern France has allowed the development of age models based on ChronoModel. These age models provide more reliable chronological windows for the observed cultural changes in Neanderthals and Anatomically Modern Humans (AMH) in Western Europe.
Despite the improved paleoclimatic and archeological chronologies, the identification of a potential synchrony between climate and cultural changes still remains difficult due to new uncertainties. Nevertheless, this study suggests that the progressive opening of landscape since the D-O 12 (~47 ka) favoured the arrival of AMH in Western Europe, leading to competition with Neanderthals for the same ecological niches, and thus to the disappearance of the latter at ~40 ka.