Opportunities to synchronise and date archaeological and climate records in Northwest Africa using volcanic ash (tephra) layers
Résumé
Archaeological sites in Northwest Africa are rich in human fossils and artefacts providing proxies for behavioural and evolutionary studies. However, these records are difficult to underpin on a precise chronology, which can prevent robust assessments of the drivers of cultural/behavioural transitions. Past investigations have revealed that numerous volcanic ash (tephra) layers are interbedded within the Palaeolithic sequences and likely originate from large volcanic eruptions in the North Atlantic (e.g., the Azores, Canary Islands, Cape Verde). Critically, these tephra layers offer a unique opportunity to provide new relative and absolute dating constraints (via tephrochronology) to synchronise key archaeological and palaeoenvironmental records in this region. Here, we provide an overview of the known eruptive histories of the potential source volcanoes capable of widespread ashfall in the region during the last ~300,000 years, and discuss the diagnostic glass compositions essential for robust tephra correlations. To investigate the eruption source parameters required for ash dispersal towards NW Africa, we simulate plausible ashfall distributions using Ashfall3D. This work constitutes the first step in developing a more robust tephrostratigraphic framework for distal ash layers in NW Africa and highlights how tephrochronology may be used to robustly synchronise and date key climatic and cultural transitions during the Palaeolithic.