West African Middle Stone Age Timeline using ESR dating of quartz

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The evolution of H. sapiens in Africa is intrinsically linked to the expansion of the Middle Stone Age (MSA). West Africa is one of the last frontiers for human evolutionary research and has long been considered to have played virtually no role in our species' biological, cognitive and behavioural evolution. Recently-excavated MSA sites across West African changed this perception, but there is still a critical need for reliable chronometric dates to establish a secure timeline for the MSA. While the Optically Stimulated Luminescence (OSL) dating applied to quartz has already provided some key chronological constraints, the method has also shown some clear limitations as it cannot chronologically cover the entire MSA time range. WATIME project aims to explore the potential of the Electron Spin Resonance (ESR) dating, the key alternative method to date quartz. The project is built on promising results from a pilot study at Bete I-Anyama site (Ivory Coast), which not only demonstrated the potential and feasibility of using Titanium (Ti) signals to date quartz samples from West Africa, but also led to the identification of some specific methodological issues worth investigating further to ensure the reliability of the ESR dating method. WATIME will address them by developing and quantifying and measurable accurate criteria to assess the suitability of Ti ESR signal, improving spectral resolution, measurement precision and signal characterization. Implementing a new rapid and accurate laboratory ESR dating procedure will help resolve the chronology of MSA West African sites that cannot be dated by other means. WATIME opens an innovative way to date the key changes in cultural/behavioural patterns from the archaeological record in West Africa. The results will be broadly communicated through open access and open peer reviewed article resources, and targeted public outreach activities.