WATIME · West African Middle Stone Age Timeline using ESR dating of quartz

West African Middle Stone Age Timeline using ESR dating of quartz

The WATIME project, hosted at the Centro Nacional de Investigación sobre la Evolución Humana (CENIEH, Spain), focused on improving the accuracy of dating methods used to build the chronology of the Middle Stone Age (MSA) in western Africa. Dating archaeological sites in this region remains a major challenge, as conventional methods such as radiocarbon or argon-argon dating cannot be applied due to the absence of suitable materials such as bones, charcoal, shells, or volcanic minerals. Quartz, however, is a common mineral present everywhere and represents an excellent candidate for dating using trapped-charge techniques such as Optically Stimulated Luminescence (OSL) and Electron Spin Resonance (ESR). Until now, OSL has been almost exclusively used as the main alternative dating technique to establish the chronology of western African Stone Age sites. However, this method presents clear limitations: it cannot be extended beyond approximately 150,000 years and is therefore unable to cover the full temporal range of the MSA. Before 2021, the earliest evidence of human occupation in western Africa was dated to ca. 130,000 years ago. Earlier occupations were unknown, leaving a major chronological gap in our understanding of the presence and adaptation of early Homo sapiens in this region. The main objective of WATIME was to refine and enhance the precision of the ESR dating method applied to quartz grains, in order to overcome the limitations of OSL and provide the first robust chronological framework for key MSA sites across western Africa. The project also tests the potential of ESR to push back the antiquity of human presence in the region by applying this method to key archaeological sites defined as early to late MSA. This approach makes it possible to extend the dating range beyond that achievable by OSL (Middle–Early Late Pleistocene), thereby shedding new light on the timing, environmental context, and behavioural evolution of early human populations, mainly in tropical and coastal western Africa.

Data: CORDIS, © European Union