Constraining the age of the Middle Stone Age locality of Bargny (Senegal)
through a combined OSL-ESR dating approach

Eslem Ben Arous,
Former Fyssen 2020

K. Niang, J.A. Blinkhorn, M. Del Val, A. Medialdea, C. Coussot, M.J. Alonso Escarza, M.D. Bateman, A. Churruca Clemente, A.F. Blackwood, J. Iglesias-Cibanal, C. Saíz, E.M.L. Scerri, M. Duval

“Constraining the age of the Middle Stone Age locality of Bargny (Senegal) through a combined OSL-ESR dating approach”

The Middle Stone Age (MSA) is the earliest cultural period associated with the emergence of Homo sapiens. Although the MSA constitutes a major change in evolutionary and cognitive history of our species, vast swathes of Africa such as West Africa have seen less investment in research, in contrast to other regions of the continent. This paper documents one of the oldest human occupations in West Africa preserved in the sites Bargny 1 and 3 (Senegal), and associated with classic Middle Stone Age (MSA). The combination of two dating methods, Optically Stimulated  Luminescence (OSL) and Electron Spin Resonance (ESR) allowed to propose a consensual age of the human occupation at Bargny to around 130 thousand years, confirming the early presence of MSA occupations along the Senegambian coast around the MIS 6-MIS 5 transition, into the late Middle Pleistocene. In combination with the associated estuarine environments and mangrove forest already documented in another study published in 2023 (https://doi.org/10.1038/s41559-023-02046-4), the evidence from Bargny adds to the known diversity, and likely complex behavior, of early human populations living by Africa’s coastlines.

Eslem is an African Pleistocene Geochronologist and Archaeologist interested in building the timeline of human occupations in Africa over the last 600,000 years. Her main research focus on using and developing the ESR dating (quartz and enamel), U-series (enamel) and OSL dating (quartz) to date ESA and MSA sites. Her ongoing research aims at pushing back the limits of the ESR dating method on the African continent.

After her PhD at the MNHN (Paris, France) that she got in 2019, Eslem joined the Max Planck Institute of Science of Human History (Now, Max Planck Institute of Geoanthropology) in Jena (Germany), into the Pan-African Evolution Research Group and the Human Palaeosystems Research Group (dir. Eleanor Scerri) to led her Fyssen Postdoctoral Fellow (2020-2022) and a Postdoctoral Researcher position (2022-2023). She led a pilot project to investigate the potential of paired ESR and OSL dating on MSA sites located in West African Tropical forest. Her research is demonstrating the great potential of the ESR dating as a key alternative dating method to build the evolution timeline of our African Pleistocene ancestors.

Eslem is currently conducting her MSCA Fellow (2023-2025) under the supervision of M. Duval to lead the project WATIME « West African Middle Stone Age Timeline using ESR dating of quartz » (https://cordis.europa.eu/project/id/101107408) which aims to establish the ESR chronology of West African early MSA and MSA.

Photo: View of the MSA Bargny 3 site during the excavations led by Dr Khady Niang  (Credit: Dr Khady Niang)