Strontium isoscape of sub-Saharan Africa allows tracing origins of victims of the transatlantic slave trade.

Strontium isotope (Sr/Sr) analysis with reference to strontium isotope landscapes (Sr isoscapes) allows reconstructing mobility and migration in archaeology, ecology, and forensics. However, despite the vast potential of research involving Sr/Sr analysis particularly in Africa, Sr isoscapes remain unavailable for the largest parts of the continent. Here, we measure the Sr/Sr ratios in 778 environmental samples from 24 African countries and combine this data with published data to model a bioavailable Sr isoscape for sub-Saharan Africa using random forest regression.

Making beads and bead making: an introduction.

Beads are a prominent category of material culture in the African past. Crosscutting their study across temporal periods and geographical areas are some general methodological and theoretical convergences: the categorisation of beads in terms of materials and methods of manufacture, an emphasis on provenance and distribution, and the analysis of beads as 'social signals' in relation to identity, networks and status. This paper outlines the conceptual framework of 'making' and discusses how such a framework can expand on existing analyses and provide new avenues for studying beads in the African past.