Radiocarbon Dating Skeletal Remains in the Tropics: Can we Radiocarbon Date Tooth Enamel Accurately?

Rachel Wood1*, Ling Wa Eric Shi1, Caitlin Raymond2, and James McCullagh3

Radiocarbon dates on skeletal remains are essential to build robust chronologies, e.g., of cemetery sites, the domestication of a species, or the production of a bone technology. However, protein rapidly degrades in warm environments, making the radiocarbon dating of bone extremely challenging. In many tropical locations it is impossible to radiocarbon date bone that is more than a few thousand years old, resulting in low quality chronologies based on the dating of samples that are poorly associated with the event of interest e.g. charcoal from burial contexts. Tooth enamel may provide an alternative to bone, as it contains carbon in the form of both protein and carbonate within the bioapatite mineral. Currently radiocarbon dating of enamel is undertaken on the carbonate within bioapatite, but dates are rarely accurate: samples that are >50,000 years old are often underestimated by 30,000 years.  This presentation will explore new methods to prepare tooth enamel based on a more thorough understanding of enamel diagenesis. It will show that ages produced on carbonate in tooth enamel – the traditional target for dating – can be drastically improved, but that it is not currently possible to accurately date enamel. The presentation will also explore the potential for dating the protein in tooth enamel – a novel method which may allow accurate dating of Pleistocene-aged skeletal remains in the tropics.