Towards a pretreatment for radiocarbon dating tooth enamel

Radiocarbon dating bone that is more than a few thousand years old in tropical and arid regions of Australia and South East Asia is hampered by the rapid degradation of the protein normally targeted for dating. In the best-case scenarios, a few bones with a little protein can be found when large numbers of bones are screened. However, we often find that no collagen remains. This can result in low quality chronologies because in many contexts the only samples available for radiocarbon dating are poorly associated with the event of interest, such as charcoal from burial contexts.
Tooth enamel may provide an alternative skeletal material to radiocarbon date, but little work has examined diagenesis mechanisms, or how contaminating carbon can be removed. Dates are rarely accurate: typically at least 5-10% of the carbon in enamel is a contaminant after routine pretreatment causing a sample of 50,000 years to appear 20,000 year old.
This presentation will explore new methods to clean tooth enamel based on a more thorough understanding of enamel diagenesis. It will show that ages on tooth enamel can be drastically improved, but accurate dates are not yet obtained. It will also discuss implications for stable isotope analysis of tooth enamel, often claimed to be relatively immune from diagenetic alteration.