RADIOCARBON DATING HUMAN SKELETAL MATERIAL ON RAPA NUI: EVALUATING THE EFFECT OF UNCERTAINTY IN MARINE-DERIVED CARBON

A primary concern with dating skeletal material from oceanic environments is the effect of marine-derived carbon on resulting radiocarbon ages. Due to uncertainties in local marine reservoir effects and the proportion of marine carbon incorporated in bone, dates from archaeological skeletal material exhibiting marine dietary signatures have previously been characterized as problematic and removed from further analysis. While in certain instances this may be appropriate, in others it is not. This article presents 26 new C-14 dates obtained from human teeth (dentin collagen) on Rapa Nui. The effect of the local marine reservoir on 14C ages is evaluated assuming a range of incorporated marine-derived carbon. The results indicate that the Rapa Nui 14C ages are not significantly different under varying realistic extreme ranges in estimates of the proportion of marine carbon consumed. The article argues that this is primarily due to the small local marine reservoir effect measured in Rapa Nui and relatively lower reliance on marine resources in the prehistoric and protohistoric population.