Radiocarbon Dating of Algal Bioclasts in Beach Sites of Guam

Direct radiocarbon dating of algal bioclasts of Halimeda sp. demonstrates accurate age estimates in relation to archaeological layers in three beach sites of Guam in the western Pacific region. These case studies illustrate the technical requirement of identifying intact (non-eroded) bioclasts for dating, as well as the methodological parameters for interpreting the relationship between depositional context of these bioclasts in relation to the archaeological point of interest. In the many island and coastal beach sites world-wide that are composed of bioclastic sands, this approach offers new possibilities for dating of ancient site deposits.