Radiocarbon Dating and Bayesian Modelling of the Late Iron Age Cremation Burial Cemetery at Westhampnett (West Sussex / GB)

Abstract

The work reported here is one of the first systematic radiocarbon dating studies of a Late Iron Age cremation burial cemetery. The Westhampnett cemetery in southern England was excavated before it was possible to date cremated bone. The 1^st century BC date (Lt D1b-D2a) for the site proposed in the 1997 publication was based on brooches present in the graves and their continental parallels. 44 of the 161 cremation burials were radiocarbon dated (27 %) and the results modelled using Bayesian statistics. Two models are presented, the »Primary Model« and the »Charcoal Outlier Model«. The latter model addresses the potential problem of carbon exchange between the bioapatite (the datable fraction of the cremated bone) and the carbon (CO and CO₂) from the fuel for the pyre, which could be earlier in date (i. e. an »old wood effect«). Both models are internally consistent and suggest the same end date for the use of the cemetery. However, the early start date suggested by the »Primary Model« is difficult to reconcile with current typo-chronologies for the brooches. The start date indicated by the »Charcoal Outlier Model« is also earlier than expected but not incompatible with recent continental dating for one-piece filiform brooches. Whilst further studies are needed, it is clear that radiocarbon dating of cremated bone has great potential to help develop a more rigorous independent chronological framework for the Late Iron Age across Europe.