SNN111422 - Dating Briar Hill: interpreting controversial results from the Neolithic causewayed enclosure at Briar Hill, Northamptonshire

The Neolithic causewayed enclosure at Briar Hill, Northamptonshire, excavated in the mid-1970s became the subject of controversy when radiocarbon dating appeared to show that it had been constructed in the fifth millennium cal BC, and maintained for about a thousand years. If true, this interpretation made Briar Hill the earliest known causewayed enclosure in Europe and Britain's earliest agricultural site. Doubts were raised about the contextual reliability of the radiocarbon samples, given the artefactual evidence, which only indicated occupation from the later fourth millennium cal BC onwards. This report assesses the usefulness of each radiocarbon result, and the plausibility of the various interpretations of these result, against criteria that were accepted at the time of the controversy. The results and interpretation are then reassessed, using new techniques of radiocarbon calibration and chronological modelling. The report finds that only the final phase of maintenance of the enclosure can be confidently dated to the later fourth millennium cal BC, and that the original interpretation depends entirely on the contextual reliability of two samples. It cannot be proved that these samples were residual, but there are reasons to suspect that they were, in addition to the artefactual evidence. This conclusion can be tested by dating the surviving remains of some samples.