Accelerator mass spectrometry (AMS) radiocarbon dating
Christopher Bronk Ramsey, Radiocarbon Accelerator Unit, The University
of Oxford, sampling the base of the Musée Barrois reliquary.
To determine the age of a wooden carving, a small sample is needed for AMS radiocarbon dating. With the wooden sculptures, the aim was to ensure a date closest to the felling of the tree, ideally by sampling any remaining sapwood, but where this was not present, the outer-most edges of the carvings. This technique is especially important for slow growing woods, which can be several centuries old at the pith as opposed to the much younger sapwood. Sometimes, samples were also taken along the width of the carving to investigate the age of the tree. All sampling was done as discreetly as possible, often within already present cracks or the underside of the carving. The approach was further fine-tuned by sampling the resin used in inlays, where evident, which should give a more definitive date of the object’s final stages of manufacture. Dating cotton fibre (or ‘lint’) does not pose these ‘in-built’ age issues, as cotton is an annual plant, and was in constant demand for making hammocks and other necessities.
Follow the links below to see the results of the radiocarbon dating analysis.