Gristhorpe Man: a Raman spectroscopic study of 'mistletoe berries' in a Bronze Age log coffin burial

Abstract

In 1834 in a tumulus at Gristhorpe, North Yorkshire, UK, an intact coffin fashioned from the hollowed-out trunk of an oak tree was found to contain a well-preserved skeleton stained black from the oak tannins, wrapped in an animal skin and buried with a range of grave artefacts, including a bronze dagger, flints and a bark vessel. The remains were deposited in the Rotunda Museum at Scarborough, where closure due to refurbishment in 2005–2008 provided an opportunity for the scientific investigation of the skeletal remains and artefacts using a wide range of techniques. Dendrochronological and radiocarbon dating has established the age of the skeleton as 2140–1940 BC at 95% confidence, in the Early Bronze Age. As part of this project, Raman spectra of several mysterious small spherical objects discovered in the coffin underneath the skeleton and initially believed to be ‘mistletoe berries’ associated with ancient burial customs have been recorded non-destructively. The interpretation of the Raman spectral data, microscopic analysis and comparison with modern specimens has led to the conclusion that the small spheres are phosphatic urinary stones, which reflect the archaeological dietary evidence and stable isotope analysis of bone collagen of Gristhorpe Man