Posted on 13 January 2014
Star Carr (near Scarborough) is an archaeological site of international renown due to the spectacular organic artefacts first uncovered in the late 1940s. The site dates to just after the end of the last Ice Age, and the wealth of the bone and wood archaeology (including antler head-dresses) is unparalleled in Europe.
However, recent fieldwork has revealed that the organic remains which made the site so famous, despite having survived for ~ 11,000 years, have become seriously degraded since the initial excavations 60 years ago. All the bone and antler recently found in the wet deposits are severely deteriorated: pieces of antler were completely flattened and had the consistency of leather; one of the only two pieces of bone found was completely demineralised (nicknamed ‘jelly-bones’); wood showed serious deterioration, with decay of the cellulose, leaving only a lignin-rich skeleton.
Why this was happening to the organic artefacts, and the rates of decay (and therefore the rapidity of the potential loss of the archaeology), were an unknown. Through a NERC CASE studentship in conjunction with York Archaeological Trust, Kirsty High has been studying the mechanisms and rates of degradation in wood and bone using a range of analytical techniques. These include pyrolysis - gas chromatography and infrared spectroscopy for investigating chemical changes to wooden artefacts, and amino acid racemisation analysis and powder XRD to determine changes to the bone structure. These are supplemented by techniques such as TEM, SEM and mass loss analysis. The evidence built up so far has provided critical data on the stability of archaeological material; relevant not only to this unique site, but others across Europe. This study will help mitigate against future losses of heritage of international importance.
Visit the programme's web page (Star Carr feature is 14.5 minutes after the beginning)
A range of artefacts from Star Carr are on display at the Yorkshire Museum until May 2014.