For the archaeologist there can be no greater satisfaction than revealing the hidden stories of ancient relics.
For the archaeologist there can be no greater satisfaction than revealing the hidden stories of ancient relics. It’s a long and challenging process of conserving the fragile remains – from the excitement of discovery by the metal detectorist, to their excavation and study.
Dr Graeme Earl and his team at the µ-VIS Centre for Computed Tomography, University of Southampton, have developed a very powerful scanning method, which can penetrate very dense material, and it is being adapted for archaeological material such as cauldron blocks.
Alexandra Baldwin is an archaeological conservator working for the Department of Conservation and Scientific Research at the British Museum. She describes how an unprecedented 13 cauldrons were excavated in Chiseldon, UK in 2005, the most Iron Age vessels ever found together in a deposit. The painstaking conservation process began in 2010.
Baldwin says, ‘normally archaeological finds are x-rayed prior to removal from the block to aid conservation and reveal details hidden beneath corrosion, however due to the thinness of the metal, a fraction of a millimetre in places, and the density of the soil, conventional x-ray was not an option.’ They asked the µ-VIS team at Southampton for help.
Hospital Computed Tomography (CT) scanning has been used for a number of years to reveal information about archaeological objects such as Egyptian mummies. But these CT scanners are specially developed to scan human tissue and are unsuitable for denser objects. The µ-VIS scanner system uses a combination of very high energy and sharp focus, with a visualization tool to penetrate the dense cauldron material.
The high kV microfocus scanner was developed for high-resolution work on critical metallic components such as turbine blades. µ-VIS Centre director, Professor Ian Sinclair, explains that the same combination of high energy and sharp focus transfers to archaeological material without major changes required. Sinclair describes how ‘the artefacts are X-rayed from many (thousands) of angles about a fixed rotation axis.’ The information is captured from many different angles. Then computer manipulations of the data provide incredibly detailed 3D images of the material’s structure for analysis.
Baldwin looks forward to continuing the collaboration with the team at Southampton. The team hopes to obtain funding for even higher energy scanning equipment, to get them deeper into the molecular structures of these mysterious relics from our past.