From Micro to Macro. Application of X-Ray Computed Tomography to investigate the manufacturing techniques and the state of conservation of archaeological artefacts.

Abstract

Computed tomography (CT) is a non-destructive three-dimensional method that uses the ability of X-ray radiation to penetrate objects. This thesis aims to provide new insights on the potential versatility of the CT in elucidating the manufacturing processes and the state of conservation of archaeological artifacts of different materials and dimensions. Tokusyu-kidai are large ceremonial pot stands that were made for ritual use and buried with the dead as funerary objects during the Yayoi period (300 BCE - 300 CE ) in Japan. Micro-CT, combined with 3D image analysis, were used to obtain a textural characterization for both the Yayoi pottery sample as a whole and its thin section. A first screening of the principal mineral components and a mapping of the porosity system, (coupled to the SEM results from the Be-Archeo project), could be a suitable approach to a preliminary investigation of the firing temperatures. The same analysis applied to two glass Scythian beads from Khortytsia Island, Ukraine, gave an insight into their inner structure, material distribution and air bubble shapes, with the aim to know more about the production and decoration steps. CT-scan is a versatile technique also in terms of the dimension of artefacts that could be investigated, as demonstrated in the analysis of a Chinese wooden statue representing a Bodhisattva seated with his hands in inverse Vitarkamudra (MAO Asian Art Museum - Torino). The acquisition of the statue was performed with the apparatus located in the Centro Conservazione e Restauro “La Venaria Reale” (CCR). The study intended to investigate the construction techniques, the state of conservation and the authenticity of the artwork, and its results have been presented as part of the museum’s exhibition “Buddha10”.