X-ray Computed Tomography for the anatomical and dendrochronological analysis of archaeological wood

The analysis of archaeological wood is of great importance in historical research because of its status as an outstanding information carrier. Dendrochronology, in particular, is an important method for dating and provenancing; but applied in the conventional way it would, in most instances, require a large interference with the object. X-ray Computed Tomography offers a non-destructive technology for the analysis of ring widths while at the same time enabling wood species identification, which is essential for dating. The technology was tested on two specific cases: firstly, on wood block-lifted together with the surrounding soil and other objects and, secondly, on wood preserved through mineralisation on iron objects. Both micro- and submicron-computer tomography scanners were employed for these tests. The results demonstrate that it is possible to perform wood species identification based on reconstructed CT-scan images, under certain conditions even in soil blocks, and that ring widths can be measured. The results are dependent upon the resolution and contrast that can be achieved in a measurement which, apart from the characteristics of the scanner, is affected by both object size and wood species.