The application of 3D computed tomography with X-rays and neutrons to visualize archaeological objects in blocks of soil

The examination of archaeological objects lifted in blocks of soil is very time-consuming; both this fact and the array of findings make it imperative to find new techniques of analysis and documentation to ensure archaeological interpretation. Computed tomography of such blocks of soil could be a non-destructive alternative to conventional methods. In the present study, the use of 3D computed tomography with X-rays (XCT) and neutrons (NCT) was reviewed and compared with conventional radiography and the manual unearthing and documentation of the objects. In almost every case it was possible to resolve all relevant archaeological questions by XCT. In some special cases it was not possible to visualize all organic materials. In contrast to XCT, NCT, which is very sensitive to hydrogen, visualizes organic materials much better than X-rays. On the other hand the high water content in the plaster and soil around the objects caused some problems because of this sensitivity to hydrogen. However, very good results were obtained with NCT when applied to already separated single metal objects with organic remains on their surface.