Identifying Late Iron Age textile plant fibre materials with microscopy and X-ray methods — a study on finds from Ravattula Ristimäki (Kaarina, Finland)

In Finland, the earliest remains of a Christian church and cemetery date to the Late Iron Age (800–1150/1300 AD) and have been excavated in Ravattula Ristimäki, in Kaarina, southwestern Finland. In this study, seven assumingly plant fibre textile samples from individual inhumation graves were analysed to identify their materials. The aim of the study was to investigate the possibilities of identifying archaeological plant fibre samples using a three-stage procedure by observing the surface characteristics, microfibrillar orientation and cross section of the fibres via transmitted light microscopy (TLM). The identification process was based on such a TLM characterisation. Additionally, parts of the samples were studied with X-ray microtomography (micro-CT) and wide-angle X-ray scattering (WAXS) to test the possibilities of using the X-ray methods in research and to identify bast fibre textiles. Both flax and nettle were found in the samples, indicating a preference for these two fibre plants in Late Iron Age Finland.