New Insights from the Viksø Helmets: Evidence of Bronze Age Birch Tar Use as an Organic Construction Material Heide W. Nørgaard

https://www.academia.edu/179623950/New_Insights_from_the_Viks%C3%B8_Helmets_Evidence_of_Bronze_Age_Birch_Tar_Use_as_an_Organic_Construction_Material A scientific re-examination of the horned helmets from Viksø enabled the age of the organic material inside the horn openings to be determined using radiocarbon dating, establishing a terminus ante quem for the active use of the helmets before 906–850 cal BCE. Microscopic and organic analyses of the organic substance revealed two distinct layers. The black substance that filled the horn opening was determined to be birch tar obtained by the per descensum process. It was also found to be present at the joints inside the helmet. We believe the brown fibrous structure to be raffia, an organic material that may have been used to secure any decorative elements that were glued into the openings. A source-critical comparison of Late Bronze Age birch tar products highlights the originality of its use for the construction and decoration of high-status ritual artefacts. The various uses of birch bark tar in the manufacture of the Viksø helmets illustrate the link between the production technology of tar and its areas of application in the Late Bronze Age, and attest to the specialised knowledge required in the production of adhesives. Since awareness of the relationship between material quality and technology is a driving force in the establishment of trade networks, this study includes a state-of-the-art catalogue of Scandinavian tar finds from the Bronze Age as well as an in-depth analysis of the use of adhesives in southern Scandinavia to identify potential future research directions.