Tracking adhesive technologies from the Early Mesolithic to the Late Iron Age

Adhesives are an important part of early human technological innovation. Prehistoric humans used naturally available tree resins, bitumen, or synthetic glues such as birch tar, for hafting, repairing, decorating and water-proofing. Previous research focused on chemically identifying adhesives, experimental replication and mechanical testing, providing insights for our understanding of past material choices and technological know-how. However, evidence of adhesives is still scarce compared to other artefact types, limiting our ability to address wider questions regarding adhesive production techniques, material diversity and functionality.
This thesis addresses five core areas of study, the aim of which is to investigate adhesives in Europe, by exploring a variety of geographical and chrono-cultural contexts. The first study aims to correlate aceramic birch tar production techniques with Mesolithic artefacts to understand adhesive use in hafting and decoration. Another study focuses on the use of birch tar for its hydrophobic properties in Neolithic fishing equipment. A large-scale investigation on Iron Age artefacts aims to assess material diversity, and identify compositional variations in birch tars found on ceramics. A separate study examines metal objects to explore adhesive diversity and function in metal working. Finally, a collaborative study tests the potential of combining molecular characterisation with DNA analysis to provide insights into past technological processes, as well as dietary and cultural practices.
This work reinforces that birch tar is the most commonly found adhesive from the Mesolithic to the Iron Age in Europe, with compositional differences likely resulting from production or processing for specific functions. However, over time, the range of materials diversifies to more frequently include resins, beeswax and bitumen. The findings suggest that adhesive functionality evolved alongside new emerging technologies, reflecting adaptations to the changing requirements of stone tools, ceramics, and metalworking. This opens up perspectives for future research using experimental and biomolecular approaches to investigate ancient adhesives.