Metalcraft within the Nordic Bronze Age: Combined metallographic and superficial imaging reveals the technical repertoire in crafting bronze ornaments

Abstract

The study presents two major approaches in the analysis of metal working techniques in the Nordic Bronze Age; a comparison of experimentally-crafted ornaments as a means of defining characteristic traces of known crafting techniques, and a scientific analysis (metallographic imaging) used to explain recognisable superficial crafting traces. This analysis results in a definitive explanation of superficial crafting traces through their specific microstructure and will thus be of significant interest for further research concerning prehistoric crafting. The metallographic investigation of 24 artefacts, which date to the early period of the Middle Bronze Age (around 1470–1290 BC) and originate in the central Lower Saxony region, revealed a much more varied technical repertoire in metalcraft than has previously been presumed. Superficial traces related to the crafting process and tested on experimentally-crafted bronzes indicated a mixture of cast technology and cold working. Thus, several samples indicated that the lost-wax technique was favoured within the Lüneburg group but, in addition, that intensive post-casting reworking was common. The high skill of Bronze Age metalworkers can be highlighted through the assessment of localized techniques applied to the artefacts, such as annealing or intensive cold working, without causing damage to the object. This knowledge of the technical possibilities of metalcraft in the Nordic Bronze Age allows for further research to concentrate on regional peculiarities using the traces of the crafting process presented here as a facilitating tool.