PREHISTORIC TIN MINING: DETERMINING THE DURATION OF TIN ALLOY PRODUCTION VIA ANALYSIS OF METALLURGICAL CRUCIBLE FRAGMENTS FROM WEST SERBIA

The integration of tin in metallurgy was the primary technological innovation of the Bronze Age (3000-1200 BCE). The mixing of tin and copper forms bronze, an alloy of greater hardness utilized for weaponry and tools, and has an aesthetically pleasing golden hue utilized in ornaments and jewelry. Accordingly, the common use of bronze continued for millenia. While Medieval tin workings are known across temperate Europe, evidence of older tin mining is scarce because it was conducted via the panning of fluvial sediments (placer deposits), which leaves little trace of extraction activities. Thus, little is known of the origin and of tin, and the nature of tin mining and trade in European prehistory.

Spasovine, on the south flank of Mt. Cer in West Serbia, is one of the rare localities where Late Bronze Age tin mining activities have been documented. Archeological pedestrian surveys on this river terrace unearthed ceramic fragments with irregular vitreous coatings, thought to be fragments of crucibles or other technical ceramics. Several of these are typologically datable to the Roman Period ca. 200-300AD. Similarities in broad macro-visual features (color, characteristics of temper and pores) identified three groups of fragments, and chemical and heavy mineral analysis suggests that they may represent up to eight separate crucible vessels. SEM-EDS analysis has shown that the fragments are enriched in various metallic residues (Zn, Sn, Cu, Pb in various combinations). Of the fourteen sherds studied, ten contained interior Zn coatings, 3 of which also contained Sn +/- Cu in glassy residues. Given that the Cu-Zn alloy brass was not used in Serbia until the Roman Period, it is likely that all or most of the technical ceramics from Spasovine are of that age. Thus, the site was actively mined in at least two periods over a timespan of 1500 years. This demonstrates that small placer tin deposits likely played an important role in regional tin production throughout European prehistory.