Spatial investigation of technological choice and recycling in copper‐base metallurgy of the South Caucasus

Abstract

Recent research has brought the prolific bronze industry of Bronze Age Colchis (modern western Georgia) into focus, but many aspects are still poorly understood. This study synthesizes and reinterprets legacy Cu alloy compositional data to investigate technological choices and spatial patterning. It reveals a massive injection of fresh copper into the system during the Late Bronze-Early Iron Age, and a high degree of selectivity in the alloys used for different objects, with colour being as important as hardness in determining these choices. Spatial analyses show significant geographical variability in alloying practices, which map onto topographical zones in unexpected ways. We also explore recycling practices and argue that the term encompasses a range of different reuse activities, which may be employed under differing economic conditions. Finally, the data suggest relatively extensive primary alloying of tin and copper in the Late Bronze and Early Iron Ages, which further substantiates the speculation that some local tin sources were exploited.

Non‐invasive surface analysis of ancient bronze arrowheads with scanning electron microscopy and X‐ray powder diffractometry

“…Due to the high volatility, admixtures of antimony or arsenic may indicate that the arrowheads were not manufactured by remelting other bronze objects with small amounts of these two elements 13 . If remelting of any older metal objects was carried out, which was a common practice in ancient metallurgy, 25,26 they had to be made out of As or Sb rich alloys, that is, arsenical or antimonial copper, respectively.…”

“…24 Due to the high volatility, admixtures of antimony or arsenic may indicate that the arrowheads were not manufactured by remelting other bronze objects with small amounts of these two elements. 13 If remelting of any older metal objects was carried out, which was a common practice in ancient metallurgy, 25,26 F I G U R E 2 Electron images and maps of distribution of copper (Cu Lα 1,2 ), tin (Sn Lα 1 ), and lead (Pb Mα 1 ) for series A. Electron images and maps of distribution of copper (Cu Lα 1,2 ) and tin (Sn Lα 1 ) for series B and lead (Pb Mα 1 ) for B5…”

New scientific analyses reveal mixing of copper sources in the early Iron Age metal production at Ili, western China

“…Although more research is necessary to investigate the underlying causes of this change, it is reasonable to say that the pure copper technology for cauldrons was not an isolated case in a broader archaeological context. Intriguingly, in different parts of Eurasia such as the Iranian plateau, east Mediterranean Sea, Caucasus, and the Central Plains of China, local production of metal saw increasing emphasis in tin and bronzes, even though many of these regions already stepped in early Iron Age (Cuénod et al, 2015; Ho & Erb‐Satullo, 2021). The decline of tin in Xinjiang around the late second to early first millennium BC appears rather distinctive.…”

Towards a Spatial Archaeology of Crafting Landscapes

“…Neither recent surveys nor extensive Soviet-era excavations yielded any casting moulds at these smelting sites, further reinforcing the impression that secondary processing and artifact manufacture took place elsewhere. Chemical analysis of ingots and unformed chunks of raw metal recovered in hoards shows that most are relatively pure copper, strongly suggesting that most arsenical copper and tin bronze alloys were produced at secondary sites (Ho & Erb-Satullo 2021). The low quantities of non-metallurgical ceramics and the absence of architecture suggest that smelting did not occur within settlements (Fig.…”