Discerning social interaction and cultural influence in Early Iron Age Mongolia through archaeometallurgical investigation

The cultural groups that resided in the Early Iron Age Eurasian steppe in the first millennium BCE are well-known for the establishment of trade networks that became increasingly active with the advent of horse riding, resulting in the transmission of metal, iconography, and other material goods throughout the region. The spread of metal types and forms iconography can be examined and taken as supportive evidence for the social and cultural interactions that existed between mobile pastoralists, who transversed the steppe and surrounding territories, with each other and sedentary groups. To better understand the extent of these interactions, chemical and lead isotopic data for 104 copper-alloy objects were acquired from three prominent cultural groups that existed in Mongolia [Slab Grave (n = 45), Pazyryk (n = 26), and Chandmani (n = 33)] and used to ascertain ore exploitation preferences and metal circulation patterning. In this assemblage, there is a clear compositional difference between the artifacts that originated near the Altai-Sayan Mountains in western Mongolia and those from east of the Khangai Mountains. In the former, the artifacts are characteristically arsenical copper and contain antimony, suggesting the exploitation and smelting of local fahlore deposits. For the latter, the artifacts are more commonly tin bronze with arsenic and lead; a composition similar to the alloys found in contemporary northern China. Overall, the chemical composition and isotopic signatures of these objects are varied—even within the same cultural group's assemblage—and can be explained by the seasonal migration of Mongolian herding communities and a tendency to exploit metallogenically diverse ore deposits. The nomadic nature of these communities likely resulted in the varied exploitation of ores throughout the year and the mixing of new and existing metal stock from the steppe and abroad.