The diversity of bronze production technologies during the Eastern Zhou dynasty revealed by analysis of slags from the Baidian and Xincun sites in Central China

The Eastern Zhou period of China, characterised by complex interactions among vassal states, witnessed significant advancements in bronze production technology. However, the investigation of interactions based on technological comparison among dominant and dependent states remains limited. Focusing on two newly excavated foundry sites, Baidian in Houma, Shanxi, and Xincun in Hebi, Henan, this study provides crucial insights into the bronze production technologies and material sources used by Jin, a major vassal state in Central China, and Wei, a dependent state of Jin, during the Eastern Zhou period. Elemental analysis and microstructural examinations of slags, fragments of crucible wall and furnace wall, show the diversity of bronze production techniques between these two sites: in the Baidian site, bronzes were predominantly produced by co-melting of metallic copper and tin, and remelting of recycled bronzes, whereas in the Xincun site, bronze were probably made by co-melting of copper and tin ore. Furthermore, lead isotope analysis results suggest that the lead materials used for the bronze production at both the sites were likely from the Xiaoqinling region. Integrated with the historical background of complex interactions among vassal states, these findings not only shed light on the technological advancements and resource networks of the Jin and Wei states but also explain the relationships between technology, resources and social dynamics from various perspective. Hopefully this research would promote archeometallurgical study among regions and be applied to other Bronze Age cultures in the world.