Imitation or importation: Archaeometallurgical research on bronze dagger-axes from Shuangyuan Village Cemetery of the Shu State in the Eastern Zhou Dynasty

•There is no correspondence between the types of dagger-axes and alloy ratios.•The lead isotope ratio can distinguish whether some Central Plains-style dagger-axes are imitations or originals.•There exited the resource sharing or exchange between Shu and the Central Plains civilization. The dagger-axe is a kind of artifact with rich local features in the Shu State (c. 2000–316 BCE) during the Bronze Age. In this paper, 18 Eastern Zhou (770–256 BCE) dagger-axes excavated from Shuangyuan Village are used as examples, and an attempt is made to show the relationship between the type and alloy characteristics and the source of their raw materials, and to identify imitations. Most of them belong to the Ba-Shu system, but some are of the Central Plains style. The composition results obtained by pXRF show that they contain on average over 15% tin, with some well below 1% and some significantly above 2% lead, suggesting that there is no significant relationship between their types and their alloy composition, especially the lead content. The data on lead isotopes (by MC-ICP-MS) compared to earlier dagger-axes indicate that the sources of lead materials in the Chengdu Plain have undergone diachronic changes that seem to originate from further south in Huili rather than locally. Some datas slightly similar but not identical to Central Plains dagger-axes of the same period, suggest that there was long-distance exchange or sharing of mineral resources occurred at that time, but the items themselves were not imported and may be excellent imitations.