The prestigious tin-lead horse fittings in the Warring States Period: Evidence from funerary artefacts of a Warring States Tomb at Shouxian, Anhui

Tomb M25 of the Xijuan cemetery at Shouxian was identified as a Cai elite tomb dated to the fifth century bce. From this tomb, 182 metal items were unearthed, and two-thirds of them were found made with Sn-Pb alloy via portable X-ray fluorescence (pXRF) and scanning electron microscopy with energy-dispersive spectroscopy (SEM-EDS) analyses. Lead isotope analysis (LIA) revealed that leaded bronze and Sn-Pb alloy did not share the same source of lead. The isotopic feature of tin-lead objects is varied from most reported Early-Middle Warring States bronzes from the Nanyang-Huaihe area, but coincides with artefacts from the Chu state core area in the Jianghan basin as well as some Zeng state artefacts from the Suizhou area. A general review of the Early-Middle Warring States Chu tombs shows that two types of gold-foiled tin-lead horse fittings from tomb M25 were also present in almost all high elites tombs, but were barely found in those of the lower elites. It is argued that these horse fittings were prestigious artefacts and made with tin-lead raw materials from south China. They might be distributed as finished artefacts or raw materials via a gift-giving system controlled by the Chu court.