Casting core analysis reveals production techniques and the diverse provenance of Shijia Cemetery’s bronze vessels

Shijia Cemetery and the adjacent Yucun Site are the first systematically excavated large-scale Zhou Dynasty (ca. 1046–256 BCE) funerary and settlement sites in eastern Longdong, Gansu Province, China. Bronzes from these sites show hybrid traits, blending Zhou culture traditions with Qin culture and Northern Steppe culture influences. This study examines the casting cores using petrography, major and trace elements, and REE and Sr isotopes. The analyses indicate that the casting core is primarily made of easily available loess without any temper or levigation. Rude Medium and miniature ritual vessels were cast locally from loess. By contrast, finely crafted miniature and large ritual vessels from medium tombs display distinct geochemical deviations, indicating non-local production. Although their specific provenance remains undetermined, these results not only indicate diverse sources of bronze metalwork in the Longdong region during the Zhou Dynasty but also reflect active intercultural exchange and the circulation of bronzes across the northwestern frontier.