Regionalism and diversity: the supply characteristics of metal resources in Southwestern China during the Eastern Han dynasty reflected by the bronzes from Zhaotong, Yunnan Province

The Yunnan, Guizhou, and Sichuan regions in southwestern China have excellent metallogenic conditions and abundant mineral resources. The Han Dynasty bronzes developed on this basis contain important metal mineral and cultural information. Zhaotong is a key transportation hub in southwestern China, playing an important role in mineral development, collection, and transportation. Based on the examination of Eastern Han Dynasty bronzes excavated from Zhaotong, combined with modern geological survey data, historical documentation and metallurgical archaeological research, it is speculated that the metal resources used may have come from Sichuan-Yunnan-Guizhou adjacent metallogenic regions. This provides a basis for further research into the early exploitation of mineral resources in the southwest region. By comparing the lead isotopes of Han dynasty bronzes from adjacent areas, the data from the Zhaotong bronze reflect the supply characteristics of metal resources in southwest China during the Eastern Han period and the change in resource management policy of the Eastern Han government towards southwest China.