Lead isotope reveals the mineral source change of late Bronze Age bronze mirrors excavated in Hunan Province, Southern China

Abstract

The late Bronze Age was the first golden period for bronze mirror production in ancient China. In this paper, scientific analysis and research were carried out on 28 late Bronze Age bronze mirrors excavated in Hunan Province, Southern China. All bronze mirrors are Cu-Sn-Pb materials, and their lead isotope data are in line with the characteristics of common lead. Among them, 4 bronze mirrors containing metal bodies all show bronze casting structures with high tin features, and there are some differences in the elemental composition distribution range between them and previously tested bronze mirrors. This paper significantly reveals that the lead mineral source of Hunan bronze mirrors underwent two obvious changes during the late Bronze Age. The Warring States bronze mirrors excavated in Hunan mainly used lead ore from the Nanling region and Northern Hunan region, and Changsha should be the center of mirror-production and mirror-circulation in Southern Chu Kingdom. However, the lead ore consumed by the Western Han bronze mirrors excavated in Hunan primarily came from the East Qinling region, which was close to the core region under the rule of the Western Han government. In the middle and late Eastern Han Dynasty, with the frequent metal production activities in the Nanling region and the prosperity of private mirror-casting industry in Southern China, lead ore from the Nanling region was re-introduced in the production of Hunan bronze mirrors.