Lead Isotope Ratio Analysis of Several Zhou Dynasty Bronzes Unearthed in Northern Anhui Province

BACKGROUND The northern Anhui region is located north of the Huaihe River in Anhui. It was an important channel for cultural exchanges between the north and the south during the pre-Qin Period. It was also a necessary area for transporting copper resource on the Yangtze River to the Central Plains. Bronzes in this area are very important for exploring the relationship between copper mines in the Middle-Lower Yangtze River and the bronze culture of the Central Plains. OBJECTIVES In order to understand the diachronic changes of mineral resources in different periods in northern Anhui and the interaction with the surrounding bronze culture. METHODS Laser ablation multiple-collector plasma-mass spectrometry (LA-MC-ICP-MS) and X-ray fluorescence spectrometry (XRF) were used to analyze the composition and the lead isotope ratios of 4 bronzes unearthed in northern Anhui and 4 bronzes unearthed from the Warring States Chu Tomb in Jijiayuan, Hubei Province. RESULTS Results showed that among the 4 bronzes in northern Anhui, there were 3 lead-tin bronzes and 1 tin bronze. The copper content ranged from 60.69% to 76.65%. The tin content was generally higher, 9.66% to 33.24%, and the lead content was 0.43% to 18.07%. The composition had a large variation. The lead isotope analysis results showed that the lead isotope ratios of the samples were within the range of common lead. Two tin bronzes (WB-3, JJY-1) indicated the source of copper materials, and the rest of the samples reflected the source information of lead materials. Comparing the ores in different region, it was found that the data of the bronzes in the northern Anhui during the Western Zhou Period and the Tonglushan mining area in Hubei were relatively close. During the Warring States Period, the bronzes in the northern Anhui began to use minerals from the southern Anhui mining area. Therefore, from the Western Zhou Period to the Warring States Period, the metal resources used in the northern Anhui area began to gradually change from the Tonglushan area in Hubei to the area along the Yangtze River in southern Anhui. CONCLUSIONS This research provides a new scientific basis for the source of minerals used in bronzes in the Zhou Dynasty in the region, and the exchange of bronze culture between northern Anhui and the surrounding areas.