Cassiterite U-Pb geochronology: A framework for tin provenance in the Bronze Age world.

The origin of Bronze Age tin is one of the most compelling mysteries in global archaeology. A number of studies were carried out to identify fingerprints to determine tin sources, but all failed to suit the contexts of Bronze Age China. This study provides the first comprehensive provenance analysis of the tin ore utilized during the Shang dynasty of China. Using U-Pb dating analysis on cassiterite grains surviving in various contexts including primary smelting site, metal resource hoard, and bronze casting workshop, this study demonstrates that cassiterite materials from the Great Hinggan Range polymetallic belt, Northeast China, were transported to the Middle Huai River region over 1,500 km to the south for tin bronze production during the Middle Shang period. This finding reveals a long-distance, continental-scale metal circulation system comparable to contemporaneous tin supply networks across the world, extending the concept of "bronzization", the Bronze Age as premodern globalization, into East Asia. It also establishes a methodological framework for resolving the tin provenance questions of Bronze Age China and beyond.