The production of bronze weapons in the Chu state: a case study of bronze arrowheads excavated from the Yuwan cemetery in Hubei, China

During the Eastern Zhou Dynasty (770–222 BC), a large number of bronze arrowheads were unearthed from the Chu tombs, which is of great significance to the study of bronze weapons in the Chu state. However, little is known about the production technology, mode, and provenance of the raw materials for bronze weapons in the Chu state. Therefore, we conducted archaeometallurgical analyses of 16 bronze arrowheads excavated from the Yuwan cemetery using metallographic microscopy, inductively coupled plasma atomic emission spectroscopy, and multi-collector inductively coupled plasma mass spectrometry. The results indicate that the arrowheads are all copper-tin–lead ternary alloys with a high tin content and adequate mechanical properties. The differences in the production process, lead–tin content, and copper groups indicate that bronze arrowheads were produced at a high rate and in multiple batches. Furthermore, comparative lead isotope studies of galena from different regions revealed that during the Warring States period, the Chu state possessed a strong supply network of metal resources, and after occupying regions with abundant metal resources, it was transported to the Chu state for bronze production.