Provenance and firing temperatures of Shang dynasty (1600–1300 BC) pottery from the Shuyuanjie site, China: an integrated study using EDXRF, XRD, FTIR and thermal dilatometry (TD)

This study employed a combined analytical approach utilizing EDXRF, XRD, FTIR, and thermal dilatometry (TD) to comprehensively analyze the raw material characteristics, provenance, mineral composition, and firing temperatures of Shang dynasty grey pottery excavated from the Shuyuanjie (SYJ) site. Based on significant differences in the SiO₂, K₂O, and CaO content, the grey pottery bodies can be classified into three distinct raw material types. The chemical compositions of pottery from the SYJ and Xiaoshuangqiao (XSQ) sites are highly similar, suggesting a possible common raw material source. The principal phases within the grey pottery bodies are quartz and microcline, with some samples containing trace amounts of cristobalite and rutile. XRD and FTIR analyses confirmed that this batch of grey pottery underwent high-temperature firing, with firing temperatures all exceeding 750 °C. Thermal dilatometry analysis (using a single heating cycle combined with the first derivative curve) determined that the firing temperatures of the grey pottery range between 870 °C and 990 °C; all samples are underfired bodies. For pottery of unknown firing histories, water absorption and apparent porosity cannot serve as reliable proxies for determining the high or low firing temperature of the body.