Scientific and archaeological study on residues in the pottery lamp from the Yuan Dynasty shipwreck at Shengbeiyu Island Site, Zhangzhou, Fujian Province

This study focuses on the fuel residues preserved in a pottery lamp unearthed from the Yuan Dynasty shipwreck at the Shengbeiyu Island site in Zhangzhou, Fujian Province. To systematically identify the residue composition and clarify the lamp’s functional context, multiple analytical techniques were employed, including optical microscopy (OM), micro-Fourier Transform Infrared (micro-FTIR) spectroscopy, and pyrolysis–gas chromatography/mass spectrometry with thermal-assisted hydrolysis and methylation (THM-Py–GC/MS). The results indicate that the main components of the residues are long-chain fatty acids, ketones, and benzene derivatives. Through comparative analysis with reference materials of drying oils, the residues were definitively identified as boiled tung oil—a type of lighting fuel more suitable for navigation due to its superior performance in harsh environments. Additionally, morphological observations of the fuel residues suggest they underwent combustion, confirming that the pottery lamp was actively used for lighting during the ship’s maritime navigation. As the important published research to systematically analyze lighting fuel residues from underwater archaeological shipwreck discoveries, this study not only provides direct scientific evidence for the utilization of boiled tung oil as maritime lighting fuel in the Yuan Dynasty but also fills a gap in the study of ancient nautical lighting technology and material culture, offering new insights into the technological choices, resource utilization, and onboard life of Yuan Dynasty maritime navigation.