Abstract:Qiongdongnan basin is recognized for its promising natural gas hydrate (NGH) resource potential, with Quaternary strata serving as the primary NGH occurrence horizon. However, the provenance evolution of these Quaternary sediments remains poorly understood. This study investigates the source and migration pathways of these Quaternary sediments in the Qiongdongnan basin and their implications for hydrate exploration. Using heavy mineral and geochemical data from 8 wells, combined with mathematical statistical analysis, we reveal the provenance contributions to the basin during the Quaternary period. The Red River, Yingxi, and Hainan Island are identified as the primary sediment sources, and provenance contributions vary across different basin regions. The northern depression area is characterized by hematite, limonite, ilmenite, zircon, and magnetite, primarily sourced from Hainan Island. The provenance exhibits a vertical migration path driven by gravity and an eastward migration path influenced by ocean currents.Sediments in the Yingqiong Junction area are influenced by both Red River and Hainan Island provenance, with the latter' s influence increasing closer to the Qiongdongnan basin. The central depression receives a mixed sediment supply from all three provenance regions, mainly from Yingxi. The provenance of Yingxi migrated westward, mixing with Hainan Island and Red River sediments before being re- supplied to the central depression. In addition, characteristic authigenic mineral anomalies associated with NGH, such as barite and pyrite, are observed in the sediments of the central sag. This suggests that the southeastern Lingshui sag is a favorable exploration area for hydrates, especially near the LS6 well. Moreover, the underbed southeast of the Ledong depression there exhibits significant potential for natural gas development.