The researchers in this study reconstructed the source and deposition areas of sediment in the Qikou sag of the Bohai Bay Basin. They used gravity anomalies, heavy mineral characteristics, seismic reflection, and sandbody distribution to determine the provenance-sedimentary system of the Paleogene Shahejie Formation. The results showed five main sediment sources in the area, with different migration directions and extents. The Gegu source was the largest supplier, while other sources like Xiaozhan, Zengfutai, Qianquan, and Beidagang buried hill also contributed sediment to the region. The sediments filled into different sags like Banqiao and Qibei, forming fan delta sedimentary deposits.