The researchers studied the source rocks in Sikeshu Sag of the Southern Junggar Basin to understand how hydrocarbons accumulate there. They analyzed drilling and geochemical data, along with seismic and sedimentary facies analysis. The main source rocks are dark mudstones in the sag and dark rocks in the lower Jurassic Sangonghe Formation. These rocks are thick, rich in organic matter, and well-evolved thermally. The distribution of source rocks is influenced by tectonic-sedimentation patterns, with hydrocarbons mainly found in the central-southeast of the sag. The quality of hydrocarbons decreases from south to north in the area.