The Junggar Basin contains six distinct sets of petroleum source rocks spanning the Carboniferous to the Quaternary periods. These include formations from the Carboniferous, Permian, Triassic, Jurassic, Cretaceous, and Paleogene, distributed across various depressions within the basin. Among them, the Permian period is notable for its widespread lacustrine clastic deposits, present in all depressions of the basin, and serves as the primary source rock, accounting for more than half of the basin’s oil and gas resources. In the western region of the basin, the Fengcheng Formation and Lower Wuerhe Formation are key contributors, while in the eastern region, the Pingdiquan Formation dominates. In the southern area, the Lucaogou Formation and Hongyanchi Formation are prominent. These source rocks are composed primarily of mudstone, shale, tuffaceous dolomite, and occasionally coal seams, with depositional environments ranging from semi-deep lakes to fluvial-deltaic systems. The organic matter is predominantly of Type I1 to Type II2, characterized by high organic content. Volcanic activity in the region provided heat and catalytically beneficial trace elements, creating favorable conditions for the generation and accumulation of the basin’s oil and gas resources.