Abstract:

Junggar Basin is one of the major oil and gas bearing basins in Northwest China.It covers an area of 13?10⁴ km².During its longtime succesive subsidence,the basin received sediments over 10000m thick,especially the thickness in the south margin gets near 20000m.Since Late Devonian,Junggar-Turpan back-arc basin and Northern Junggar arc-basin tectonics formed after the uplift of the West Tianshan-Jiolotag island arc due to the subducting of the Tarim Plate toward the Altan-Junggar Plate.In the late stage of the Early Permian,the Tarim Plate collided and connected with the Altan-Junggar Plate,en-tering the development stage of back-arc remnant basin.The intermont basin stage began in the end of Jurassic resulted by northward subduction of the Indian Plate.Junggar Basin is a large composite basin superimposed by multi-prototype basin which provides favourable and stationary environment for the formation and evolution of the source rocks.The Middle and Upper Carboniferous,Lower Permian are pricipal source rocks,and the Triassic-Jurassic Systems are also important.Various traps developed well in the basin and hydrocarbon potential is fine.