Junggar Basin is one of the major oil and gas bearing basins in Northwest China.It covers an area of 13?10

4

km

2

.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.