Abstract:

Tarim Basin is a large,superimposed basin which had a long evolutional history.The evolution can be divided into seven stages,three tectonic cycles of the Proterozoic,Paleozoic and Meso-Cenozioc.Eight prototype basins were superimposed and formed in the central and marginal areas of the basin:Middle Proterozoic-Paleozoic half-graben rift basin,passive continental marginal basin,back-arc fore-land basin,epicontinental sea basin and Meso-Cenozoic back-arc foreland basin,collided foreland basin and reactived collided piedmont basin.Eight hydrocarbon-bearing formations of marine,continental, marine-continental alternative facies(P_t2-P_t3,ε-O,S-D,C-P,T-J,K₂-E,N₁)were deposited.The basin can be divided into eight structure-depression superim posed regions such as central back arc rift-depressed region,northwest passive continental margin-collided foreland depressed region,north pas-sive continental margin-collided foreland-collided piedmont-collided reactive piedmont depredssed re-gion,northeast passive continental margin-collided foreland depressed region;southeast and southwestback arc foreland-collided piedmont-collided reactived piedmont depressed regions;the collided de-pressed regions of the east and west ends.Four depressed belts,thirteen fault-uplifted and overthrust-folded belts formed in the former six depressed regions.The Tarim Basin is rich in hydrocarbon re-sources and central rift depressed region is especially the first order oil potential area.It is estimatedthat it has the largest potential reserves among the basins in China.In addition,there is geological condi-tion to form inorganic gas reservoirs in the deep of the basin.Five kinds of roof-like,superimposed 3-D hydrocarbon resources are formed in the basin and enriched hydrocarbon zones are as many as 10.These zones are the targets for seaking big,huge even super oil and gas fields.