| Foreland thrust belt locating in southern Junggar basin is the important component of large-scale multi-cycle superimposed basin in junggar basin. It is superimposed and modified by Hua lixi, Indosinian, Yanshanian and Himalayan movement in different period. Several oil-reservoir combinations is formatted in the period. So, developing study of evolution of sediment and tectonic, and finding relationship to accumulation of oil and gas, it is very important for exploration.According to fold theory relating to fault, the article analyses importantly tectonic patterns of middle part in southern Junggar basin. Based on characteristics of regional unconformity surface, dividing tectonic sequence for stratum after late Permian. By use of analytical method of palaeocurrent, component of gravel and debris of sandstone, studying provenance of stratum after late Permian in southern Junggar basin. Recovering prototype basin after late Permian on the basis of division of tectonic sequence and analysis of provenance. At last, studying simply relationship between tectonic and accumulation of oil and gas. The following is the main conclusion:(1) Tectonic patterns are composed of the composition faults and folds mostly. It can be divided into three major type including thick-skinned structure, thin-skinned structure and mixed structure. Tectonic deformation exists subsection longitudinally, different belt latitudinally and incoordination vertically.(2) Stratum after late Permian can be divided into three tectonic sequences of Indonisian cycle, Yanshanian cycle and Himalayan cycle, and ten small tectonic sequences further.(3) The tectonic evolution of southern Junggar basin can be classified into six stages: stage of weak extension and peneplane from late Permian to early Triassic; stable depression stage in middle-late Triassic; maximal basin formation phase in the setting of weak extension in early-middle Jurassic; inactive depressed basin formation phase in thrust setting in middle-late Jurassic; stable depression stage in Cretaceous and Eogene; foreland depressed basin formation phase in thrust setting in Neocene and Quaternary.(4) The southern Junggar basin develops chiefly three hydrocarbon source rock, they are lucaogou and hongyanchi formation of middle Permian, shuixigou formation of early-middle Jurassic, anjihaihe formation of Eogene respectively.(5) The first row anticlinal structure find mainly oil and gas accumulation of Triassic and Jurassic. Finding mainly down-generating and up-preserving reservoir in the second and third row anticlinal structure, oil and gas are from Jurassic.(6) Fault doesn't only controls formation and evolution of secondary tectonic unit, but also controls Jurassic hydrocarbon reservoir.
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