THE CENOZOIC STRUCTURAL EVOLUTION AND ITS RELATIONSHIP WITH OIL AND GAS ACCUMULATIONIN THE SOUTHWESTERN TARIM DEPRESSION

The southwestern Tarim depression is a compound foreland depression with a longstructural history during the Cenozoic.It has undergone a relatively tranquil phase of theEarly Tertiary,the important Miocene development phase of structures, the relatively quiet phase of the Pliocence and the formation phase of structures of the Quaternary. Thestructural deformation is characterized by the development of fold-thrust belts and a rapidtectonic subsidence,which has resulted from the collision between the india plate and theEurasian plate and from long lasting compression and pushing. The deformation of thestructures is weakened from backland to foreland. The subsidence of the depression has resulted from structural and sedimentary loading. The Himalayan tectonic movement has enhanced the thermal evolution of the source rocks and formed lots of fault-related folds,which provided good conditions for oil and gas migration and accumulation.