Abstract:

Different structural trap series developed in different evolution stages of the faultdepression process in the south of Songliao Basin. During fault-depressing period,extensionalstructures mainly developed in cracking stage under the influence of extension fracturing,andtraps formed in this period are primarily syngenetic drape structures and growth anticlineslreversal structures that resulted from the compressional tectonics of Dengluku stage developed well,the structural traps formed in that time are mostly reversed anticlines. During depressing period,gentle structures occurred in subsiding stage, and the traps formed in thisstage are basically inherent syndepositional anticlines, syndepositional anticlines; compressional and strike-slip structures developed in fold-uplifting stage due to the influence of LateNenjiang-Late Mingshui tectonics and structural traps formed then are reversal anticlines,fault-block anticlines and flower shape structures. It is suggested that the syngenetic drapestructures, syndepositional anticlines, reversal anticlines, especially multi-stage inherentstructural traps are the most favourable targets for deep-seated hydrocarbon exploration.