Structural, sedimentary characteristics and rules of oil and gas accumulation in Moliqing Fault Depression were analyzed. Then the evolution characteristics and meanings for oil and gas exploration of strike slip fault zone in the northwestern margin were summarized. The results show that the northwestern margin fault is a high-angle strike-slip and tensional fracture in basin forming period which is inversed by extrusion stress action in Neogene. Then the strike slip fault zone of northwestern margin is formed in which many structures such as sub-thrust faults being of strike-slip nature, compressive fold and flower liking structure are developed. From a macroscopic point of view, the northwestern margin fault has gone through two evolution stages: early strike-slip extension and lately strike-slip extrusion. The strike slip fault of northwestern margin has great significance for the oil-gas exploration: the favorable formation conditions for effective reservoir bodies of underwater fans are created by the deep fault through providing tectonic environment of large slope, effective source and preservation conditions, and oil and gas productivity is high in braid channel micro-facies of middle fan. The effective traps for oil and gas accumulation are provided by factors as structure traps inside the fault zone and oil and gas sealed by thrusting fau the strike slip fault zone in the northwestern margin is made to be a favorable oil and gas accumulation zone by effective allocation of various conditions.%通过对莫里青断陷构造、沉积特征及油气成藏规律系统分析,总结出西北缘走滑断裂带演化特征及其对油气勘探的意义.研究结果表明:西北缘断裂成盆期为一条高角度的走滑张性断裂,新近系受挤压应力作用发生反转,形成了内部发育众多具走滑性质的次级逆冲断层、挤压褶皱、花状等构造的西北缘走滑逆冲断裂带;宏观来看西北缘断裂经历了早期走滑拉张和晚期走滑挤压2个演化阶段:西北缘走滑断裂对油气勘探具重要意义:深大断裂通过提供大坡度构造环境、有效物源及保存条件为湖泊水下扇有效储集体形成创造了有利条件,且水下扇中扇辫状水道微相上的油气产能较高:断裂带内部形成断褶皱等构造圈闭、具有挤压性质的逆冲断层封堵油气等因素为油气聚集提供了有效圈闭条件;各条件有效配置使得研究区西北缘走滑断裂带成为较有利的油气富集区带.
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