【摘要】 2008年的汶川地震为分析龙门山与四川盆地形成演化过程中的山-盆相互作用及其动力耦合机制提供了新的视角与依据。在总结分析龙门山与川西前陆盆地地层构造特点的基础上,从汶川地震的基本特征分析入手,探讨了龙门山与四川盆地的现代动力耦合作用机制及其对川西深层油气二次运移聚散的影响。龙门山的形成演化与地震孕育主要受其西侧松潘-甘孜地块的逆冲和其东侧四川盆地的俯冲的非对称相向挤压控制。龙门山南北两段的地质构造与构造动力环境有较大差异。龙门山晚三叠世开始隆升,其形成早于青藏高原的隆升,与印-亚板块的碰撞无关;但喜马拉雅期以来的演化受印-亚板块碰撞和太平洋板块俯冲的影响。龙门山的冲断褶皱变形垂直于山脉走向从西北向东南,即从松潘-甘孜地块向四川盆地逐渐扩展;平行于龙门山走向发育的断裂带控制川西油气聚散带的分布,前山断裂带上盘及以西地层中的油气基本散失,山前隐伏断裂带有利于深生浅储气藏的形成。更多还原

【Abstract】 The Wenchuan earthquake in 2008 offers us a new perspective and evidences to analyse the interaction and dynamic coupling mechanism between the Longmenshan and Sichuan Basin in the formation and evolution of the mountain-basin system.Based on summarization of the strata and structural features of the mountain-basin system and the characteristics of the Wenchuan earthquake,the authors analyse the modern dynamic coupling mechanism between Longmenshan and Sichuan Basin and its impact on the hydrocarbon migration in the West Sichuan deep strata.The formation and evolution of the Longmenshan and the earthquake preparation in the Longmenshan is dominanted by the unsymmetric bilateral stresses of the thrusting pressing stress from the Songpan-Ganzi block on the west side and the subduction pressing stress from the Sichuan Basin on the east side.The geologic-tectonic features and tectonic environment of the south segment and north segment of the Longmenshan are quite different.The Longmenshan began to uplift at Late Triassic,earlier than the uplift of the Tibet plateau.Thus,the formation of the Longmenshan has nothing to do with the India-Asia plate collision.However,the evolution of the Longmenshan is dominanted by the India-Asia plate collision and the subduction of the Pacific plate since Himalayan period.The thrusting and folding deformation of the Longmenshan orogenic zone gradually expands from northwest to southeast,i.e.from the Songpan-Ganzi block to Sichuan Basin.The fault zones extending along the strike of the Longmenshan dominate the distribution of the natural gas accumulation zones in West Sichuan.The hydrocarbon in the hanging wall strata of the Guanxian-Jianyou fault may has dissipated in geological historic large earthquakes in the Longmenshan.The Dayi-Guangyuan buried fault is propitious to the formation of the shallow gas reservoirs with a deep hydrocarbon source in the West Sichuan foreland basin.更多还原