四川盆地东北缘构造几何学和运动学特征

The northeast Sichuan Basin is located at the superimposed zone of the Dabashan structural belt and Chuandong structural belt, and the tectonic characteristics are dually controlled by both of them. There are very obvious differences in their structural styles between the two belts for their various deformation hostory and dynamtic machanism. The previous studies on the this area are restricted for the absence of high-resolution seismic data, and the quantitative analysis of deformation characteristics in the northeast Sichuan Basin are still in poor constrained. At the same time, it is potential for oil and gas exploration in this area, and the hydrocarbon migration and accumulation are controlled by the tectonic deformation, so there are very important theoretical meanings and realistic values to carry out the study of the structural geometry and kinematic characteristics. In our study, mainly based on the latest two-dimensional and three-dimensional seismic data, together with the drilling and logging data and the field data, the structural geometry, the petrology of the detachment layer, kinematics and dynamtic mechanism will be studied. The deformation characteristics will be studied by the refined interpretation of the seismic data, and the deformation stages and evoltion history will be studied through the balanced cross sections from interpreted seismic profiles and the structural chronological analysis. On the basis of studies metioned, the relationship between the Dabashan structural belt and Chuandong structural belt, and the relationship between the structural deformation and hydrocarbon accumulation will be discussed.

四川盆地东北缘位于大巴山构造带和川东构造带的交汇处，构造变形受两大构造体系的双重控制。由于大巴山和川东两构造体系具有不同的变形过程和动力来源，其构造变形特征也存在迥然差异。前人研究因缺乏高分辨率地震资料约束，对四川盆地东北缘构造变形定量研究比较欠缺。同时研究区又处于油气勘探的有利区带，构造特征与油气运移聚集关系密切，因而在该区开展构造几何学和运动学特征研究具重要的理论意义和现实价值。本项研究拟以最新采集的二维和三维地震数据为主要依托，结合钻测井数据及野外地质调查，开展四川盆地东北缘构造变形几何学特征、滑脱层性质、运动学特征以及动力学成因研究。通过地震剖面精细解析明确研究区的构造特征，对区域地震剖面进行构造平衡恢复和构造年代学分析，确定研究区主要构造变形期次和构造演化过程，进而明确大巴山构造带和川东构造带之间交接关系，探讨构造变形与油气成藏关系。

四川盆地川东褶皱冲断带位于扬子板块西缘，以发育一系列近平行隔挡式背斜为特征，属于扬子板块内部构造变形体系。因受地表地质及资料等条件制约，前人研究缺乏对该区构造变特征尤其深层构造的系统研究。同时，研究区处于油气勘探的有利区，构造变形与油气运移聚集关系密切，因而开展构造变形特征及其成因研究具重要的理论意义和现实价值。随着油气勘探的进展，大量新的钻井，测井，岩心和地震数据是本项研究顺利开展的基础。项目以最新采集的二维和三维地震数据为主要依托，结合野外地质认识，对四川盆地东部褶皱冲断带开展滑脱层性质、构造变形几何学特征、运动学特征以及动力学成因研究。通过地震剖面精细解析研究褶皱带的构造特征，对区域地震剖面进行构造平衡恢复，探讨了构造带形成的构造演化过程和动力学成因。