伸展断层相关褶皱的几何学分析及其在车镇凹陷中的应用  

Geometric Analysis of Extensional Fault-Related Folding and Its Applications on Chezhen Depression

作　　者：苏金宝[1] 朱文斌[2] 贾东[2] 杨彦峰 王志强 

机构地区：[1]中国地质科学院地质力学研究所,北京100081 [2]南京大学地球科学与工程学院,南京210093 [3]中石化胜利油田河口采油厂地质所,山东东营257068

出　　处：《地质学报》2011年第10期1563-1573,共11页Acta Geologica Sinica

基　　金：国家科技重大专项大型油气田及煤层气开发项目(编号2008ZX05009-001)资助成果

摘　　要：本文总结了伸展断层相关褶皱的发育类型,主要包括伸展断层传播褶皱与伸展断层转折褶皱(也叫断弯褶皱)等。伸展断层传播褶皱多形成在较陡的正断层之上,正断层向上传播使断层顶部地层弯曲,进而形成一个伸展的断层传播褶皱,其发育模式与三剪变形发育模式一致。车镇凹陷是渤海湾盆地南部一个典型的中新生代半地堑盆地。本文通过对横穿车镇凹陷的地震反射剖面进行精细的构造解析,以及车镇凹陷南部斜坡带小断层的精细解释,发现这个半地堑盆地的伸展构造具有明显的向斜构造特征,这种向斜构造并不是挤压所致,其发育符合伸展断层传播褶皱模型。由此运用伸展断层相关褶皱理论,同时按照三剪变形发育模式,模拟了车镇凹陷伸展构造的发育过程。经过对盆地内部构造变形的反复拟合和测算,我们确定了车镇凹陷伸展断层相关褶皱的构造几何学特征及其运动学过程,进而深化对渤海湾盆地半地堑构造的理解。This paper summarized the structural styles of extensional fault-related folding, which includes extensional fault-propagation fold and extensional fault-bend fold and etc. Extensional fault-propagation fold formed upon a steep normal fault, which propagated upward and resulted in bending of the covering strata, forming a fault propagating folding. Its development model is similar to that of tri-shear deformation. The Chezhen depression is a typical Mesozoic-Cenozoic half-graben basin in the southern Bohai Bay Basin. Based on detailed structural geometric analysis of the seismic profiles across the Chezhen depression and south slope zone of the Chezhen depression, an obvious structural style of syncline has been identified, which did not result from structure compression but from extensional fault-propagation folding. Using the theories of extensional fault-related fold and the tri-shear model, we modeled the kinematic process of extensional faults in the Chenzhen depression. Using repeated modeling and measurements for the structural deformation within the basin, we present the geometric features of extensional fault-related folds and the process of deformation in the Chezhen depression, which further deepens understanding of the structural styles of half-graben of Bohai Bay basin.

关 键 词：伸展断层传播褶皱 三剪变形 济阳坳陷 渤海湾盆地 

分 类 号：P542.2[天文地球—构造地质学]