泌阳凹陷新生代构造特征与形成机制及其与油气成藏的关系

根据地层层序特征 ,叠加在东秦岭造山带之上的泌阳凹陷伸展作用可以划分出 6个伸展作用幕。核二段沉积前泌阳凹陷以北东—南西向的伸展作用为主 ,构造变形受以正断层为主兼具左旋走滑分量的唐河—栗园断裂控制。核二段沉积期——廖庄组沉积末期构造应力场发生转变 ,以北西—南东向伸展作用为主 ,构造变形主要受以正断层为主兼具右旋走滑分量的泌阳—栗园断裂控制。断裂活动引起上盘构造变形 ,对先成构造进行改造。廖庄组沉积末期发生区域性的隆升作用 ,北西—南东向的伸展作用导致边界断裂上盘发生断块掀斜 ,地层遭受强烈剥蚀。核二段沉积以来尤其是廖庄组沉积末期 ,受北西—南东向不均匀伸展作用的影响 ,北西向走滑断层活动并影响盖层构造样式

Cenozoic Structural Characteristics and Mechanism and Their Relationship with Oil and Gas Reservoir in the Biyang Depression

The formation mechanism of the Cenozoic structure in the Biyang Depression is discussed according to the latest structural theories and research methods. The Biyang Depression superimposes the Qinling orogenic belt, and its stratigraphic sequence suggests that its extension process can be divided into six extensional episodes. Before the 2nd member of the Hetaoyuan Formation (Eh 2, middle Oligocene), the structural deformation was influenced by a NE-SW extensional stress and controlled by the Tanghe-Liyuan Fault, which was a normal fault with a left lateral slip component. From the H 2 member to the end of the Liaozhuang Formation (El, upper Oligocene), the structural deformation was influenced by a NW-SE extensional stress and controlled by the Biyang-Liyuan Fault, which was a normal fault with a right lateral slip component. During this period, the earlier structural styles were reformed in the deformation of the hanging wall of the Biyang-Liyuan Fault. At the end of El, influenced by a NW-SE extensional process, a regional uplift and fault block tilting led to the erosion of the strata. Since period Eh 2, particularly from the end of El, as the result of the heterogeneity of the NW-SE extension, a NW strike-slip fault became active, and influenced the structural activity of the cover.