河南东濮凹陷构造样式分析

东濮凹陷古近系整体构造特征表现为复杂半地堑结构,具有"东西分带和南北分段"的特征。NNE向基底断裂发育,呈带状分布。大致沿白庙—南何家一带、毛岗—柳屯一带发育两条EW向的区域性构造变换带,将古近系伸展断陷分为南、中、北3个区段,不同区段横剖面上的构造样式、沉积格局、乃至油气聚集特征均有很大的差异。在复杂的构造发展过程中,东濮凹陷参与构造变形的岩石类型既有碎屑岩又有盐岩,构造应力场性质以张性为主,后期叠加了扭性应力。因此,在东濮凹陷不同构造部位形成了以伸展断裂构造、变换构造、伸展褶皱和盐构造为主的伸展构造样式,伴有走滑构造样式,盆地性质为裂谷盆地。

The Structural Styles in Dongpu Sag, Henan

Complex half-graben structures developed in the Paleogene hanging wall along Lanliao fault in Dongpu sag.Dongpu sag,which forms plenty of north-northeast basement faults,has a structural architecture with east-west zonation and south-north subsection.There are two regional transfer zones,which extend from east to west along Baimiao-Nanhejia and Maogang-Liutun respectively,and partition the Tertiary extensional fault-sag into south,middle and north districts.Each district has different features in structural styles,depositional configuration and hydrocarbon accumulation.During the complicated tectonic history,not only the clastic rocks,but also the salt rocks have taken part into deformation in Dongpu sag;the tectonic stress-field is mainly extensional at earlier stage and is superposed by wrench stress later.Therefore,four structural styles,such as extensional faulted structures,transform structures,extensional fold structures and salt structures,accompanied with strike-slip structures have developed in such a tectonic setting,which comprised the main structural types of Dongpu sag characterized by rift basin.