论文部分内容阅读
本文通过三维地震资料解释和构造制图分析了辽河西部凹陷断裂系统的构造几何学和运动学特征,论证了郯庐断裂在辽河西部凹陷的表现型式.研究表明如下几点:(1)辽河西部凹陷新生代构造可以划分为伸展构造和右旋走滑构造两种构造变形系统.伸展构造由一系列NNE-NE向的正断层构成,主要在古近纪发育,并控制了古近系的充填,使辽河西部凹陷古近系表现为发育在NNE-NE向的台安-大洼断层(F1)上盘、具有“东断西超”结构特征的一个复式半地堑断陷;右旋走滑构造包括2～3条NNE-NE向基底右旋走滑断层(F2,F3和F4)及其伴生构造,主要在渐新世以后发育,走滑相关的断层可以切割到新近系-第四系.(2)受基底走滑断层位置和走向变化的影响,辽河西部凹陷古近系复式半地堑断陷在中、北部与南部有明显不同的结构特征,在凹陷南部主要表现为伸展-走滑变形特征,仍保留“东断西超”的复式半地堑结构,而在凹陷北部主要表现为收缩-走滑构造变形特征,改造成为西侧受逆-走滑断层限制、东侧以反转正断层为边界的复杂“地堑”结构.(3)郯庐断裂带从辽东湾海域东部向北分为两支,其中东支向北纵贯辽河坳陷东部凹陷至沈阳附近与敦化-密山断裂连接,西支从辽河西部凹陷中北部、大民屯凹陷穿过并与依兰-伊通断裂相连;辽河西部凹陷的基底走滑断层属于“郯庐断裂带”西支渐新世以来发生右旋走滑位移的表现,切割了控制古近纪沉积凹陷的伸展断层,并诱导盆地盖层沿着基底走滑断裂带发育一系列近EW向的盖层正断层.
This paper analyzes the tectonic geometry and kinematics characteristics of the fault system in western Liaohe depression by means of three-dimensional seismic data interpretation and tectonic mapping, and demonstrates that the faulting pattern of Tanlu fault in the western Liaohe depression shows the following: (1) The Cenozoic tectonics can be divided into two tectonic deformation systems of extensional structure and dextral strike-slip structure.The extensional structure is composed of a series of normal faults of NNE-NE direction, developed mainly in Paleogene and controlled the filling of Paleogene, The Paleogene in the western Liaohe depression is characterized by a complex half-graben fault developed on the NNE-NE fault in the Tai-F1 fault (F1) with a “East-West fault” structural feature. The strike-slip structure consists of 2 ~ 3 dextral strike-slip faults (F2, F3 and F4) and their associated structures from the NNE-NE to the basement, mainly developed after the Oligocene. The strike-slip related fault can be cut into the Neogene- (2) Influenced by the change of the location and trend of basement strike-slip faults, the Paleogene double-graben faults in the western Liaohe Sag have distinct structural features in the central, northern and southern parts and mainly extend in the southern part of the depression - Strike deformation characteristics, still retain “East off In the northern part of the sag, the shrinkage-strike-slip tectonic deformation features are mainly manifested, which is transformed into the west-side restricted by the inverse-strike-slip fault and the east by the inversion of the normal fault. (3) The Tanlu fault zone is divided into two parts from the eastern part of Liaodong Bay sea area to the north, with the east branch extending northward from the eastern depression of Liaohe depression to Shenyang near Dunhua-Mishan fault and the west branch From the central and northern parts of the western Liaohe depression and the Damintun depression to the Yilan-Yitong fault, the basement strike-slip faults in the western Liaohe depression belonged to the dextral strike since the ”Tanlu Fault Zone" Slip displacement, cut the extensional fault controlling the Paleogene sedimentary depression and induced a series of caprock normal faults along the basement strike-slip fault zone in the basin cover.