渤海湾盆地临清坳陷东部边界断裂——兰聊断层几何学、形成演化与成因机制

Geometry,formation evolution and mechanism of Lanliao fault:The boundary of eastern Linqing depression,Bohaiwan Gulf

充分利用钻井、测井、分层和地震资料,并结合区域地质背景和前人研究成果对临清坳陷东部地区地震资料进行了详细解释,以此为基础对临清坳陷东部边界—兰聊断层的几何学特征、形成演化及其形成的动力学背景进行了深入分析。研究认为:兰聊断层为—上陡下缓的铲式正断层,在基底发生滑脱;兰聊断层具有多期活动的特征,不同构造阶段断层性质不同;兰聊断层活动具有分段性,南段从J_3—K_1开始活动,而北段则是从Ek-Es_4开始活动;兰聊断层的形成演化主要受华北板块与其周围板块的相互运动所控制,其中伊泽奈岐板块和太平洋板块向欧亚板块俯冲运动导致岩石圈发生拆沉作用,并引起地幔上涌,由此所产生的水平拉张应力场是控制兰聊断层形成演化的根本原因。

We interpreted the seismic data detailed by using drilling, logging, layering and seismic data combined with the regional geological setting and the results of previous studies on eastern Linqing depression. Based on the results of seismic interpretation we analyzed the geometry characteristics, evolutionary process and the formation kinetics backround of Lanliao fault which is the eastern boundary of Linqing depression. The research results can be described as follows ： Lanliao fault is a listric normal fault which is steep in the shallow layer and low in the deep layer and detach in the basement; Lanliao fault is characterized by multiperiodic activity and the fault nature varied in different structural stage; Lanliao fault can be divided into two parts and their active time is different that the southern part began to develop in J3-K1 while the northern part in Ek-Es4 ; the formation and evolution of Lanliao fault is mainly controlled by the reciprocal movement of Huabei plate and its surrounding plates ; the Yizenaiqi plate and Pacific plate underthrusted to the Eurasian plate which led to delamination of lithosphere and mantle upwelling; the horizontal stress produced by mantle upwelling is the key reason for the formation and evolution of Lanliao fault.