潍北—莱州湾凹陷郯庐断裂带新生代走滑特征

The Cenozoic strike-slip characteristics along the Tan-Lu Fault Zone of the Weibei-Laizhouwan area

横切潍北—莱州湾凹陷郯庐断裂带的地震反射剖面和断裂带内的凹陷断层、沉积相和油气特征,直接或间接显示了郯庐断裂带的延伸、运动性质和活动时限。郯庐断裂带在海域和陆上的几何形态及其组合基本一致,根据切过断裂带的剖面和平面上断层的组合特征,判断其为兼具垂直位移的走滑运动断层系。走滑断裂带的活动控制着凹陷内同构造沉积以及构造样式,表明郯庐断裂带的活动时限具分段性,相当于渤海湾盆地孔店组(E_(1-2)k)—沙四段(E_(2-3)s^4)沉积期(古新世—早始新世)—孔店组—沙二段(E_(2-3)s^2)沉积期(古新世—始新世)—孔店组—沙一段(E_(2-3)s^1)(古新世—渐新世)沉积时期,走滑拉分活动由南向北迁移;活动方式也由古新世—早始新世的左旋走滑活动,被早始新世之后的右旋走滑活动所替代。

The Laizhouwan transitional zone of the Tancheng-Lujiang Fault lies between the north of Weifang and the south of the Bohai Bay. The date from seismic profiles which crosscut the Tan- Lu Fault Zone and the characteristics of sedimentary and hydrocarbon in this zone directly/ indirectly indicate the extending, kinematics property,and the activity time limit. The Tan-Lu Fault Zone has similar characteristics of geometry shape and geometry array in land area just as it appears in sea area. It can be inferred that Tan-Lu Fault Zone is a faulting system with vertical displacement. Syntectonic deposits controlled by the movement of strike-slip fault zone show a sectional feature of the activity time limit of Tan-Lu Fault Zone. From south to north,it equals to E1-2k deposition to the E2-3^s^4 （Paleocene to Early Eocene）, E1-2k deposition to the E2-3^s^2（Paleocene to Eocene）,E1-2k deposition to the E2-3^s^1 （Paleocene to Oligocene）in Bohai Bay Basin. The direction of the strike-slip pull-parting migrated from south to north. The fault zone experienced sinistral strike-slip movement from Paleocene to Early Eocene, after Early Eocene, the strike-slip direction is instead of right-lateral strike-slip movement.