【摘要】 高分辨三维地震可视化及方差切片分析显示,郯庐断裂渤海海域莱州湾段北北东向断裂系发育。断层在水平方差切片上的拖拽现象、断裂带内部断层的组合关系以及凹陷沉积中心的迁移等,表明古新世以来该区存在右旋走滑运动。假设在东、西两支断层的走滑拉分作用下,根据可容纳空间不变原理,设计了三角形模型、长方形模型、半地堑型模型以及地堑型模型共四种模型,计算莱州湾凹陷南北长度和凹陷深度的关系,其中半地堑模型计算得到的郯庐断裂的水平位移为7km。结合断层的平面分布和断层的切割关系,表明古新世以来郯庐断裂的走滑拉分作用难以控制莱州湾凹陷的形成,走滑拉分作用只是在走滑断裂带内部形成了局部小型洼地,其规模很小,影响非常有限。更多还原

【Abstract】 This paper focus on the shape and geometrical relation between the main strike-slip faults and associated faults in the Laizhou bay area based on three-dimensional seismic visualization and seismic variance slice.Subject to influence of old uplift and dextral strike-slip,NE extensional faults are widespread in the Laizhou bay.Seismic variance slice analyses confirm the dextral movement of the Tan-Lu faults during Neogene.Considering strike-slip movement,we design four pull-apart models:triangle model,rectangle model,graben model,and half-graben model.Depending on these models we calculate the horizontal displacement of strike-slip faults in the Laizhou bay.According to half-graben model the displacement of strike-slip faults is 7km.Combined with other evidences,it can be deduced that the dextral pull-apart movement of the Tanlu faults in the Laizhou bay can hardly form a sag.The strike-slip faults only formed mini basins between two strike-slip faults as evidenced by the 3D visualization.更多还原