【摘要】 为了考察渤海湾盆地临南洼陷张扭构造的发育特征和成因机制,在解释30余条三维地震剖面的基础上,估算及分析伸展率在时间和空间上的变化规律,绘制了Es3—Es1、Ed和Ng—Nm3个时期的断层平面展布图,利用FEPG有限元软件,建立二维线弹性数值模型,模拟了3个时期的构造应力场。结果表明,临南洼陷的最大主应力和最大剪应力,在平面上都是东北部大、西南部小;从Es3时期到Nm时期,最大主应力和最大剪应力都是逐渐减小的,数值模型边界上的剪应力分量均大于张应力分量,而且剪应力分量与张应力分量的比值是逐渐增加的。通过研究,将临南洼陷张扭构造发育的力学机制量化,并为郯庐断裂和兰聊断裂在惠民凹陷乃至渤海湾盆地的作用时间、方式的研究提供参考。更多还原

【Abstract】 To investigate characteristics and formation mechanism of transtentional structures developed in Linnan subsag of the Bohai Bay basin,more than 30 3-D seismic sections have been interpreted,temporal and spatial distributions of extension rates have been estimated and analyzed,and the planar distribution of faults in three stages,Es3-Es1,Ed and Ng-Nm,have been plotted.2-D linear elastic numerical models have been established to simulate the stress field of the above mentioned three stages,using finite element software FEPG.The results reveal that,the maximum principal stress and maximum shear stress in the northeast of Linnan subsag are larger than those in the southwest; from Es3 to Nm,all the maximum principal stress and maximum shear stress decrease gradually; the shear stresses are larger than tensile ones on the boundary of numerical model at all the three stages,while the ratio of shear to tensile stress increases gradually.Through the study,dynamical mechanism of tense-shearing structure developed in Linnan subsag can be quantified,which is helpful to study the time and ways of Tanlu fault and Lanliao fault effects on Huimin depression or even on Bohai Bay basin.更多还原