高邮凹陷南断阶西部断裂特征及其成因机制

在断层基本特征及构造演化史分析的基础上,明确了高邮凹陷南断阶西部断裂各断层的发育顺序,并对断层级别进行了划分,结合构造应力场数值模拟法对各级别断层的成因机制进行了探讨.研究表明真①断层早在泰州期便开始发育,真②断层主要形成于戴南期,这2条断层的发育演化受区域伸展及郯庐断裂带影响明显;真①与真②断层之间的三级断层主要形成于阜宁期,其形成发育主要受真①断层派生的古局部构造应力场控制,在黄珏南和许庄地区最小主应力高值区断层发育密集,最小主应力不仅控制了断层的发育位置,还控制了断层的活动强度;剪应力控制了断层的平面展布,左旋剪应力区主要发育近东西走向断层,右旋剪应力区主要发育北东走向断层.

Characteristics and genetic mechanism of the faults in the west of south fault terrace in Gaoyou Sag

Based on the analysis of the basic characteristics of the faults and the tectonic evolution history,the development order of the faults is confirmed,the grade of the faults is divided.The genetic mechanism of the faults is researched according to numerical simulation of tectonic stress field.The result show that Zhen ① fault was formed before Taizhou sedimentary period,Zhen ② fault was formed in Dainan sedimentary period,the development and evolution of two faults were obviously effected by the regional extension and the Tan-Lu fault zone.The third-class faults between Zhen ① and Zhen ② fault were formed in Funing sedimentary period,their development and evolution are controlled by the local ancient tectonic stress field which was derived from Zhen ① fault.The faults intensively developed in Huangjue and Xuzhang area where the minimum principal stress is high,the minimum principal stress not only control the location of the fault development,but also control the intensity of the fault activities.The shear stress controls the planar distribution of the faults,in sinistral shear stress area were developed the faults with nearly EW strike and in dextral shear stress area are developed the faults with nearly NE strike.