塔北隆起西段沙井子断裂带西北缘构造特征解析

Analysis of tectonic characteristics of northwest margin of Shajingzi fault zone in the west of Tabei uplift

基于塔北隆起西段区域大量的钻井、测井资料及二维地震资料,开展精细构造解释,分析沙井子断裂带西北缘的构造特征,厘定其运动演化期次。结果表明,沙井子断裂带北缘由三条呈锐角相交、近雁列式展布的断层组成,具有明显的分段特征,根据构造特征及断层发育情况,自南向北可分为南西、中及北东三段。Fsjz1断层具有多期活动的特征,为沙井子断裂带的主控断层,Fsjz2断层及Fsjz3断层对沙井子断裂带形态起到一定调节改造作用。结合主要区域不整合面及断层活动期次认为,沙井子断裂带自寒武系沉积末期开始发育,经历多期构造运动,至第四系沉积末期定型。

Based on a large number of drilling,logging and 2D seismic data in the western Tabei uplift,a detailed geometry and kinematics research was carried out to analyze the structural characteristics and evolutionary stages of northwest margin of Shajingzi fault zone.The results indicate that the northwest margin of Shajingzi fault zone is composed of three faults that intersect at an acute angle and are distributed in near echelon style,which has obvious segmentation characteristics.According to its structural characteristics and fault development,it can be divided into three sections from south to north:south-west,middle and northeast.Fsjz1 fault is characterized by multi-stage activity and is the main control fault of Shajingzi fault zone.Fsjz2 and Fsjz3 faults play a role in regulating and reconstructing the shape of Shajingzi fault zone.Combined with the main regional unconformities and fault activity stages,it is considered that the Shajingzi fault zone developed from the Cambrian,experienced several tectonic movements,and finally settled at the end of quaternary deposition.