淮南煤田顾桂矿区走滑构造特征及成因演化研究

Study on strike-slip structure characteristics and genetic evolution of Gugui Mining Area in Huainan Coalfield

顾桂矿区位于淮南煤田中部S形转折端位置,区内主要发育NW向、NE向和EW向3组断裂系统,其中NW向与NE向断层系统共同组成X形共轭状,并呈现出明显的走滑构造特征,自西向东该构造带发育程度具有减弱的趋势。根据矿井资料揭示,NE向断层多被限制在NW向断层之间或被其错断,显示其为NW向断层的派生断层。通过对平、剖面断层几何学特征分析,NE向断层多表现为右行张扭性,NW向断层多表现为左行张扭性,局部为左行压扭性活动特征,在2组走滑断裂交汇部位常形成古隆起或古洼陷。结合区域构造应力演化背景,顾桂矿区内走滑断裂系统分别经历了印支期NW向横断层形成阶段、燕山运动早期压扭性活动阶段、燕山晚期至喜山期伸展改造阶段3个演化过程。通过对顾桂矿区走滑构造的详细研究,对认识该地区地下水流场、地温场、地应力场的变化特征及构造控制具有重要的指导意义。

The Gugui Mining Area is located at the S type turning point in the middle of the Huainan Coalfield.There are three groups of fault systems,NW,NE and EW,in the area,the strike-slip structural features are obvious,and the development of this structural belt from west to east shows a decreasing trend.According to mine data,NE-trending faults are mostly confined between NW-trending faults or by their wrong sections,which shows that they are NW-trending faults.Based on the analysis of the geometrical characteristics of the faults in the plane and section,the NE-trending faults are mainly characterized by right-lateral tension-torsion,and the NW-trending faults are mainly characterized by left-lateral tension-torsion and local left-lateral compression-torsion,paleo-uplifts or paleo-depressions are often formed at the intersection of the two strike-slip faults.Combined with the background of regional tectonic stress evolution,the strike-slip fault system in Gugui Mining Area experienced three evolution stages:the Indosinian NW transverse fault formation stage,the early Yan Mountains Movement compressive and torsional activity stage,and the late Yan Mountains to Himalayan extension and reconstruction stage.Through the detailed study of strike-slip structure in Gugui Mining Area,it is of great significance to understand the variation characteristics of groundwater flow field,ground temperature field,ground stress field and structural control in this area.