沽源-红山子铀成矿带广兴源地区断裂构造特征及其找矿意义

Characteristics of Fracture Structure and Prospecting Significance of Guangxingyuan Area in Guyuan-Hongshanzi Uranium Metallogenic Belt

广兴源地区位于沽源-红山子铀成矿带北东端,区内断裂构造发育,已发现的南窝铺、灶火沟门两个铀矿床及多个铀-多金属矿化点、带受NE向断裂构造控制明显,但对区内断裂构造特征的解析及铀矿化与断裂构造的具体关系仍缺乏深入研究。文章通过对近年来的基础地质调查及深部揭露成果进行综合分析,认为区内存在NE向、NW向和近SN向三组断裂构造,具有先压扭后伸张的特征,构造活动期次由早到晚依次为NE→NW→近SN。其中,NE断裂构造控制着区内矿化点(带)的总体展布方向;NW向断裂构造是区内重要的储矿构造,矿化赋存于NW向与NE向构造叠加部位;近SN向断裂构造在空间上往往错断NE、NW向断裂,对矿体产出具有一定的破坏作用,因此在后续找矿中应充分考虑近SN向构造对矿体的影响。

Guangxingyuan area is located in the northeast of Guyuan-Hongshanzi uranium mineralization belt.Fracture structures are strongly developed,Nanwopu and Zaohuogoumen uranium deposits and some uranium-polymetallic mineralization points have been found in the area.The mineralization is controlled by the fracture structure.Although the researches have found that the NE trending fault is the main ore controlling fault in the area,few detailed researches focused on the characteristics of fault structures and the relationship between uranium mineralization and fault structures.Through the comprehensive analysis and study of the results of geological survey and deep drilling in recent years,this paper made systematic study of the fault and got some new recognitions.The fault was classified into three groups:NE trending,NW trending and near SN trending,which experienced compressing and twisting at first and then elongation,and the sequence of tectonic activity from early to late was NE→NW→near SN.Among them,the NE fault structure controls the overall spread direction of the mineralizations in the zone;the NW directional fault structure was an important storage structure in the region,and the mineralization was deposited in the superposition of the NW direction and the NE directional structure;the near-SN-trending fault structure often broke the NE and NW-trending faults in space,which resulted a certain destructive effect on the ore body output,so the influence of the near-SN-trending structure on the ore body should be fully considered in the subsequent prospecting.