易门狮子山铜矿床构造控矿规律及深部找矿效果

Ore-control Structures of Shizishan Copper Deposit in Yimen Country and Deep Prospecting

易门狮子山铜矿床位于武定‒易门‒元江裂陷带中段,是区内受构造控制的典型矿床之一,矿区多期构造活动强烈,构造形式多样。综合运用构造地质学、矿田地质力学等理论与方法,对深部16至18中段(1187~1087 m标高)坑道中出露的构造进行系统研究,厘定了成矿期和成矿后构造的空间分布、运动形式及力学性质,探讨了深部构造控矿规律,进行深部找矿预测。研究表明,矿区深部隐伏矿体主要受NW向和NWW向两组断裂控制:NE向断裂为成矿期主要控矿构造,在该期断裂构造内发育的刺穿构造进一步控制了矿体的空间产出;NWW向断裂为成矿后构造,该期构造为左行压扭性断裂,依据断裂的运动学特征(擦痕判断为上盘斜上)、断距和旁侧构造形迹,推测该期Fy2断裂将深部矿体往SWW向错断了80~120 m左右。经钻孔验证,靶区内存在高品位的矿体,为矿区升级和新增(332+333)铜金属资源量4.2万吨。该认识为深部隐伏矿体预测提供了重要依据。

The Shizishan copper deposit is located in the middle part of the Wuding-Yimen-Yuanjiang fault depression.It is one of the typical structure-controlled ore deposits in the area.Multistage tectonic activities resulted in the strong geological deformation in the mining area,and multiple tectonic styles have been recognized through systematical structural investigation at the deep tunnels(1187-1087 m level)of the Shizishan deposit.This study focused on the spatial distribution,movement styles and mechanical properties of the syn-ore and post-ore stage structures,and explored the structural controls of ore emplacement,and conducted deep prospecting.The results showed that the deep concealed ore bodies in the mining area are mainly controlled by the NE-and NW-trending faults.The diapir breccia structures are the secondary faults of the NE-trending ore-controlling faults,which controlled the spatial distribution of ore bodies.The NWW-trending faults are post-ore structures.The post-ore structures are left-lateral compression-torsion faults based on their kinematic characteristics,including slip and traces of lateral characteristic(scratch indicates that the upper plate is inclined to rise).The speculation is that the Fy2 fault in this period pushed the ore body in SWW direction with about 80 to 120 m.The deep exploration has discovered high-grade ore-bodies at depth,and the newly discovered ores have proved copper metal resources of 42000 tons.The progress in deep exploration showed that the structural control features of the deposit can be a useful guide for the prediction of deep concealed ore bodies.