CSAMT法在江西银珠山铜多金属矿区水文地质勘查中的应用

The Application of CSAMT Method to Hydrologic Exploration of Yinzhushan Copper Poly-metallic Mining Area of Jiangxi

以燕山期火山盆地边缘发现的贵溪银珠山铜多金属矿床为例,在矿区地质情况复杂、断裂构造较为发育、部分钻孔已出现有涌/漏水的条件下,利用可控源音频大地电磁法(CSAMT)探测深度大、分辨率高的优势,布置了3条测线以探明矿区水文地质情况。基本查明矿区主要断裂为F_(D1)、F_(D2),富水地层主要为侏罗系鹅湖岭组,富水位置为测区中部,富水埋深为-100 m至-400 m,验证了北东向主断裂构造F_(D1)、F_(D2)的空间分布特征,且F_(D2)为主导水构造带,并推断了北西向次级含水断裂构造带F_(D3)、F_(D4)。受导水断裂构造带作用,区内圈定了一个封闭于侏罗系鹅湖岭组中的相对低阻异常区,推测该低阻异常区地层中充填水。本次工作表明利用CSAMT法在低阻区域进行断裂储水构造的区分和深部水文地质勘查具有较好的效果。

The Yinzhushan copper polymatallic deposit is located in Guixi,developed at the edge of volcanian basin of Yanshan period.Under the conditions of complex geological conditions,relatively developed structural faults and some boreholes with inrush/leakage,three survey lines were laid by taking advantages of controllable source audio magneto-telluric method(CSAMT),in order to find out the hydrogeological conditions.The main faults in the mining area are F_(D1)and F_(D2),and the water-rich strata are mainly Ehuling formation of Jurassic.The water-rich position is in the middle of the survey area,and the water-rich buried depth is between-100 m and-400 m.The spatial distribution characteristics of the main fault structures F_(D1) and F_(D2) in NE direction are verified.The F_(D2) is the main water-bearing structural belt,and F_(D3) and F_(D4) as secondary water bearing structure in NW direction are deduced.The main faults in the mining area are F_(D1) and F_(D2),and the water-rich strata are mainly Ehuling formation of Jurassic.The water-rich position is in the middle of the survey area,and the water-rich buried depth is between-100 m and-400 m.The spatial distribution characteristics of the main fault structures F_(D1) and F_(D2) in NE direction are verified.The F_(D2) is the main water-bearing structural belt,and F_(D3) and F_(D4) as secondary water bearing structure in NW direction are deduced.Under the action of the water-conducting fault structural belt,a relatively low-resistance abnormal area is defined in this area,which is enclosed in the Ehuling formation of Jurassic.It is speculated that the stratum in this low-resistance abnormal area is full of water.This work shows that the CSAMT method is effective both in distinguishing fault water storage structures from low resistance areas and in deep hydrogeological exploration.