综合物探法在寻找隐伏半隐伏萤石矿中的应用

Application of Comprehensive Geophysical Exploration Method in Searching for Concealed and Semi Concealed Fluorite Mines

冀北地区萤石矿均为低温热液型,其与构造关系极为紧密。本次在冀北某萤石矿普查工作中,在隐伏半隐伏地区利用活性炭测氡法圈定断裂构造位置,利用激发极化法确定萤石矿化体蚀变带在地表的分布范围及其垂向分布特征。结果表明,萤石矿化体位于主断裂附近的次级断裂中,次级断裂因萤石填充堵塞氡气运移通道,氡浓度值相对较低,但活性炭测氡法对主断裂构造仍具有较好的指示作用,因此利用活性炭测氡法寻找主断裂构造位置,结合地质填图及槽探工程等手段在主断裂附近可以有效圈定萤石矿化范围;激电中梯剖面或面积测量可有效圈定矿化蚀变带在地表的分布范围,激电测深反演能够直接反映矿化体在深部的垂向分布特征。活性炭测氡法与激发极化法相组合的方法,辅以其它地质工程手段在冀北地区寻找隐伏、半隐伏低温热液型萤石矿床效果显著。

Fluorite deposits in the northern Hebei region,all low-temperature hydrothermal typesare closely related to the structures.During the general survey of a fluorite deposit in the north of Hebei province,the active carbon radon measurement method was used to delineate the location of fault structures in the hidden and semi-hidden areas.The distribution range and vertical distribution characteristics of the alteration zone of fluorite mineralized body were determined by induced polarization method.The results show that the fluorite mineralized body is located in the secondary fault near the main fault.And the radon concentration in the secondary fault is relatively low,because the fluorite is blocking the radon migration channel.However,the active carbon radon measurement method still has a good indication to the main fault structure.Therefore,the active carbon radon measurement method is used to locate the main fault structures.The distribution of mineralized alteration zones on the earth’s surface can be effectively delineated by induced polarization(IP)middle gradient section or area measurement.IP sounding inversion can directly reflect the vertical distribution characteristics of mineralized bodies in the deeppart.The integration of active carbon radon measurement and induced polarization method,together with other geological engineering methods,has achieved remarkable results in the search for concealed and semi-concealed low-temperature fluorite deposits in northern Hebei province.