VLF-EM和EH4在浅覆盖区萤石矿床勘查中的应用——以林西水头萤石矿区为例

Exploration of fluorite deposit by the combination of VLF-EM and EH4 on shallow-covered area——A case study of the Shuitou deposit

为探究甚低频电磁法(VLF-EM)和EH4连续电导率成像系统(EH4)的组合运用对浅覆盖区萤石矿床的勘查效果,以内蒙古林西县水头萤石矿床为例,开展隐伏-半隐伏萤石矿体的定位预测工作。在野外地质勘查的基础上,通过对VLF-EM和EH4原始数据的处理和分析解译,并结合地质事实进行对比验证。结果表明:VLF-EM可以快速判定浅部(一般<60 m)低阻带展布特征和定位构造格局,EH4能够探明构造低阻带在深部空间(可达1 000 m左右)的延伸变化信息;两者的有效组合,一浅一深,可以做到相互检验和优势互补,结合地面地质调查和地球化学分析结果,能够有效地预测隐伏-半隐伏萤石矿体。

To explore the effect of VLF-EM and EH4 for semi-concealed fluorite deposits in the grassland,Shuitou fluorite deposit in Linxi area is selected as the case study. Through the raw data processed and interpreted on the basis of the geological fact,the results show that VLF-EM can rapidly evaluate the shallow（ less than60 m） distribution features of the structures with low resistivity to ore or mineralized bodies. The survey with EH4 can reveal the spread distribution of structural belts in deep space（ almost reach 1 000 m）. Based on the geological or geochemistry data,the effective combination of VLF-EM and EH4 can be efficient to forecast the location of the buried ore bodies. It has many advantages over traditional models.（ 1） The two methods,from shallow to deep,can be compared and complemented one another.（ 2） It can provide a scientific basis for further exploration of fluorite deposits.（ 3） It is one way of exploring the concealed and semi-concealed deposits.