综合物探方法在内蒙古巴彦图嘎萤石矿区水文地质勘查中的应用

Application of Integrated Geophysical Prospecting Methods to Hydrogeology Survey on Bayantuga Fluorite Mine in Inner Mongolia

内蒙古中北部火山岩地区水资源匮乏,地下水埋藏复杂,找水难度大。为解决当地工业生产及畜牧用水等问题,本文以研究区水文地质调查工作为基础,结合区内地质资料和岩石物性特征,明确了以构造裂隙地下水为最主要储存形式和找水方向,圈定了本次综合物探工作的勘查靶区,建立了以视电阻率联合剖面法、可控源音频大地电磁法(Controlled Source Audio-frequency Magnetotelluric Method,简称CSAMT)为核心的隐伏构造探查技术体系。通过物探资料的解释分析,获得了靶区地下1 km以浅的电性分布特征,展示了三维空间内CSAMT反演电阻率断面及600~1200 m不同海拔电阻率切片,查明了三条富水北西向隐伏断裂构造的产状、位置、深度及规模,最终为确定水文地质钻探井位井深提供依据。本次研究构建了深浅结合、水平与垂向结合的立体勘查模式,证明了综合物探方法在火山岩地区水文地质勘查工作中隐伏构造探查技术的重要性,可为今后同类型地下水资源勘查提供参考。

The volcanic rock area in the middle and north of Inner Mongolia is short of water resources,and the groundwater is complicated,making it difficult to find water.In order to balance the water use in local industrial production and livestock water use,based on the hydrogeological investigation work in the study area,combined with the geological data and rock physical properties,this paper clarifies the main storage form and water prospecting direction of structural fracture groundwater,delineates the exploration target area of this comprehensive geophysical exploration,and establishes the technical system of concealed structure exploration with the core of apparent resistivity combined profile method and controlled source audio magnetotelluric sounding method.Based on the interpretation and analysis of geophysical data,the electrical properties of the target area at a depth of 1 km below ground are obtained,and the resistivity sections of the CSAMT inversion and the resistivity sections at different altitudes of 600 m~1200 m in the 3D are shown,the occurrence,location,depth and scale of three water-rich NW-trending concealed fault structures are identified,which provides a basis for determining the depth of drilling wells in hydrogeology.In this study,a three-dimensional exploration model is constructed,integrating various factors,depth and shallow,horizontal and vertical,which proves the importance of the integrated geophysical method in the exploration of concealed structures in the hydrogeological exploration of volcanic rock areas,and can provide reference for the exploration of the same type of groundwater resources in the future.