音频大地电磁测深法在深部地热构造勘查中的应用

Application of Audio Magnetotelluric Sounding in Deep Geothermal Structure Exploration

为探测江苏泗洪县柳山湖景区的深部地热构造,搜集已有的地质地球物理资料和已知勘探钻孔资料,布置了14条音频大地电磁测深(AMT)测线,通过资料采集、预处理、反演,得到了研究区2000 m以浅地质体电阻率空间分布情况。勘探结果表明:研究区存在较好的低阻分布带,且连续性好,推测发育两条深部构造断裂带f_(1)和f_(2),其中f_(2)断裂带规模较大,破碎带中含水,而断裂带上部为完整-较完整的高阻层,可能是良好的盖层。因此,推测深部断裂破碎带f_(2)可能是良好的含水和储水通道,建议在构造带低阻异常中心位置重点研究,为下一步钻孔布设提供依据。

In order to investigate the deep geothermal structure in Liushan Lake Scenic Area,Sihong County,Jiangsu Province,geological and geophysical data and known exploration borehole data were collected,14 Audio Magnetotelluric Sounding(AMT)survey lines were laid,and the resistivity distribution of the shallow geological body at 2000 m in the study area was obtained through data acquisition,pre-processing and inversion.The exploration results show that there was a good low resistance distribution zone in the study area with good continuity,and two deep structural fault f_(1)and f_(2)are inferred.Among them,fault f_(2)is presumed to be large in scale and contains water in the fracture zone,while the upper part of the fracture zone is a complete-more complete high-resistance layer,which may be a good cover layer.Therefore,it is speculated that the deep fracture zone f_(2)has good water-bearing and storage channels,and it is suggested to focus on the location of the low resistance anomaly in the tectonic zone to provide a basis for the next drilling placement.