可控源音频大地电磁法在宣下煤田勘查中的应用

Application of controllable source audio magnetotelluric method in Xuanxia coalfield exploration

可控源音频大地电磁法可有效克服高阻盖层的屏蔽效应,对深部地质体反应敏感,该方法在宣下煤田勘查中得到成功应用。针对侏罗系下花园组普遍反映为低电阻率的电性特点,测定工作区高低阻地层结构及断裂构造,总结含煤岩系沉积规律,划定含煤希望区。经过钻探施工揭露,煤层存在位置与物探推断结论相一致,成功指导了找煤工作,为煤田进一步开展地质勘查积累了经验。

The controllable source audio magnetotelluric method can effectively overcome the shielding effect of high-resistance caprock and is sensitive to the reaction of deep geological bodies. This method was successfully applied in the exploration of coalfields. According to the electrical characteristics of low-resistivity of the Jurassic Lower Garden Group, the structure and fault structure of the high and low resistance strata in the working area were determined. The sedimentary laws of the coal-bearing rock series were summarized and the coal-bearing zone was delineated. After drilling construction, the location of the coal seam was consistent with the inferred conclusions of geophysical exploration, which successfully guided the coal-seeking work and accumulated experience for further geological exploration of the coalfield.