可控源音频大地电磁法在浅覆盖区区域地质调查中的应用——以1∶5万大汶口、楼德幅为例

Application of Controlled Source Audio Magnetotelluric Sounding in Regional Geological Survey of Shallow Covering Area——Setting Dawenkou and Loude Sheets with the Scale of 1∶50000 as an Example

摘要:

根据已有地质和地球物理研究结果，大汶口、楼德地区存在多条隐伏断裂。为了查明该区基岩面的起伏情况、断裂的空间展布情况，在研究区完成了10条可控源音频大地电磁测深剖面。结合区域地质资料对研究区域进行了综合地质解释，结果表明：可控源音频大地电磁法可以反映不同深度电阻率分布情况，能够较好地描绘出测线通过地段地层和地质构造空间分布情况；并揭示了蒙山断裂、顺义庄断裂等隐伏断裂的构造位置、性质、产状等，与已有的区域地质资料给出的信息基本一致，为地质分析工作提供了可靠的基础资料；CSAMT法已经成为探测隐伏断裂的一种重要的地球物理手段，在浅覆盖区区域地质调查工作中有着广阔的应用前景。

Abstract:

According to the results of geological and geophysical studies, there are several hidden faults in Dawenkou and Loude areas. In order to find out the raise and fall of bedrock and the spatial distribution of faults, 10 controlled source audio magnetotelluric sounding profiles have been completed in the study area. Combining with regional geological data, comprehensive geological interpretation of the study area has been carried out. It is showed that the controlled source audio magnetotelluric sounding method can reflect the resistivity distribution at different depths, and describe the spatial distribution of strata and geological structures in the section through which the survey line passes. The structural location, properties, and occurrence of hidden faults, such as the Mengshan fault and Shunyizhuang fault have been revealed, which are basically consistent with the information provided by existing regional geological data. It will provide reliable basic data for geological analysis work. The CSAMT method has become an important geophysical tool for detecting hidden faults and has broad application prospects in geological surveys in shallow coverage areas.