应用大地电磁测深勘查北京平谷盆地隐伏含水岩溶系统的结构

将大地电磁测深用于寻找深层地下水,在北京东部平谷盆地实施3条剖面25个测点,在资料分析过程中,对部分测点实施Mohr圆阻抗张量分解技术;在自动反演过程中,引入Rhoplus和Rebocc反演程序。通过对反演解释结果的分析,认为测区第四系地下水含量丰富,断裂构造及含水岩溶发育。对比3条剖面的电性分布特征,推测存在走向NNE的区域性断裂F1,其所经之处控制基岩中含水岩溶的发育;与F1相交的NW向次级断裂带控制了另一深部含水岩溶发育区,不同方向的含水岩溶发育区因断裂构造相通,呈现“网络”式的分布格局。

Magnetotelluric Survey and Structure of Water-Bearing Karst System of Pinggu Basin, Beijing

Magnetotelluric survey with 25 sites of three profiles was applied to underground-water-searching in Pinggu basin, east Beijing. In the process of data-analyzing, Mohr circle impedance tensor decomposition technology was imported to reduce the effect of local electro inhomogeneity; Using programs as Rhoplus and Rebocc to automatic one dimensional and two dimensional inversion. The interpretation results of inversion clearly reflect that the survey area is rich of Quaternary underground-water,the fault structure and water-bearing karst are well-developed; furthermore, presume that there exists F1 fault in NNE direction, it controls the water-bearing karst zone, while the deeper water-bearing karst zone is controlled by the fault in NW direction, both water-bearing karst zones intersecting at the place where two faults meet, which shows a network structure of underground-water distribution.