北京二十里长山-平谷盆地MT测量与地层含水性研究

在北京东部的顺义二十里长山-平谷盆地进行了75个测点的大地电磁测量.通过应用TE与TM联合模式下的Occam以及Rebocc二维反演方法获得的电性结构模型,揭示了该区第四系覆盖层的厚度、基岩顶部电性分布特征、断裂构造以及含水岩溶发育情况.测量结果表明,测区第四系覆盖层普遍富水,二十里长山断裂两侧为2个差异明显的水文地质单元,断裂构造控制了基岩中含水岩溶的发育;在平谷盆地,含水岩溶明显受断裂构造控制,呈现出一种上下相通的"网络状"分布格局.

Magnetotelluric Survey and Water-Bearing Ability of Stratum across Ershili Changshan-Pinggu Basin,Beijing

75 magnetotelluric sites have been surveyed at Ershili Changshan-Pinggu Basin,Beijing. With Occam and Rebocc two-dimensional inversion under combined TE and TM mode,the stable and convergent electric structure models are obtained. From these models,we can get the Quaternary coverts thickness, the characteristic of electrical distribution at the top of the bedrock, the faults and the water-bearing karst. In the survey area,the Quaternary is rich of water; the two sides of the Ershili Changshan are two different hydrology and geology units. The faults control the water-bearing karst zone, especially in Pinggu Basin, while the water-bearing karst shows a network structure of underground-water distribution.