关键词: 大地电磁测深, 二维反演, 结构特征, 深圳断裂带

Abstract: The magnetotelluric method was used to study the active fault in Shenzhen city.Four magnetotelluric profiles with densified sites were laid out across Shenzhen Fault zone.The remote reference technique was used in both data observing and processing to eliminate the electromagnetic noise near the survey sites,and rather smooth apparent resistivity curves were obtained finally.TM mode data and two-dimensional inversion method as NLCG were used to obtain the electrical structures underground.According to the surficial geology survey results on regional strata and distribution of magmatic bodies and faults,the electrical structures of the depth less than 2000m of each profile were interpreted firstly,two regional faults,namely,the Henggang-Luohu Fault and the Liantang Fault,and seven local faults consistent with the electrical boundaries were verified or found.The strata in the survey area were then related with the change of resistivity.The horizontal electrical slices of depths less than 5000m indicate the Henggang-Luohu Fault and the Liantang Fault bifurcate at the shallow part but tend to merge at depths.

Key words: magnetotellurics, two-dimensional inversion, structure, Shenzhen Fault zone