摘要
The magnetotelluric sounding method was used to study the active fault in Shenzhen city.Four magnetotelluric profiles with a dense station interval were laid out across the Shenzhen fault zone.The remote reference technique was used in both data observation and processing to eliminate the electromagnetic noise near the survey sites,and relatively smooth apparent resistivity curves were obtained.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 at depths less than 2000m of each profile were interpreted.Two regional faults,the Henggang-Luohu fault and the Liantang fault,and seven local faults consistent with the electrical boundaries were verified or discovered.The strata in the survey area were then related with the change of resistivity.Electrical horizontal slices of depths less than 5000m indicate that the Henggang-Luohu fault and the Liantang fault bifurcate at the shallow part but tend to merge in the deep part.
The magnetotelluric sounding method was used to study the active fault in Shenzhen city. Four magnetotelluric profiles with a dense station interval were laid out across the Shenzhen fault zone. The remote reference technique was used in both data observation and processing to eliminate the electromagnetic noise near the survey sites, and relatively smooth apparent resistivity curves were obtained. 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 at depths less than 2000m of each profile were interpreted. Two regional faults, the Henggang-Luohu fault and the Liantang fault, and seven local faults consistent with the electrical boundaries were verified or discovered. The strata in the survey area were then related with the change of resistivity. Electrical horizontal slices of depths less than 5000m indicate that the Henggang-Luohu fault and the Liantang fault bifurcate at the shallow part but tend to merge in the deep part.
基金
sponsored by the "Program for Active Fault Detection and Earthquake Risk Assessment in Shenzhen City",China
