1. Beijing Institute of Geo-exploration Technology,Beijing 100120,China 2. Institute of Geology and Geophysics,Chinese Academy of Sciences,Beijing 100029,China
The survey of pluton distribution is vital to the study of geothermal system. Using the latest gravity, CSAMT, microtremor survey and previous magnetic data, the authors studied the spatial distribution of several plutons in northwest Beijing. The results show that these plutons have different geophysical characteristics, which suggests that they were formed in different intrusive periods and were developed in different tectonic environments. There are thick dolomite strata of Quaternary period and Jixian System between Huata pluton and Gecun pluton in the southwest of the study area, which may be the main flow channel of underground hot water. The intrusive occurrence of Yangfang pluton exhibits gentle slope in the west and steep slope in the east. The distribution of these plutons is controlled by Nankou Mountain front fault, Nankou-Sunhe fault and Yingbishan fault.
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