Abstract:

     This paper presents that Sunhe fault in Beijing plain is a buried active normal fault zone about 3 km wide based on the analysis of gravity,resistivity and CSAMT(controlled source audio-frequency magnetotelluric) data and some exploration data of geothermal wells.Geothermal and geological structure profiles reveal that Sunhe fault is of multi-phase activities and has twice tectonic activities at least since Late Jurassic. This paper also analyzes the control effect of fractures in Sunhe fault zone on the geothermal and geological condition of the Jurassic volcanic rocks;it points out that the southwest of the Houshayu geothermal field is located at a tectonic uplift,and Sunhe fault zone is the geothermal source of the geothermal field.

Key words: Sunhe fault, Jurassic volcanic rock, structural crack, geothermal reservoir, geothermal geology