Abstract:

      More attention has been paid to the investigation and development of geothermal resources in the northern uplift of the urban Beijing geothermal field since the geothermal well in Peking University was successfully drilled in 2001. Regional geological conditions of the study area are described in this paper. Based on geological survey of several geothermal wells, the structure of geothermal reservoirs, geothermal geological characteristics and hydrochemistry of thermal groundwater are also examined. The results show that the Babaoshan fault is characterized by multi-activity from a reverse fault to a normal fault and the geothermal reservoir consisting of dolomite of the Wumishan Group of the Jixian System is a nose-type-anticline uplift. Conductive heat flow from beneath mainly flows along the hanging wall of the Huangzhuang-Gaoliying fault. The cold groundwater in the shallow carbonate of Palaeozoic age causes the geothermal gradient of the Qingbaikou reservoir higher than that in the Beijing plain. Thermal groundwater near the deep and huge faults has high Ra contents. ¹⁴C age of the hot water indicates that little recharge occurred in the western uplifted mountain area. Hydraulic heads at the geothermal wells reflect a flow trend from south to north of thermal groundwater in the Wumishan Group due to the obstructing of the Huangzhuang-Gaoliying fault.

Key words: geothermal energy, geothermal reservoir, the Wumishan Group of the Jixian System, age of thermal groundwater, Beijing