Characteristics Of The Geothermal Field And Formation Of The Thermal Groundwater In The Xiaotangshan Area Of Beijing

More than thirty years has passed since the perambulation and exploration of geothermal resource in Beijing since the beginning of 1970s. The survey on the geothermal geology and study on geochemistry and heat reservoir engineer have promoted the geothermal exploration in early times. Thus further understanding of the geological structure of the geothermal field has been made in Beijing, which is still improving. With the development and usage of geothermal resources, the continual use of geothermal resources have increasingly been paid attention to, thus there are higher request for resource exploration and evaluation. Meanwhile, the blindness and risk improve since the exploration rate is greater than the level of perambulation evaluation and research in geothermal resources. Ground temperature situation in one area is a comprehensive reflection of its geological structure and geological history. Therefore, further research on the geological temperature characteristics in a certain area and analysis on the genetic modal of the underground hydrothermal thermal will provide some reference to the geothermal exploration in the area where no work have been carried on . What's more, decreasing the exploration risk is an emphasis topic in geothermal study at present. In this case, this paper focuses on the characteristics of the geothermal field and analyzing its formal modal of Xiaotangshan area in Beijing.Firstly the paper collect and analyze the geothermal perambulate, drilling, geophysical and chemical exploration data of the Xiaotangshan area at present and carry further research on the distribution, depth and lithologic features of various thermal reservoirs. We classify and the accumulated data in the past, carry on research by comprehensive methods such as geothermal research theory, adopt geothermal geology, hydrology, physical geography, geochemistry and so on. And then under the great regional underground formation mechanism, we dissect the geological structure, underground water distribution characteristics, discuss the relationship between upwelling channels and heat transfer mechanism and that between the geothermal field and geological structure of underground water, hydrogeochemical types, hydrothermal age and reservoir temperature, analyze the genesis of thermal groundwater, set up the geothermal and geological modal to show the geothermal field characteristics and genetic mechanism and provide scientific proof for the exploration and usage of the geothermal resources in this area and to guide the peripherally geological examination of the known geothermal field and the prospecting evaluation to the geothermal resources in the unknown area.The Underground hydrothermal in Xioatangshan area develop in carbonate rocks stratum, which belongs to karst fissure media and depositional basin conduction type geothermal system. The basement rocks include three thermal reservoirs, which are the Precambrian, the Tieling Group of the Jixian System and the Wumishan Group of the Jixian System. The origin of the underground comes from the relative homogeneous heat flow in a deeper basin, which redistribute in the lower and the origin of supply mainly lie in the atmospheric precipitation in the north and west of Yanshan area. Underground hydrothermal communicate with deep heat source near Huangzhuang-Gaoliying discordogenic fault. After abundantly absorbing the deep heat, some of it continue to travel to the base rock in the deep of the plain and some of it travel and becomes occurrence along Daliushu-Huluhe fault, which is held up at Asuwei-Xiaotangshan fault, and then drain along the carbonate rock karst fissure, ascend to the surface and thus the Xiaotangshan hot spring comes into being.