The Formation Conditions And Main Controlling Factors Of Geothermal Resources In Songjianghe Area Of Changbai Mountain

The Changbai mountain area is located on the edge of the east Asian continent,and it is close to the strong fold belt of the Pacific subduction Eurasian plate,and has experienced many times of crustal activity,forming a unique topography.Because of the overburden of the large area basalt in the study area,the internal tectonic characteristics and stratigraphic distribution are not clear,which impedes the development of geothermal resources.Songjianghe lies in the northwest of Changbai mountain area,fully equipped with formation and development,mainly including archaean group,yuan of the ancient world,upper Paleozoic,Mesozoic and Cenozoic,Jurassic in the study area and the strongest period volcanic activity in northeast China,this period to form the east basin,volcanic basin,such as Korean pine,FuSong basin.In addition,intrusive rocks in this area are mainly formed in the Jurassic.Geothermal systems based on SongJiangHe area as the research object,through the analysis of geochemical characteristics of the structure,the deep structure,the geothermal fluid,dominated by geological and geophysical comprehensive study,the combination of regional geology and drilling data,and make full use of the hydrogeochemical and rock geochemical test data,the geothermal resources form the basic conditions,combined with the area around the data of other favorable geothermal area,combined with the field survey,clear structure partition in the study area,and its internal stratum distribution characteristics,summarizes the main controlling factors of geothermal resources formation.Further improve the formation mechanism of geothermal resources and provide theoretical support for the rational exploration and development of geothermal resources in the region.The results are as follows:1.Songjianghe area has good regional thermal background conditions,the area at the edge of the Eurasian plate subduction of the Pacific plate,tectonic movement is frequent,fracture development,is a good thermal conductivity of water medium;At the same time,the area is located in the sedimentary basin,and it has a good thermal reservoir and cover layer,which provides favorable conditions for underground hot water storage.The water system in this area is developed and the rainfall is higher,which provides sufficient water for geothermal water in this area.2.Mainly for the normal terrestrial heat flow heating,mainly for atmospheric precipitation and surface water mixed with water,heat reservoir are mainly Palaeozoic group Cambrian and Ordovician limestone,Mesozoic small subgroup of sandstone,cover mainly for the Mesozoic andesite,Cenozoic basalt,main migration channel for the development of active fault.3.Combined with the formation conditions of geothermal resources,it is believed that the sufficient heat source is the primary control factor for the formation of large-scale geothermal resources,regardless of the type of geothermal system.The Songjianghe region is located within the Donggang basin and belongs to the sedimentary basin type geothermal system.It is the main controlling factor of geothermal formation in sedimentary basin.At the same time,the drilling shows that the underground hot water resource is rich,also belongs to the hydrothermal type geothermal system,the development of fracture becomes the indispensable factor.4.The development of fracture is also a main control factors of the geothermal resources,played the original geothermal resource extraction,distillation process,looking for favorable position of the fault,is looking for "dessert" area of geothermal water resources.For the sedimentary basin type geothermal system,the sedimentary basin is obviously stratified,and the deposition thickness is large,and the water stored in the deep reservoir can not be developed very well.Plays an important part and the development of fracture happens to hydraulic connection,is not only the migration pathway of atmospheric precipitation,cutting cover at the same time,direct thermal reservoir,makes the hot reservoir of underground hot water springs are formed by fracture rose to the surface.