Study On The Reserve Regularity And Hydrochemical Characteristics Of Geothermal Resources In Changbai Mountain Basalt Region

The object of this study is the rich geothermal resources in Changbai Mountainbasalt region. Based on the basic data collected, including meteorological, geological,hydrogeological and survey data by the investigation in the study region, theformation mechanism of geothermal resources in Changbai Mountain basalt regionwas analyzed and researched from four aspects, which are the occurrence regularity ofgeothermal, hydrogeochemical characteristics, heat reservoir temperature estimation,the cold—hot water mixing.Geothermal resources are kinds of useful component which can be developedrefer to the current technology, economic and geological environment conditions, itbelongs to a renewable resource which generally exists in the rock and geothermalfluid. The early development of the geothermal is widely used for bathing, however,the application of geothermal resource has been increased to more aspects of heating,aquaculture, tourism, convalescence and holiday in recent years. Geothermal resourceis extremely rich in China that has a huge potential for development and utilizationvalue, high temperature tropical and mid—low temperature geothermal water arewide distribution.This study region is located in Changbai Mountain basalt region in Baishan city,Jilin province. There are two famous modern volcano activity regions include TianchiLake volcano group and Longgang volcano group in this region. A total of4geothermal fields have investigated that consist of10artesian hot springs, there arerespective Changbai geothermal field, Jinjiang geothermal field, Xianrenqiaogeothermal field, Shibadaogou geothermal field. The strata in the study region areArchean, Proterozoic, Paleozoic, Mesozoic and Cenozoic. The region is mainlycontrolled by collision of Philippines plate and the Pacific plate subduction, and two groups of NNE and NE continental rifts and fault systems were formed in this region,the condition provides a good environment for heat storage in Changbai Mountainvolcanic cluster. Changbai Mountain volcano group belongs to magmatic heat sourceheat source that mainly from the deep crustal magma chamber.The temperature of10surveyed hot springs are between35℃and84℃. Inaddition to Julong spring belongs to the medium temperature spring and other allbelong to mid-low temperature spring. In terms of water chemistry, the cation ofgeothermal water is based on Na+and the anionic is based on HCO3-. Water chemicaltype are most HCO3—Na, salinity is between1g/L and2g/L. The content ofmetasilicate in geothermal water is higher than other kinds of water, and tracecomponent mainly strontium, lithium and aluminum elements.Four different geothermometers were used to estimate the heat reservoirtemperature in study region, and a variety of judging method were applied todetermine the appropriate geothermometer. The final estimate result shows that heatreservoir temperature of different geothermal field were between72℃and169℃.The possibility of mixing between hot water and cold water is occurred based on theanalysis of characteristic of Schoeller diagram and Scatter diagram, silicon—enthalpies has used to estimate the mixing ratio of different hot springs were inthe12.7%～43.04%.