The Main Factors Of δ¹⁸O’s Enrichment About Deep Geothermal Water Of Guanzhong Basin

Carry out the research on the abdominal deep origin of geothermal water in guanzhong basin, which is a matter of the sustainable development and utilization ofgeothermal water, national economy and people’s livelihood, low carbon environmental protection, which is of great significance to promote the rational development and utilization of the geothermal water in the western China. The relationship between water samples of underground hot water in Yangbajing and other 30 rift basins and modern circulation water closely, and brine in the Guanzhong Basin deep underground water and Sichuan Basin are far from atmospheric precipitation, δ18O drift significantly, in this regard, scholars and experts at home and abroad have different understandings on main factors causing δ18O in Guanzhong Basin under hot water enrichment.Therefore, use isotope hydrology geochemistry method in this paper and combine with the guanzhong basin tectonic evolution, which is the underground hot water in Guanzhong Basin can be updated, genetic types provide isotopic and hydrogeochemical evidence.Theoretical study shows that the Guanzhong Basin deep underground hot water with δ18O enriched with higher underground water temperature and longer retention time, deep buried depth, low water rock ratio, higher total dissolved solids(TDS) and the strong water and rock between δ18O exchange, these all provide the evidence that δ18O enrichment is controlled by hydrothermal reaction.Under natural conditions water evaporation experiment show that Guanzhong Basin deep underground hot water before entering into the formation as the presence of water on the surface of the water supply, there is a certain degree of evaporation, the evaporation slope of 4.62, and Guanzhong Basin deep underground hot water oxygen and deuterium drift line slope of 2.42 there is a difference of 2.2, and slope of the Guanzhong Basin deep underground hot water oxygen and deuterium drift line 242 less than relative humidity was 3.9% of the slope, the two were further confirmed δ18O enrichment controlled by hydrothermal reaction. Evaporation simulation of underground water evaporation under different closed conditions shows that the evaporation of underground hot water is closely related to the degree of evaporation of groundwater and the degree of thermal storage environment. Under the same evaporation condition, the evaporation decreases with the degree of closure, but the evaporation is negligible in the whole closed state. Xi’an depression and Xian Li fault terrace West thermal storage environment in semi open state, evaporation and water rock reaction also exist, but controlled the enrichment of δ18O in the hydrothermal reaction, part of evaporation. Xian Li fault terrace East to order thermal storage environment more closed and there is no evaporation, the δ18O enrichment controlled in the hydrothermal reaction, there less evaporation. The thermal reservoir environment of the city is completely closed, and the evaporation is not basically, and the enrichment of δ18O is mainly controlled by the water rock.. The results of ultrafiltration experiments show that the enrichment of δ18O in deep underground hot water of Guanzhong Basin is not influenced by the ultrafiltration experiment.Theoretical and experimental study results show that the Guanzhong Basin deep underground hot water before entering into the formation as the presence of water on the surface of the water supply when the δ18O enrichment controlled evaporation and infiltration into a closed heat storage environment is controlled in the influence of hydrothermal.