Hydrogeochemical Characteristics and Genesis of Geothermal Fields in the Henan Section of the Neihuang Uplift
The Henan section of the Neihuang Uplift is rich in geothermal resources,with relatively high temperature gradients.However,there has been limited research on the transport mechanism of geothermal fluids in this area.Hydrogeochemical methods,temperature calculations of geothermal reservoirs,and hydrogen-oxygen isotope techniques were utilized to analyze the hydrochemical types,hydrochemical evolution,reservoir temperatures,and deep hot water recharge sources of geothermal waters.The results show as follows.The hydrochemical types of the Neogene geothermal reservoirs are predominantly Cl-Na,while those of the Eogene geothermal reservoirs are mainly Cl-Na and Cl·SO4-Na types.The Na+and Cl-in geothermal waters primarily originate from the dissolution of minerals,while the dissolution of sodium silicate minerals and the cation exchange adsorption also contribute to the source of some Na+in geothermal waters.The precipitation-dissolution equilibrium of carbonate,sulfate,and silicate minerals collectively influences the concentrations of Ca2+and Mg2+.The primary source of replenishment for geothermal waters is atmospheric precipitation,with the replenishment elevation ranging from 789 to 1,417 meters.Most geothermal waters exhibit δ18 O shift characteristics,indicating relatively intense water-rock interactions.The main geothermal reservoir temperature ranges from 45 ℃ to 53 ℃,and the circulation depth of geothermal water is between 947 and 2 070 meters.The proportion of cold water mixing is 55.3％to 66.5％,and the geothermal reservoir temperature before the cold water mixing is 78.05 ℃ to 102.9 ℃.The geothermal information,including reservoir temperature,sources of geothermal water replenishment,and circulation depth,in the Henan segment of the Neihuang Uplift has been explored,leading to a systematic understanding of the geothermal genesis mechanism in the area.
geothermal genesisNeihuang Uplifthydrogeochemistryisotope technologyconceptual model
万方数据
维普
