Groundwater Hydrogeochemistry And Environmental Isotope Characteristics In Xinji Mining Area

In order to verify the composition and evolution characteristics of groundwater ions in the main water-filled aquifers in the Xinji mining area,a total of 193 water samples including secondary water,sandstone water,too-grey water and austria-grey water in the study area were collected and collected to test and analyze conventional ion and Isotope data,using multivariate statistics,correlation analysis,ion ratio coefficient and saturation index,to explore the characteristics and causes of groundwater hydrochemistry at different levels in the study area,analyze the main factors affecting the evolution of groundwater hydrochemistry in the study area,and reveal the impact The main hydrogeochemical effects of the law of dissolved inorganic carbon,sulfate and chlorine isotope in groundwater,thereby analyzing the evolution of groundwater hydrochemistry,the following main research results have been achieved:?1?The general content of HCO₃^-in water chemistry types is relatively high.The main types of water chemistry of the second type include HCO₃-Ca type and HCO₃-Na type.The coal type water chemistry type is single,and the water chemistry type is mainly Cl-Na type.The chemical types of grey water are mainly Cl-Na type,HCO₃-Na type,and the HCO₃^-content in Taihui aquifer is higher than other aquifers,which may be affected by the leaching effect of rock mineral components;the main cation composition in Austrian grey water is Na+,The anions are mainly HCO₃^-and Cl^-,and the type of water chemistry is similar to that of gray water.?2?The groundwater leaching effect is obvious,showing relatively good runoff conditions.The main water chemistry in the second water cut is carbonate dissolution,and the water-rock effect is strong;HCO₃^-and Cl^-may be from the same source in too-grey water,and the dissolution of sulfate rock is less,mainly salt rock dissolution and carbonation Dissolution of salt rock minerals;SO₄^2-and Cl^-in Austrian lime water may come from the same source,and carbonate rock dissolution is less,mainly dissolution and sulfate rock mineral dissolution.Groundwater calcite and dolomite in the study area are non-reactive minerals,showing a precipitation trend,and carbonate rocks do not become the main components of groundwater in the mining area.Calcite is the main rock-forming mineral in Taihui,and dissolution occurs under the erosion of groundwater flow.?3?Groundwater recharge in the study area includes not only atmospheric precipitation and surface water,but also ancient leaching-infiltration water formed under paleoclimate conditions.Some water sample points clearly deviated from the Chinese atmospheric precipitation line,and?¹⁸O drift occurred.The dissolution of a large number of carbonate rocks is strong during the secondary water cycle.Chlorine comes from rock filtration and is also affected by surface water mixing;the main source of carbonate in coal-based water is organic matter in coal-based formations,and sulfate Higher,?³⁴S_SO4O4 value and?¹⁸O_SO4O4 value indicate the occurrence of bacterial sulfate reduction;silicate minerals with low ⁸⁷Sr/⁸⁶Sr value in coal series water contain chlorine with high?³⁷Cl value,which is gradually accounted for with the filtration of rocks Dominant position;carbonate minerals in Taihui water are relatively abundant,and carbonate rock dissolution is weak;?¹⁸O in carbonate dissolved in Austrian grey water changes smoothly with D,from sandstone water to Taihui water,as the coal seam decreases,DIC The proportion of CO₂ derived from soil decreases,and the proportion of carbon derived from carbonate rocks increases.In shallow groundwater,the ⁸⁷Sr/⁸⁶Sr value is gradually unified due to the mixing of deeper ancient water.