Distribution Characteristics And Genesis Of Strontium-containing Mineral Water In Tailai Basin

Strontium is an essential trace element of the human body.With the improvement of people living standards in recent decades,the development and utilization of Sr-rich groundwater resources has widely been concerned.The Tailai basin is one of the known hydrogeological units hosting strontium groundwater.Study on the genesis and distribution of strontium groundwater in the Tailai Basin can provide direction for investigation and development of strontium groundwater in the future.On the basis of the division of different water-bearing rock groups and sampling of Karst water,fissure water,porosity water and surface water in the Tailai basin,the hydrogeochemical characteristics and the evolution of strontium groundwater were investigated,which has of theoretical and practical significance.The main findings are shown as follows.?1?The four types of water are characterized by calcium-rich,magnesium-rich,low-sodium,low-potassium and weak alkaline,with the main hydrochemical type of HCO₃·SO₄-Ca·Mg.The distribution types of major anions were evolved from HCO₃,HCO₃·SO₄,SO₄·HCO₃ to SO₄ from south to north on the south bank of Mouwen river,while from HCO₃·SO₄,SO₄·HCO₃,HCO₃·Cl,HCO₃·NO₃ to Cl on the north bank of Muwen river.Since 1970s,the hydrochemical types were gradually evolved from HCO₃-Ca to HCO₃·SO₄-Ca.?2?Water chemistry was mainly controlled by rock weathering and evaporation and concentration.The relationship between c(Mg²⁺)/c?Na⁺?and c(Ca²⁺)/c?Na⁺?indicated that groundwater were mainly controlled by the weathering of carbonate rocks,which was confirmed by the positive correlation between concentrations of Sr²⁺and Ca²⁺,Mg²⁺and HCO₃^-.?3?Concentration of Sr²⁺was the highest in karst water,the lowest in fissure water and surface water,and between the two in pore water.The low concentrations of Sr²⁺in fissure water and surface water were due to the low contents of calcareous mineral dissolution in aquifers.In the process of groundwater run off,carbonate mineral dissolution occurs in karst aquifers,resulting in relatively high concentrations of Sr²⁺.However,pore water Sr²⁺was controlled by both surface water and karst water.?4?Stable isotopes of hydrogen and oxygen showed that groundwater were also affected by evaporation and concentration.The effect of evaporation and concentration on fissure water was the least,while the highest on surface water.Evaporation and concentration of karst water and pore water affected the dissolution and precipitation of carbonate minerals and further controlled concentrations of Sr²⁺in groundwater.The Sr²⁺concentrations in surface water,pore water and karst water were affected by evaporation and concentration,while in fissure water was less affected.