Sulphate forming from groundwater in eastern Weibei karst area, Shaanxi Province

A composition of isotope and chemical data of the groundwater in the eastern Weibei karst area indicates that the sulfate in the groundwater of study area mainly form from marine sulphate dissolves. Secondly the age-old deposit salt water is interfused into the groundwater from the south. The higher salinity in groundwater is resulted from the dissolving action.