THE EFFECT OF EVAPORITIC FORMATIONS ON THE QUALITY OF KARST WATER

Although a great proportion of geological formations surrounding Sarvestan plain are karstified carbonatic units, the quality of ground water is unexpectedly poor. The results of chemical analyses of 52 operational wells in Sarvestan plain indicate that Sarvestan aquifer can be chemically divided into three sulphate, carbonate and chloride regions. In order to determine the sources of the dissolved constituents in the three main types of groundwater, a chemical mass balance approach is adopted. The results reveal a close relation between the dissolved constituents and the corresponding geological formations of the drainage basin. The anomalous Mg content of groundwater can be used as an indicator for the intrusion of Maharlu lake water into the aquifer.