Hydrogeochemistry of CO 2 -rich Çorak, Karakaya and Gümüşkent mineral waters in Nevşehir [CO 2 ' ce zengin Çorak, Karakaya ve Gümüşkent (Nevşehir) mineralli sularinin hidrojeokimyasi]

Çorak, Karakaya and Gümüşkent mineral springs are located in Nevşehir and its vicinity. The springs generally emerge along faults in the study area where the rocks have different hydrogeological properties due to the heterogeneity and tectonic activity. The marbles of the Bozçalda? metamorphic basement rocks form the confined aquifer of the springs. The hydrochemical facies of the springs are Na-Ca-HCO 3 of Karakaya cold springs, Ca-HCO 3 of Gümüşkent mineral springs; and Na-CI-HCO 3 of Çorak and Karakaya mineral waters, respectively. Because of the gas-mineral-water interaction, total mineralization are high in a CO 2 dominated and low temperature mineral waters. Ionic quantities of Çorak and Karakaya mineral waters are higher due to the high solubility of evaporates. Based on the environmental isotope ( 18 O, 2 H, 3 H) and water chemistry analyses, the springs are of meteoric origin. Çorak and Karakaya mineral waters might be contributed by older waters. The Karakaya cold spring is shallow circulated, while the mineral springs which have high the free CO 2 -gas are deep circulated groundwaters