Investigation of hydrogeochemical properties of the hüda (Afyon-sandıklı) geothermal systems, SW Turkey

Abstract

Sandi{dotless}kli{dotless}-Hüdai geothermal field is one of the geothermal systems in Afyon and environ, located approx imately 40 km southwest of Afyon. The study area consists of volcanic, sedimentary and metamorphi rocks. Kestel greenschist formation of Paleozoic age forms the basement rock in the area while quartzit which is a member of the Kestel greenschist formation serves as the reservoir rock of Sandi{dotless}kli{dotless}-Hüda geothermal system. Geothermal waters from the study area are classified as Na-SO4-HCO3 type waters The waters plot along SO4-HCO3 end of the Cl-SO4-HCO3 triangle diagram suggesting same origin for the geothermal waters. δ18O and δD isotope ratios of the Sandi{dotless}kli{dotless} waters plot along the continenta meteoric water line, indicating meteoric waters that were unaffected by evaporation. The tritium value imply that the fluids were deep circulating and recharged from older waters. Furthermore, oversatura tion of the geothermal fluids with quartz confirms these findings showing long time residence of thes groundwaters. © Indian Academy of Sciences.