Hydrogeological and hydrogeochemical investigation of the bayatçik geothermal field (Afyonkarahisar)

The purpose of this study is to determine the type of the cap and aquifer rocks; origin, heat source and chemical composition of the water, circulation time underground, reservoir temperature, water-rock interaction, mineral density and also to make a conceptual hydrogeochemical model of the area. Oyuklutepe marble is the most important reservoir rock in the region. While Bayramgazi schist forms the impermeable basic unit, volcano-sedimentary unit from the miocene epoch forms the cap rocks. Originating to the north and at higher altitudes of the study area, Ömer-Gecek thermal waters follow the fault fractures, then move into the Bayatcık region and become enriched with Ca & HCO3. Thermal fluids in the study area is generally Na-Ca-HCO3-Cl type. Results of the applied geothermometer methods show that aquifer temperatures is around between ~ 82°C-106°C. Isotope analyses show that waters that have 0.47 TU, contains tritium, and these waters are 55 years or older; waters that have around 0.47 TU is a mixture of old and recent waters.