Hydrogeochemical and Environmental Isotopic Survey in Saraykent (Yozgat) Geothermal Field, Central Anatolia, Turkey

Abstract

Saraykent geothermal field is located in Central Anatolia (Yozgat, Turkey). The hydrogeochemical and environmental isotopic data obtained there was used in the assessment of geothermal resource potential and development. According to the extended sampling programme, it included samples of Saraykent precipitation, surface water, geothermal and cold water springs for isotope and hydrogeochemical analyses performed in 2014. In order to identify some chemical and physical properties of water samples, Electrical Conductivity (EC), pH and temperature were measured in-situ. Geothermal fluid from discharged well temperature ranged from 48.2° to 73.6°C in September 2014. The major ion analysis results of geothermal and cold water springs were evaluated by using Schoeller and Piper Diagrams. When these Diagrams assessed origin relationships of waters in the field, cold and geothermal water samples were determined to demonstrate different water type. While water types of cold water samples were classified at Ca-HCO3 and Ca-SO4 type, water types of geothermal water samples were at Na-Cl and Na-SO4 type. Reservoir temperature is calculated as about 108-132 °C from geothermometers. The geothermal waters, which is ?18O shifted from local meteoric water line, indicate the meteoric origin and deep circulation system. Tritium content has about zero in geothermal water springs samples in Saraykent, which suggest that the circulation time is more than 60 years. This study was supported by Scientific Research Projects Coordination Unit in Hacettepe University (H.U. BAP).