The geothermal waters in Kursunlu and environs within the continental rift zone of the Gediz in the Menderes Massif can be considered as Na-HCO3 type waters. In these waters, we describe Na+K>Ca> Mg as dominant cations and HCO3>Cl>SO4 as dominant cations. The results of geochemical thermometers (quartz, Na-K and Na-K-Ca) show reservoir temperatures 120 degrees C in Camurlu and 148-205 degrees C which correspond with calculations based on SiO2 versus enthalpy mixing model and enthalpy versus Cl mixing model of the geothermal waters in Kursunlu and Camurlu. The mixing ratio of geothermal waters with ground waters can be calculated due to indicators such as Cl-, B, Li, and temperatures; there is a mixing ratio of 42,5 percent geothermal waters and 57,5 percent groundwaters in Camurlu. In Kursunlu, we have calculated a mixing ratio of 83 percent geothermal waters and 17 percent groundwaters. (C) 2017 The Authors. Published by Elsevier B.V.