Аңдатпа
The Kizildere thermal waters are located in the northern part of the Büyük Menderes rift zone. The Paleozoic metamorphic rocks form the basement of the studied area and are discordantly overlain by Pliocene clastic sediments. The thermal waters are associated with NE-SW- and NW-SE- oriented faults, representing a compressional event that followed extensional formation of the rift zone. The hydrothermal alteration includes phyllic, argillic, silicic, hematitized, and carbonatized alteration zones. Precambrian to Cambrian metamorphic and Pliocene sedimentary rocks are distinguished from one another by enrichment patterns for Hg, Sb, As, Tl, Ag, and Au, and depletion patterns for alkaline and alkaline-earth elements in connection with degree of hydrothermal alteration. The thermal waters have surface temperatures of up to 100°C and reservoir temperatures from 148 to 198°C in the Sazak formation and from 200 to 212°C in the Igdecik formation. Hydrogeochemically, Kizildere thermal waters are of the Na-HCO3-(SO4) type. Metalloids of As and Sb and some trace elements (e.g., B and F, indicating high-temperature water-rock interaction), are found in high concentrations. Isotopic data reveal that Kizildere thermal waters do not contain measurable 3H. Conversely, some nearby thermal springs with temperatures of up to 88°C contain atmospheric and anthropogenic 3H (up to 6.5 TU). Therefore, there is evidence for a mixing process between the fresh groundwater and deep thermal water. The Kizildere thermal waters are of meteoric origin. Stable isotope values of σD and σ18O show that the mixed groundwater-thermal water systems lie along the meteoric water line, whereas high-temperature, deep groundwater systems deviate from the meteoric water line in showing a water-rock interaction at high-temperature conditions. These data agree well with the results of hydrogeochemical analyses indicating intensive water-rock interaction and reactions with silicates. Due to the deep circulation, the water is heated by recent subvolcanic activity. Overprinting by reactions with crystalline rocks was intensified by outgassing of magmatic CO2 and H2S, proven by isotope analyses of σ13C, σ34S, and σ11B. Although intense geochemical near-surface reactions occur, the geochemical features of high-temperature, water-rock interaction dominate the chemical and isotopic characteristics of the studied waters.