Formation and hydrogeological characteristics of the kapullu bath spring (Beypazari/Ankara)

Kapullu spring is located to the southern edge of Beypazari Granitoid pluton. Granite, granodiorite, monzonite and quartz monzonite are formed the main lithology of the Beypazari Granitoid. All these subunits have mafic magmatic microgranular enclaves ranging in size from 1 cm up to 40 cm in the composition of diorite, quartz diorite and monzodiorite. Kapullu spring run out from the monzonitic rocks of Beypazari Granitoid at southern edge of the study area on the Sakarya River. The monzonite mostly composed of K-feldspar, oligoclase, amphibole, biotite, with rare amount of quartz and pyroxene. The microscopic textural features of the monzonite around Kapullu is changing from the holocrystalline granular texture to cataclstic texture and the to the mortar texture towards the Kapullu spring in the region. The results of the structural discontinuities and the microscopically textural features of the region reveal that the Kapullu bath spring is located on the compressed normal fault at the direction of NE-SW. Kapullu bath spring has a temperature of 40.5 degreeswith the 10 l/s flow yield. The results of the determination show that Kapullu bath geothermal spring formed because of dynamic local metamorphism along a normal fault on the Sakarya River. The electrical conductivity of Kapullu bath spring is around 6500 S/cm with the Na+ and SO42- hydrochemical facies. The electrical conductivity of other cold springs is between 340-700 S/cm with the Ca2+ and HCO3 ions overpowering. The isotopic data indicate that the Kapullu bath spring has derived from deep circulation with meteoric origin fluids. The developing of the Kapullu bath spring may cause to increase the quality and the temperature of the spring