| Abstract |
The study area is situated west of the Pontides Tectonic Zone, at the Middle Sakarya Sections, approximately 60 km southwest of Ankara. This area is in the Central Anatolia Plains District, which is the one of the five Neotectonic Districts of Turkey (Şengör, 1980). Generally, the area around the study area is not very important for geothermal energy. In the study area there are some geothermal manifestations such as a hot springs with temperatures of 38 oC. Granitoid of Maastrichtian-Danian age is widespread in the area. This unit is unconformably overlain by the Middle Miocene Bozkır Formation which consists of conglomerates, sandstone, shales, interstratified pyroclastics, claystone, clayey limestone and gypsum beds. Alluvium of Quaternary age is the uppermost (Figure 1, Figure 2). Basic rocks in the granitoid pluton have the same age as the pluton and have signs of the cooling model, crystal-liquid fraction, and magma mingling. Some segments are graded at the granite-basic rocks contact, and some segments are sharp. Graded contacts act like faults for geothermal fluid. At the area some discharges are seen at this contact. Radioactivity in granitic areas is the most important factor for heating, which is the most important parameter for geothermal systems in studied area. After the geological and hydrogeochemical investigation of the field was performed, a geophysical investigation of field was performed. In this investigation geophysical measurements were taken by resistivity (VES) and SP methods at specified stations. However, morphology was not suitable to gather data about geothermal anomalies. According to geological evidence at the end of the investigation, a drill location was determined. According to hydrogeochemical results, we concluded that only a little more warmth from the heat of the spring (38 0C) can obtain the SiO2 (chalcedony) and Na-K-Ca geothermometer of the hot water samples gathered; reservoir rock temperatures ranging from 33 0C to 44 0C have been calculated. A well was drilled to a depth of 236 m and hot fluid (43°C) was taken out at a flow rate of about 17 l/s. |