Hydrogeological and hydrogeochemical studies of the Çanakkale Çan geothermal systems

The Çan Basin is located on the central part of the Biga Peninsula in the northwest of Turkey. Volcanics are dominant rock type in this region. Alteration zones and clay minerals are very common in these rocks. Sediments, metamorphics, magmatics and alluvium are other geological units seeing in the region. These units include common fracture zones because of tectonic activity. Thermal waters have reached to the surface via these fracture zones. There are 4 geothermal fields in the Çan Basin. The probable source of Çan Hot Spring is Şahinli Formation and Çamlıca Metamorphics. Mean surface temperature of this spring is of 44.4 celcius degrees. Karaılıca Hot Spring is come from Ezine Volcanics and discharges at three points whose the temperatures are 35.4, 40.6, 47.0 celcius degrees. Alibeyçiftliği Hot Spring is fed from Ezine Volcanics and temperature of this spring is 23 celcius degree. Bardakçılar Hot Spring has three discharge points whose mean temperatures are 46.5, 48.3 and 47.8 celcius degrees. Source of this spring is Evciler Pluton. Calcite and anhydrite minerals have precipitation trend with cooling in thermal water. Alluvium is the most productive aquifer in all geological units. Transmissibility and permeability coefficients are high of this unit. Groundwater depth changes between 0.1 and 8.3 m. According to water classification method given from the IAH, thermal waters are sodium - calcium - sulphate type, cold waters are generally calcium-magnesium-bicarbonate type and snow samples are mixed water type. Geothermometer equations were used for prediction of reservoir fluid temperatures of the geothermal systems in the region and temperature value was obtained as maximum 207 celcius degree. Deuterium, tritium and oxigene - 18 isotope analysis show that these thermal waters have meteoric origin and minimum age is 45- 50 years.