Kuzey Anadolu Fay Zonu’nda Traverten Çökeliminde Sıcak Su Kaynağı Olarak Görev Yapan Bir Açılma çatlağı: Reşadiye Çatlak Sırtı

* Correspondence / Yazışma: mesci@cumhuriyet.edu.tr Abstract: The Reşadiye (Tokat) geothermal field is located in the northern part of the right-lateral North Anatolian Fault Zone. Geothermal waters at temperatures between 48-52°C from this geothermal field are currently used mostly in hotels, pools and bathrooms and provide significant tourism potential for the region. The area where the geothermal sites are located includes a ~NW-SE trending fissure-ridge type travertine with a length of about 600 meters. Approximately 500 meters south of the geothermal field and parallel to the Kelkit River, the active segment of the North Anatolian Fault Zone comprises the Kelkit Valley fault segment extending N72°W. The average strike direction of Reşadiye fissure-ridge type travertine is around N33°W. There is an angle of 39° between the master trend of NAFZ and the direction of the Reşadiye fissure-ridge travertine. This 39° angle between the extensional cracks in the fissure-ridge travertine and the NAFZ is compatible with extensional fractures developing in wellformed strike-slip faults at an angle of ~45° with the master fault. U/Th determination of two samples from banded travertines from the travertine deposits yielded ages of 7,563 and 12,529 years. Combined with other evidence, the samples indicate an opening rate of 0.093 mm/year for the Reşadiye geothermal travertine field.