The Mount Sabalan district is regarded as the best place to investigate geothermal activities in northwest Iran. Since the last episode of volcanic activity in the Plio-Quaternary time, hot springs and surficial steams as conspicuous manifestation of geothermal activities have appeared around the slopes of Mount Sabalan. | Evaluation of hydrogeochemical and isotopic properties of the geothermal waters in the east of Mount Sabalan, NW Iran