Fault Structures and their significance in thermal springs distribiution in the Sabalan Area , Ardabil Province, Iran
Volcanic activity in Sabalan area came to the end in Early Pleistocene, and the Sabalan Stratovolcan complex was completed to the present morphology by eruption of three dioritic domes, through the previous caldera.
A relatively dense network of intersecting faults and lineaments is spread over the Sabalan complex. As a result, the impermeable nonreservoir rocks of monzonitic nature have changed into permeable reservoir rocks, extended throughout the area.
50 thermal springs were geographically defined and their water samples were analyzed for detailed hydrochemical studies. Geological and hydrogeological observations proved that these 50 springs are directly connected to the major and minor faults within the network in the area. Consequently, changes in quality and/or quantity of water in the main geothermal reservoir would be reflected immediately on the near local springs and thereafter throughout the Sabalan area.