In the region of Mount Kerkini (Belasitsa mountain), the most common rocks are gneiss and migmatitis in a mixture of shale, gneiss, quartz etc. In the area there are thermal springs and geothermic underground currents in the basin of Serres.
In the area of Irakleia-Lithotopos a new geothermic field has been discovered in depth of 220-450 m with low salinity waters and high temperatures (>60ο C).