The main two sources that contribute to the surface heat flow density value are (1) heat production within the crust due to decay of unstable isotopes of Uranium 238 (U), Thorium 232 (Th), Potassium 40 (K), and (2) heat flow density from the mantle. Heat production can be calculated using the regional radioactive U, Th and K values. In this
study radiogenic heat production values were estimated from U238, Th232 and K40 concentrations from Marmara Region. The crustal temperature distribution has been modelled by the measured values of temperature gradient wells in the region and temperature values in crust and mantle boundary were obtained. The mechanical
behavior characteristics and composition of the crust were revealed by correlating earthquake depth in region and heat modeling data.
Keywords: Radiogenic heat production, Heat flow, Earthquake focal depth, Crustal temperatures, Marmara region.