Abstract:
The Sofia Basin was formed as a result of active neotectonic movements, which led to subsidence and block differentiation of the substrate, filled with lake and river sediments. The Kazichene – Ravno Pole region is particularly interesting due to the presence of a Triassic carbonate block with anomalously high temperatures, covered by Neogene sediments (Gnilyanska Formation). The study aims to determine the boundaries, parameters, and resources of the hydrogeological systems and their geothermal characteristics, as a basis for future geophysical studies. Two main thermal aquifer horizons have been identified: Lower Neogene (40–64°C) and Middle Triassic (50.7–78.4°C, with recorded temperatures above 80°C). The relationship between them has not been fully clarified. This study forms the basis for developing a 3D geothermal model and identifying priority areas for further research.