Geothermal map - Expected temperatures at a depth of 5000 m

The underground geothermal conditions can be presented, irrespective of the aquifers' position, with the appropriate geothermal maps. This map represents the expected temperatures at a depth of 5000 m and is made with data from 192 boreholes. It is made on the basis of measured temperatures in accessible boreholes throughout the country. However, since the temperature field depends on the geological structure in the depths and tectonic characteristics, the course of the isotherms is a result of many influences, such as thermal conductivity of rocks, permeability and fracturing of rocks, all of which are reflected in the measured temperatures in boreholes. In this depth also a radiogenic heat production in the rocks has smaller influence, especially in magmatic and metamorphic rocks. The distribution of boreholes, which were useful for the measurement of temperature, is very uneven and different as regard the depths. Following the expected temperatures at a depth of 5000 m a stronger positive anomaly is in the northeastern part of Slovenia, from the line Maribor-Rogatec to the east. In the northeastern part of the country the anomaly is the result of the thinning of the Earth's crust and greater conductive heat flow from the Earth's mantle. Elsewhere temperatures are much lower, especially in the western mountainous parts they are lower than expected mean values for the continents.