Regional and local phenomena influencing the thermal state in the Flysch belt of the northeastern part of Slovakia

Abstract

The locality of the northeastern most part of Slovakian Flysch belt belongs
to interesting areas in terms of the interpretation of geothermal conditions in mutual
relation with the lithosphere structure and their tectonic development. The evaluation
of the geothermal energy sources parameters of this locality is likewise worthwhile. The
region under study has the centre in position of the borehole Zboj ZB-1 and spreads out
Slovakia also in Poland and Ukraine.
Our contribution provides the analyses of existing geothermal data enhanced by the
construction of temperature field models corresponding to the global and local aspects that
influence the temperature and heat flow density distributions. The analyses are related to
the structures and effects of separate phenomena along as well as across the Carpathian
arc. The model calculations were carried out both by analytical and numerical methods
of solving the heat transfer equations including their steady state forms and transient
cases too.
Besides the regional trend of thermal activity decrease in direction from East-Slovakian
Basin to the outer Carpathian units the combined local influences are applied: subsurface
thermophysical parameters of rock complexes distributions, non-stationary sources from
supposed subvolcanic bodies in close surroundings of borehole Zboj ZB-1, and the effects
of the hydrological factors. Considering the observed higher thermal activity in arched
zone along the Carpathian structures we discussed the thermal effects of rock complexes
supposed as a source of regional Carpathian Conductivity Anomaly and the transfer of
heat from East-Slovakian Basin to Outer Carpathian Flysch units. The analysis and themodelling results suggest that the mentioned activity is caused by the influences of source
type phenomena mainly related to deep fault systems at the margin of the European
Platform.