The west Lithuania is situated in the central part of the Baltic sedimentary basin. 
The Phanerozoic sediments of about 2 km thick overly the Early Precambrian basement 
of the East European Craton. In west Lithuania the basin is characterised by high 
heat flow ranging from 70 mW/m2 to more than 90 mW/m2. The inventory of the drill 
core material of the crystalline basement of more than 100 wells shows that the 
maximum heat flow is confined to the Middle Proterozoic anorogenic granitoids 
intruding the Lower Proterozoic crust. The anorgenic granitoids are characterised by 
the high production in the range of 4-19 μW/m3 against the much lower potential of 
the hosting rocks having the heat production 0.8-2.4 μW/m3. Due to the high heat 
flow anrogenic intrusions are considered as highly prospective bodies for developing 
enhanced geothermal systems in west Lithuania. The geometry of intrusions was 
reconstructed by 23/4D modelling of the gravity and magnetic fields. The 
distribution of the geotherms was modelled using 2D FE techniques seeking to obtain 
the depth of prospective temperatures. The isotherm 150oC is predicted at the depth 
of 4.2-5.0 km. The high geothermal potential is related to activity of the mantle 
processes, the high heat production of granitoids, and thermal blanketing by 
sediments. The most prospective site is related to the Zemaiciu Naumiestis intrusion 
that is as large as 30*40 km and as thick as 4 km. The interpretation of the 
potential fields indicates that it was established at the intersection of the three 
large-scale shear zones that resulted in complex geometry of the intrusion. The 
reservoir properties of granitoids have not been tested. However, the drill core 
material indicates significant variations in rock structures that may have 
considerable influence on the potential of the intrusions, ranging from massive to 
brecciated and cataclistic granitoids.

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