| Abstract |
The LodzTrough is one of the Laramian structures parallel to the Trans - European Suture Zone (TESZ) of the Alpine foreland developed during the epivariscan stage of the development of the West - European Palaeozoic Platform. Geothermal waters with temperatures between 200 C to 1000 C occur in sandstones and carbonates of the Mesozoic and Permian. Geothermal waters with temperatures of 60oC and efficiencies of 65 - 300 m3/h from Lower Cretaceous sandstones have been exploited by geothermal heating plants in UniejÛw (the ?Ûd? Trough) and MszczonÛw (The Warsaw Trough) since 2002. However, the most favourable geothermal parameters have been found in Lower Jurassic sandstones. Perspective resources of geothermal water with temperatures exceeding 100oC occur in limestones of the Middle Triassic at depths of 3000 - 5000 m, and could be utilized by a geothermal heating plant of 20 Mw capacity. Geothermal waters also occur in limestones and dolomites of the Upper Permian at the Lodz Trough flanks. Surficial heat flow increases from 50 to 90 W/m2 in the northern part of the Lodz Trough. In author's opinion, suitable geothermal conditions in theLodzTrough are related to geological development during pre-inversion and inversion stages. In the deep basement at the eastern side of the trough, global geotectonic units, the East European and the West European Platforms, adjoin and the Moho is lowered to 50 km. During the pre - inversion stage, the development of the Mid - Polish Trough on the Caledonian and Variscan basements and sedimentation of the Permian and Cretaceous deposits took place. Subsidence and sedimentation in a marine basin caused lowering of the Moho with subsequently occurrence of halokinetical processes as well as a temperature raise in the Permian and Mesozoic. Transformation of the Mid - Polish Trough into the Mid - Polish Swell and adjoined troughs caused suitable hydrogeological and structural conditions. |