Budowa geologiczna obszaru południowobałtyckiego (bez kenozoiku)
Abstract
GEOLOGY OF THE SOUTHERN BALTIC REGION (WITHOUT CENOZOIC)
Summary
New sejsmic and wells carried on by "Petrobaltic" in the South Baltic Sea as well as by both State Geological Institute and Oil-Gas Enterprise on shore in the eighties resulted in data processing recognition of subsurface geology of relevant areas. The South Baltic is located on the border zone of both East European and Central European Platforms which differ in paleotectonic evolution during Paleozoic and Mesosoic. On the East European Platform prevail Lower Paleozoic sediments among which the Silurian reach up to 3000 m. Considerable areas lacked Upper Paleozoic rocks removed by epigenetic erosion. They are preserved only in the eastern part of the South Baltic Sea as well as in the Soviet Baltic Republics, excluding Permian (mainly Zechstein) sediments occurrenced along near coast offshore belt. Mesosoic cover is severly reduced, the most common are Upper Cretaceous sediments. The present tectonic framework of the Baltic Syneclise between Baltic Shield and Mazury - Byelorusia Massifis due to Caledonian and Varisscian deformation. On the southern slope of this structure the younger, Peribaltic Syneclise filled up by Zechstein - Triassic sediments can be distinguish. On the western, lower part of the Platform, the systems of NW - SE strike-slip and thrust faults were imposed which consist the Teisseyre-Tornquist and Teisseyre-Sorgenfrei Zones. These systems foundated at Carboniferous were most active during Jurassic and Cretaceous as result of the tension in Tethys realm. On the Central European Epicaledonian Platform the strike - slip orogen of Pomerania terran has been identified. This terran consists of Ordovicien – Lower Silurian sediments (shales and mudstones with few intercalations of pyroclastics) up to few thousands meter thick folded during the Taconian tectonic polyphase. They are overlayed by Devonian - Carboniferous rocks of variable thickness. Their framework has got block pattern during Varisscian tectonic epoch. The volcanic formation of Lower Permian up to 800 m thick covers large parts of both Western Pomerania and The South Baltic Sea areas. Sedimentary Rotliegendes varies from few up to 600 m and wedges north-ward. Zechstein consists of ewaporites (salt, anhidrites, few layers of limestone) locally deformed by salt tectonics into pillow structures up to 1800 m thick. The thickness of Mesosoic sediments is larger then on East European Platform, it reaches up to few thousands meter in the Central Polish Aulacogen. The present structural framework of the Mesosoic cover in the Epicaledonian Platform was formed by post Cretaceous inversion due to compression of the Tethys geosyncline.
Summary
New sejsmic and wells carried on by "Petrobaltic" in the South Baltic Sea as well as by both State Geological Institute and Oil-Gas Enterprise on shore in the eighties resulted in data processing recognition of subsurface geology of relevant areas. The South Baltic is located on the border zone of both East European and Central European Platforms which differ in paleotectonic evolution during Paleozoic and Mesosoic. On the East European Platform prevail Lower Paleozoic sediments among which the Silurian reach up to 3000 m. Considerable areas lacked Upper Paleozoic rocks removed by epigenetic erosion. They are preserved only in the eastern part of the South Baltic Sea as well as in the Soviet Baltic Republics, excluding Permian (mainly Zechstein) sediments occurrenced along near coast offshore belt. Mesosoic cover is severly reduced, the most common are Upper Cretaceous sediments. The present tectonic framework of the Baltic Syneclise between Baltic Shield and Mazury - Byelorusia Massifis due to Caledonian and Varisscian deformation. On the southern slope of this structure the younger, Peribaltic Syneclise filled up by Zechstein - Triassic sediments can be distinguish. On the western, lower part of the Platform, the systems of NW - SE strike-slip and thrust faults were imposed which consist the Teisseyre-Tornquist and Teisseyre-Sorgenfrei Zones. These systems foundated at Carboniferous were most active during Jurassic and Cretaceous as result of the tension in Tethys realm. On the Central European Epicaledonian Platform the strike - slip orogen of Pomerania terran has been identified. This terran consists of Ordovicien – Lower Silurian sediments (shales and mudstones with few intercalations of pyroclastics) up to few thousands meter thick folded during the Taconian tectonic polyphase. They are overlayed by Devonian - Carboniferous rocks of variable thickness. Their framework has got block pattern during Varisscian tectonic epoch. The volcanic formation of Lower Permian up to 800 m thick covers large parts of both Western Pomerania and The South Baltic Sea areas. Sedimentary Rotliegendes varies from few up to 600 m and wedges north-ward. Zechstein consists of ewaporites (salt, anhidrites, few layers of limestone) locally deformed by salt tectonics into pillow structures up to 1800 m thick. The thickness of Mesosoic sediments is larger then on East European Platform, it reaches up to few thousands meter in the Central Polish Aulacogen. The present structural framework of the Mesosoic cover in the Epicaledonian Platform was formed by post Cretaceous inversion due to compression of the Tethys geosyncline.