Hydrocarbon Plays of the Carpathian Foreland Plate (S Poland) - New Concepts Based from Reinterpreted Seismic Data
Carpathian thrust belt is a classical petroleum province, where first commercial discoveries of hydrocarbons took place. Jurassic to Miocene shortening events led to considerable displacement and overthrusting of the Outer Carpathian thrust sheets towards the north, above the foreland plate. Due to very complex Phanerozoic history of this area, structure and stratigraphy of this plate is highly diversified. Carboniferous and Permian disintegration of the Hercynian Europe followed by Mesozoic extension led to development of the Tethyan rift system with its important element Polish Basin. It extended at least as far to the south as the present-day Carpathian thrust front. During Late Cretaceous to Palaeogene times Mid-Polish Trough was inverted and uplifted. Inversion led to significant uplift and partial or total erosion of the Mesozoic sedimentary cover. Recently completed reinterpretation of good quality seismic data from southern Poland allowed to formulate new hypotheses related to potential new plays within the foreland plate of the Carpathian orogenic belt. First type of play is related to the sedimentary infill of deep paleovalleys present beneath the frontal part of the orogenic belt. These paleovalleys have been eroded after inversion of the Permo-Mesozoic Polish Basin, located to the north, and served as conduits for sediments being transported towards the south, into the Carpathian basins. Erosion generally followed NW-SE trending basement fault zones, that have been reinterpreted as normal (often listric) fault zones, rooted within the Palaeozoic or even Precambrian basement. Presently, they area filled by up to several hundreds of sediments, and sealed at the top by the Miocene foredeep evaporites. Potential traps include pinch-out zones along the scarps, and axial coarse siliciclastics, Miocene evaporites might provide additional seal. Another type of new plays could be related to the Upper Jurassic (Oxfordian) carbonate build-ups, recently discovered on reinterpreted seismic data from the axial part of the Nida Trough (i.e. southern segment of the Permo-Mesozoic Polish Basin). Such build-ups are related to commercial accumulations of hydrocarbons slightly further to the south, between Krakow and Tarnow. Additionally, within the marginal Nida Trough oil accumulations are known from combined Upper Jurassic - Cenomanian reservoir. Newly discovered structures within this oil and gas prone basin might provide attractive future exploration targets.
AAPG Search and Discovery Article #90090©2009 AAPG Annual Convention and Exhibition, Denver, Colorado, June 7-10, 2009