Where is There Chance to Find Deep Prospects Below the Outer Western Carpathian Thrust Belt?

Abstract

In the period of 80 and 90th, the intensive deep drilling and seismic profiling program in the Outer Western Carpathian belt has been realized for confirming the idea about the existence and opening of new promising plays beneath some of these thin-skinned belts. Many trans-Carpathian 2D seismic transects opened discussion on the understanding of the complex structure of thrust belts and its basement. The recent development of exploration, based on the new modern play concepts, has brought new light on this problem. The new 3D and the reprocessed 2D seismic sections from Czech and Slovak part of the Western Carpathian Flysch Belt disclosed several potentially new prospects, combined with the cover of the foreland of European plate. New significant reserves of hydrocarbons may occur in subthrust autochthonous and parautochthonous series buried below the frontal zones of thin-skinned thrust belts. The study of the deepest parts of the Carpathian Flysch belt has been based on the complex geochemical, structural analyses and geophysical Data reprocessing, supplied by verification along the chosen balanced sections. Four examples of 2D seismic transects, with registration up to 9-12 seconds, that present different tectonic style of structures of Flysch Belt and its platform basement, influenced by older large-scale faults, is presented from the western, northern and eastern parts of the Outer Western Carpathians. From point of view of hydrocarbon prospection, the most important features of the seismic profiles are the anticline structures of the North European Platform (NEP) below the thrust stack of the Flysch Belt. From the west to east the Týnec-Cunín, Drietoma, Orava and Zbudza elevations can be distinguished, created by a passive margin of the European plate, in the second and third structures probably by parautochthonous blocks of the same plate.