POLYSTAGE DEVELOPMENT OF NW-SE FAULTS AT THE EASTERN MARGIN OF THE WESTERN CARPATHIAN INTERNIDES

Abstract

NW-SE faults has plaged a decisive role in the Alpine development of the eastern margin of the Wes-tern Carpathian Internides. Both the space position of rock sequences and morphostructural pattern of the Gemeric and Veporic units of the area are principally controlled by their network. One of the essential Western Carpathian discontinuities of the region - the Margecany shear zone, i.e. the boundary between the Gemeric and Veporic units belongs to this fault set. Three following activity stages have been recognized within the Alpine development of the NW-SE faults: (i) - the Cretaceous stage, (ii) - the Neogene stage, (iii) - the Quarternary stage. Within the Cretaceous stage two development phases of the fault set activity has been verified. The Early Cretaceous - the compressional semi-ductile one, is connected with overall the north-vergent crustal reduction of the Western Carpathian Internides. The Late Cretaceous - the extensional stage exemplified by a postkinematic recrystalization of the previous tectonites is bound to the ongoing upheaval of the Western Car-pathian Veporic dome. The Neogene fault set activity iniciated likely by the eastern escape of the Western Carpathians is ma-inly typical by strike - slip motion of reactivated and/or newly created NW-SE fault structures. The Quarternary - up to the recent activity of the faults includes predominantly vertical motions.