THE NEOGENE EVOLUTION OF THE OUTER CARPATHIAN FLYSCH UNITS (POLAND, UKRAINE AND ROMANIA) - KINEMATICS OF A FORELAND FOLD-AND-THRUST BELT SYSTEM

Various techniques of geometric and kinematic analyses, including cros s-section balancing and forward modeling, have been applied successful ly to the outer Carpathian flysch units along regional geologic profil es crossing the belt from its undeformed foreland to the Pieniny klipp en belt (western Carpathians, Poland) or to the central east Carpathia n allochthon (eastern Carpathians, Ukraine and Romania). The amounts o f Neogene shortening as well as the mode and the location of basement consumption are discussed on the basis of balanced cross-sections comp iled along the three most representative regional traverses. In additi on, the complete kinematic evolution of complex Carpathian structures, such as the Fore-Dukla triangle zone (southeastern Poland), the Boris lav-Pokut duplexes (Ukraine) and the Marginal Folds (Romania) are desc ribed in more detail by using a forward modeling approach. Major resul ts concern the tectonic heritage of Laramian inverted structures (Meso zoic normal faults reactivated as reverse faults during the Late Creta ceous-Paleocene compression or transpression) in the development of th e Neogene outer Carpathian edifice. Pre-Eocene deformation and erosion effectively induce discontinuities in the Mid-Cretaceous blackshale d etachment horizon, and help to localize the Neogene deformations in co mplex triangle zones. The thrust sequence itself evolves alternatively in a piggyback or in an out-of-sequence mode. Clearly, the critical t aper of the outer Carpathians is preserved by a constant balance betwe en erosion and thrust reactivations in the inner part of the wedge, an d sedimentation and tectonic accretion at its front.