Evolution of Late Cretaceous–Palaeogene synorogenic basins in the Pieniny Klippen Belt and adjacent zones (Western Carpathians, Slovakia): tectonic controls over a growing orogenic wedge

Ab stract: The Pieniny Klippen Belt and neigh bour ing zones of the West ern Carpathians rep re sent an an cient accretionary wedge that de vel oped dur ing the meso-Alpidic (Coniacian–Eocene) tec tonic ep och. Af ter an over view of the ex ten sive lit er a ture data, the au thors pres ent an in ter pre ta tion of the synorogenic sed i men tary re cord of these zones as be ing re lated to var i ous en vi ron ments of the fore land ba sin sys tem con sist ing of the trench-foredeep and wedge-top depositional ar eas. The pe riph eral trench-foredeep depozones mi grated from the South PenninicVahic oce anic realm to wards the Oravic con ti nen tal frag ment in an intra-Penninic po si tion, where the synorogenic de pos its were laid down with coars en ingand thick en ing-up ward trends be fore be ing overthrust by the prop a gat ing orogenic wedge tip. The de vel op ment of wedge-top, pig gy back bas ins (Gosau Supergroup) was con trolled by the dy nam ics of the un der ly ing wedge, com posed of fron tal el e ments of the Fatric and Hronic cover nappe sys tems of the Cen tral West ern Carpathians (Austroalpine units). Sev eral compressional and extensional events are doc u mented in the com plex sed i men tary and struc tural rock re cords within the wedge and re lated bas ins. The suc ces sive transgressive-regressive depositional cy cles and cor re spond ing de for ma tion stages are in ter preted in terms of a dy namic accretionary wedge that main tained the crit i cal taper only tran siently. The super criti cal taper states are re flected in re gres sion, shallowing and ero sion in the wedge-top area, while the trench was sup plied with large amounts of clastics by var i ous grav ity-flow types. On the other hand, the col lapse stages tend ing to subcritical wedge taper are in di cated by wide spread ma rine trans gres sions or in gres sions in the wedge-top area and a gen eral deep en ing of all bas ins to bathyal con di tions. Ac cord ingly, the evo lu tion of the en tire trench-foredeep and wedge-top ba sin sys tems was prin ci pally con trolled by the com plex in ter play of the re gional tec tonic evo lu tion of the Al pine-Carpathian orogenic sys tem, lo cal wedge dy nam ics and eustatic sea-level fluc tu a tions.