Trencianska kotlina and Ilavska kotlina basins - Remnants of an inverted Early Miocene wedge top basin (Western Carpathians, Slovakia)

摘要

The paper summarizes the latest knowledge about the Early Miocene Trencianska kotlina and Ilavska kotlina basins, Slovakia. The studied basins are located at the boundary between the Internal and External Western Carpathians and overlie the Pieniny Klippen Belt and Internal Carpathian Mesozoic nappes (Tatricum, Fatricum and Hronicum). This research is based on the results of geological mapping in the northwestern Trencianska kotlina Basin and westernmost part of the Ilavska kotlina Basin and summarizes all previous (bio)stratigraphic, sedimentological, geophysical and borehole (PB-1, HVJ-25) data. Sedimentary fill of the basins is represented by the transgressive Eggenburgian Causa and Karpatian Zavod formations. Sedimentary record is fragmentary since the Lower Miocene formations are reduced. Youngest sediments are represented by the Pliocene gravels and Quaternary fluvial and eolian deposits. Both Trencianska kotlina and Ilavska kotlina basins formerly represented one Early Miocene wedge top basin connected with nearby Vienna Basin, Blatne depression, Banovska kotlina, Hornonitrianska kotlina and Turcianska kotlina basins. The present shape of the Trencianska kotlina and Ilavska kotlina basins is a result of inversion, rotation, and backthrusting occurring since the Karpatian-Badenian with additional inversion during Pliocene-Quaternary. There are no strong arguments for interpretation of the pull-apart nature of the basins as it was considered in the past.