Calcareous nannofossil age constraints on Miocene flysch sedimentation in the Outer Dinarides (Slovenia, Croatia, Bosnia-Herzegovina and Montenegro)

Abstract

AbstractFlysch deposits are associated with the Outer Dinaride nappe front. They overlie Eocene platform carbonate to bathyal marl successions that subsequently cover Cretaceous platform carbonates of Apulia and the Dinaride nappes. Planktonic foraminifer biostratigraphy indicates Eocene age of flysch sedimentation. New calcareous nannofossil data reveal that several assemblages are present; besides the dominant Mid-Eocene species, Cretaceous, Paleocene, Oligocene and Miocene taxa were also identified throughout the entire flysch belt. Widespread occurrence of nannofossil species of zone NN4-6 indicates that flysch deposition lasted up to at least the Mid-Miocene. Ubiquitous occurrence of various pre-Miocene taxa demonstrates that extensive, possibly submarine, sediment recycling has occurred in the Cenozoic. As flysch remnants are typically sandwiched between thrust sheets, these new stratigraphic ages give a lower bracket on deformation age of the coastal range. The data provide a link between Cretaceous compression in the Bosnian Flysch and recent deformation in the Adriatic offshore area.