The Late Badenian shallow-water marine deposits ofthe southwestern Dacian Basin, Serbia

This study presents late Badenian (= early Serravallian) shallow-water marine environments in the Veliki Izvor and Nikoličevo areas in eastern Serbia. Biostratigraphically, the Upper Badenian Bulimina-Bolivina Zone and Ammonia/Elphidium impoverishment ecozone are documented and correlated with the M6 zone, characterized by the presence of Orbulina suturalis. The Upper Badenian coarse- to medium-grained marine clastics transgressively overlie older Cretaceous flysch, carbonates, and volcanoclastics as well as early Miocene continental deposits. Comparative sedimentological and palaeontological analyses of the two outcrops reveal different depositional environments, water level fluctuation, and redepositional processes. The Veliki Izvor area represents a shallow-marine, tidally influenced system, whereas Nikoličevo is characterized by a more proximal, fluviodeltaic setting with evidence of episodic carbonate influx. Numerous well-preserved fossils of corals, bivalves, and gastropods, along with poorly preserved foraminifera and ostracods, indicate a marginal marine, well- oxygenated environment of normal salinity. Benthic foraminiferal assemblages (dominated by Elphidium–Biasterigerina–Ammonia specimens) suggest deposition in a well-oxygenated inner to middle shelf setting. A higher proportion of euryhaline genera such as Elphidium and Ammonia points to episodic freshwater inflows into the marine environment. Rare occurrences of Bolivina and Heterolepa specimens indicate brief periods of low oxygen conditions, while the Elphidium–Biasterigerina assemblage reflects recovery phases with renewed vertical water circulation and bottom water oxygenation. Low-diversity ostracod assemblages further support the shallow marine environments. These findings contribute to a better understanding of marginal Miocene basins in southeastern Europe and highlight the complexity of shallow-water marine depositional systems.