PALAIOS, 2019, v. 34, 1–25 Research Article DOI: http://dx.doi.org/10.2110/palo.2018.052 AGE AND MODE OF THE MIDDLE MIOCENE MARINE FLOODING OF THE PANNONIAN BASIN— CONSTRAINTS FROM CENTRAL SERBIA OLEG MANDIC, 1 LJUPKO RUNDIC ´ , 2 STJEPAN C ´ ORIC ´ , 3 ÐURÐICA PEZELJ, 4 D ¨ ORTE THEOBALT, 1 KARIN SANT, 5 AND WOUT KRIJGSMAN 5 1 Geological-Paleontological Department, Natural History Museum Vienna, Burgring 7, 1010 Wien, Austria 2 Department of Regional Geology, Faculty of Mining and Geology, University of Belgrade, Kameniˇ cka 6, 11000 Belgrade, Serbia 3 Geological Survey of Austria, Neulingg. 38, 1030 Wien, Austria 4 Department of Geology and Paleontology, Faculty of Science, University of Zagreb, Horvatovac 102a, 10000 Zagreb, Croatia 5 Paleomagnetic Laboratory Fort Hoofddijk, Department of Earth Sciences, Utrecht University, Budapestlaan 17, 3584 CD, Utrecht, The Netherlands email: oleg.mandic@nhm-wien.ac.at ABSTRACT: The timing and mode of the marine flooding of the southern margin of the Pannonian basin in SE Europe is still a matter of debate. In central Serbia, integrated bio-magnetostratigraphic data and quantified high-resolution records are completely missing. Here, we provide paleoenvironmental and paleoecological constraints from the Slanci section located near Belgrade that has an excellent preservation of micro-fauna and flora, i.e., planktonic and benthic foraminifera and calcareous nannoplankton. We integrate their quantified records with sedimentological, natural gamma radioactivity and magnetic susceptibility logs and include the non-quantified records of mollusks, corals, and ostracods to reconstruct the regional depositional history. The section shows upper bathyal to outer shelf depositional settings and alternating nutrient bottom conditions. The shallowing upwards trend marked by increasing terrestrial input, attributes it to the early Highstand Systems Tract of the first marine third order sequence in this part of the Pannonian Basin. We infer that the marine flooding in central Serbia took place at an age of ~ 14 Ma, slightly predating the Langhian/Serravallian boundary (13.82 Ma) and the Badenian Salinity Crisis (~ 13.8–13.4 Ma) in the Central Paratethys. Our results support an eastwards directed, tectonically forced, flooding of the southern Pannonian Basin. This major paleoenvironmental turnover was forced by syn-rift tectonics in the Pannonian Basin system, which started in the late early Miocene in the Styrian Basin (SE Austria) and ended more than 3 Myr later in the late middle Miocene in the Morava depression (E Serbia). INTRODUCTION The Dinarides-Carpathian-Tisza junction area in the Southern Panno- nian Basin (SPB; SE Europe) contains a (~ 20 Myr) long Oligo–Miocene record of terrestrial sedimentation (Schmid et al. 2008; Mandic et al. 2012; De Leeuw et al. 2012; Kova ´ˇ c et al. 2016, 2017b). In the early Miocene, post-orogenic extension initiated a large-scale subsidence, installing marine depositional environments (Matenco and Radivojevi´ c 2012; Rundi´ c et al 2013b). The marine flooding of the SPB marked the southwards extension of the Paratethys, an early Oligocene to Pliocene giant epicontinental sea settled between the North Alpine foreland and the Central Asian plain (Popov et al. 2004). The age and mode of that major environmental turnover is still a matter of debate (e.g., Sant et al. 2017; Kova ´ˇ c et al. 2017a, 2018). In particular, the age estimates for the SPB flooding event vary with ~ 2 Myr, ranging between 17 and 15 Ma (Hajek- Tadesse et al. 2009; C ´ ori´ c et al. 2009; Grizelj et al. 2017; Premec Fu´ cek et al. 2017; Paveli´ c and Kovaˇ ci´ c 2018: Sant et al. 2018). A recent review of the middle Miocene marine records of the Central Paratethys pinpointed tectonics as a major controlling factor of the spatial distribution of the flooding of the Pannonian Basin System (Sant et al. 2017). The present study contributes to this discussion by introducing new data from the stratigraphically underexplored area of central Serbia. We conducted an integrated bio-magnetostratigraphic research of the marine transgression in the Slanci section (Fig. 1A–1D), the most complete surface outcrop in Serbia (Schwarzhans et al. 2015). The Slanci sediments are deposited in open marine settings and show excellent preservation of microfossil assemblages essential for biostratigraphic correlations and precise reconstruction of paleoenvironmental settings. We present quantified records of calcareous nannoplankton, planktonic and benthic foraminifera to elucidate the marine flooding of long-lived continental environments in central Serbia. Furthermore, we integrate these records with sedimentological, magnetostratigraphic, natural gamma radiation (NGR), magnetic susceptibility (MS), and non-quantified mollusk, coral and ostracod data to provide an accurate stratigraphic and paleoenvironmental reconstruction. These integrated data allow the correlation with coeval successions from the Paratethys and Mediterranean and will help to evaluate the driving forces behind the regional paleoenvironmental and paleogeographic changes corresponding to the flooding in the southern margin of the Pannonian Basin. GEOLOGICAL SETTING Southern Pannonian Basin and the Paratethys The Slanci section (Belgrade area, Serbia, SE Europe) is located on the southeastern margin of the Pannonian Basin, which is a large-scale back- arc passive-rift basin settled between the Carpathian, Alpine and Dinarides fold and thrust belts (Fig. 1B). Its tectonic origin, forced by the extensional disintegration of orogenic terrains, dates back to the early Miocene (~ 18 Ma; Mandic et al. 2012; Horvath et al. 2015; Kova ´ˇ c et al. 2017b; Luka ´cs et Allen Press, Inc.  18 January 2019  3:11 pm Page 1 //titan/Production/p/palo/live_jobs/palo-34/palo-34-01/palo-34-01-06/layouts/palo-34-01-06.3d Published Online: Month 2019 Copyright Ó 2019, SEPM (Society for Sedimentary Geology) 0883-1351/19/034-000