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The biostratigraphy and paleoenvironments of the İhsaniye Formation exposed at Karaburun in northwest Turkey is described based upon the study of abundant and well-preserved foraminifera, calcareous nannofossils and palynomorphs. The studied succession is Early Oligocene in age, with calcareous nannofossil zones upper NP21 (Subzone CNO1) to lower NP23 (Subzone CNO3) and planktonic foraminifera zones O1 (~P18) and O2 (~P19) represented, and palynological assemblages suggestive of zones D13 to D14a. Based on these new data, a revised interpretation of the stratigraphic succession is presented. Deposition was controlled by a now inverted normal fault, with deposition of older stratigraphy (upper NP21 to NP22) restricted to the original hanging wall. During NP23, deposition commenced on the footwall, resulting in progressive onlap of an exposed Eocene reefal limestone (Soğucak Formation). Three primary sedimentary facies are present: marls with thin calcareous siltstones, marls with synsedimentary slumps and debris flows, and coarse pebbly sandstones. The coarse pebbly sandstones were deposited in a fan-delta/shoreface paleoenvironment and represent the initial phase of onlap during biozone NP23 onto a rocky shoreline on the footwall side of the fault. The marl-dominated facies represent deposition in outer shelf?upper bathyal environments. The succession demonstrates evidence for a near-end Eocene relative sea-level fall. Changes in the abundance of planktonic foraminifera and the onlap onto the footwall demonstrate maximum subsequent transgression within NP23. This reflects eustasy rather than Paratethyan relative sea-level. No interpretation of sea-water salinity reduction can be made for the sediments deposited during biozone NP23 in the studied sections, although this is noted in coeval sediments in parts of Paratethys (the "Solenovian Event"). Together with the open marine nature of the diverse and abundant fossil assemblages, it is suggested that deposition of the Karaburun section was strongly influenced by a connection to the global ocean, via the Çatalca Gap, as suggested in a recent study.

U radu su opisani transgresivni marinski sedimenti koji se proslojavaju s tufovima na lokalitetu Nježić na jugozapadnim obroncima Papuka. Fosilne zajednice vapnenačkog nanoplanktona, bentičkih i planktonskih foraminifara, kao i radiometrijsko datiranje minerala sanidina iz tufa ukazuju da je marinska transgresija započela ne prije 14, 8 Ma , a da najmlađi sedimenti na 100 metara debelom stupu naslaga nisu mlađi od 14, 2 Ma. Snimljeni slijed naslaga predstavlja transgresivni dio drugog badenskog, odnosno T.B. 2.4. transgresivnog ciklusa.

M20 M21

The spatial and temporal evolution of the Paratethys Sea during the Early to Middle Miocene, as well as the chronologic framework to disentangle geodynamic and climatic processes affecting the depositional environments, is still not resolved (HILGEN et al., 2012 ; de LEEUW et al., 2018 ; SANT et al., 2017 ; KOVÁČ et al., 2018). Covering almost the entire area of northern Croatia and situated southeast of the Hrvatsko Zagorje Basin (HZB ; AVANIĆ, 2012), North Croatian Basin (NCB ; PAVELIĆ & KOVAČIĆ, 2018) evolved during the Early Miocene, and belongs geo-tectonically to the south-western margin of the Pannonian Basin (PB, part of Carpathian-Pannonian Region, CPR ; HORVÁTH et al., 2015 ; BALÁZS et al., 2016). Typical syn-rift sedimentary successions of the initial basal Lower‒Middle Miocene (Ottnangian–Lower Badenian according to PAVELIĆ & KOVAČIĆ, 2018 and references therein) NCB comprise continental, alluvial and lacustrine (Southern Pannonian Basin Lake System, SPBLS sensu MANDIC et al., 2019a) sediments unconformably overlying a strongly tectonized basement. According to ĆORIĆ et al. (2009), MANDIC et al. (2012, 2019a, 2019b), MARKOVIĆ (2017) and PAVELIĆ & KOVAČIĆ (2018 and references therein), initial Miocene marine flooding of the NCB corresponds to the main Badenian (Middle Miocene) transgressive pulse of Central Paratethys, that is Middle Badenian (NN5 Zone, TB 2.4 after HOHENEGGER et al., 2014). These recent studies are based on radiometric dating (40Ar/39Ar dating) of the pyroclastic horizons (intercalated with alluvial, lacustrine and marine NCB deposits ; MANDIC et al., 2012 ; MARKOVIĆ, 2017) and integrated biostratigraphy, which constrained the age of Lower–Middle Miocene NCB deposits analyzed therein (e.g., Mts. Medvednica and Papuk localities). However, according to BRLEK et al. (2018), the exact timing of the initial Early‒Middle Miocene flooding of different parts of NCB, necessary for reconstructing Early–Middle Miocene stratigraphic evolution of the NCB (e.g., PAVELIĆ & KOVAČIĆ, 2018), is still unresolved due to: 1/ sparse and uncomprehensive integrated calcareous plankton biostratigraphic determinations of Lower–Middle Miocene NCB marine sediments which are insufficiently calibrated (together with lacustrine sediments) with high-precision geochronological studies (especially necessary in semi-enclosed Paratethys Sea ; HILGEN et al., 2012 ; SANT et al., 2017 ; KOVÁČ et al., 2018), 2/ absence of uniform biostratigraphic zonation and regional Early–Middle Miocene chronostratigraphic (and sequence stratigraphic) division of Central Paratethys (e.g., HARZHAUSER & PILLER, 2007 ; PILLER et al., 2007 ; HILGEN et al., 2012 ; HOHENEGGER et al., 2014 ; SANT et al., 2017 ; KOVÁČ et al., 2018), especially of Early/Middle Miocene boundary, as well as of Karpatian and Badenian regional stages (HOLCOVÁ et al., 2018 ; KOVÁČ et al., 2018). This prevents reliable stratigraphic correlation to be made based solely on biostratigraphic data. As well, 3/ assumption that initial transgression may be diachronous across the NCB (as it is diachronous across the southern margin of Pannonian Basin and across other Central European basins ; MANDIC et al., 2012, 2019b ; SANT et al., 2017) and/or that different parts of NCB could have been initialy flooded during different Early–Middle Miocene transgressive pulses of Central Paratethys (MANDIC et al., 2012, 2019b ; SANT et al., 2017 ; HERNITZ KUČENJAK et al., 2018 ; KOVÁČ et al., 2018). Excellent Mt. Požeška gora (Slavonian Mts. complex, Croatia) outcrop conditions (Croatian Geological Survey data) enable analysis of continuous transition from basal NCB Ottnangian–Karpatian alluvial coarse-grained deposits (“Daranovac unit”) with aeolian siltstones, through Lower Badenian SPBLS brackish-lacustrine deposits (“Košćević unit” ; HAJEK-TADESSE et al., 2009 ; MANDIC et al., 2019a) into Middle Badenian Central Paratethys marine deposits (offshore marls - “Vejalnica unit”) with intercalated pyroclastics (ŠPARICA et al., 1979, 1980 ; PAMIĆ, 1997 ; HAJEK-TADESSE et al., 2009). However, the above mentioned stratigraphic ranges (KOVAČIĆ & PAVELIĆ, 2017) are uncertain. Therefore, integrated biostratigraphic (calcareous plankton) and high-precision geochronological (EARTHTIME initiative) studies are being conducted on Mt. Požeška gora marine and pyroclastic deposits. Determination and constraint of the age (time-stratigraphic correlation), stratigraphic relationships, and time-framed palaeoenvironments of Mt. Požeška gora deposits should: 1/ provide clues for the timing of the Central Paratethys initial transgression in the NCB, 2/ add new high-resolution data necessary for reconstructing Early–Middle Miocene syn-rift stratigraphic evolution of the NCB (with potential tectono-eustatic implications), 3/ provide new high-resolution data required for calibration and synchronization of NCB and in general Central Paratethys biostratigraphic zonation scheme(s)/bioevents, and 4/ provide Central Paratethys and Pannonian Basin chronostratigraphic (and sequence stratigraphic) implications.

North Croatian Basin (NCB) is located in the Central and Eastern Croatia and represents a south-western part of the Pannonian Basin System. The formation of the NCB commenced 18 million years (Ma) ago and is still lasting today. In this period, except the period of Middle Miocene when it was a part of the Paratethys sea, NCB represented an isolated basin characterized by alluvial, fresh-water and brackish lake deposition (RÖGL, 1996 ; PAVELIĆ, 2001 ; PAVELIĆ & KOVAČIĆ, 2018). These periods were characterized by the evolution of endemic species which make the correlation of the beds from the NCB with the beds from the surrounding basins difficult (HARZHAUSER & PILLER, 2007). The most intensive period of volcanic activity was during the Karpatian and the Early and Middle Badenian. Karpatian and Early to Middle Badenian ages are marked by the numerous layers of tuff in the investigated area (PAMIĆ, 1997). Although layers of tuff represent a potential stratigraphic marker, especially in non-marine sediments they haven’t been used for this purpose in the NCB. The aim of this research is the reconstruction of the time frame of the evolution of NCB based on the 40Ar*/39Ar dating of the tuffs from different localities and different stratigraphic levels. Facies analysis and the determined fossil assemblage found in sediments of the investigated area point to freshwater, brackish and marine depositional environment. The palynomorph assemblages imply that the deposition took place in a moderate to subtropical climate. According to the results of the 40Ar*/39Ar dating on sanidine, tuffs have been dated in the range from 17 Ma to 14.4 Ma (Table 1). The fossil assemblage of foraminifera, ostracods, nannoplankton and palynomorphs shows that the tuffs older than 15.1 Ma were deposited in freshwater or brackish lake environments, while those dated as 14.8 to 14.4 Ma old were deposited in marine environments. Formation of the NCB started in Ottnangian with the deposition of coarse grained sediments, dominantly conglomerates intercalated with layers of tuffs in the Kalnik area which have been dated at 18 Ma (MANDIC et al., 2012). Alluvial environments have been gradually replaced with freshwater lake environments. This type of environments lasted up to 15 Ma ago. Layers of tuff found within freshwater lake sediments at the sites of Sjeničak and Paripovac in Banovina area, whose age is determined at approximately 16 Ma (MANDIC et al., 2012) and the tuff determined in the same area at Jovac locality with a determined age of 15.1 Ma confirm that claim. The existence of the freshwater lake environment, with possible marine influences, was also revealed at the locality of Laz on Medvednica Mt. where the age of the tuff was determined at 15.4 Ma. The layers of tuff found within the marine sediments have an age of 14.8 Ma, at the locality of Čučerje-1 on Medvednica Mt. and 14.4 Ma on the locality of Nježić in Slavonija. The mentioned results indicate that the marine transgression in the area of the North Croatian Basin took place around 15 Ma ago, while according to the previous studies (PAVELIĆ, 2001) it was supposed to have started at the beginning of the Karpatian.

Fosilna zajednica foraminifera, ostrakoda, nanoplanktona i palinomorfa pokazala je da su tufovi stariji od 15, 1 Ma taloženi u slatkovodnim ili bočatim jezerskim okolišima, a oni datirani na 14, 8 do 14, 4 Ma u marinskim okolišima. Time je marinska transgresija u Sjevernohrvatskom bazenu, ranije uglavnom smještena na početak karpata, pomaknuta na približno 15 Ma, tj. na granicu donjeg i srednjeg badena.

U radu je opisana zajednica nanoplanktona koja ukazuje na taloženje sedimenata tijekom kasnog badena, sarmata i početkom panona.

Mesozoic (Upper Cretaceous and Triassic) basement limestone lithoclasts occurring in basal conglomerates (overlain by rhodolith-bearing and maërl deposits) of the Middle Miocene transgressive deepening-upward successions of northeast Mt. Medvednica (North Croatian Basin, Central Paratethys ; BRLEK et al., 2016) show abundant Gastrochaenolites and Entobia borings (represented by an in situ rocky substrate community of bivalves and sponges, respectively), with Gastrochaenolites being the dominant ichnogenus and together with Entobia often occurring on all sides of limestone clasts. Gastrochaenolites torpedo and Gastrochaenolites lapidicus are the two most commonly recorded ichnospecies of bivalve borings (with possible occurrence of G. dijugus, G. cluniformis, and G. orbicularis). Gastrochaenolites-Entobia ichnofossil assemblage related to the Entobia subichnofacies and in turn assignable to the Trypanites Ichnofacies, is very typical of Neogene rocky shores (DE GIBERT et al., 2012). This ichnoassociation characterizes littoral rockground environments indicating wave-cut platforms and marine flooding surfaces (transgressive surfaces) with a low or null rate of sedimentation (BROMLEY & ASGAARD, 1993). Actualistic comparison was made in order to make more accurate palaeoecological and palaeoenvironmental interpretations (based on e.g., ecology of possible tracemakers, as well as recorded trace fossil assemblages, orientation, preservation, and succession of ichnocoenosis with possible cross-cutting relationships) of the basal Middle Miocene conglomerates. Modern Northern Adriatic rocky coast endoliths (Lithophaga lithophaga, Rocellaria/Gastrochaena dubia, clinoid sponges) and their bioerosion trace fossils (Gastrochaenolites torpedo, Gastrochaenolites dijugus, ? G. lapidicus, Entobia sp.) were analysed from breakwater limestone boulders of the west Istrian coast (DEVESCOVI & IVEŠA, 2008). The Badenian, regarded as Middle Miocene regional stage of the Central Paratethys, has recently been subdivided by HOHENEGGER et al. (2014) based on paleoclimatic events (e.g., MMCO and MMCT), sea-level changes and biostratigraphic data. According to ĆORIĆ et al. (2009), the initial Middle Miocene marine flooding of the North Croatian Basin corresponds to Middle Badenian transgressive pulse (NN5 Zone, TB 2.4) of the Central Paratethys (HOHENEGGER et al., 2014). The co-occurrence of calcareous nannoplankton Sphenolithus heteromorphus and Helicosphaera waltrans (with absence of Helicosphaera ampliaperta) in some marl intervals (which represent the uppermost part of the Middle Miocene trangressive deepeningupward successions on northeast Mt. Medvednica) analysed here, points to the lower part of nannoplankton Zone NN5. HOHENEGGER et al. (2014) correlated this part of NN5 with Orbulina suturalis Plankton Zone of the Middle Badenian (TB 2.4 – main Badenian transgressive pulse of the Central Paratethys), which is also supported by the recorded co-occurrence of planktonic foraminifera Orbulina suturalis and Praeorbulina glomerosa circularis. Somewhat younger age (the upper part of NN5 Zone) of some successions is suggested by the occurence of Orbulina universa, supported also by recorded nannoplankton assemblage with Reticulfenestra minuta, Coccolithus pelagicus and Helicosphaera carteri. Besides the Badenian transgressive pulse(s) of the Central Paratethys being the probable cause for the development of Mt. Medvednica transgressive successions, possible local tectonic influence must also be taken in consideration due to possible age difference and stratigraphic position of closely spaced Mt. Medvednica outcrops on the Badenian sea-level curve.

Paleogene strata in Herzegovina are exposed from Livno in the north to Metković in south, and west and east of the river Neretva. They occur in folded structures as isolated patches within Cretaceous rocks and in a hanging-wall of bauxite deposits. Their outcrops are NW-SE oriented and tectonically deformed. Their northern part is exposed in the southern slopes of the Čabulja and Velež Mountains, the eastern part along the Neretva, and the southern part in south and central Herzegovina with bauxite deposits (Hrvatović 2006, Jungwirt 2001). In Herzegovina the authors have a long experience in the study of large foraminifers, especially alveolinas and nummulites, conical foraminifers, large miliolides, planktonic foraminifera and nannoplakton (Slišković et al. 1978, Babić et al. 1985, Drobne & Šikić, 1986, Sakać et al. 1987). Research localities with a rather complete succession of beds were chosen from initiation of deposition to deepening and overlying by flysch beds. A special role was played by alveolinas that were traced from the NW part of Paleogene Adriatic carbonate platform. They appear separately in two phylogenetic lines as Alveolina histrica > Alv. septentrionalis > Alv. rakoveci, only in Cuisian (Up.Ypresian) E1 = Lower Eocene), in the northern part of the platform. The second line belongs to Alveolina levantina > Alv croatica > Alv. hottingerina from Mid. Cuisian to Low. Lutetian, in the southern part to Greece. Their assemblage is quite uniform in the whole western part of the Central Tethys. We established in selected profiles: 1. Start of sedimentation: in the north and east of Neretva in Paleocene, and in southern Herzegovina in Cuisian - E1. 2. Alveolinas from the Alv. histrica line only in the northern arc, and alveolinas of the Alv. levantina line only in the southern part. 3. Gradual passages from platform regime to flysch occurred first in the north already in E1 after Ilerdian in Cuisian time, later in the southern part in E2 in Mid. or Up. Lutetian. In view of the common paleontological, stratigraphical and facial characteristics of strata on platforms, the model of BioZ 1-5 biosedimentary zones was introduced (Drobne et al. 2009). It enables a chronological zonation of the uniform platform into distinct units, their spatial delimitation, origin and subsidence through deepening. The model was applied for SW Slovenia and NE Italy. Accordingly it can be established in Herzegovina BiosZ 1 – in the north in the POTOČANI traverse with nannoplakton proving Paleocene, Selandian-Thanetian (after Ćorić), BiosZ 2 – in the north GORANCI traverse, east of Neretva GUBERAČA, PODVELEŽJE (Paleocene and Ilerdian), followed by flysch in the Cuisian, BiosZ 3 – in the north DOBRINJ, GRABOVA Draga and east of Neretva Stolac – HRGUD and Metković – SJEKOŠE traverses (Paleocene, Ilerdian and Cuisian), following by the flysch at the end of the Cuisian and in the Lower Lutetian (Charvet 1978, Drobne et al. 1986, Trutin et al. 2000), and BiosZ 4 – in the southern part, at KADIM, POSUŠJE with surroundings and ZAMAČE traverses (Mid. Cuisian to Mid. Lutetian), carbonates, followed by the transition to flysch are of Up. Lutetian and partly Bartonian age. With these BiosZ zones the Herzegovina Paleogene can be connected to the Dalmatian region and Adriatic islands toward Istria and Slovenia, and belongs to the common Paleogene Adriatic carbonate platform (PgAdCP), marked A on the tectonic map by H. Hrvatović (cf. 2006), being exotic part of the Dinaric carbonate platform.

Paleoenvironmental analyses based on calcareous nannoplankton and foraminiferal distribution were carried out on samples from locality Bogutovo near Ugljevik. During the middle Miocene, the region was positioned on the southern margin of the Pannonian Basin and the Central Paratethys Sea. The studied section is a sedimentary succesion that is dominated by marine marls with a single limestone package near the middle. Continious ocurences of the calcareous nannoplankton zonal marker Sphenolithus heteromorphus and the absence of Helicosphaera ampliaperta in the middle and the upper part of the section allow placement in Zone NN5. The last occurence of S. heteromorphus indicates that the Zone NN5/NN6 boundary can be placed in the top portion of the studied interval. Using the standard Central Paratethys ecozones for benthic foraminifera, the analysed time interval includes two zones: the early Badenian (Moravian) upper Lagenidae Zone and the middle Badenian (Wielician) Spirorutilus carinatus Zone.

U radu je opisana biostratigrafska i litološka granica između sedimenata srednjeg i gornjeg miocena na lokalitetu Vranović kod Našica.

Pre Karst and Bosnian Flysch Unit tectonically belong to the Dinarids, spreading from Croatia in the northwest to Serbia and Montenegro in the southeast. The main part of Bosnia Flysch Unit however is placed in Bosnia and Herzegovina. This tectonic unit is sandwiched between the High Karst Unit of the External Dinaridic Platform in the south and the Dinaride Ophiolite Zone in the north. It forms an about 3000m thick stack of intensely folded rocks, comprising two formations: Ugar Fm. and Vranduk Fm. Investigations of calcareous nannofossils (Mikes et al., 2008) documented a Late Cretaceous age for the Ugar Fm. and Latest Jurassic-Early Cretaceous age for the Vranduk Fm. Sedimentation of the Flysch started during the latest Jurassic and became progressively younger in the more external parts (Schmid et al. 2008). The age of this unit is generally and traditional regarded as the Upper Cretaceous, according to sheets of Geological map (OGK, Osnovna Geološka Karta ; 1:100.000). The investigated area is situated in Western Bosnia, NE of the city of Jajce, locality Donji Bespelj (Fig. 1). During prospection for bauxite in this area, a detailed geological mapping and intensive drill campaign were performed. Stratigraphic investigation of calcareous nannoplankton was performed on 20 samples from the Donji Bespelj - Daljevac flysch section and borehole DB2. Standard methods were used for the preparation of smear slides, which were analysed under the microscope in normal and cross-polarized light at x1000 magnification. All investigated samples yielded generally well preserved calcareous nannofossils assemblages allowing stratigraphic attribution of this part of the Bosnian Flysch succession. Calcareous are abundant in this Upper Cretaceous assmblage, but are moderately preserved nannoplankton. The occurrence of Micula prinsii in the assemblage including Arkhangelskiella cymbiformis, Arkhangelskiella maastrichtiana, Eiffellithus gorkae, Micua decussata, Micula murus, Placozygus fibuliformis, Prediscosphaera cretacea etc., allows attribution to the uppermost Maastrichtian Subzone UC20d (Burnett, 1998). Accumulation of Palaeocene sediments from Danian to Thanetian was documented by the nannoplankton Zones NP1-NP9 (Martini, 1971). Nannoplankton Zone NP1 was documented by the occurrence of Biantholithus sparsus in the assemblage with high percentage of Thoracosphaera spp. The assemblage of Zone NP2 is characterised by a large amount of Coccolithus pelagicus co-occurring together with: Braarudosphaera bigelowii, Cruciplacolithus tenuis, Ericsonia subpertusa, Markalius inversus, Placozygus sigmoides etc. Nannoplankton Zones NP3-NP8 contain zone markers: Chiasmolithus danicus, Ellipsolithus macellus, Fasciculithus tympaniformis, Heliolithus kleinpellii and Heliolithus riedelii. Stratigraphicaly youngest sediments contain calcareous nannoplankton with Discoaster multiradiatus, D. lenticularis, D. delicatus and can be attributed to the NP9 (uppermost Palaeocene ; Thanetian). Beside Palaeocene sediments occurring in the High Karst Unit in North Bosnia (covering Ophiolitic Units), this is the very first documentation of sediments in this part of Dinarides.

A new and precisely defined timing, chronometric and chronostratigraphic subdivision of the Badenian (Middle Miocene, regional stage of Central Paratethys) is presented based on data from the classical Vienna and Styrian basins and the Alpine- Carpathian Foredeep using global events, mainly geomagnetic polarity reversals as correlated chronometric boundaries, climate and sea level changes in addition to isotope events and biostratigraphic data.

Open mine pit Bogutovo Selo near Ugljevik in NE Bosnia and Herzegovina is positioned at the southern margin of the Pannonian Basin System. The Oligocene lignite bearing lacustrine deposits are superposed there by Middle Miocene marine sediments. The measured section is about 60 m thick and beside marine sediments includes the uppermost part of the lake deposits, comprising clays, sands and coal seams. The marine ingression is marked by the first occurrence of the marine macrofauna in a sandy marl horizon comprising mollusk accumulations. About 20 m of gray marls with two dark clay intercalations follow, superposed by a massive, 10 m thick carbonate body. Its sedimentary structures and lower contact point to deposition by debris flow. The topmost 40 m of the logged succession include in its lower part two subordinate, 1m thick carbonate beds, followed in very top by subordinate diatomite intercalations, volcanic ash layers and fossiliferous beds with well preserved, marine fish remains. The assemblages of benthic and planktic foraminifera allow the biostratigraphic correlation of the marine transgression horizon with the Lower Badenian. Benthic foraminifera record with 84 detected species shows distinct changes in composition and diversity across the section, reflecting changes of the paleoenvironment., i.e. depositional depth, oxygen content and organic matter content. Within the first meter of the marine part of the section shallow water assemblage predominates, reflecting highly oxic environmental conditions. The most common are Asterigerinata planorbis, Elphidium rugosum, Lobatula lobatula and Ammonia viennensis. Gradually, deep water middle to outer shelf assemblage installs, showing a stable moderately oxic bottom environment. The characteristic representatives are Valvulineria complanata, Cassisidulna laevigata, Heterolepa dutemplei together with Bulimina elongata. Slightly preceding the first dark clay intercalation the environmental perturbation starts pointed out by repetitive change of diversity index, species dominance and bottom water oxygen content. Some sea level fluctuation is present with distinct shallowing peak directly above the thick carbonate body. Within following meter distance the most distinct change develops with installation of low oxic near-bottom conditions remaining stable until the section top. The benthic fauna of that latter interval is characterized by low diversity and high dominance fauna comprising oxygen depletion indicators such as Praeglobobulimina pyrula or Bolivina ssp. The benthic foraminifera assemblage allows a good correlation of the marine deposits with the Badenian regional stage. The lowermost part of the section Ugljevik comprising the lake sediments is barren of autochthonous calcareous nannoplankton. Continuous occurrences of zonal marker Sphenolithus heteromorphus and the absence of Helicosphaera ampliaperta in the middle and the upper part of the section allow stratigraphical attribution to the nannoplankton Zone NN5. 218 13th Congress RCMNS - 2nd - 6th September 2009, Naples, Italy Based on the last occurrence of S. heteromorphus, NN5/NN6 boundary can be placed about 10 m below the top of the section below the diatom bloom event. Together with blooms of small reticulofenestrids, which are characteristic in Badenian marine deposits of the Central Paratethys, nannoplankton assemblages contain also: Braarudosphaera bigelowii, Coccolithus pelagicus, Coronocyclus nitescens, Coronosphaera mediterranea, Cyclicargolithus floridanus, Helicosphaera carteri, H. walbersdorfensis, Holodiscolithus macroporus, Reticulofenestra gelida, R. pseudoumbilica, Sphenolithus moriformis and Umbilicosphaera jafari. Blooms of small reticulofenestrids and very rare or absent discoasterids in all investigated samples point to nearshore paleoenvironmental conditions. Stable isotopes of carbon and oxygen as well as the content of total organic carbon (TOC), carbonate and sulphur have been analyzed within a geochemical study on bulk sediment samples. The lake sediments at the base of the section are characterized by very low isotopic values (mean: -8.2‰ for 13C, -5.4‰ for 18O), low TOC values (mean: 0.23%), a variable carbonate content ranging from 1-35% and a sulphur content between 0.3-1.3%. The overlying marine sediments show in their lower part a mean isotopic value of -0.9‰ for both, the 13C and 18O signals. TOC values of 0.4-3.9%, carbonate content between 19-85% and a sulphur content ranging from 0.8-3.7% have been evaluated for the whole section. These preliminary results are consistent with a transgressive setting ; increases in TOC and sulphur content up-section reflect a decrease in bottom-water oxygenation favoring organic carbon preservation as a result of the deepening environment.

The Pannonian Basin System (PBS) originated during the Early Miocene as a result of extensional processes between the Alpine-Carpathian and the Dinaride Orogenic Belts. The Paratethys Sea flooded the new basins successively during the Karpatian (late Burdigalian, Early Miocene) and the Early Badenian (middle Langhian, Middle Miocene). The North Croatian Basins (NCB) occupied the south-western margin of the PBS and the Central Paratethys Sea. Their initial marine flooding has until now been dated as Karpatian in age. The transgression into the NCB invaded a lacustrine environment therein, representing the northern prolongation of the vast Dinaride Lake System extending southwards as far as the Adriatic Plate. We reinvestigate two sections from opposite margins of the NBS - from Mt. Medvednica on the west and from Mt. Požeška on the east - including corresponding lowermost marine Miocene deposits to critically examine the Karpatian datum. Our new biostratigraphic data – integrating calcareous nannoplankton, planktic and benthic foraminifera, diatom and mollusk records – have substantially revised the previous interpretation. The presence of a calcareous nannoplankton assemblage of the NN5 Zone and the planktic and benthic foraminifera of the regional Lower Lagenidae Zone now place the transgression into the main Early Badenian transgressive pulse of the Central Paratethys. Consequently, the initial marine transgression correlates accurately with the middle part of the Early Badenian, which is more than 2 m.y. younger than the previously inferred datum and at least 1 m.y. younger than the lower boundary of the Badenian and the Middle Miocene, respectively. Finally, the basal lacustrine infill of the NCB, previously dated as Ottnangian (middle Burdigalian, Early Miocene) and continuously grading into marine deposits, has to be reconsidered as Early Badenian as well.

Integrated calcareous nannoplankton/planktonic foraminifera biostratigraphy has been recently proved for a powerful tool in solving stratigraphic paradigms around the Karpatian/Badenian boundary. Therefore the re-investigation of two most representative boundary outcrops was initiated for stratigraphic re-evaluation and re-calibration of the Miocene marine flooding of the southern Pannonian Basin System.The initial marine sediments at Sokolina (Poljanska) on the Mt. Papuk contain nannoplankton assemblages characterising the NN5 Nannoplankton Zone. In contrast the underlying lacustrine to brackish limy silts and siltstones comprising very poor nannoplankton assemblages point clearly to sudden but continuous transition from fresh-water lake into a marine environment. These new results change dramatically the paleogeographic and geodynamic concept of the southern Pannonian Basin System shifting the datum of its initial marine flooding event for more than 2 m.y.

Die sarmatische (mittelmiozäne) Mikrofauna und Mikroflora aus einem Aufschluss entlang des ehemaligen Donau-Prallhanges bei Petronell (NÖ) wurde taxonomisch untersucht. Die Foraminiferen-Vergesellschaftungen sind typisch für die Anomalinoides transcarpaticus-Zone und Elphidium reginum-Zone des frühen Sarmatiums. Besonders die Anomalinoides transcarpaticus-Zone ist Aufschlussen im Wiener Becken nahezu unbekannt. Die Grenze zwischen beiden Zonen korreliert mit einem sedimentären Wechsel von sanden zu siltigen Mergeln, der als Ausdruck einer transgressiven Phase interpretiert wird. Das Fahlen von Sphenolithus heteromorphus erlaubt die Einstufung in die Discoaster exilis-Zone (NN6) der Nannoplankton-zonierung von Martini (1971). Alle Proben lieferten reiche, gut erhaltene Nannoplankton-Vergesellschaftungen mit endemischen Formen (Calcidiscus leptoporus ssp. centrovalis, Calcidiscus pataecus, Perforocalcinella fusiformis), die das sarmatische Alter belegen. Die Diatomeen-Vergesellschaftung erlaubt eine Korrelation mit der Coscinodiscus doljensis-Zone.

The dating of the flysch sediments of the coastal Dinarides is critical for considering the evolution of the Dinaric chain. The flysch of the Pazin Basin, Istria has been considered to be Late Lutetian to Late Eocene in age by many workers. The recently reported Late Oligocene age of a part of this flysch (ŠPARICA et al., 2005) is highly relevant when considering the sedimentary and tectonic evolution of the area, as well as the western Dinarides in general. The importance of the Late Oligocene dating, and the character of the succession of the area in question, which shows similarities with Middle Eocene sediments in other parts of the basin, provoked the need for a reevaluation of the dating of these specific sediments. The results presented here support the Middle Eocene age of these sediments, which is consistent with the dating proposed by previous workers, and agrees with the character of the relevant sedimentary succession.

The paper in hand is an abstract of an equally named article by the same authors, published 2006 (Roetzel, Ćorić, Galović & Rögl, 2006). In the Alpine-Carpathian Foredeep, Lower Miocene clays of the Zellerndorf Formation and intercalated diatomites of the Limberg Member occur between the villages Parisdorf, Oberdürnbach, Limberg and Niederschleinz, E to NE of Maissau (Lower Austria). These sediments show distinct features for coastal upwelling conditions along the steep southeastern scarp of the Bohemian Massif during the Ottnangian. They were deposited in a deep marine sublittoral environment. The communities of diatoms, calcareous nannoplankton and planktonic foraminifera clearly point to the influence of cold and nutrient-rich deep-water currents, typical for upwelling zones. The very high content of smectitic clay minerals in both the sediments and volcaniclastics of time equivalent strata in this area indicate prominent acidic volcanic input. Thus, besides the nutrient rich deep-water currents, the induced high silica content in the sea also boosted biogenic productivity, especially for diatoms. The diatomites show rhythmic bedding laminations which are probably cyclic. The finer and light layers with rich accumulations of well- preserved, mostly planktonic diatoms represent rapid sedimentation rates. In contrast, the thicker and darker interlayers with higher inorganic siliciclastic content and mostly fragmented siliceous plankton tests are an indication for slower sedimentation (tending to obscure annual events) and thicker bedding units. In the Limberg Member, the diatoms are the most abundant siliceous microfossils. Together with the less abundant silicoflagellates, as well as chrysomonads with archeomonad cysts and ebridians, they are the principal rock-forming components of the diatomites. The diatom assemblages show low species diversity with about 90 taxa belonging to 46 genera. The most frequent genera are Thalassionema, Chaetoceros, Coscinodiscus, Rhizosolenia, Stephanopyxis and Thalassiosira. In the Parisdorf pit, the whitish layer surfaces commonly comprise horizontally oriented, large disc-shaped Coscinodiscus tests. In the upper part of the Parisdorf profile, tests of the genera Thalassionema, Chaetoceros, Rhizosolenia, Thalassiosira and Stephanopyxis dominate. The diatom flora of the Limberg Member stratigraphically belongs to the upper part of the Lower Miocene (Ottnangian-Karpatian). The diatomites of the Limberg Member from Parisdorf lack calcareous nannoplankton. Laminated calcareous layers of the Zellerndorf Formation in the Parisdorf pit are very rich in well-preserved nannoplankton assemblages dominated by two taxa: Coccolithus pelagicus and Coronosphaera mediterranea. The accompanying assemblages consist of Coccolithus miopelagicus, Cyclicargolithus floridanus, Helicosphaera ampliaperta, H. carteri, H. euphratis, H. mediterranea, Pontosphaera multipora, Reticulofenestra bisecta, R. daviesii, R. pseudoumbilica, Sphenolithus disbelemnos and Sphenolithus moriformis. Helicosphaera ampliaperta (stratigraphic range: from upper NN2 to the NN4/NN5 boundary) is rare but present in investigated sediments from Parisdorf and Niederschleinz. Although Sphenolithus belemnos was not observed, the co- occurrence of S. disbelemnos with H. ampliaperta and H. mediterranea, as well as the absence of Sphenolithus heteromorphus, indicate the uppermost part of nannoplankton Zone NN2 and Zone NN3 (Martini, 1971). This also corresponds to the regional Ottnangian position of the succession. Within the lower part of the sequence, overlying the Limberg Member diatomites, a horizon of agglutinated Bathysiphon filiformis was observed. The foraminiferal fauna in more calcareous clays is dominated by very small planktonic species, with floods of Tenuitellinata selleyi, Tenuitellinata and Turborotalita. From the same groups, Tenuitella clemenciae, T. minutissima and Turborotalita quinqueloba occur throughout. Other common small globigerinids are Globigerina lentiana, G. ottnangiensis and G. praebulloides. The planktonic foraminiferal assemblages show high numbers of Globigerina ottnangiensis and few Globigerinoides specimens together with Globoturborotalita woodi, indicating an Early Miocene age. In the benthic assemblages, agglutinated and miliolid species are scarce. Abraded tests occur regularly. The calcareous benthic fauna consists of small species or specimens, often in small numbers but with high species diversity. The richest assemblage was observed in the marly bed. Most common are Amphimorphina haueriana, Myllostomella advena, M. recta, Fursenkoina halkyardi, Bolivina dilatata, Pseudoparrella exigua, in some samples also Melonis and Nonion. In marly sediments from Parisdorf and Niederschleinz the fauna changes to a Lenticulina-Uvigerina assemblage. For the first time in Ottnangian sediments, Uvigerina acuminata occurs frequently, together with U. cf. saprophila and U. mantaensis. The new species Nonion gudrunae Rögl was described from the Ottnangian Zellerndorf Formation in the diatomite pit Parisdorf, and the lectotype of Nonion commune (d’orbigny, 1846) was designated (Roetzel et al., 2006).

Endemical forms are restricted by changed salimity conditions.