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The formations underlying the Neogene infill of the Vienna Basin are still poorly documented. Until now correlation of subsurface lithostratigraphic units with those of the Rhenodanubian nappe system and the Magura nappe system, outcropping at the basin margins, has been based on extrapolations. A recent drilling campaign in the Bernhardsthal oil field of the northern Vienna Basin in Austria reached the pre-Neogene basement and provided cuttings for biostratigraphic and paleoecological analyses. Based on these data, acquired by using detailed micro- and nanno-paleontological analyses, a Lutetian age (middle Eocene) and a bathyal depositional environment for the Flysch of the Harrersdorf Unit was documented. The lithological similarity of the drilling with the Steinberg Flysch Formation of the Greifenstein Nappe and its Lutetian age suggests, that the middle Eocene part of the Harrersdorf Unit represents a continuation of the Greifenstein Nappe of the Rhenodanubian Flysch, rather than a frontal part of the Rača Nappe of the Magura Flysch as previously thought.

The Miocene evolution of the area transitional from the Eastern Alps to the Pannonian Basin System was studied through the paleogeographic evolution of the Slovenj Gradec Basin in northern Slovenia. It is based on mapping, section logging, nannoplankton biostratigraphy, and petrography. The results are correlated with the lithological column of the borehole MD-1/05. The evolution of the basin is connected with the development of the Pannonian Basin System, and the global 3rd order cycles, which influenced the connection with the Mediterranean Sea. Sedimentation started in the Karpatian in a fluvial to lacustrine environment and terminated at the end of the Early Badenian. During this period, three transgression–regression cycles were recorded. The first transgression occurred in the Karpatian and corresponds to the TB 2.2. cycle. The sediments reflect proximity of the hinterland. After a short break in sedimentation, the Early Badenian deposition followed. It marks the second transgression into the SGB, the first Badenian, correlated with the TB 2.3 cycle. There are signs of a transitional environment, which evolved to marine in advanced stages. At the high-stand system tract, the sea flooded the entire Slovenj Gradec Basin. Subsequent reduced quantity and diversity of the microfossils marks the onset of the second regression stage. It is followed by the third transgression, the second in the Badenian, correlated with the TB 2.4 cycle. The late Early Badenian deposition continued in the lower-energy, though occasionally still turbulent environment. Silty sediments with upward increasing content of organic matter indicate shallowing of the basin, until its final diminishing. Layers of fresh-water coal already bear witness to the existence of restricted swamps. After the Early Badenian, the area of the Slovenj Gradec Basin became dry land, exposed to erosion.

Sediments belonging to the Oligocene Vima Formation (located in the north-western part of the Transylvanian Basin, Romania) have been investigated for calcareous nannofossils content. Biostratigraphically, the sedimentary succession is late Rupelian–Chattian in age, belonging to the NP24 — Sphenolithus distentus and NP25 — Sphenolithus ciperoensis biozones, to CP19a — Cyclicargolithus floridanus and CP19b — Reticulofenestra bisecta Subzones and to the interval from CNO4 — Sphenolithus distentus/Sphenolithus predistentus CRZ to CNO5 — Sphenolithus ciperoensis TZ. The palaeoenvironment of the Fântânele section was reconstructed by means of calcareous nannofossils and statistics. Multivariate statistics were applied to the composition of autochthonous assemblages and the obtained clusters were used to assess the palaeoecological preferences of the nannofossils. We document changes from more stable open-marine regime, with temperate sea-surface temperatures interfering locally with influx of cooler water and enriched cool-nutrient supply for the late Rupelian–earliest Chattian (NP24), to shallower and possibly warmer near-shore marine eutrophic environment, with salinity fluctuations, increased terrigenous material run-off and freshwater influx for the remaining early Chattian (NP25).

Massive evaporites were discovered in the Soltvadkert Trough (Great Plain, Hungary) correlating to the Badenian Salinity Crisis (13.8 Ma, Middle Miocene) on the basis of nannoplankton and foraminifera biostratigraphy. This new occurrence from Hungary previously thought to be devoid of evaporites is part of a growing body of evidence of evaporitic basins inside the Carpathian Arc. We suggest the presence of evaporites perhaps in the entire Central Paratethys during the salinity crisis. Different scenarios are suggested for what subsequently happened to these evaporites to explain their presence or absence in the geological record. Where they are present, scenario A suggests that they were preserved in subsiding, deep basins overlain by younger sediments that protected the evaporites from reworking, like in the studied area. Where they are absent, scenario B suggests recycling. Scenario B explains how the supposedly brackish Sarmatian could have been hyper/normal saline locally by providing a source of the excess salt from the reworking and dissolving of BSC halite into seawater. These scenarios suggest a much larger amount of evaporites locked up in the Central Paratethys during the salinity crisis then previously thought, probably contributing to the step-like nature of cooling of the Mid Miocene Climate Transition, the coeval Mi3b.

The depositional environments and hydrocarbon potential of the siliciclastic, clayey and carbonate sediments from the Middle Miocene succession in the Varna-Balchik Depression, located in the south-eastern parts of the Moesian Platform, were studied using core and outcrop samples. Based on the lithology and resistivity log the succession is subdivided from base to top into five units. Siliciclastic sedimentation prevailed in the lower parts of units I and II, whereas their upper parts are dominated by carbonate rocks. Unit III is represented by laminated clays and biodetritic limestone. Units IV and V are represented by aragonitic sediments and biomicritic limestones, correlated with the Upper Miocene Topola and Karvuna Formations, respectively. Biogenic silica in the form of diatom frustules and sponge spicules correlates subunit IIa and unit III to the lower and upper parts of the Middle Miocene Euxinograd Formation. Both (sub)units contain organic carbon contents in the order of 1 to 2 wt. % (median: 0.8 for subunit IIa; 1.3 for unit III), locally up to 4 wt. %. Based on Hydrogen Index values (HI) and alkane distribution pattern, the kerogen is mainly type II in subunit IIa (average HI= 324 mg HC/g TOC) and type III in unit III (average HI ~200 mg HC/g TOC). TOC and Rock Eval data show that subunit IIa holds a fair (to good) hydrocarbon generative potential for oil, whereas the upper 5 m of unit III holds a good (to fair) potential with the possibility to generate gas and minor oil. The rocks of both units are immature in the study area. Generally low sulphur contents are probably due to deposition in environments with reduced salinity. Normal marine conditions are suggested for unit III. Biomarker composition is typical for mixed marine and terrestrial organic matter and suggests deposition in dysoxic to anoxic environments.