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The carbonate production event in the Moravian part of the Carpathian Foredeep is known as a deposition of a carbonate-siliciclastic complex in the marginal part of the basin, correlating with the time period from the last occurrence of Helicosphaera waltrans (14.36 Ma) to the last occurrence of Sphenolithus heteromorphus (13.34 Ma). Sedimentological and microfacial data, analysis of foraminifera, calcareous nannoplankton, red algae, mollusks, palynology, as well as oxygen and carbon stable isotopes from foraminiferal tests, were used to interpret the specific paleoenvironment of the carbonate production event. The event was accelerated by a decrease of terrigenous input due to a large transgression and, primarily, an increasingly arid climate. Production of carbonate was related to oligotrophic conditions, expansion of sea-grass meadows, summer downwelling circulations and winter stratification of the water column. Autochthonous and semi-autochthonous carbonates were deposited in shallow-water near the fair-weather wave-base; allochthonous carbonates were transported to the outer shelf by gravity flows. Climatic instability and relative sea-level changes, induced mainly by substantial tectonic activity, caused the carbonate bodies to be small with a high ratio of siliciclastic components, indicating only a short-term and spatially restricted environment suitable for carbonate production. Exceptionally, carbonate production persisted longer during the whole sea-level cycle ('Rousínov Ridge'). Siliciclastic intercalations in these larger limestone bodies represent catastrophic rain events that transported a higher amount of terrigenous material into the basin. The specific climatic conditions of the carbonate production event, namely climatic instability and aridification with episodic intensive rain, were associated with the Middle Miocene climatic transition in the study area. [ABSTRACT FROM AUTHOR]

The robustness of the Strontium Isotope Stratigraphy (SIS) as a chemostratigraphic tool was tested in the Miocene epicontinental Central Paratethys using new 87Sr/86Sr results obtained for 129 foraminiferal tests and various marine invertebrate shells that were converted to numerical ages using the global 87Sr/86Sr curve for the Phanerozoic open oceans. These ages were compared with those expected from either magnetostratigraphic, radiometric or biostratigraphic studies applied to selected sections from different Central Paratethys basins. The results from different basins showed variations in 87Sr/86Sr values for specific time intervals; therefore, it is not possible to construct a unique 87Sr/86Sr curve for the Central Paratethys region that can be used for chemostratigraphic purposes. The 87Sr/86Sr signal in semi-enclosed basins tends to reflect the lithology of the source areas. For example, marine basins surrounded by areas of Mesozoic carbonate rock cover are associated with a reduced 87Sr/86Sr signal compared to the global 87Sr/86Sr signal primarily due to the drainage of these Mesozoic carbonate rocks and transfer of their specific Sr signal. By contrast, areas affected by continental runoff from crystalline terrains in combination with limited connection to surrounding marine domains were found to show an elevated 87Sr/86Sr signal compared to the global one. Additionally, it was demonstrated that infaunal, eutrophic and hypoxic species (foraminiferal genus Uvigerina and molluscs) show a shift towards a relatively higher 87Sr/86Sr signal. Therefore, our data show that variable 87Sr/86Sr patterns occur in semi-enclosed domains, primarily reflecting local settings and thus hampering reliable SIS ages. In particular, the best SIS results in the studied Paratethys area occur during periods of maximum marine connectivity, when other (biostratigraphic) methods can be applied, and then become unreliable as connectivity diminishes. • Case study – application of 87Sr/86Sr chemostratigraphy in a diversified marginal sea. • 87Sr/86Sr differ for each individual basin within studied single time intervals. • Areas with dominant Mesozoic carbonate cover – relatively decreased 87Sr/86Sr signal. • Areas with dominant crystalline basement rocks – relatively elevated 87Sr/86Sr signal. [ABSTRACT FROM AUTHOR]