engleski

Diachronous Flooding During Pannonian Basin Extension (Central Europe): Constraining the Miocene Incursion of the Central Paratethys using High-Precision Geochronology

The epicontinental Paretethys Sea covered large parts of Europe and western Asia during the Oligocene and Miocene, and due to complicated geodynamics and eustatic sea-level changes, paleoenvironments varied spatially and temporally across various basins during this time. During continental extension during the Early and Middle Miocene, the Pannonian Basin hosted transgressions of the Central Paratethys, allowing open sea connections into the Mediterranean and potentially the Indian Ocean. However, the overall evolution of the Paratethys Sea is still poorly constrained. Consequently, it can be difficult to assess whether the flooding events are synchronous across the basin surface, and if not, what processes may drive diachronous continental flooding. However, this understanding is crucial, as formation of continental seaways and continental floodings create new conduits for oceanic circulation and influence global climate. Exposures of Miocene stratigraphy throughout the Pannonian Basin indicate the existence of smaller basins with unique depositional histories. Since the extension was accompanied by regional scale ignimbrite volcanism integrating the depositional environments of sub-basins with high precision geochronology can allow insight into the development and flooding of these sub-basins during extension. New high-precision CA-ID-TIMS U- Pb zircon geochronology from nine volcanogenic samples from across Croatia highlight the complexity of both the volcanic events during this period, and the Miocene evolution of the Pannonian Basin and Dinaride lake system in the Sinj basin. While zircon age spectra are often heavily complicated by inheritance, these data indicate there are at least eight individual ash fall events recorded within the North Croatian and Sinj Basins between approximately 15-18 Ma, commonly obfuscating previous correlations across the region. Incorporating new geochronology from the North Croatian Basin into the regional stratigraphy confirms that the Middle Miocene (Badenian) Central Paratethys flooding event was diachronous within the Pannonian Basin, beginning within some sub-basins as early as 15.345 ± 0.020 Ma, and continuing for over the next million years.

Central Paratethys ; Transgression ; CA-ID-TIMS geochronology ; Pannonian Basin, Miocene

nije evidentirano