The mid-Langhian flooding in the eastern Central Paratethys: integrated stratigraphic data from the Transylvanian Basin and SE Carpathian Foredeep

Abstract

The mid-Langhian ("Badenian") flooding fully reconnected the semi-isolated Central Paratethys realm with the Mediterranean and, thereby, drastically changed the middle Miocene paleogeography of Central Europe. Due to the scattered stratigraphic record and scarcity of independent age constraints in some areas, the precise age and underlying mechanism are still debated. We present integrated chronostratigraphic data from five sections in the eastern part of the system to reconstruct the flooding event distal from the strait to the Mediterranean. By applying modern Mediterranean biochronology (planktonic foraminifera and calcareous nannofossils), supplemented by an 40 Ar/ 39 Ar age on a tuff, we demonstrate that the widespread open marine settings in the NW Transylvanian Basin were definitely installed after 14.9 Ma (MMi4d biozone), and in most areas before 14.4 Ma. In the marginal study area in the SE Carpathian Foredeep, fully marine conditions likely set in slightly later (14.6-14.4 Ma). There, short-lived marine incursions into the brackish environment occurred since the latest Burdigalian ("pre-flooding phase"). The new ages overlap with the flooding in the majority of the Central Paratethys (~ 14.9-14.4 Ma), and with marine overflow into the Black Sea (14.85 Ma). We suggest that the transgression was driven by subsidence of the Pannonian Basin, by creating accommodation space and diminishing barriers between sub-basins, but was likely enhanced by a global sea-level rise. Finally, we speculate that the scarcity of all calcareous material in the SE Carpathian Foredeep before the mid-Langhian flooding might be related to pulses of nutrient-rich brackish and low pH water from the neighboring Black Sea Basin.

Facies analyses, biostratigraphy and radiometric dating of the Lower-Middle Miocene succession near Zajecar (Dacian basin, eastern Serbia)

“…Contrary, other authors mentioned that the Badenian Sea of so-called the Vienna type, mainly comes through SW Romania to the north-western part of Bulgaria (KRSTIć et al, 2012). Recently, similar paleogeographic reconstructions based on biochronology and ar/ar radiometric age of tuffs from the NW Transylvanian basin and SE Carpathian foredeep indicate that the marine transgression of the Paratethys occurred during Middle Badenian between 14.9-14.4 Ma (SaNT et al, 2019).…”

Salt is the Seed of Life: a Geotourism Potential Analysis of Salt Areas in Buzău Land, Romania

“…Peryt 2006;Kováč et al 2007), but mostly to the collisional setting that generated the rise of the Carpathian Mountains (e.g. Sant et al 2019). The territory itself is located close to the continental triple junction between the East European megaplate, and the Moesian and Tisia-Dacia microplates, in a highly active seismogenic area (e.g.…”

Miocene syn-rift evolution of the North Croatian Basin (Carpathian–Pannonian Region): new constraints from Mts. Kalnik and Požeška gora volcaniclastic record with regional implications

“…The spatial and temporal evolution of the semi-enclosed Central Paratethys sea during the Early to Middle Miocene, as well as the chronologic framework to disentangle geodynamic and climatic processes affecting depositional environments, is not yet resolved (Hilgen et al 2012;Sant et al 2017;Kováč et al 2018). The CP evolution likely reflects both geodynamically induced changes in basin connectivity (due to development of Alpine-Carpathian-Dinaride orogenic systems), as well as changes in eustatic sea level (Sant et al 2017(Sant et al , 2019Kováč et al 2018;de Leeuw et al 2018). Although there has been recent progress (e.g., de Leeuw et al 2018;Sant et al 2019Sant et al , 2020, a general lack of high-precision geochronology makes correlation within and between CP basins difficult, as well as making it complicated to correlate these basins to the global time scale (Holcová et al 2018;Kováč et al 2018).…”

“…The CP evolution likely reflects both geodynamically induced changes in basin connectivity (due to development of Alpine-Carpathian-Dinaride orogenic systems), as well as changes in eustatic sea level (Sant et al 2017(Sant et al , 2019Kováč et al 2018;de Leeuw et al 2018). Although there has been recent progress (e.g., de Leeuw et al 2018;Sant et al 2019Sant et al , 2020, a general lack of high-precision geochronology makes correlation within and between CP basins difficult, as well as making it complicated to correlate these basins to the global time scale (Holcová et al 2018;Kováč et al 2018). In addition, Sant et al (2017) stated the need for using the recently revised Mediterranean Early-Middle Miocene calcareous plankton biochronology in full extent to re-date the Paratethyan successions (due to the connection of the CP with the Mediterranean through e.g., Trans-Tethyan-Trench Corridor; Holcová et al 2018;Kováč et al 2018;Sant et al 2019).…”

“…Although there has been recent progress (e.g., de Leeuw et al 2018;Sant et al 2019Sant et al , 2020, a general lack of high-precision geochronology makes correlation within and between CP basins difficult, as well as making it complicated to correlate these basins to the global time scale (Holcová et al 2018;Kováč et al 2018). In addition, Sant et al (2017) stated the need for using the recently revised Mediterranean Early-Middle Miocene calcareous plankton biochronology in full extent to re-date the Paratethyan successions (due to the connection of the CP with the Mediterranean through e.g., Trans-Tethyan-Trench Corridor; Holcová et al 2018;Kováč et al 2018;Sant et al 2019). Kováč et al (2018) also emphasized the importance of taking into account the diachronism of the lithostratigraphy, as well as first appearances of index species.…”