U–Pb zircon age and mineralogy of the St Georgen halloysite tuff shed light on the timing of the middle Badenian (mid-Langhian) transgression, ash dispersal and palaeoenvironmental conditions in the southern Vienna Basin, Austria

Abstract

Thanks to the favourable position within the Middle Miocene marine succession of the Vienna Basin, a geochronological study of the St. Georgen tuff becomes essential for the understanding of the timing of the middle Badenian transgression. This contribution reports new data on separated zircon U-Pb ages/phase chemistry and the clay mineralogy of altered tuff used to infer on tephra provenance and paleoenvironmental conditions. The ages ranged between 15.78 ±0.27 and 14.36 ±0.31 Ma, with a weighted mean age of 14.59 ±0.2 Ma. This defines the onset of the second Badenian transgression in the Central Paratethys, which was the strongest transgression in the entire Miocene record of the Vienna Basin. The compositional and temporal relationship between the tuff and neighbouring volcanism indicates the Harsány eruption in the central Pannonian Basin as the most plausible tephra source region. Eastern and NE directed tropospheric trade winds or easterlies are responsible for the transport of the Harsány tephra to its present location. Prevalence of halloysite, as well as post-depositional alteration reactions (glass-smectite-halloysite and kaolinite-halloysite) call for tephra fallout in the very shallow sea, which might have been affected by seasonal wetting and drying cycles at the onset of ash deposition. Supplementary material: https://doi.org/10.6084/m9.figshare.c.6294944

Middle Miocene volcanic flare up preceding and synchronous with the Langhian/Serravallian sea‐level decline in the North Pannonian Basin: Insights from 40Ar/39Ar dating, geo‐seismic analysis and 3D visualization of the subterranean Kráľová stratovolcano

“…With respect to basin analysis these data enable the calibration of other dating methods, and they permit dating of significant events in basin evolution including palaeoenvironmental conditions and palaeontology (e.g. Bojar et al., 2018; Brlek et al., 2020; de Leeuw et al., 2010, 2018; Lukács et al., 2015, 2018; Pálfy et al., 2007; Sant et al., 2019, 2020; Šarinová, Hudáčková, et al., 2021; Šarinová, Rybár, et al., 2021; Šegvić et al., 2023). As was mentioned before, Danube Basin is one from nortwestern‐most part of the Pannonian Basin system.…”

“…In present time, thanks to this development, many workers in CPR are devoted to inquiry about radioisotope age data from altered pyroclastic rocks; to the age refinement of volcanic stages; as well as to the correlation of products of volcanic activity in time and space (e.g. Badurina et al., 2021; Bojar et al., 2018; Brlek et al., 2020, 2023; Bukowski et al., 2018; de Leeuw et al., 2010, 2018; Karátson et al., 2000, 2007; Lukács et al., 2015, 2018, 2021; Marković et al., 2021; Pálfy et al., 2007; Roetzel et al., 2014; Rybár et al., 2019; Sant et al., 2019, 2020; Šarinová, Hudáčková, et al., 2021; Šarinová, Rybár, et al., 2021; Šegvić et al., 2023; Śliwiński et al., 2012; Wijbrans et al., 2007). These data allow to improve the statement about genetic evolution and also estimates of the extent and strength of eruptions (e.g.…”