A 13.06 Ma widespread ignimbrite in the Pannonian Basin captured a snapshot of shallow marine to coastal environment in Central Paratethys.

Voluminous Miocene silicic volcanism sourced mainly from the extensional Pannonian Basin played a major role in the evolution of the Central Paratethys. Here, we identify a widely distributed (> 3150 km) member of the Upper Rhyolite Tuff in Hungary, called the Dobi Ignimbrite, with a precise sanidine/plagioclase Ar/Ar age of 13.064 ± 0.065 Ma (~ Badenian/Sarmatian boundary in Central Paratethys chronology). It has distinctive glass geochemistry with wide compositional variations, which conforms with large-scale silicic explosive eruptions. In line with this, the calculated minimum volume (~ 200 km) of the Dobi Ignimbrite is consistent with a high-end VEI 7 eruption, with possible ultradistal transport distance of over 300 km. Most of the pyroclastic succession, which erupted in two phases, was emplaced on land, as it contains leaves and tree trunks in the basal layer that we correlate with the Badenian/Sarmatian 'volcanic floras' of northern Hungary. At the same time, the ignimbrite has a strongly phreatomagmatic character, and, together with the presence of free-floating foraminifera, this suggest that the source vent was located in coastal waters of the Central Paratethys. These findings indicate either a late Badenian marine incursion prior to the eruption, or the shift of the eruption center toward the sea.