The large Rupelian Rhodope Massif eruptions as the source of airfall tuffs in SE, S and Central Europe: 40Ar/39Ar and U–Pb age constraints

Numerous Priabonian and Oligocene tuff layers within the Eastern and Central Europe Paratethys and Tethyan sedimentary basins attest for extensive volcanic activity during that period. However, the sources of these eruptions are completely unknown. Using precise radioisotopic dating, along with their stratigraphic relationships, we correlate some of these tuff layers with Rupelian eruptions from the Rhodope Massif, South Bulgaria. Three major silicic eruptions of ignimbrites and ash falls, namely Dazhdovnitsa, Borovitsa and Perelik, with ages of 33.2 Ma, 32.8 Ma and 31.6 Ma, respectively, have been identified in the Rhodope Massif. The ejected tephra was dispersed over more than 1,000,000 km² and the combined estimated volume of thousands cubic kilometers, which marks this period as one of the most voluminous sequence of volcanic eruptions/explosions in Europe in the Rupelian Stage. The areal coverage and estimated volumes meet the requirements for volcanic supereruptions and the wide geographic occurrence of the products can be used as stratigraphic isochronous marker horizons for correlating, dating, and synchronizing deposits and events in geologic and paleoenvironmental studies. Further, the volcanic products were deposited during the early Rupelian anoxic Paratethys events and we explore the possible influence of volcanic eruptions on the process of anoxia.

Graphical abstract