Comments on the paper of Peter Marchev et al. “Early Oligocene supereruption in SE Europe outlined by 33.3 Ma U-Pb ages for Lemnos tuff and correlation with regional ash deposits” – C. R. Acad. Bulg. Sci., 74, 3, 2021, 396–405.

Abstract

These critical notes challenge the interpretation of the authors of the article that the volcanic source of the described tuffs on the island of Lemnos (Greece) is the source of Dazhdovnitsa tuffs (beginning of the Oligocene) and that it is located in the Bororvitsa caldera, Eastern Rhodopes. However, there are large regions between this caldera and the island of Lemnos (e.g. between the villages of Podkova and Dobromirtsi in the southern part of the Eastern Rhodopes), where no pyroclastic layers are found at the base of the Oligocene section, corresponding to the stratigraphic position of the Dazhdovnitsa tuffs. It has been suggested that the volcanic source of Lemnos tuffs may be located in the Kalotiko volcanic region, situated essentially in Northern Greece. It has a multi-phase Rupelian volcanic activity, but it is not dated in detail.