How to drain a megalake: Comments on a study by Palcu et al. (2021) Scientific Reports 11, Art. Nr.: 11471.

In a recent paper by Palcu et al. (2021: Scientific Reports 11, Art. Nr.: 11471), the Cape Panagia section on the Taman peninsula (Russian Black Sea) was dated using magnetostratigraphy, in order to calibrate the timing of previously published regressions of the Paratethys megalake. The authors of the paper claim that this “largest megalake in the geological record” experienced four major desiccation episodes in the period between 9.75 and 7.65 million years ago. In our opinion, the conclusions drawn in this contribution are not always fully justified, and reflect a somewhat selective approach to existing data. The sedimentological and biostratigraphic record of Cape Panagia does not lend itself to interpretation as reflecting major lake-level drops. The observed changes in the depositional record might be explained by other factors, such as regression due to filling of the accommodation space, or local uplift of the area. None of these, however, were considered, being simply excluded from the options. The lack of convincing evidence for the high-resolution events described in the region, compounded by inconsistencies in the paleogeographic reconstructions, give rise to concern about the reliability of the model presented in the paper.