| dc.description.abstract | Establishing an unambiguous timescale for the Late Neogene deposits of the Eastern Paratethys region has been a problem for years due to contradicting paleomagnetic results and local biostratigraphic schemes. This work aims to create a reliable magnetostratigraphy for key sections in Azerbaijan. The boundary between the Productive Series and Akchagylian regional stages, as observed in the Lokbatan section, has in the most likely scenario an age of 2.5 Ma, as opposed to 3.4 Ma in most existing correlations. The younger regional stages, the Apsheronian and the Bakunian, yield ages for their lower boundary of older than 1.8 Ma, and 0.88 Ma. In this new chronostratigraphic framework, transgressions at the base of both the Akchagylian and the Bakunian fall within cold intervals of the Pleistocene (marine isotope stages 100-96 and 22 respectively), and are thus likely to have an origin related to Northern Hemisphere glaciation. Existing hypotheses explain Late Pleistocene icedammed lakes and reversed river drainage stretching from Scandinavia to West Siberia as a possible cause for transgressions. A similar hypothesis is proposed for the Akchagylian transgression. Species with an Arctic origin found in the Caspian Sea prove this connection with the Arctic ocean. Of these species the Caspian seal is an interesting example, especially since it is hypothesized to have entered the Caspian Sea around 2-3 Ma. | |
