Cloudina-Namacalathus-Korilophyton association in the Vendian of Altai-Sayan Foldbelt (Siberia)

The Cloudina–Namacalathus association was first described from the Upper Proterozoic Nama Gr of central and southern Namibia. In the following years, the geography of its occurrences was significantly widened. Cloudina now has a worldwide distribution in Late Vendian deposits (Namibia, Brasilia, Canada, China, Oman, Spain, Russia and others) [1–5] constrained by U–Pb-zircon dates of 548.8 ± 1 [4] and 542.0 ± 0.3 Ma [6] from Namibia and Oman. In Russia, the association was found in the Vostok-3 borehole section drilled in the Fore-Yenisei Petroleum sub-Province (Tomsk Region) [7]. We discovered new occurrences of Cloudina and Namacalathus in association with calcareous algae Korilophyton in several parts of the Altai–Sayan Foldbelt (Kuznetsk Alatau, northwestern part of Eastern Sayan, Gornaya Shoriya) that prove the Late Vendian age of the Tarzhul’, Anastas’ino, West Siberian and Belka formations.