Late Vendian (Ediacaran) index-fossil Namacalathus in the Nepa-Botuoba Anteclise of eastern Siberia (parametric borehole Chaikinskaya-279)

Borehole Chaikinskaya-279 is located in Nyuya Zone of the Fore-Patom–Vilyui Area of Sibirean Craton. The Vendian aluminosiliciclastic and carbonate succession in this area comprise the Bilir, Yuryakh, Kudulakh, Uspun, Biuk, Parshin, Talakh, Khoronokh and Betichin formations that overlie the Riphean Talakan Fm and are overlaid by the Lower Cambrian Yuryagin Fm [1]. Nearly all of these stratigraphic units are represented in the section of borehole Chaikinskaya–279, except for the Khoronokh and Betichin formations.