UNIQUE LOWER VENDIAN KEL'TMA MICROBIOTA, TIMAN RIDGE: NEW EVIDENCE FOR THE PALEONTOLOGICAL ESSENCE AND GLOBAL SIGNIFICANCE OF THE VENDIAN SYSTEM

Abstract

The recognition of the Vendian as a terminal Precambrian system and the biostratigraphic subdivision of its upper part were an important step in constructing the general chronostratigraphic scale for the Upper Proterozoic (and references therein). Unfortunately, no microbiota of the so-called Pertatataka type described from the Lower Vendian sections of southern China, central Australia, Spitsbergen, the Lesser Himalayas, where they occur slightly above Lower Vendian tillites, and from some formations in the interior areas of the Siberian Platform has yet been found in the stratotype region of the system, i.e., in the East European Platform. It is conceivable that its absence in Vendian type sections influenced the decision of the International Union of Geological Sciences to accept the Ediacarian System, instead of the Vendian one, as a terminal Precambrian unit of that kind. It was defined in southern Australia using quite different principles and is significantly smaller in its stratigraphic range as compared with the Vendian System.