The Baikalian in a type locality

A scheme of regionalization of the Baikalian in the Baikal-Patom Upland, it s stratigraphy in different structure-facies zones, and correlation of thei r reference sections are refined. The paper proves the synchronous occurrence of the events which determined the borders of the Baikalian and divided it into two parts. The nature of t hese events is substantiated in the context of geodynamics. It has been established that the Baikalian microfossil complex is an interm ediate complex between the Lachandinian and Vendian ones. The Baikalian ass ociation of stromatolites significantly differs from the Lachandinian one i n numerous new taxons, including those typical of the uppermost Riphean. Th is indicates that the Baikalian in a type locality corresponds only to the upper part of the Upper Riphean. Substantiation of the age of the Baikalian in a type locality permits revea ling its analogs in reference sections in different regions of Siberia. The characteristics of Baikalian supplemented from the carried out comparison helps refining section correlations and taking its complex characteristics as a model of the Cryogenian of the International Precambrian Scale. In con trast to the Cryogenian, the Baikalian is a typical chronostratigraphic uni t. To reveal multivariant correlation of the Baikalian with the section of the Ural Riphean stratotype calls for additional purposeful study of the up per part of the Riphean.