Precambrian geochronological scale of Eastern-European platform and its framing

The data on the stability of different isotopic geochronological systems to te applied effects are summarized. The arguments in favour of chronostratigraphic Proterozoic separation are given and the geochronological scale of Pre-Cambrian of the European part of the USSR is substantiated. It is suggested that the main scale boundaries should not be referred to the moment of completion of tectonic magmatic cycles as it is done now, but to their beginning and to the foundation of a new structural plan. To change the current stratigraphic USSR Precambrian scale a two-member division of Archean, Early Proterozoic and vend, is suggested. The isotopic age of lower boundaries of recent Archean, Early proterozoic, its upper part (Svecofennian), Early, medium and recent Riphean, vend and recent vend is estimated 3200±100, 2500±50, 1970±20, 1650±20, 1350±20, 1000±50, 650±20 and 620±15 m years, respectively