Geochronological boundaries of the Early Precambrian of the Ukrainian Shield and their correlation with the International scale of geological time of Precambrian

摘要

In the Precambrian of the Ukrainian Shield on the grounds of datum isotope marks seven geochronological boundaries are established, which correspond to lower boundaries of stratigraphic subdivisions. In comparison with International scale of geological time in the Early Precambrian of the Ukrainian Shield boundaries of 3000 and 2020 Ma are distinctly manifested.