Proterozoic stromatolite zonation

The zonation of the Proterozoic of the USSR is reviewed and extension to other places is attempted. Preliminary results are: some of the columnar stromatolites of northern Eurasia occur in other continents and in the same stratigraphic ranges; some of the forms (9species9) of the distinctive columnar types have intercontinental distribution, such as Gruneria biwabikia from Australia and North America. Pre-upper Proterozoic (pre-Riphean) strata also contain distinctive stromatolites of intercontinental distribution not known in younger strata, such as the new groups (9genera9) Gruneria and Katerina. The above, together with progress in microbiota studies offers hope that at least a gross worldwide biological subdivision of Proterozoic will be practicable. The Belt Series seem to represent only one of the Soviet stromatolite zones.