Differentiation and correlation of the Riphean rocks of Eastern Siberia

The Riphean (upper) portion of the Proterozoic interval is treated as an era divided into four systems on the basis of stromatolith morphology. The evolution of the stromatoliths is traced into the Lower Cambrian in order to demonstrate that divisions of system rank can be identified by the stages of stromatolith morphogenesis, from columnar through tabular and, in the Lower Cambrian, "nodular" and laminar. The Riphean stromatoliths, in the main, represent Baicalia and Conophyton, even through other major taxons are present. The authors, at the present stage in the the development of Riphean stratigraphy, seem to assign the rank of genera to Baicalia and Conophyton. --Mark E. Burgunker.