Features of the Upper Ludlow deposits in the Silurian key section on the western slope of the Subpolar Urals

Silurian key succession of the western Subpolar Urals is exposed on the Kozhym River, in the section 236. In this paper, lithology of carbonate rocks of the Sizim Stage (Ludlow) exposed in that section is discussed. It is demonstrated that in formation of limestones and dolostones significant role was played by various benthic organisms, including cyanobacteria - the main builders of stromatolites which existed in extremely shallow-water conditions.