Detailed lithostratigraphy of the Ordovician lower Volkhovian limestone along the eastern part of the Baltic‐Ladoga Glint, northwestern Russia

Billingenian and lower Volkhovian strata are known in northwestern Russia under the informal name “Dikari”. This stratigraphic interval consists mostly of hard, bedded limestones, which have been quarried for more than two centuries. About 15 informal units within the “Dikari” are recognized on the basis of differences in lithology, bioturbation character, and hardground surfaces. Some of them can easily be traced on the eastern part of the Baltic‐Ladoga Glint over a distance of more than 250 km. A detailed lithostratigraphic nomenclature of these units, proposed in this paper, is adopted from the informal subdivisions established by quarrymen in the Putilovo quarry. Up to seven major distinctive correlatable lithostratigraphic levels can be recognized in the Billingenian and lower Volkhovian sections of northwestern Russia