The reference section of Silurian-Lower Devonian boundary deposits in the eastern slope of the Urals

Carbonate and volcanogenic-sedimentary deposits composing the upper Pridoli an Substage and Lochkovian stages in the area between Boksity Station in th e south to the Sos'va River in the north (eastern slope of the northern Ura ls in the vicinity of Severoural'sk) are described with consideration of ra nges, boundaries, distribution, and lithological and paleontological charac teristics of the Severoural'sk, Sarainaya and Sauma horizons. Correlation o f carbonate and volcanogenic-sedimentary successions, and formation history of the whole sequence are also discussed.