TY JOUR TI Regional carbon isotope curve and biotic events in the Silurian of the Western slope of the Subpolar Urals and Chernov Uplift KW carbon isotope record KW event stratigraphy KW Silurian KW Chernov Uplift KW Subpolar Urals JO Vestnik of geosciences AU Beznosova, T.M. AU Matveev, V.A. PY 2022 IS 0 PB FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences"