TY JOUR TI Cementstones origin in the Upper Silurian lagoon deposits of the Northern Urals KW Upper Silurian KW cementstones KW paleokarst KW C and O isotopes JO Vestnik of geosciences AU Ponomarenko, E.S. PY 2022 IS 0 PB FSBI FIC "Komi Scientific Center of the Ural Branch of the Russian Academy of Sciences"