EVENT STRATIGRAPHY AND CORRELATION OF KAZANIAN MARINE DEPOSITS IN THE STRATOTYPE AREA

Abstract

In the history of the Kazanian sea basin in the Russian plate, periods of quasi-stationary shoreline position alternated with quick phases of transgressions and regressions. The last events were responsible for appearance of facies boundaries in the Kazanian Stage sections. These “transgression–regression” boundaries are most distinct in sections of supratidal zone deposits of diverse facies composition. Boundaries of that kind are isochronous and enable the detailed correlation of marine deposits in remote sections. In this work, the lower Kazanian deposits of the Toima–Izh interfluve (lower courses of the Kama River) are correlated with their stratotype at the Sok River (Samara region). Gray deposits of the interfluve area are attributed to the Baitugan Beds separating two red-bed sequences, namely the underlying deposits of the Ufimian Stage and overlying Kamyshlov Beds. Both units of red beds are of continental origin, whereas the Baitugan Beds include the seabar, lagoonal, and deltaic facies tracts.