Biostratigraphic Scheme of the Devonian of the Russian Platform

Abstract Devonian biostratigraphy of the Russian platform and correlation of marine and lagoon-continental deposits present in this region are discussed. Biostratigraphic data of numerous investigators on brachiopods, foraminifers, ostracods, conodonts, ammonoids, fishes, miospores, etc., from the M. uniformis zone of the Lower Devonian to the Wocklumeria-Kalloclymenia Zone of the Upper Devonian inclusively are collated. Data on biostratigraphic subdivision and correlation of the Devonian deposits of the Russian platform in the light of the present data are also generalized. Early studies of the Devonian of the Russian platform are reflected in the classic R. Murchison, E. Verneuil and A. Keyserling treatises (1841–45). P. N. Wenjukov, D. V. Nalivkin, B. P. Markovsky, D. V. Obruchev, P. F. Gekker, N. N. Tikhonovich, V. N. Tikhii, A. K. Krylova, T. I. Fedorova, M. F. Mikrojukov, E. N. Polenova, R. M. Pistrak, A. I. Ljaschenko and others have made great contribution to the perception of Devonian stratigraphy and fauna of the Russian platform. The results of these investigations were used as the basis for the Devonian unified scheme of the Russian platform compiled under B. P. Markovsky’s guidance in 1962 (Resolutions. . ., 1965). Since then interesting data on the stratigraphy, paleontology and correlation of the Devonian deposits of this region have appeared (Stratigraphy of the USSR, 1973; Lyashenko, 1979 etc.; Tikhomirov, 1967; Resolutions on working out of Pribaltic stratigraphic schemes, 1976; Devonian deposits of the Volga-Urals province, 1978; Resolutions on working out of Byelorussia unified schemes, 1983; Stratigraphy of the UkrSSR, 1974; Shelf geology, 1984; Khomenko, 1986 and other works). The study of new groups of organisms, especially conodonts (Khalymbadzha, 1981; Ovnatanova, 1984; Aristov et al., 1981, 1986) which helped subdivide and correlate the Devonian sections, including correlation with the type western European sections made a great contribution to the compilation of the scheme. Using many groups of organic remains the zonal scales have been worked out to the present time and on many of them colloquiums (1984–1986) have been organized: conodonts — leader — V. G. Khalimbadga, brachiopods — M. A. Rzhonsnitskaya, ostracods — E. H. Polenova, V. A. Tschigova, fish fauna — V. N. Talimaa, L. A. Ljarskaja, and spores — E. V. Tschibrikova. Other groups were analyzed by B. I. Bogoslovsky (ammonoids), V. F. Kulikova (bivalve mollusks), G. P. Ljaschenko (tentaculites), G. V. Lakhov (corals), O. V. Bogojavlenskaya (stromatoporoids), Zh. A. Poljarnaja (crinoids), Ja. N. Spassky (trilobites), A. F. Abushik (Early Devonian ostracods), E. A. Reitlinger and N. B. Gibshman (foraminifers). Generalization of all these materials allowed unification of the main regional subdivisions almost over the whole territory of the platform and also correlation between marine and lagoon-continental deposits. New data revealed a wider distribution of Lower Devonian deposits than had been known earlier and helped refine boundaries in accordance with their stratotypes. These data are plotted on the suggested biostratigraphic scheme of the Devonian of the Russian platform (). The Lower Devonian boundary is drawn at the base of the Borschchov horizon, corresponding to the base of the Monograptus uniformis Zone. The Upper Devonian boundary is drawn at the base of Gattendorfia Genozone in accordance with the Resolution of the Plenum of the Devonian and Carboniferous Commissions of ISC (Minsk, April 14–17, 1986). According to the conodont scale this boundary approximates the base of the Siphonodella sulcata Zone, i.e. with the boundary recommended by the International working group on the Devonian and Carboniferous boundary (Paproth and Streel, 1985).