The foraminiferal zonal scale of the Devonian–Carboniferous boundary beds in Russia and Western Kazakhstan and its correlation with ammonoid and conodont scales

This paper reviews the foraminiferal biostratigraphy of the Devonian–Carboniferous (D–C) boundary beds in Russia and Western Kazakhstan. The regional records of the zonal successions of Russia are summarised from sections and boreholes of the Volga-Urals Subregion of the East European Platform (Syzran no. 401 Borehole, Melekesskaya no.1 Borehole); Timan-Pechora Province of the East European Platform (Kamenka Section); South Urals (Sikaza, Zigan, Ryauzyak and Dzerzhinka sections); Middle Urals (Pershino Section); and West Siberia, Vagai-Ishim Basin (Borehole no. 1 Kurgan-Uspenskaya), and the zonal successions of Western Kazakhstan are summarised from the Mugodzhary Mountains. Three foraminiferal biozones can be defined in the interval comprising the latest Devonian and earliest Carboniferous: Quasiendothyra kobeitusana Zone, the Tournayellina pseudobeata – remnant Quasiendothyra Zone, and the Earlandia minima Zone. The D–C boundary interval is situated within the Tournayellina pseudobeata–remnant Quasiendothyra Zone. A correlation with the ammonoid and conodont zonations is proposed, which is useful for correlating deep-water and shallow-water successions