New Rugose corals and refinements of the Tournaisian biostratigraphy of the Donets Basin (Ukraine)

1. IntroductionIn the Donets Basin (Ukraine) the Tournaisian rocks are commonly fossiliferous carbonates. A detailed lithostratigraphic and biostratigraphic division has been achieved over the last decades (Aizenverg et al., 1963; Poletaev et al., 1990; Poletaev et al., 2011). Rugose and tabulate corals are widely distributed in some part of the sections. M.I. Lebedev and K.I. Lisitzin first identified Tournaisian corals of the Donbas early in the 20th century and used these fossils as guides to divide the sections and to correlate them with England and Belgium. I.I. Gorsky and V.D. Fomichev studied the Early Carboniferous corals of the Donets Basin during the 1920’s, but their studies have never been completed, and their collections were lost. Only brief and limited results of these studies have been published by Fomichev (1953) and Vassilyuk (1960). Vassilyuk studied the Early Carboniferous corals of the Donets Basin in detail and has proposed a coral zonation for the Lower Carboniferous strata (Poletaev et al., 1990). The stratigraphic distribution of corals taxa in the Tournaisian strata is highly heterogeneous. Most corals are found in the middle part of the Tournaisian (C1tc Zone) (Ogar, 2010). In the lower and upper parts of the Tournaisian, corals are much rarer. Unexpected new findings are reported in this paper, together with the redescription of specimens from Vassiljuk’s collection.2. SettingsThe southern part of the Donets Basin is the only area in Ukraine where