ウクライナ，ドネツ炭田における上部石炭系Bashkirian-Moscovian境界

抄録

 To better understand and update knowledge of the stratigraphy and foraminiferal and conodont faunal successions of Bashkirian-Moscovian (Pennsylvanian/Upper Carboniferous) boundary intervals in the Donets Basin of Ukraine, we studied the C₂¹ to C₂⁶ suites (Limestones F to L) of the following eight stratigraphic sections located in the eastern part of the basin. These are the Karaguz, Volnukhino, Kriven'ky Yar, Rudnya, Zolotaya, and Malonikolaevka sections in Lugansk county and the Soroch'ya and Kholodnaya sections in Donetsk county. Among them, the Malonikolaevka section, which is located about 35km southwest of Lugansk and is documented for the first time in this study, provides important data on the faunal successions of the Bashkirian-Moscovian boundary interval, ranging from Limestones I₂ to K₃. Both the conodont and fusuline faunas record the appearances in the basal part of the C₂⁵ (K) Suite of several new taxa that are more characteristic of the early Moscovian. These forms include Declinognathodus donetzianus at the top of K₁ in conodonts and Eofusulina triangula, E. trianguliformis, and a large Neostaffella species (N. vozhgalica) at K₂ in fusulines. Thus, the K₁-K₂ interval is very promising as the potential position of the formal Bashkirian-Moscovian boundary in the Donets Basin. The data from the Malonikolaevka section, together with those from other sections in the present study, would be significant for future investigations of the Task Group to establish a GSSP close to the existing Bashkirian-Moscovian Boundary organized in IUGS Subcommission on Carboniferous Stratigraphy (SCCS).