Late Moscovian fusulinids from the “N” Formation (Donets Basin, Ukraine)

Abstract

A fusulinoidean taxonomic study of the Gurkovo and Kalinovo sections allows us to refine the biostratigraphy of the poorly studied Myachkovian (upper Moscovian) strata of the “N” Formation in the Donets Basin. Three fusulinid biozones,Hemifusulina graciosa–Fusiella spatiosa,Fusulina cylindrica–Fusulinella pseudobocki, andFusulinella?kumpani, are proposed in the interval from the top of Limestone M10to the base of N3, and they are correlated with coeval strata in the historical type area of the Moscow Basin. A total of 33 fusulinid species and subspecies belonging to eight genera are described, including three new species:Hemifusulina gurkovensisn. sp.,Beedeina innaeformisn. sp., andFusulina sosninaen. sp. The main evolutionary trend in fusulinoidean morphology in the late Moscovian is the appearance of massive secondary deposits in the limestone of the “N” Formation.Specific temporal and distributional patterns of the Middle Pennsylvanian fusulinoidean assemblages indicate variations in sea level stand. Variations are cyclic, with periods ∼600,000–1,000,000 years. AHemifusulina-association indicates the beginning of transgression; the late transgression–high sea level stand is designated by theBeedeina–Neostaffella–Ozawainella–Taitzehoellaassemblage which is successively replaced by the most diverseFusulinella-dominant association, which occupied a progressively shallowing sea.The similarity of fusulinoidean assemblages in the Moscow and Donets Basins and their cognate evolution trends reveal a connection between both regions at least during Podolskian–Myachkovian time.

Climate- and eustasy-driven cyclicity in Pennsylvanian fusulinid assemblages, Donets Basin (Ukraine)

“…B is the Beedeina-dominated assemblage; C 1 and C 2 are combined into the Fusulinella-Fusulina-dominated assemblage (C). From one biocycle to another all fusulinid genera exhibit evolutionary changes at the species level that enable a biozone definition and correlation with coeval strata from the Moscow Basin (Khodjanyazova et al, 2012;Khodjanyazova and Davydov, 2013) and other basins of the Paleotethys. A similar trend of the fusulinid distribution is recognized in the Moscow Basin (Khodjanyazova et al, 2012).…”

Fusulines from the Central Asturian Coal? eld (Pennsylvanian, Cantabrian Zone, Spain) and their signi? cance for biostratigraphic correlation

“…Such a type of Carboniferous succession exists in the Donets Basin and in the Cantabrian Zone, in which the marine and terrestrial fossils have been studied for a long time (for the Donets, see Aisenverg et al, 1979;Fissunenko & Laveine, 1984;Izart et al, 1996Izart et al, , 1998Ueno & Nemyrovska, 2008;Khodjanyazova & Davydov, 2013;Khodjanyazova et al, 2014; and for the Cantabrian Zone, see van Ginkel, 1965van Ginkel, , 1971van Ginkel, , 1973van Ginkel, , 1987van Ginkel & Villa, 1996;Villa, 1995;Villa et al, 2015;Villa & Merino-Tomé, 2016;Wagner & Winkler Prins, 1985a, 1985bWagner et al, 2002;Wagner & Álvarez-Vázquez, 2010). However, the correlation of the marine and terrestrial biostratigraphic units from both areas is a problematic issue.…”

“…Also signifi cant is Fusulina cotarazoe, which occurs abundantly in lower Myachkovian strata throughout the Cantabrian Zone. Compared to the Donets Basin, the Entrerregueras Limestone could be roughly equivalent to or slightly older than the N1 limestone, whereKhodjanyazova & Davydov (2013) established the Hemifusulina graciosa-Fusiella spatiosa Zone.…”