The Pennsylvanian (Moscovian) Izvarino Section, Donets Basin, Ukraine: A Multidisciplinary Study on Microfacies, Biostratigraphy (Conodonts, Foraminifers, and Ostracodes), and Paleoecology

Abstract

The mid-Moscovian Izvarino section, Donets Basin, eastern Ukraine, exhibits a complete sedimentological record of siliciclastics (sandstones, siltstones, and calcareous shales) with limestone intercalations and, rarely, coal seams. A multidisciplinary study including microfacies analysis, systematic paleontology (conodonts, fusulinoideans, and ostracodes), biostratigraphy, and paleoecology was focused on the limestones, from limestone L4 through limestone M1, and the adjacent marine shales. Based on sedimentology and fossil associations, the cyclic sediments of the Izvarino section were interpreted as entirely marine deposits of open- and shallow-marine, nearshore and offshore environments with variable terrigenous input.The well-preserved ostracode faunas are dominated by representatives of the families Amphissitidae, Hollinellidae, Healdiidae, Cavellinidae, and Paraparchitidae. The total fauna is 18 species, of which four are new: Hollinella (Hollinella) granuloba Fohrer, n. sp., Hollinella (Praehollinella) kamenka Fohrer, n. sp., Jordanites krasnodonensis Fohrer, n. sp., and Asturiella donbassica Fohrer, n. sp. The conodont fauna includes 21 species belonging to nine genera and includes one new species: Idiognathodus izvaricus Nemyrovska, n. sp. The conodont faunas are dominated by idiognathodontids. Representatives of Diplognathodus and Neognathodus play a subordinate role. A total of 56 fusulinoidean species referable to 20 genera has been identified; one is new: Eostaffella brazhnikovae Ueno, n. sp.Conodont and fusulinoidean biostratigraphy led to surprising differences in the age assignment of the Izvarino section and its correlation with the nearby Moscow Basin, Russia. The interval studied is lower Kashirian (Tsninskaya) to middle Kashirian (Narskaya), according to conodonts. It extends to the base of the Podolskian, however, according to fusulinoideans. This discrepancy is possibly related to problems in correlation of the type sections in the Moscow Basin. It calls for reexamination of the mid-Moscovian boundary interval and shows the limits of interbasinal correlations based on a single fossil group.

High‐precision U‐Pb zircon age calibration of the global Carboniferous time scale and Milankovitch band cyclicity in the Donets Basin, eastern Ukraine

“…The new radiometric ages obtained in our study require significant revisions to the absolute age calibration of the global Carboniferous time scale. Our new ages meet the necessary prerequisites for global time scale calibration: all radiometric samples were collected and documented within the well‐established local lithostratigraphic framework of the Donets Basin [ Aisenverg et al , 1963, 1975], and the collected samples are therefore precisely constrained within the exceptionally complete biostratigraphic framework of the basin [ Aizenverg et al , 1979; Davydov , 1992; Davydov et al , 2008; Fohrer et al , 2007; Nemyrovska et al , 1999; Poletaev et al , 1991]. As we have emphasized in our description of the Donets Basin succession, its multitaxa biostratigraphy may be straightforwardly correlated with the Tournaisian and Visean type sections in western Europe, and the Serpukhovian, Bashkirian, Moscovian, Kasimovian, Gzhelian and Asselian type sections in the Moscow Basin and Urals (Figure 2).…”

“…Conodonts are locally abundant in the Carboniferous of the Donets Basin, but have been studied only since the late 1970s [ Kozitskaya et al , 1978]. Study has focused in the Bashkirian, Moscovian and lower Kasimovian portions of the successions [ Fohrer et al , 2007; Nemyrovska , 1999; Nemyrovska et al , 1999]. Conodonts provide reasonable correlation in the Mississippian and Late Pennsylvanian, and an excellent zonation and correlation for early Middle Pennsylvanian (Figure 2), although they are quite provincial in the middle Moscovian [ Goreva and Alekseev , 2007].…”

“…The Donets Basin of eastern Europe contains one of the most complete global Carboniferous sedimentary successions, with few gaps in its depositional record [ Aisenverg et al , 1975; Davydov , 1990; Fohrer et al , 2007]. These marine to paralic strata of the Donets Basin host over 250–300 limestones and about 250 coal horizons [ Aisenverg et al , 1963, 1971; Levenshtein , 1963] and thus contain exceptionally well‐established marine invertebrate and terrestrial floral biostratigraphic records, which are important standards for global marine and continental correlation.…”

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

“…Existing fusulinid distribution data was integrated with the results of this study (Brazhnikova, 1939a(Brazhnikova, , 1939b(Brazhnikova, , 1951Putrja, 1940Putrja, , 1956Manukalova, 1950aManukalova, , 1950bPogrebnyak, 1975;Ueno in Fohrer et al, 2007;Davydov and Khodjanyazova, 2009). …”

“…The lower part of the "N" formation from limestone N 1 to the N 4 or N 5 limestone was correlated with Myachkovian strata in the Moscow Basin. Subsequent research (Solovieva, 1986;Vachard and Maslo in Izart et al, 1996;Ueno in Fohrer et al, 2007) accepted the biozonation proposed by Kireeva (1951). A recent detailed biostratigraphic study (Khodjanyazova et al, 2011, Khodjanyazova et al, 2012 revealed an inconsistency in the generally accepted Donets biostratigraphy and proposed a new biostratigraphic zonation ( Fig.…”