Ostracoda of the marginal parts of the Borisphen Gulf of the Eastern Paratethys in the Middle Sarmatian


  • O. V. Bondar Dnipropetrovsk National University Oles Gonchar
  • H. L. Samoilenko Dnipropetrovsk National University Oles Gonchar
Keywords: ostracoda, Miocene, Middle Sarmatian, palaeoecology, Borisphen Gulf, Eastern Paratethys

Abstract

This work continues the analysis of assemblages of ostracoda  from  the  Middle Sarmatian deposits of the Borisphen Gulf of the Eastern Paratethys. Ivanova at al. (2007), Bondar (2015) present data on the history of the study of Sarmatian ostracods, on the factual data, methods of study, and lithological and palaeontological description of the composite Sarmatian sections of the marginal parts of the Borisphen Gulf. This publication presents a palaeoecological analysis of the ostracod assemblages, which contributes to the description of the shallow-marine environment which existed in the Middle Sarmatian basin. The material studied consists mainly of benthic ostracods, closely associated with the near-bottom environment of the basin. This makes them a reliable indicator of the palaeoecological environment. Any changes of the living environment is leaded to restructuring of the entire ostracod assemblage. The main environmental factors,  influencing the systematic and quantitative composition, and the domination of one taxa over others, include water depth, salinity, hydrodynamic conditions in the basin, temperature conditions, substrate type, and organic carbonate and oxygen content of the water. The reconstruction of the palaeoenvironment is based primarily on the actualistic approach, where the environmental parameters of modem communities are extrapolated to the ancient fauna with certain assumptions. A total of 16 species of ostracod, belonging to 6 genera of 6 families, were identified in the Middle Sarmatian deposits. Investigation of these ostracod assemblages included taxonomic, quantitative, taphonomic and palaeoecological analyses. The palaeoecological analysis of ostracods from the deposits of the marginal parts Middle Sarmatian sea demonstrates that the assemblages developed in the more or less favorable environments of a warm shallow basin (deep up to 20 m, temperature about 20 ºC). Limited diversity of the species, abundance of certain specimens, large and heavy shells of ostracods are typical of the shallowest parts of a basin with active hydrodynamic environments (Aurila). The highest taxonomic diversity of the ostracod associations was encountered in the fairly shallow and calm environments with low sorting of substrate and weak near-bottom hydrodynamics (Loxoconcha, Leptocythere). The salinity of the basin was unstable. So there are Cyprideis torosa, Cyprinotus luminosus in the assemblages.

Author Biographies

O. V. Bondar, Dnipropetrovsk National University Oles Gonchar
Dnipropetrovsk National University Oles Goncharassistant professor (docent) Department of geology and hydrogeologyCandidate of Geological  Sciences (PhD)
H. L. Samoilenko, Dnipropetrovsk National University Oles Gonchar
studentDnipropetrovsk National University Oles Gonchar

References

Belokrys, L.S., 1976. Sarmat yuga USSR [Sarmatian of the south of USSR]. Stratigrafiya kajnozoya Severnogo Prichernomor'ya i Kryma, 3-21 (in Russian).
Belokrys, L.S., 1984. Klimaticheskie izmeneniya v miocenovuyu ehpohu v Chernomorsko-Kaspijskoj oblasti i ih vliyanie na gidrologiyu bassejna i sedimentacionnye processy [Climatic changes in the Miocene epoch in the Black Sea-Caspian region and their influence on the hydrology of the basin and sedimentation processes]. Stratigrafiya kajnozoya Severnogo Prichernomor'ya i Kryma, 10-21 (in Russian).
Bondar, O.V., 2007. Biostratyhrafiia seredno- ta verkhnomiotsenovykh vidkladiv Pivdennoi Ukrainy za ostrakodamy [Biostratigraphy of the Southern Ukraine Middle and Upper Miocene deposits by ostracods]. Dniepropetrovsk (in Ukrainian).
Bondar, O.V., 2015. Novyi vyd ostrakodiv rodu Loxoconcha z sarmatskykh vidkladiv Cerednoho Prydniprov’ia [A new ostracods’ species of genus Loxoconcha from Sarmatian deposits of the Middle Dnieper region]. Paleontolohichnyi zbirnyk, № 47, 96-100 (in Ukrainian).
Chekunov A.V., Veselov A.A., Gil'kman A.I., 1976. Geologicheskoe stroenie i istoriya razvitiya Prichernomorskogo progiba [The geological structure and history of development of the Black Sea depression]. Naukova dumka, Kyiv (in Russian).
Dykan, N.I., 2006. Systematyka chetvertynnykh ostrakod Ukrainy: dovidnyk-vyznachnyk [Systematization of quaternary ostracoda of Ukraine (a reference book)]. IGN NANU, Kyiv (in Ukrainian).
Ivanova, T.A., Barg, I.M., Bogdanovich, E.M., Bondar, O.V., Stefansky, V.L., Petrenko, A.A., Stefansky, M.V., Majboga, I.E., 2007. Opornyj razrez miocenovyh otlozhenij yugo-vostochnoj chasti Dneprovsko-Doneckoj vpadiny (p.g.t. Gubiniha) [Demonstrative section of Miocene deposits of the south-eastern Dnieper-Donetz depression (country Gubiniha)]. Paleontolohichni doslidzhennia v Ukraini: istoriia, suchasnyi stan ta perspektyvy, Kyiv, 306–314 (in Russian).
Kontrovitz, M., Myers J.H., 1988. Ostracode eyes as paleoenvironmental indicators: рhysical limits of vision of some podocopids. Geology, V.16, 293-295.
Korallova, V.V., 1989. Klimat sarmatskogo veka na Ukraine (po palinologicheskim dannym) [The climate of the Sarmatian century in Ukraine (according to palynological data)]. Geologicheskij zhurnal, № 1, 69-74 (in Russian).
Myers J.H., Kontrovitz M., 1987. Geometrical optics of some ostracod eyes. Evolutionary biology of Ostracoda, Tokyo, Kodansha, 187-193.
Nikolaeva, I.A., Pavlovskaja, V.I., Karmishina, G.I, Kovalenko, A.L., Aladin N.V, 1989. Prakticheskoe rukovodstvo po microfaune, 3. Ostrakody kainozoja [Practical manual on microfauna of the USSR, 3. Cenozoic ostracoda]. Nedra, Leningrad (in Russian).
Schornikov, E.I.,1971. Funkcional'naya morfologiya rakovin ostrakod kak paleoehkologicheskij indikator [Functional morphology of the shells of ostracods as a paleoecological indicator]. Tez. III Vsesoyuz. kollokviuma po ostrakodam. Tallinn, 36-39 (in Russian).
Schornikov, E.I., Zenina, M.A., 2014. Ostrakody kak indikatory sostoyaniya i dinamiki vodnyh ehkosistem (na primere zaliva Petra Velikogo Yaponskogo morya) [Ostracods as indicators of conditions and dynamics of water ecosystems]. Dalnauka, Vladivostok (in Russian).
Zaharov, V.A., 2016. Glubiny paleobassejnov i podhody k ih rekonstrukcii [Depths of paleobasins and approaches to reconstruction]. Paleontologiya, stratigrafіya, astrobіologіya, Moscow, 208-228 (in Russian).
Published
2017-07-06
How to Cite
Bondar, O., & Samoilenko, H. (2017). Ostracoda of the marginal parts of the Borisphen Gulf of the Eastern Paratethys in the Middle Sarmatian. Journal of Geology, Geography and Geoecology, 25(1), 3-11. https://doi.org/https://doi.org/10.15421/111701