Micropaleontological (Ostracoda) content and mineralogical properties of the Neogene Ergene Formation (SW Thrace region): implications for the evolution of Thrace Basin


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Şafak Ü., Güldürek M., Nurlu N., Güney A.

Arabian Journal Of Geosciences, no.15, pp.1-23, 2022 (SCI-Expanded)

  • Publication Type: Article / Article
  • Publication Date: 2022
  • Doi Number: 10.1007/s12517-021-09356-6
  • Journal Name: Arabian Journal Of Geosciences
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Agricultural & Environmental Science Database, Aquatic Science & Fisheries Abstracts (ASFA), Geobase, INSPEC
  • Page Numbers: pp.1-23
  • Çukurova University Affiliated: Yes

Abstract

This study encompasses micropaleontological and mineralogical research conducted in the Neogene cover deposits of the Thrace Basin, within the Çelebi and Sinanlı members of the Ergene Formation. The chronostratigraphic, paleoenvironmental, and paleobiogeographic features of the two members of this formation are studied in detail. Ostracod genera and species were found out, and those were also defined both in Tethys and Paratethys regions in silty clay and clayey levels of the Celebi Member of the Ergene Formation. Ostracod faunas, which have developed in brackish sedimentation and are specific to Central and East Paratethys basin, are firstly identified in the clayey limestone levels of the Sinanlı Member. Micropaleontologically, the calcareous nannoplankton and ostracod assemblages of the units were investigated, but calcareous nannoplankton species were not identified in the samples from the Ergene Formation in the study area. The measured stratigraphic sections were taken from two locations where the Ergene Formation and its two members could be best observed throughout the study. As a result of the micropaleontological evaluation of the washing samples taken from these sections, three ostracod species and three species were reported in the Çelebi Member within the formation; eight ostracod genera and eight species were also defined in the Sinanlı Member. Ostracod genera and species such as Cyprideis pannonicaIlyocypris cf. bradyiHeterocypris salina, and Heterocypris sp. were defined within the Çelebi Member. Micropaleontological findings based on ostracods were obtained for the first time in the Sinanlı Member, the second member of the formation. Ostracod genera and species such as Euxinocythere (MaeotocytherepseudodiafanaCaspiocypris aff. altaTyphlocypris eremitaTyphlocypris sp., Caspiolla bacuanaCaspiolla fastigataCaspiolla sp.1, Caspiolla sp. 2, Caspiolla sp.3, Pontoniella srebarnensisSerbiella cf. bacevicaeCandona aff. elongata, and Stanchevia sp. were defined in the Sinanlı Member. The described ostracod species were the same as the Paratethys species defined in Bulgaria, Hungary (Central Paratethys), Romania, Crimea, Black Sea, Turkmenistan, and Azerbaijan (Eastern Paratethys). These species were first described in this study, especially in the second member of the Ergene Formation in Thrace, during the Late Miocene-Pliocene. It was determined that the ostracod genera and species found are communities in the brackish water system, compatible with the oligo-mesohaline salinity criteria. In this study, where the petrography of the basement units under the sedimentary cover was investigated, the lithology and mineralogical characteristics of the Ergene Formation were evaluated in terms of the paleoenvironmental interpretation of the related unit. The presence of montmorillonite-type minerals in the clay lithology of the formation confirms its terrestrial origin.