A Strontium Isotopic, Micropaleontological Characteristics and Environmental Interpretation of Neogene Sequence of the Ayrancı Basin (Berendi, Divle, Kıraman, Çatköy/Karaman)


Sonsun H., Şafak Ü., Nurlu N.

74th Geological Congress of Turkey, Ankara, Turkey, 11 - 15 April 2022, vol.1, no.1, pp.1

  • Publication Type: Conference Paper / Summary Text
  • Volume: 1
  • City: Ankara
  • Country: Turkey
  • Page Numbers: pp.1
  • Çukurova University Affiliated: Yes

Abstract

The research was carried out by examining the ostracod fauna in the Ayrancı Basin (Divle, Kıraman, Berendi, Çatköy, Ereklidere/KARAMAN). In the study, it was aimed to examine the basin in detail stratigraphically, Strontium isotopic and micropaleontological. For this purpose, 6 measured sections and 3 isotopic samples (1 Mazı Fm., 2 Divlek Fm.) were taken in the Ayrancı Basin, and a generalized stratigraphic section of the basin in the Neogene system was formed. Among the ostracod species found in the Mazı Formation, which is reefal limestone in the studied sequences; Neomonoceratina helvetica-Aurila soummamensis Zone (Burdigalian-Early Langhian) and Carinocythereis initial level (Langhian) as well as Praeorbulina glomerosa curva-Orbulina suturalis (Langhian) were defined and in addition, Orbulina universa (Serravallian) planktonic foraminiferal zones were revealed. Neomonoceratina helvetica, Hermanites haidingeri minor, Aurila soummamensis, Pokornyella deformis minor, Krithe papillosa are found in the Neomonoceratina helvetica-Aurila soummamensis Zone. Ostracod fauna such as Carinocythereis antiquata, Olimfalunia quadridentata, Aurila freudenthali are located in the zone starting with the Carinocythereis level. Furthermore, in the Praeorbulina glomerosa curva zone, Praeorbulina glomerosa curva; In the Orbulina suturalis zone, Praeorbulina glomerosa glomerosa, Orbulina suturalis, Globoquadrina dehiscens, Sphaerulodinellopsis disjuncta and Orbulina universa zone, Orbulina universa, Globigerinoides trilobus were identified. In the light of these data, the Mazı formation is an Early (Burdigalian)-Middle (Langhian-Serravallian) Miocene unit deposited in the Burdigalian-Langhian-Serravallian age range. The ratio of 87Sr/86Sr analysed from the carbonate sample obtained from the Mazı formation is 0.708399. The age of the Mazı formation was calculated as 20.4 Ma with this isotope data. On the Mazı Formation, the Divlek/Tırtar/Ballı Formation is overlain with a compatible transition. In this formation with abundant fossils, oolitic nodules, clayey limestone and marl intercalations, the Initial Cyprideis Level was defined in the Late Serravallian-Late Miocene (Tortonian). The age of the formation is Late Serravallian-Tortonian and the Divle-Kıraman regions of the Divlek formation are rich in ostracod fauna, and the genera and species identified are not well preserved. In the studied sequence, ostracod genera and species such as Cytherella glypta, C. vulgata, Neomonoceratina mouliana, Schneiderella dromas, Cyprideis seminulum, C. anatolica, Krithe monosteracensis, K. citae, Carinocythereis carinata, Costa edwardsii, Cistacythereis pokornyi, C. caelatura, Pokornyella deformis minör, Hermanites haidingeri minör, Occultocythereis bituberculata, Semicytherura boldi, Paracypris polita have been defined and and echinid spines, as well as numerous fish teeth have been revealed. In the Divlek formation continuing in the Çatköy region, within the Ostrea shelled clay limestones, well-preserved ostracod species have been defined such as Neonesidea corpulenta, N. interiecta, N. acupicta, N. laskarevi, Miocyprideis konyaensis, K. compressa dertonensis, Acanthocythereis hystrix, C. batei, Chrysocythere paradisus, Echinocythereis isabenana, Talmannia hodgii, Ruggieria tetraptera tetraptera, Hermanites haidingeri minör, Hiltermanicythere rugosa, Aurila convexa, A. ulicznyi, A. soummamensis, A. albicans, Tenedocythere salebrosa, T. prava, Urocythereis seminulum. The 87Sr/86Sr ratios analyzed from two carbonate samples obtained from the Divlek formation are 0.708926-0.708951. The age of the Divlek formation was calculated as 7.1-8.6 Ma based on these isotope data.