Environmental Properties and Ostracod Fauna of Oligocene-Mio-Pliocene Sediments in the Tekirdağ (HacusungurDrill) Region

Tekirdağ Yöresi Oligosen-Miyo-Pliyosen Çökellerinin (Hacusungur Sondajı) Ostrakod Faunası ve Ortamsal Özellikleri

Abstract

This micropaleontological research has been carried out by MTA in order to analyse the samples of the borehole which was opened for the coal investigation in the Hacusungur Village. The results of the micropaleontological research show that Pliocene and Oligocene has been drilled from top to bottom. The succession starts with yellowish clay, which passes to lignite-banded organic tape clay, laminated greenish silt, fine sand with organic painted clay, herb-banded silt and ends with alternations of clay-coal, siltstone, sandstone, claystone including the fish scale. After a detailed examination of samples obtained from drilling, the ostracod fauna has been obtained; Cytheromorpha zinndorfi (Lienenklaus), Cladarocythereapostolescui(Margerie),Hemicyprideis montosa(Jones&Sherborn), H. elongata Keen, Cytheridea pernotaOertli&Keij, LoxoconchaaequapunctaDeltel, Ilyocypris boehliTriebel, Candona (Pseudocandona)sp., Cypridopsis soyeri(Margerie), Cypriasp. and apart fromostracod fauna there are some micro-mollusks identified such as Avimactra, Viviparus, Valvata, Modiolus,Planorbis, Potamides.Among the ostracod, pelecypod and gastropod species obtained, Cladarocythere brackish, Cytheromorpha, Hemicyprideis, Loxoconcha indicate brakish-lithoral, Cytheridea indicates brackish-epineritic,Ilyocypris, Candona, Candona (Pseudocandona), Cypridopsis, Cypriaoligohaline salinity-fresh water: Avimactraindicates brackish;Viviparus, Valvata, Modiolus, Potamides, Planorbis indicate fresh water conditions: The fauna recovered from this drilling suggest that the deposition of the layers with lignite occurred in lagoonal-littoral conditions and took place in lagoon and lake areas that were formed by continued influx of fresh water.In addition to the previous studies conducted in the study ares, the findings were compared with the other ostracod studies carried out in the northwest Europe and Paris-Akiten Basin, and similar results were obtained.

Özet

Bu çalışma, Hacusungur Köyü (Tekirdağ)'nde MTA tarafından kömür arama amaçlı açılmış sondajdaki örneklerin mikropaleontolojik incelemesi amacıyla yapılmıştır. Mikropaleontolojik incelemeler, yapılan sondajla üst seviyeden tabana doğru Miyo-Pliyosen ve Oligosen yaşlı çökellerin kesildiğini göstermiştir. İstif tavandan tabana doğru sarımsı renkli kille başlayıp, linyit bantlı-organik izli kil, laminalı-yeşilimsi gri renkli silt, ince kum bantlı-organik boyamalı kil, bitki izli silt ile devam etmekte, kil-kömür ardalanımı, silttaşı, kumtaşı, balık pulu fosili içeren kiltaşı istifi ile sona ermektedir. Ostrakod faunasına dayalı ayrıntılı inceleme sonucunda sondajdan alınan yıkama örneklerinde Cytheromorpha zinndorfi (Lienenklaus), Cladarocythere apostolescui (Margerie), Hemicyprideis montosa (Jones&Sherborn), H. elongata Keen, Cytheridea pernota Oertli ve Keij, Loxoconcha aequapuncta Deltel, Ilyocypris boehli Triebel, Candona (Pseudocandona) sp., Cypridopsis soyeri (Margerie), Cypria sp. gibi ostrakod faunası yanında Avimactra, Viviparus, Valvata, Modiolus, Planorbis, Potamides gibi mikro mollüskler tanımlanmıştır. Cladarocythere brahik, Cytheromorpha, Hemicyprideis, Loxoconcha brahik-litoral, Cytheridea brahik-epineritik, Ilyocypris, Candona, Candona (Pseudocandona), Cypridopsis, Cypria oligohalin tuzluluk-tatlısu; Avimactra brahik; Viviparus, Valvata, Modiolus, Potamides, Planorbis tatlısu koşullarına işaret eden ostrakod, pelesipod ve gastropod cinsleridir. Bu sondajda tanımlanan fauna ile linyitli düzeylerin çökelme ortamının, lagün-litoral koşulların yanı sıra ortama tatlı su gelişinin de devam etmesi sonucunda oluşan lagün ve göl alanları olduğu gözlenmektedir.