Foraminiferal paleontology, biostratigraphy and sequence stratigraphy of the Permian-Triassic boundary beds of the Bolkar Daği Unit (Central Taurides, turkey)


Tezin Türü: Yüksek Lisans

Tezin Yürütüldüğü Kurum: Orta Doğu Teknik Üniversitesi, Mühendislik Fakültesi, Jeoloji Mühendisliği Bölümü, Türkiye

Tezin Onay Tarihi: 2011

Öğrenci: AYSEL HANDE ESATOĞLU

Danışman: DEMİR ALTINER

Özet:

The aim of this study is to designate paleontologic, biostratigraphic and sequence stratigraphic characteristics of the Permian-Triassic Boundary beds of the Bolkar Dağı Unit in the Hadim region (Central Taurides). For this purpose a 48,06m thick stratigraphic section, composed of limestone, siltstone and sandstone, was measured and 116 samples were analyzed through the Permian TaĢkent Formation and the Triassic Ekinlik Formation which belong to allochthonous Bolkar Dağı Unit in Central Taurides. By the detailed examination of thin section samples, 37 species and 29 genera of foraminifera were identified. Based on these determinations two foraminiferal assemblage zones have been defined including the Permian-Triassic boundary. These assemblage zones are the Changhsingian ―Nodosaria‖ elabugae-Nestellorella dorashamensis - Reichelina changhsingensis Assemblage Zone and the Greisbachian Spirorbis phlyctaena-Rectocornuspira kalhori Assemblage Zone. In order to establish the sequence stratigraphic framework of the study area detailed microfacies analysis carried out and according to these, 12 microfacies types were defined. Basing on interpretations of the vertical configuration of these microfacies types 6 main and 10 sub-type cycles were designated. Throughout the measured section 24 shallowing-upward meter-scale cycles and two sequence boundaries were determined. These sequence boundaries coincide well with the global sea level changes across the Permian-Triassic boundary and the Changhsingian-Greisbachian boundary falls within the transgressive systems tract of a third-order depositional squence spanning from latest Changhsingian to Greishbachian.