Timing of depositional regime changes during the Late Cretaceous evolution of the Southern Pontides (Ankara, Central Anatolia, Turkey)

Üniversitemiz öğretim üyelerinden Prof. Dr. Sevinç Özkan Altıner ve Prof. Dr. Demir Altıner’in yazarları arasında bulunduğu “Timing of depositional regime changes during the Late Cretaceous evolution of the Southern Pontides (Ankara, Central Anatolia, Turkey)” başlıklı makale Cretaceous Research’te yayınlandı.

During the Cretaceous, vast amounts of marine sediments were deposited along the south-facing active margin of the Eurasia. A stratigraphic section of 91 m was analyzed for planktonic foraminifera (75 samples), with the aim of establishing a refined biostratigraphy of Cenomanian–Campanian deposits in Central Anatolia. A biostratigraphic framework comprising nine biozones was established. In ascending order, the Rotalipora cushmani, Whiteinella archaeocretacea and Helvetoglobotruncana helvetica zones were defined in the uppermost Cenomanian–Turonian interval. The lack of Coniacian index markers suggests the existence of a hiatus for this interval. In the upper part of the section, the Dicarinella asymetrica, Globotruncanita elevata, Contusotruncana plummerae, Globotruncanella havanensis and Globotruncana aegyptiaca zones were identified for the Santonian and Campanian deposits. The presence of Gansserina gansseri, Globotruncanita angulata, G. conica and G. pettersi in the uppermost part of the section shows that the section ends at the base of the Gansserina gansseri Zone, indicating uppermost Campanian. The planktonic foraminifera biozonation framework provides strong evidence for the timing of the depositional history of the active continental margin that developed south of the Pontides. These phases are mainly the formation of olistostromes of pre-Santonian age, following condensed carbonate deposition during the Santonian and finally the switch from forearc deposition to the formation of a thick sequence of siliciclastic succession starting in the Campanian.

Sarıaslan, N., Özkan-Altıner, S., & Altıner, D. (2020). Timing of depositional regime changes during the late cretaceous evolution of the southern pontides (ankara, central anatolia, turkey). Cretaceous Research, 112 doi:10.1016/j.cretres.2020.104455

Makaleye erişim için: https://www.sciencedirect.com/science/article/abs/pii/S0195667119304197?via%3Dihub

Anahtar sözcükler:

Biostratigraphy; Cenomanian–Campanian; Microfacies; Planktonic foraminifera; Southern Pontides

Diğer Yazarlar:
Sarıaslan, N. (ODTÜ)

Ek Bilgiler:
This study was supported by Middle East Technical University (grant number 718 BAP-07-02-2014-007-404 ). N.S. is particularly thankful to Doğuş Ural and Cahit Kargı for their assistance in the field and for processing samples, to Orhan Karaman (Department of Geological Engineering, Middle East Technical University) for preparing numerous thin sections, to Serkan Yılmaz for his extensive work in the SEM laboratory (Department of Metallurgical and Materials Engineering, Middle East Technical University), and to Brian Huber and Martin Langer for reviewing and improving earlier versions of the manuscript. We also want to express our gratitude to Aral Okay, Brian Huber and Eduardo Koutsoukos for their constructive comments on the latest version of the manuscript.