Integrated bio- and chemostratigraphy of the Upper Ordovician and lower Silurian of the Central and Eastern Taurides, Türkiye

 

Authors: Tanrikulu S, Loydell DK

Published in: Bulletin of Geosciences, volume 100, issue 4; pages: 505 - 528; Received 29 March 2025; Accepted in revised form 30 June 2025; Online 31 August 2025

Keywords: Ordovician, Silurian, biostratigraphy, palynology, chemostratigraphy, graptolites, Türkiye,

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Abstract

New palynological and graptolite data are presented from the Halevikdere and Pekmezli-4 sections in the Eastern Taurides and the Hırmanlı Yol-1 and -2 sections in the Central Taurides. These are supplemented by δ13Corg data from the Halevikdere Section. In combination, these data enable dating of the Upper Ordovician strata largely to an Armoricochitina nigerica local range Biozone, with all sampled Upper Ordovician strata in the Halevikdere section being of late Hirnantian age (based on correlation with published δ13Corg curves). The level of the Ordovician-Silurian boundary can be reasonably precisely constrained. Graptolite assemblages enable dating of the Silurian strata to biozones from the lower Rhuddanian to lower Telychian. Many graptolite species are identified from Türkiye for the first time and correlation is possible with other Gondwanan and peri-Gondwanan localities. The lyditic Llandovery strata are characterized by an amorphous organic matter (AOM)-inertinite palynofacies (containing very poorly preserved, largely unidentifiable palynomorphs), persisting for an unusually long period of time by comparison with other Gondwanan sections.

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