Ordovician Graptolites From The Basal Part Of The Palaeozoic Transgressive Sequence In The Karadere Area, Zonguldak Terrane, Nw Turkey

WOS: 000346296000008
The Karadere area to the east of Safranbolu in NW Anatolia is one of the very few localities in Turkey where the contact between the Cadomian basement and the Lower Palaeozoic transgressive succession is well exposed. The Ordovician graptolite Rhabdinopora flabelliformis (Eichwald) ssp. was found in the basal part of the Bakacak Formation, indicating an Early to early Late Tremadocian age for the beginning of the Palaeozoic transgression in the Zonguldak terrane. A few metres above this occurrence, another horizon contains Paradelograptus cf. antiquus (T. S. Hall), which mainly ranges into the Late Tremadocian. Higher up in the Ordovician succession, a new graptolite bed confirms an early Darriwilian (Dw1) age for the middle part of the Karadere Formation with the occurrence of the biozonal index Levisograptus austrodentatus (Harris & Keble) and the first record of Tetragraptus cor (Strandmark) in the area. The palaeobiogeographic distribution of these Karadere fossils is in agreement with a peri-Gondwanan affinity of the Zonguldak Terrane of the Pontides, NW Anatolia, during the Early-Middle Ordovician.
teams of the TUBITAK-BAS joint-projectTurkiye Bilimsel ve Teknolojik Arastirma Kurumu (TUBITAK) [102Y157]; Spanish MINECO [CGL2012-39471]; IGCP project [591]
The authors gratefully acknowledge Iskra Lakova for her contributions to a former version of this study with a divergent content. The members of the Turkish (G. Saglam, I. Gedik, N. Ozgul) and Bulgarian (I. Boncheva, S. Yanev and Y. Maliakov) teams of the TUBITAK-BAS joint-project No. 102Y157 are acknowledged for their involvement during the field studies. Participation of J. C. G.-M. was possible through the project CGL2012-39471 of the Spanish MINECO. This paper has benefited from the review of P. S torch (Prague) and J. Maletz (Berlin) and is a contribution to IGCP project 591.