Radiolarian fauna and biostratigraphy of the upper cretaceous sequences in the eastern black sea region

In the Eastern Black Sea Region, during the Late Cretaceous period intense volcanic activity accompanying sedimentation ensured the occurrence of the thick volcano-sedimentary sequences. 71 radiolarian species belonging to 26 genus have been identified from 15 measured stratigraphic sections taken from the typical outcrops of the Upper Cretaceous sequences between Trabzon and Giresun. These species were defined for the first time in the Eastern Black Sea Region obtained from the ?Cenomanian-early Turonian-early Coniacian beds of the Çeşmeler Formation, the Coniasian-early Santonian beds of the Elmalı Dere Formation and the late Santonian beds of the Çağlayan Formation. Radiolarian faunas recovered from the Çeşmeler, Elmalı Dere and Çağlayan formations belong to the Alievium superbum Zone-the Alievium praegallowayi Zone (lower part), the Alievium praegallowayi Zone (upper part)-the Alievium gallowayi Zone (lower part) and the Alievium gallowayi Zone (upper part), respectively. In the red-coloured limestones levels known as quide level, planktonic foraminifera as Hedbergella, Marginotruncana, Globotruncana, Contusotruncana, Archaeoglobigerina, Pseudotextularia and biserial heterohelicids as well as radiolarians were identified ranged through the Coniacian to Campanian time.