Biostratigraphy of Thanetian-ilerdian Benthic Foraminifera in the Akçataş-Cebeci (NW Tosya-SE Kastamonu) region

Abstract

In this study, the benthic foraminiferal biostratigraphy and paleoecological features of Thanetian- Ilerdian unit were investigated in the northwest of Tosya (SE Kastamonu). The range of the unit, which had been determined as Paleocene-Eocene by former studies, was established as Thanetian-Ilerdian after conducting detailed paleontological research works on this unit. The unit begins with conglomerates from the base and continues with sandstones, sandy limestones and limestones upwards. Haymanella paleocenica Sirel, Idalina sinjaica Grimsdale, Mississippina binkhorsti (Reuss) and Pseudocuvillierina? sp. was described in the Thanetian levels of the unit. The Ilerdian levels are characterized by the following benthic foraminifera assemblages: Glom- alveolina lepidula Schwager, G. subtilis Hottinger, G. pilula Hottinger, G. karsica Sirel, Alveolina ellipsoidalis Schwager, A. moussoulensis Hottinger, A. corbarica Hottinger, A. laxa Hottinger, A. ilerdensis Hottinger, A. minervensis Hottinger, A. subpyrenaica Leymerie, A. decipiensis Schwager, A. aff. pisella Drobne, A. erki Acar, A. trempina Hottinger, A. aragonensis Hottinger, Orbitolites complanatus Lamarck, O. megasphericus Zhang, Opertorbitolites lehmanni Montanari. The fossil content and sedimentological features indicate deposition in a shallow restricted platform (10-30 m depth) with low energy at the beginning and subsequently in a deeper carbonate shelf environment (40-80 m) conditions.