Planktonic foraminiferal, calcareous nannoplankton biostratigraphy, ostracod assemblage and paleoenvironmental interpretation of the Eocene Seydiler formation (Kastamonu, NW Turkey) [Eosen yaşli Seydiler formasyonunun (Kastamonu, KB Türkiye) planktonik foraminifer, kalkerli nannoplankton biyostratigrafisi, ostrakod toplulugu ve eskiortam yorumu]

Abstract

In this study, Truncorotaloides rohri, Globigerinatheka semiinvoluta and Turborotalia cerroazulensis s.l. planktonic foraminiferal zones and Reticulofenestra umbilica and Discoaster barbadiensis calcareous nannoplankton zones, indicating Bartonian-Priabonian interval, were recognized in the samples from the Seydiler formation located between Seydiler and Agli towns and Imranlar village at the north of Kastamonu city. According to distribution of the planktonic/benthonic foraminiferal ratio (%) and ostracod assemblage in the samples of the formation, it was determined that the sea was generaly in transgressive character during the Bartonian-Priabonian interval, after that it was in regressive character during the Late Priabonian time in the studied area. Moreover, abundance percentage and diversity of temperature-sensitive calcareous nannoplankton groups indicate that the sea-surface water in the study area had a tropical-temperate character in the Bartonian-Priabonian time interval. In addition, it was determined that tropical-temperate and temperate-cool phases have been occasionally prevailed on the sea and this was only related with cool-water currents at the some intervals in the Priabonian time