Mut Havzas›’nda yap›lan bu incelemede, Köselerli formasyonunun havza kenar›na ait olan çökellerinin üst seviyelerinde ölçülen 3 stratigrafi kesitinden derlenen 72 örnekte nannoplankton zonlar›ndan Reticulofenestra pseudoumbilica (Zankliyen), Dictyococcites productus (Gelasiyen), Pseudoemiliana lacunosa Zonlar›, Calcidiscus macintyrei, Helicosphaera sellii ve Küçük Gephyrocapsa Alt zonlar› (Gelasiyen-Kalabriyen) ile planktik foraminifer zonlar›ndan Globorotalia puncticulata (Zankliyen-Piasenziyen), Globorotalia inflata (Piasenziyen-Gelasiyen) zonlar› ve Globigerina calida calida Alt Zonu (Kalabriyen) tan›mlanm›flt›r. Bu çal›flmada tan›mlanan biyozonlar ile daha önceki araflt›rmalarda havza çökellerindeki yafl› geç Burdigaliyen-Langiyen olarak belirlenen Köselerli formasyonunun yafl›n›n havza kenar›n› temsil eden çökellerinde erken Pleyistosen (Kalabriyen)’e kadar ç›kt›¤› belirlenmifltir.

In this study, carried out in the Mut Basin, Reticulofenestra pseudoumbilica (Zanklian), Dictyococcites productus (Gelasian), Pseudoemiliana lacunosa (zones), Calcidiscus macintyrei, Helicosphaera sellii and Small Gephyrocapsa (Sub zones) (Gelasian-Kalabrian) nannoplankton zones with Globorotalia puncticulata (Zanklian-Piasenzian), Globorotalia inflata (zones) (Piasenzian-Gelasian) and Globigerina calida calida (Sub Zone) (Kalabrian) planktic foraminiferal zones were recognized in 72 samples collected from 3 measured stratigraphic sections at the upper levels of marginal deposits of the Köselerli formation. Based on these biozones, it is found that, age of the Köselerli formation has been extending to early Pleistocene (Kalabrian) at its marginal deposits. In the previous studies, the age of basin deposits of Köselerli formation has been determined as late Burdigalian-Langhian.