New age findings with microfossils of the Van Formation (Van, Eastern Anatolia)

Van Formation, which is mainly represented by conglomerate, sandstone, marl and limestone, covers a large area around the Van province. The age of the unit was assigned in different localities of the region as late Oligocene - middle Miocene, early Miocene, Burdigalian - Langhian (early - middle Miocene) by previous studies. In order to determine the age of the upper levels of the formation in the east and southeast of Lake Van, a total of 98 samples collected from three measured stratigraphic sections. These samples have been examined in terms of calcareous nannoplankton and planktonic foraminiferal content. 33 species of 12 calcareous nannoplankton genera and 18 species of 9 planktonic foraminiferal genera representing the Serravalian - Tortonian interval have been identified. Calcareous nannoplankton and planktonic foraminiferal biozones of the unit could not be defined in the study area because of some samples do not contain calcareous nannoplankton and planktonic foraminifera, some samples are scarce in fossils and not all of the zonal markers have been identified. Considering the stratigraphic distribution of the calcareous nannoplankton and planktonic foraminiferal species that the formation contains, age of the Van Formation in the study area is re-evaluated as Serravallian - Tortonian (middle - late Miocene). This shows that marine features continued in the Tortonian (late Miocene) in the study area.