Benthic Foraminifera Biostratigraphy of the Lower-Middle Eocene Deposits in the Agcakisla Area (Sivas-Sarkisla)

The study area is situated in the Agcakisla (Sarkisla) area of the western edge of the Sivas Basin which is one of the major Tertiary basins of Central Anatolia. The Tokus Formation, which is the subject of this study, begins with conglomerate at the base, and constitutes with pebbly sandstone and coarse-grained sandstone. The unit consists of limestone with Alveolina and Nummulites and marl with planktonic foraminifera. The benthic foraminifera such as Alveolina minuta Checchia-Rispoli, Alveolina schwageri Checchia-Rispoli, Alveolina seni Sirel and Acar, Alveolina archiaci Sirel and Acar, Alveolina cremae Checchia-Rispoli, Alveolina cremae elongata Sirel and Acar, Alveolina tenuis Hottinger, Alveolina fusiformis Sowerby, Alveolina aff. callosa Hottinger, Alveolina aff. colatiensis Drobne, Orbitolites complanatus Lamarck, Fabiania cassis (Oppenheim), Gyroidinella magna (Le Calvez), Sphaeorogypsina globulus (Reuss), Asterigerina rotula (Kaufmann), Lockhartia hunti Ovey, Lockhartia tipperi (Davies), Assilina exponens (Sowerby), Nummulites deshayesi D'Archiac, Nummulites aturicus (Joly and Leymerie), Nummulites perforatus (De Montfort) and Discocyclina sp. were described. According to fossil assemblage, Cuisian-Bartonian age was given, and shallow benthic foraminifera biozones (SBZ) were described.