Mammalian biochronology of Neogene deposits and its correlation with the lithostratigraphy in the Cankiri-Corum basin, central Anatolia, Turkey

Geologists distinguished several sedimentary units in Neogene continental deposits of the Cankiri-Corum Basin (north-central Anatolia). However, there are great disagreements on their spatial distribution, chronology and geometric relationships. In order to provide a reliable chronology for these units, all available biochronologic data obtained on mammalian faunas are reviewed, and their stratigraphic and tectonic implications are discussed. Reasonably rich mammalian associations are recorded from 17 localities; their ages range from earliest Miocene to early Pliocene. This review reveals that most previous dates attributed to these units should be modified. The deposits which yielded the Kilcak faunas (mapped as in the Hancili Formation or Kumartas Formation) belong in fact to a distinct unit underlying the Kumartas Formation. The age of the Kumartas Formation is late early and middle Miocene based on mammalian associations. Biostratigraphic data are still scarce for the unconformably overlying Hancili Formation. The Kizilirmak Formation is mainly composed of pinkish red elastic deposits and has been dated as late Miocene, thanks to two rich mammal localities. This study shows that further paleontologic evidence is needed to refine the age estimates of these formations, and that new mapping projects have to take into account the biostratigraphic results.