Study of paleoecology and paleoceanographic condition of Khangiran Formation based on the lack of Morozovella (Index genera of Eocene planktonic foraminifera)

Kopet-Dagh basin is located in north and northeast of Iran. Khangiran Formation is one of the most important formations of Paleogene deposits. For study of Khangiran Formation, Chehelkaman Syncline section was selected. This section located in southwest of Sarakhs city, east of Kopet-Dagh basin. Thickness of this section is 136 meters and lithology of this section composed alternation of olive green Marl and limy yellow Marl. In this research foraminifera fauna of Khangiran Formation was studied. The age of this section is Early-Middle Eocene, and planktonic foraminifera fauna of this section shows anomaly. Based on this anomaly, lack of Morozovellids, that are index fossils of Eocene, was observed. Eutrophic condition of this Formation as for the planktonic and benthonic foraminifera study is the reason of this subject that it's the result of changes in the paleoceanographic conditions such as situation of stratification of water column and nutrient changes. As far the Morozovellids cant accordance with eutrophic condition, lack of the species mans of this genus observed for Khangiran Formation. Khangiran Formation condition is comparable with Caucasus basin and this subject can be indicating of same condition of this two basin at least during the Eocene time.