The Distribution and Statistical Analysis of Eocene Planktonic Foraminifera in the Khangiran Formation (Chehel-Kaman Synclinal Entrance, West Sarakhs) and their Paleoecological Use

Planktonic foraminifera of the Khangiran Formation that represents the last marine deposits in the Kopeh-Dagh basin and exposed in the Chehel-Kaman synclinal entrance (west of Sarakhs) studied in this article. A sum of 32 species belonging to 11 genera of planktonic foraminifera were recorded allowing erection of seven biozones from E4 E11. indicating an age of Ypresian-Lutetian for this Formation. Based on the statistical analysis of planktonic foraminifera of the Khangiran Formation، the low and common abundances of Subbotina genus and its rare of appearance and disappearance in the upper samples of the formation and the low abundance of Catapsydrax and Parasubbotina genera and the high abundance of Acarinina genus throughout this formation indicate a warm water and intermediate trophic conditions for the depositional course of this formation in this basin.