Paleoenvironmental study of the marly beds of the Farrokhi Formation (Central Iran) based on their ostracods content

The Farrokhi Formation is the youngest sedimentary unit in Upper Cretaceous of Khur and Biabanak area. Its lithology is mainly consists of limestone, marl, marly limestone with intercalations of fossiliferous limestone. For environmental interpretation of this formation, 23 specimens of marly beds are sampled and washed.. The study led to identification of 23 genera and 29 specious of ostracods. More than 87% of determined Ostracods have straight shell, without any ornamentation and connected to each other. It is concluded that the high rate in sedimentation led to well preservation of this fauna. According to the determined Ostracods, four ecofacies "i.e. littoral, inner neritic, outer neritic and outer neritic with low to high salinity and warm" are identified for the marly beds under study.