Foraminiferal Biostratigraphy of the Qom Formation on the basis of new investigations at Navab anticline, in southeast Kashan



The sediments of the Qom Formation in the north of Navab anticline located in southeast Kashan is composed of limestone, sandy limestone, argillaceous limestone, sandstone, conglomerate, marl and gypsiferous marl with 211 m thickness. The mentioned formation disconformably overlies the Lower Red Formation and underlies the Upper Red Formation. The collection and study of 101 hard and soft samples from the Qom Formation led to recognition of 53 genera and 99 species of benthonic foraminifera and 4 genera and 6 species of planktonic foraminifera, which 33 genera and 77 species are reported for at the first time. On the basis of stratigraphic range of faunal assemblage, the age of the Qom Formation in the studied section is Aquitanian to Burdigalian. Whereas based on previous studies, it is assumbed that at least part of the sediments must belong to Oligocene. On the other hand, Zhu et al. (2007).