Foraminiferal biostratigraphy a and b Members of the Qom Formation in type area, Kuh- e- Dobaradar section, Southeast Qom

In this study, the stratigraphic distribution of planktic foraminifera of a and b Members of the Qom Formation, in Kuh - e -Dobaradar, southeast Qom has been investigated. The thickness of a and b Members in examined section is 174 m and consists mainly of marl, sandy marl and sandstone and conglomerate. With respect to importance of the Qom Formation and its vast distribution in different parts of central Iran zone and different ideas about its age, the investigation about the age of a and b Members of the Qom Formation in this area is necessary. For this purpose micro paleontological studies on 72 samples in examined section led us to recognition 7 genera and 12 species from 4 families of planktic foraminifera. According to occurrence of Globigerinoides primordius from the base of a Member (sample no. DB- 2) and Globigerinoides triloba, from sample no. DB- 6, and Paragloborotalia kugleri (sample no. DB- 42), the sediments of the a and b Members probably belong to Aquitanian.