The Qom Formation has an extensive distribution in northern to central Iran, and it is comprised of thick successions of marine marlstones, limestones, gypsum, and siliciclastics. This formation, which is composed of six lithostratigraphic units (members a to f), is important for oil and gas exploration. The purpose of this study was to identify the calcareous nannofossils in this formation in the Navab and Shurab sections of central Iran. Nannofossil assemblages were well preserved and had high abundances and diversities. According to this study, the age of the Qom Formation in both sections is Chattian to Burdigalian/Langhian in age, which is equal to Zones NP25 and NN4/NN5 of Martini (1971), Zone CNO6 of Agnini et al. (2014), and Zone CNM6-7 of Backman et al. (2012).

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