Biostratigraphy and Lithostratigraphy of the Qom Formation in the Southeast of Damavand (Varaneh Village Section)

Biostratigraphy and Lithostratigraphy of the Qom Formation in the Southeast of Damavand (Varaneh Village Section)

The Qom formation in Varaneh section with a thickness of 150.6 m generally includes thick layered marls with interlayers of sandy limestone, medium-to-thick layered limestone, alternatives of limestone and marl, and finally, gypsum. In this study, 6 stone units were identified. Based on the studies conducted in the area, units 1, 2, and 3 were equivalent to member e of the Qom Formation, and units 4, 5, and 6 were equivalent to member f of the Qom Formation. In order to determine the age of Qom Formation in the section studied, 31 thin sections were examined in detail. Finally, based on the studies, 13 genera and 14 species of benthic foraminifera and 2 genera of algae were identified. In addition, based on the distribution of microfossil stratigraphy, only one biozone was recognized. Due to the existence of indicator species including Borealis melo curdica, Meandropsina iranica, and other species such as Dendritina rangi and peneroplis, this biozone was comparable to Borelis melo group - Meandropsina iranica assemblage zone [1]. For this reason, it can be concluded that the deposits of the Qom Formation in this section are in the same age as Burdigalin.