Biostratigraphy and paleo-ecological reconstruction on Scleractinian reef corals of Rupelian-Chattian succession (Qom Formation) in northeast of Delijan area

In this research, biostratigraphy and paleo-ecological reconstruction of the Qom Formation deposits in Bijegan village, northeast ofDelijan, are discussed. The studied section is situated in the western margin of the Urumieh-Dokhtar magmatic arc (the intra-arc basin).The Qom Formation deposits at the studied area are Rupelian-Chattian in age. Larger benthic foraminifers are used for biostratigraphywith the occurrence of 14 genera and 16 species, which led to the identification of two faunal assemblages: 1 Nummulites vascus-N.fichteli, and 2. Lepidocyclina-Operculina-Ditrupa. Oligocene coral assemblages from the studied section are investigated with regardto its palaeoecological implications. These corals comprise four species of four genera and are compared with faunas from theMediterranean Tethys and Indo-pacific Ocean, and they have an affinity to corals of the Mediterranean Tethys. Re-deposited branchingPorites coral assemblages probably occurred in patchy dense frameworks which were destroyed during storm events and re-depositedin the present stratified horizons. The Porites-Faviidae assemblage represented a common feature of Oligocene coral faunas andincreasing water energy.