Microfacies and sedimentary environment of the Kazhdumi formation in the northern flank of the Khami Anticline, Zagros Basin, southwestern Iran

In this study, to investigate the microfacies and depositional environment of the Kazhdumi Formation in the eastern of the Izeh Zone, the Fath stratigraphic section was selected in the northern flank of the Khami Anticline. In this section, the Kazhdumi Formation consists of a succession of limestone, shale, and marl, which lies unconformably on the Dariyan Formation. In addition, the Sarvak Formation conformably and gradually overlies the Kazhdumi Formation. The rocks of the Kazhdumi Formation in the Fath section contain 12 microfacies. The detected microfacies show that the Kazhdumi Formation was deposited in an intrashelf basin in the studied section. In this intrashelf basin, four sub-environments including basin, outer platform, middle platform, and platform margin were identified. The microfacies of the basin in the Fath section are characterized by the presence of organic-rich shales, abundant radiolarians, and planktonic foraminifera, and the outer platform is characterized by the abundance of planktonic foraminifera and oligosteginids. The microfacies of the middle platform are characterized by the association of planktonic and benthic foraminifera, sponge spicules, and peloids, and the microfacies of the platform margin are characterized by the presence of peloids and benthic foraminifera. In this section, the microfacies of the deep environment are wider and the shallow-water microfacies are not observed except in the upper part of this formation.