Mahnaz Parvaneh Nejad Shirazi, Mahmud Rezaei
Department of Geology, Payame Noor University, Tehran, Iran
Key words: Banesh, Dariyan Formation, Carbonated platform, Ramp.
The Dariyan Formationin studied section is in the vicinity of Dare-sefid village. The studies on this region show the sedimentation of Dariyan Formation between two discontinuities in a carbonated platform of ramp type. In this region, eight microfacies including five types of faciesbelts namely open marine, restricted environment, submarine ridges (i.e. shoal), Lagoon and tidal flat environment can be detected. The comparison of analyzed facies with current environments and considering the formation environment of each set of facies, lack of reef facies, expansion of peloidsfacies and absence of iteratively deposited facies show that Dariyan Formation in Banesh region is formed in a carbonated platform of ramp type. The associated analyses show that in the length of middle aptian, carbonated depositions include aggregations saturated with foraminifera and calcareous algae within Dariyan Formation of the intended region so that the accumulation of bioclasts, especially benthic foraminifera, rise from open marine to subtidal and inter-tidal side. In section 8 (i.e. S1 Microfacies), the prevalence of foraminifera gets to more than 95% while their lowest prevalence is found in open marine and tidal flat. The formation environment of Dariyan Formation in the studied region is mainly associated with tidal to lagoon environment so that 74% of the formation is made in these two environments.