عنوان مقاله [English]
In order to study the biostratigraphy, lithostratigraphy and diagenesis of the Rute Formation in central Alborz basin, a stratigraphic section was selected in 30 km south of Amol city. This formation with a thickness of 642 m, mainly consisting limestone, dolomitic limestone and shale, disconformably lied on Sandstone of Ruteh Formation and underlied disconformably by Nessen Formation. Based on the biostratigraphy studied 31 genera and 57 species of benthonic foraminifera were identified. The age of the Ruteh Formation in the studied section was determined based on the distribution of the index benthic Foraminifera, the Early Morghabin to the Late Julfian, which is equivalent to the 3 bioZones Neoendothyra bronnimanni-Neoendothyra reicheli Assemblage Zone, Chusenella sinensis-Codonofusiella erki-Pachyphloia sp. Assemblage Zone and Paraglobivalvulina mira - Pachyphloia iranica Assemblage Zone. Petrographic studies indicating that limestone have been influenced by various diagenitic processes including of micritization, cementation, neomorphism, substitution (silicification and dolomitization) and dissolution.