Foraminiferal Assemblages, Biostratigraphy and Lithostratigraphy of the Permian Deposits in NW Iran: A Constraint for Paleogeographic Reconstruction

Abstract

This study investigates foraminiferal assemblages, biostratigraphy and lithostratigraphy of the Permian deposits in northwestern Iran, specifically focusing on the Sariqaiyeh and Alibalta sections. Our findings reveal that the Permian carbonate successions can be subdivided into 13–14 lithostratigraphic members based on distinct facies characteristics and grain composition. Detailed analysis of foraminiferal assemblages allowed us to establish several biozones, including: Schubertella-Mesoschubertella (Yakhtashian-Kubergandian), Eotuberitina, Deckerella-Paradunbarula-Globivalvulina-Tetrataxis (Early Murghabian), Protonodosaria-Pseudolangella (Middle-Late Murghabian), Paraglobivalvulina (Midian), Ichthyolaria-Dagmarita (Dzhulfian) and Paraglobivalvulinoides-Reichelina (Dzhulfian-Dorashamian). The similarities in foraminiferal assemblages and lithological characteristics between the studied sections and the Alborz structural zone suggest that both regions experienced comparable sedimentary and paleogeographic conditions influenced by the collapse of the Cimmerian terrane. This connection likely facilitated a shared faunal and sedimentological environment between the Palaeotethys and Neotethys oceans. Consequently, our study contributes to a better understanding of the paleogeographic reconstruction of the region during the Permian period and emphasises the significance of lithology and foraminifers in lithostratigraphic–biostratigraphic correlations in northwestern Iran.