Litho- and biostratigraphy of the Upper Jurassic Mozduran Formation, Kopet-Dagh, Iran, and its paleoenvironmental implications

The Upper Jurassic Mozduran Formation at Baghak section, Kopet-Dagh area northeast Iran, characterized by multiple units of carbonates and evaporates intercalated with siliciclastic deposits, yielded benthic foraminifera, calcareous algae, and crustacean coprolites, including Alveosepta jaccardi, Charentia aff. nana, Deloffrella quercifoliipora, Marinella cf. lugeoni, Favreina, and Solenopora sp. The almost consistent occurrence of Alveosepta jaccardi in the studied section, i.e., the Alveosepta jaccardi Zone, indicates late Oxfordian to the Kimmeridgian in age. Facies analysis of the formation reveals depositional settings of a peritidal zone, a lagoon, and a high-energy shoal of a carbonate ramp. Terrigenous and evaporites are found in eastern parts of Kopet-Dagh, representing a more proximal sedimentary environment. These siliciclastic inputs are associated with tectonic events during Oxfordian to Tithonian in the region. & COPY; 2022 Elsevier B.V. and Nanjing Institute of Geology and Palaeontology, CAS. All rights reserved.