Baghuk Mountain (Central Iran): high-resolution stratigraphy of a continuous Central Tethyan Permian–Triassic boundary section

Abstract. Permian–Triassic boundary sections at Baghuk Mountain (Central Iran) are investigated with respect to their lithological succession, biostratigraphy (particularly conodonts, nautiloids and ammonoids) as well chemostratigraphy (carbon isotopes). The rock successions consist of the Late Permian Hambast Formation, youngest Member (new name for “Boundary Clay”) Early Triassic Claraia beds. Correlation data allows establishment a high-resolution stratigraphy based on conodonts seven Changhsingian zones. Abundant ammonoids enable separation ammonoid assemblages successive Wuchiapingian genera Prototoceras, Pseudotoceras Vedioceras, Shevyrevites, Paratirolites, Alibashites, Abichites Arasella. Griesbachian Dienerian usually poorly preserved. Nautiloids occur predominantly in part section two dominated by Liroceratidae Tainoceratidae, respectively. Numerous strata contain microbialites various outer morphology microstructure. carbon isotope curve (?13Ccarb) shows continuous late negative excursion continuing across lightest values base Triassic.