Fossil Record 24(1): 171-192, doi: 10.5194/fr-24-171-2021
Baghuk Mountain (Central Iran): high-resolution stratigraphy of a continuous Central Tethyan Permian–Triassic boundary section
expand article infoDieter Korn, Lucyna Leda, Franziska Heuer, Hemen Moradi Salimi§, Elham Farshid|, Amir Akbari, Martin Schobben#, Abbas Ghaderi¤, Ulrich Struck«, Jana Gliwa, David Ware, Vachik Hairapetian
‡ Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Invalidenstraße 43, 10115 Berlin, Germany§ Geology Department, Faculty of Science, University of Isfahan, Isfahan, Iran| Department of Geology, North Tehran Branch, Islamic Azad University, Tehran, Iran¶ Department of Geology, Isfahan (Khorasgan) Branch, Islamic Azad University, Isfahan, Iran# Department of Earth Sciences, Utrecht University, Princetonlaan 8A, Utrecht, Netherlands¤ Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, P.O. Box 9177948974, Mashhad, Iran« Department of Earth Sciences, Institute of Geological Sciences, Freie Universität Berlin, Malteserstraße 74–100, 12249 Berlin, Germany
Open Access
Abstract

Permian–Triassic boundary sections at Baghuk Mountain (CentralIran) are investigated with respect to their lithological succession,biostratigraphy (particularly conodonts, nautiloids and ammonoids) as wellas chemostratigraphy (carbon isotopes). The rock successions consist of theLate Permian Hambast Formation, the youngest Permian Baghuk Member (new namefor the “Boundary Clay”) and the Early Triassic Claraia beds. Correlation of thedata allows the establishment of a high-resolution stratigraphy based onconodonts with seven Changhsingian zones. Abundant ammonoids enable theseparation of ammonoid assemblages with the successive Wuchiapingian generaPrototoceras, Pseudotoceras and Vedioceras, as well as the Changhsingian genera Shevyrevites, Paratirolites, Alibashites, Abichites and Arasella. Griesbachian andDienerian ammonoids are usually poorly preserved. Nautiloids occurpredominantly in the Wuchiapingian part of the section with two successiveassemblages dominated by the Liroceratidae and Tainoceratidae, respectively.Numerous Early Triassic strata contain microbialites of various outermorphology and microstructure. The carbon isotope curve (δ13Ccarb) shows a continuous late Changhsingian negative excursioncontinuing across the Baghuk Member with the lightest values at the base ofthe Triassic.