Aras Valley (northwest Iran): high-resolution stratigraphy of a continuous central Tethyan Permian–Triassic boundary section
Jana Gliwa, Abbas Ghaderi, Lucyna Leda, Martin Schobben, Sara Tomás, William J. Foster, Marie‐Béatrice Forel, Nahideh Ghanizadeh Tabrizi, Stephen E. Grasby, Ulrich Struck, Ali Reza Ashouri, Dieter Korn
Abstract
Abstract. The Permian–Triassic boundary section in the Aras Valley in NW Iran is investigated with respect to carbonate microfacies, biostratigraphy (particularly conodonts, nautiloids, and ammonoids), chemostratigraphy (carbon isotopes), and environmental setting. Correlation of the data allows the establishment of a high-resolution stratigraphy based on conodonts (with four Wuchiapingian, 10 Changhsingian, and three Griesbachian zones), ammonoids (with nine Changhsingian zones), and carbon isotopes; it forms the base for the reconstruction of the environmental changes before and after the end-Permian extinction event at the studied locality. In the Aras Valley section, there is no evidence for the development of anoxic conditions, associated with the end-Permian mass extinction.