The Permian–Triassic transition in Türkiye: New insights and 3D outcrop models for accessible, reproducible and sustainable fieldwork

Baran Karapunar , Xia Wang, Anja B Frank , Müjde Gürsoy, Stella Z. Buchwald, Mónica Alejandra Gómez Correa, Zhipeng Liu, Xuanni Xu, Lingzan Meng, Damla Demir, Erdal Koşun, William Foster

The Permian–Triassic transition is characterised by major environmental changes and the largest known mass extinction event in the Phanerozoic. However, successions with a relatively complete sedimentological and palaeontological record across the Permian–Triassic are limited to a few well-known sections. The Antalya and Aladağ Nappes in south-western Türkiye provide extensive outcrops of the Permian–Triassic transition. Some key investigations have revealed the importance and potential for these successions to improve our understanding of the events across  the Permian–Triassic. Here, we incorporate 3D open-access virtual outcrop models with a virtual field guide to introduce the Permian–Triassic transition in south-western Türkiye, to improve the accessibility, reproducibility and sustainability of fieldwork findings. The fossiliferous Upper Permian to Lower Triassic successions in the studied locations reach over a kilometre thickness. Due to the contemporaneous opening of the Neotethys Ocean, the exposures from the Antalya Nappe (Çürük Dağ in Kemer; Öznurtepe in Gazipaşa; and Demirtaş in Alanya) are considered to be deposited on a southward facing carbonate platform in the Neotethys Ocean, whilst successions from the Aladağ Nappe (Taşkent in Konya) are considered to be deposited on the northern side of the carbonate platform towards the Palaeotethys Ocean. In all sections, the Changhsingian (uppermost
Permian) is represented by highly fossiliferous platform carbonates. The Changhsingian successions terminate with a thin oolitic grainstone (‘transitional oolites’), which is identified as the Permian–Triassic mass extinction interval and is characterised by a negative carbon isotope excursion. The transitional oolites are overlain by microbialite-dominated carbonates, and then oolite-dominated carbonates deposited in the Griesbachian. This carbonate-rich deposition was replaced with a mixed carbonate-siliciclastic succession later in the Early Triassic (Dienerian–Spathian), when marine ecosystems slowly recovered. These environmental and biotic changes are similar to the known record from the tropical palaeolatitudes in the western to eastern Palaeotethys.