Digital paleogeographic reconstruction of the eastern Tethyan tectonic domain from the Middle Permian to the Middle Triassic

Abstract

Paleogeographic reconstruction studies the evolution of the earth's surface tectonic process, the pattern of land and sea, climate, and biology in time and space in geological history. With the advent of the big data era, the accuracy of the digital paleogeographic reconstruction is essential. Although there are various global paleogeographic reconstruction models, there is still a lack of paleogeographic reconstruction integrating tectonic, lithofacies, paleontology, and paleoclimate data. In this paper, a case study of the comprehensive paleogeographic reconstruction is carried out in the Middle Permian-Middle Triassic eastern Tethyan tectonic domain, which is highly concerned and rich in geological data accumulation. The digital paleogeographic map is completed by the combination of automatic mapping with machine learning and manual correction. We use the newly upgraded paleomagnetic, geological and paleontological data to reconstruct the paleoposition of the East Asian blocks at 260, 250 and 240 Ma, which shows the Paleo-Tethys Ocean (PTO) had a wider east-west range than the previous version due to adopting the method of Torsvik et al. (2008) to reconstruct the paleolongitude of South China at 260 Ma. The new model shows the PTO was semi-closed with several narrow seaways and was divided into north and south branches at 260 Ma. Based on the updated lithofacies paleogeographic map data of China and marine fossils data, we updated the paleogeographic map of the Eastern Tethyan tectonic domain on the basis of the global paleogeographic map, combining automatic mapping with machine learning and manual revision of paleotopography and paleocoastline. Based on the new tectonic paleogeographic reconstruction, we revised the paleoclimate zonation pattern of the East Tethys ocean using climate-sensitive lithologies.