Early Permian longitudinal position of the South China Block from brachiopod paleobiogeography

Abstract. Knowledge of the past location of tectonic plates is essential to understanding the evolution of climate, ocean systems, and mantle flow. Tectonic reconstructions become increasingly uncertain as one moves further back in geological time. Paleomagnetic data constrain the past latitude of continental blocks but not their past longitude. For example, the longitude of the South China Block during Early Permian times is unknown. Paleobiogeographic data, which have long been used in tectonic reconstructions, make it possible to evaluate the faunal similarity between continental blocks. In this study, we use the global brachiopod distribution for two Early Permian time periods (Asselian–Sakmarian times between ∼ 298.9 and ∼ 290.1 Ma and Artinskian–Kungurian times between ∼ 290.1 and ∼ 274.4 Ma) from the Paleobiology Database to evaluate the correlation between faunal similarity and physical distance of continental blocks for three distinct tectonic reconstruction models. We use this approach to assess which of the three tectonic scenarios places the South China Block in a location that best accounts for the Early Permian brachiopod distribution data. Based on this analysis, the preferred tectonic reconstruction places the South China Block in a central position within the Paleo-Tethys Ocean instead of on its outskirts. The framework developed in this study is openly available and our approach can be applied to other tectonic blocks, time periods, and faunal data.