Estimating the relationship between South China and Gondwana based on big data analysis

Abstract

The situation of South China within the ancient continent Gondwana remains a topic of discussion and controversy. The reconstruction of South China's linking to East Gondwana is crucial for understanding the evolutionary history of the Gondwana breakup, the growth of Asia, and the development of the Paleo-Tethys Ocean. Based on the newly established database of detrital zircons (https://repository.deep-time.org), this study integrates UPb age dating and Hf isotope analysis of detrital zircons from Early Paleozoic strata in South China. The aim is to investigate potential sources, provenance, and reconstruct its tectono-paleogeography during the early Paleozoic on the northeast margin of Gondwana. The UPb age distributions from detrital zircon populations predominantly reveal peaks in the Paleoproterozoic, Mid/Neoproterozoic, and Early Paleozoic eras, ca. 2480, 960, 830, 520, and 440 Ma, with a minor peak at approximately 1750 Ma. The significant temporal shift in the major age populations from approximately 2480 to 440 Ma reveals the global continental crustal growth of South China through a sequence of subduction and collision processes. These geodynamic processes contributed to the development of the mid-Paleozoic Kwangsian intraplate orogeny in the late early Paleozoic (ca. 440 Ma) in South China, ultimately leading to the final assembly of Gondwana. The latter orogeny is marked by regional unconformity between pre-Devonian and Devonian strata, accompanied by prevalent magmatic and metamorphic events. These earliest Proterozoic and mid-Paleozoic detrital zircon grains match with ages from India- Tethyan Himalaya region, but different from those from East Antarctica, western margin of Australia and Lhasa Block where Australia and India were detached by the Kuunga Ocean, suggesting assembly and paleogeographical constraints of South China. It fully shows that South China is located on the northeast margin of the Indian during early Paleozoic, which is of great significance for the reconstruction of the tectonic paleogeography of the continent.