Reconstructing South China in the Mesoproterozoic and its role in the Nuna and Rodinia supercontinents

Abstract

South China, consisting of the Yangtze and Cathaysia blocks (including Hainan Island), is characterized by episodic magmatism and lithospheric-scale tectonism during 1.7–1.0 Ga, and is important in the Nuna and Rodinia reconstruction. Three newly identified Mesoproterozoic magmatic intervals at 1.76–1.60 Ga, 1.53–1.37 Ga, and 1.25–1.05 Ga, were accompanied by three mineralization events at 1.65 Ga, 1.45 Ga, and 1.05 Ga. These events are also recorded by detrital zircon from ca. 1.05 Ga equivalent sedimentary sequences in both western Yangtze and central Hainan Island. These findings indicate a common Proterozoic tectonic history shared by central Hainan and Yangtze, contradicting models invoking Grenvillian-aged tectonism in South China. The Yangtze Block occupied an intracratonic position (between Laurentia and Australia) in Nuna, before it drifted away and docked to Western Australia and northern India in the reconfigured Rodinia. The Cathaysia was located close to northern India during the Proterozoic.