Detrital zircon provenance investigation from the Neoproterozoic successions of the South China Block: Paleogeographic implications

Abstract

We report U-Pb isotopic data for detrital zircons from the Late Neoproterozoic Dengying Formation on the northern margin of the Yangtze Block and the other published Neoproterozoic U-Pb isotopic data in the South China Block (SCB), which provide critical constraints on the provenance of these sediments and further shed light on the Neoproterozoic paleogeographic evolution of the SCB in the context of the Rodinia and the succeeding Gondwana supercontinents. The SCB-northern India provenance linkage has started from the Cryogenian. Single Neoproterozoic zircon population from the Upper Cryogenian suggests local detritus supply and the western margin of the Yangtze Block was possibly on an arc setting. Therefore, we speculate that the SCB was independent or located along the margin of Rodinia supercontinent during the Cryogenian. Detrital zircon age spectrum of this study shows similarity with the Cryogenian samples in the eastern Yangtze Block, but with the addition of ‘Pan-African’ age population, which implies that the SCB-India assemblage had been linked with the Gondwana supercontinent during the Ediacaran. Except for a small amount of recycled materials, the Late Neoproterozoic detritus in part of the western Yangtze Block were predominantly derived from the Panxi-Hannan Belt. Early Paleozoic detrital zircon age spectrum of the Tethyan Himalaya is similar with the Late Neoproterozoic age spectra of the Cathaysia Block, whereas appears to be different from the Late Neoproterozoic age spectra of the western Yangtze Block, which implies that the northern India was probably linked with the southern margin of the SCB during the Ediacaran time interval. Finally, the SCB assembled with the western Australia during the Early Paleozoic.