Neoproterozoic sedimentary records in the Cathaysia Block and their implications for the supercontinent reconstruction

The tectonic framework and paleogeographic evolution of Neoproterozoic-early Paleozoic successions in the South China Block provides the first-order constraint on its role in the break-up of Rodinia and the subsequent amalgamation of Gondwana. However, there still is much disagreement in defining the paleoposition of the Cathaysia Block and its relationship with the Yangtze Block. In this thesis, isotopic geochronology, Neoproterozoic glaciations, and mineralization records were found in the Cathaysia Block, providing new evidence for the stratigraphic framework. Detrital zircon U-Pb dating results provide evidence of prominent provenance transition during late Tonian to Ediacaran, and bidirectional sources in the western margin of Cathaysia Block at late Cryogenian, integrating with the evidence from a sedimentary environment of neritic shelf, a closure of paleo-South China Ocean is suggested during late-Neoproterozoic. The detrital records of the early Tonian -Ediacaran strata in the Cathaysia Block present abundant late Mesoproterozoic to early Neoproterozoic（1200-950 Ma）ages. These ages match the record of East Gondwana, and imply a peripheral setting for South China with respect to the supercontinent and most likely adjacent to India during the transitional period from the Rodinia supercontinent to the Gondwana.