Zircon U-Pb age of Wudang Group: implication to the breakup model of North Yangtze Block during the Early Neoproterozoic

The Wudang Group exposed in the northern margin of Yangtze Block is one of the most important basement of South Qinling Orogen, and it records the oldest provenance information of South Qinling Orogen. In order to explore the stratigraphic sequence of Wudang Group and rift evolution model of Nanhua period in the northern margin of Yangtze Block, we dated the zircon U-Pb age of clasolite and volcanics from typical geological sections of Wudang Group in Suizhou area, and determined the sedimentary sequence of Wudang Group. Combined with the chronological information of Wudang Group in Suizhou and Wudang area from previous researches, we find that the stratigraphic age of Wudang Group in Wudang area is older about 30 Ma than the ages in Suizhou area, which shows that the rift during Neoproterozoic may be cracking gradually like a "scissor" from west to east in the northern margin of Yangtze Block. The main age peaks of detrital zircons from Wudang Group is about 722 Ma, 759 Ma, 820 Ma, 2014 Ma and 2445 Ma, which has a good correlation with main age peaks of detrital zircons from Yangtze Block, suggesting that the main provenance of Wudang Group is coming from the Yangtze Block. The age peak of 2014 Ma shows there may be provenance information from Tongbai-Dabie area, and the age peak about 722~759 Ma represents the strongest period of breaking up in the northern margin of Yangtze Block, whick may be the embodiment of the Rodinia supercontinent break-up in the northern margin of Yangtze Block.