A New Age Constraint on the Onset of the Neoproterozoic Glaciations in the Yangtze Platform,South China

【摘要】：正A sample from the top of the Banxi Group(early Neoproterozoic) in Hunan Province(South China) was dated by the SHRIMP zircon U-Pb method.The resulting age of 725±10 Ma probably solves the debate between the synglacial and the pregkcial correlation of the Liantuo Formation and indicates that the Liantuo Formation most likely correlates with the pregkcial Banxi Group.Since the Banxi(Danzhou) Group is upwardly transitional to the glacial Jiangkou Group,the age becomes a new maximum age constraint on the onset of the Jiangkou glaciation,which therefore most likely correlates with the Sturtian glaciation.