New SIMS U–Pb zircon age and its constraint on the beginning of the Nantuo glaciation

Abstract

A new SIMS U–Pb zircon age of 654.2 ± 2.7Ma was reported from the middle Datangpo Formation in Changyang County of Hubei Province, China. The age is identical with that of 654 ± 3.8Ma from the top Datangpo Formation in western Hunan Province, revealing that the volcanic activities (~654Ma) may have occurred widely in South China. The occurrence of the tuff beds (~654Ma) at different intervals of the Datangpo Formation indicates that the erosion process after the Datangpo deposition varied significantly in different areas. It is thus consequently suggested that the rift in South China was active until the Nantuo glaciation. In addition, the new age confirms that the Nantuo glaciation started much later than 654Ma.