Recognition of Late Neoproterozoic bimodal volcanic rocks from the Yaolinghe Formation in the Suizao terrane of South Qinling massif and constraints on the continental rifting of the northern margin of Yangtze craton

Neoproterozoic tectonic evolution of the northern Yangtze craton is of great significance to the Precambrian geological evolution of South China.Zircon samples collected from the newly recognized bimodal meta-volcanic rocks of the Yaolinghe Formation in the Suizhou area were dated by LA-ICP-MS U-Pb method.Most zircons in the matabasalts are inherited zircons, their ages are consistent with those of detrital zircons from the underlying Wudang Formation in the region.Geochronological results also indicate that the muscovite-phyllites (felsic rocks) were formed at 623±3 Ma, representing the sedimentary age of the Yaolinghe Formation, synchronous with the 650-600 Ma intrusive sills in the Suizao terrane.Combined with the new geochronological data recording rifting-related magmatic-sedimentary rocks during the Late Neoproterozoic in the northern margin of the Yangtze craton, it can be advocated that the breakup of the Rodinia supercontinent in the northern part of the Yangtze craton might have been a long-lasting process.An oblique diachronous rifting model is further hypothesized for the breakup process.