Age of the Silurian Lower Red Beds in South China:Stratigraphical Evidence from the Sanbaiti Section

The age of the Silurian Lower Red Beds in the Upper Yangtze region remains debatable.Twenty-four samples were collected for conodont biostratigraphical studies from the Paiyunan Formation in the Sanbaiti Section,Huaying,Sichuan Province.The conodont fauna from the Paiyunan Formation,together with the graptolites from the underlying Lungmachi Formation,indicates that the Lower Red Beds at Sanbaiti correspond to the lower Telychian.Comparative analysis indicates that most exposures of the Lower Red Beds in the Upper Yangtze region can be assigned,in general,to the Telychian Stage,except for several localities,where the Lower Red Beds can be roughly dated as an interval between the upper Aeronian and lower Telychian.