Age assignment of the Susong Group,Hong''an Group and Haizhou Group:A discussion

This paper systematically introduces the latest progress in the study of the original Hong'an Group,Susong Group,Feidong Group and Haizhou Group.Based on disintegrating these groups into de-formed and metamorphosed intrusive bodies and phosphatic metavolcanic-sedimentary rock series,the au-thors propose new evidence for the ages of these groups and stratigraphic assignment of the phosphatic horizon.