A structural system of longitudinal folds superimposed by latitudinal folds occurs in the pre-Sinian rocks northwest of the suture zone between the Jiangnan and Cathaysia blocks. It is an intracontinental deformation system resulting from the structural stress caused by the collisions of the Huaiyu terrane moving westwards and the Cathaysia block moving northwestwards. Therefore, the superimposed fold system and the suture zone are interrelated in origin and they have the distinct deformation features in different structural positions. This structural system was formed in the pre -Sinian, probably related to the Grenville orogenic event.