Seven first-level combination types are extracted according to the combination forms of detachment-fault and deformation-structure,which are the the type of basal decollement thrust-anti-transformation in north of Subei-South Yellow Sea (Ⅰ),the type of uplift in South Yellow Sea centre(Ⅱ),the type of thrust-anti-transformation in Suzhong and south-central of South Yellow Sea(Ⅲ ),the type of siluric decollement nappe in Sunan and south of South Yellow Sea (Ⅳ),the type of basal decollement thrust in Wannan-Zhexi-Wunansha (Ⅴ),the type of thick-skinned deformation in Jiangnan uplift (Ⅵ),and the type of thick-skinned deformation in Zhangbaling-Qianliyan thick-skinned deformation (Ⅶ).Five second-level combination types are extracted according to the deformation combination characteristic of structure layers above and below detachment-fault,which are the type Ⅰ that upper palaeozoic accord with lower palaeozoic,the type Ⅱ that both upper palaeozoic and lower palaeozoic are simple,the typeⅢ that upper palaeozoic is simple and lower palaeozoic is complex,the type Ⅳ that upper palaeozoic is complex and lower palaeozoic is simple,the type Ⅴ that both upper palaeozoic and lower palaeozoic are complex.According to the three level division rule,lower Yangtze area is divied into seven first-level divisions,seven second-level divisions,and ten third-level divisions.
