During late Indo-Sinian epoch and middle Yanshan epoch

the Mesozoic and Paleozoic in Lower Yangtze region in Jiangsu changed from a stable oceanic-continental plate tectonic system into an intraplate deformation system

resulting in a ramp thrust tectonic framework with NW to SE thrusting in northern Jiangsu and SE to NW thrusting in southern Jiangsu.In northern Jiangsu

the Sinian and Lower Paleozoic overthrusted along the Doushantuo Formation and a subsidiary detachment;while in southern Jiangsu

the Upper Paleozoic overthrusted along the Gaojiabian Formation detachment

and the Lower Paleozoic became duplex thrust structure under the control of the two detachments.In middle Yanshan epoch

NNE left lateral compresso shear and NW right-lateral compresso-shear strike-slip movements modified the former thrust structures.In late Yanshan epoch

the regional stress setting turned into NE-SE extensional environment

in which the overthrust nappe slipped back along fault ramps under gravitational force

resulting in a half graben like fault depression.While in southern Jiangsu

the Lower Paleozoic duplex thrust structure and the Upper Paleozoic thrusting over Silurian made it difficult to slip back

due to limited potential energy of vertical displacement.The uplifting in late Himalayan epoch finally led to the tectonic framework of Mesozoic Paleozoic being high in southern Jiangsu and low in northern Jiangsu.