Since mid Eocene the main basin bounding faults were transverse to the orogen, which were controlled by E-W trending extension in East China circum Pacific belt and deep tectonism.

• 大致在中始新世之后，受中国东部环太平洋构造带东西向伸展作用和深部构造作用控制，横跨造山带形成近南北向的裂谷盆地。