The NWW-sense compression deriving from subconvection of the upper mantle under the above Marginal Sea area makes the Tanlu fault zone slip compressionally and dextrally.

• 晚新生代以来，西太平洋俯冲带后退，上地慢上涌力作用已退到边缘海地区，郯庐断裂带全段受到边缘海地区上地慢上涌力诱发的次级挤压作用力，形成了右旋挤压活动。