Because the back-arc deep process and magmatic activity have been sharply decreased since Pliocene,the affections to the area of northeastward compression from western China,and rifing of Baikal and Momu basins to the area ,have been Strikingly increased.

• 自上新世以后由于弧后深部作用和岩浆活动的大大减弱；来自我国西部向东北方向的挤压和贝加尔裂谷、莫穆裂谷的活动对此区的影响明显增强.