Relation between the formation of the Yellow River valley landforms from Gonghe, Qinghai to Lanzhou, Gansu and the uplifting in northeast part of Qinghai-Xizang plateau

According to a great deal of data measured practically in the typical area of the Yellow River valley from Gonghe to Lanzhou, and refering to the research results before, we propose that the valley landforms is formed by tectonic process under some conditions, and up lift rate of the valley landforms reflects two new tectonic events: one from 0.2 MaB.P.to 0.15 MaB.P.,and another from 0.01 MaB.P.to present.Since Quaternary, directing to northeast, the gradual reduction stress is indicated by the longitudinal section of the Yellow River terrace in Qinghai-Xizang plateau, the stress is disappeared in some period in Lanzhou.