【摘要】 在湟水河流域发育夷平面、阶地和不对称的山脉、沟谷等地貌,对阶地、夷平面上的条带状水成黄土层的倾向和倾斜率的系统测量,反映出流域内地表的抬升。根据对称性可分为4 个阶段,隆升在大的时间尺度上是均匀的,在小尺度上是不均匀的;当高原隆升到一定高度后,受印度板块侧向挤压,高原向四周的应力的共同作用使祁连山隆升,并伴随着气候恶化。更多还原

【Abstract】 There are level planation surfaces,terraces and unsymmetrical landforms in the Huangshui River drainage area,west to Lanzhou The unsymmetrical landform can be divided into the simple unsymmetrical gully,the step unsymmetrical gully and unsymmetrical range,which were formed by the erosion of the surface water during the unsymmetrical rising of the earth’s surface This kind of landform shows an important tectonic transition at 0.15 MaB P .Moreover,it indicates that the uplift of the Qinghai Tibet Plateau is even in the long time interval (0.2—0 9 Ma),while it is unevenly in the shorter time interval (0.01—0 1 Ma) By the action of its own gravity after the Plateau rose to the height of 3 0—3 7 km,and the stress came from the Indian Plate,the Qilian Mountains were uplifted largely at 0 15 MaB P ,and the harsh environment in the northwest China began at the same time更多还原