中文摘要：

晚新生代祁连山开始隆升的时间是制约青藏高原隆升动力学以及高原隆升与气候变化之间相互关系的重要参数。本文通过磷灰石裂变径迹和（u—Th）／He低温热年代学方法研究，获得祁连山北缘开始隆升的时间为约95Ma，隆升的速率为（0.5±0.1）mm／a，晚新生代以来与祁连山北缘断裂相关的缩短速率为（1.4±0.2）mm／a。本文得到的祁连山隆升的时间与“下地壳流动模型”和“地幔对流剥离模型”预测的高原向东北方向扩展时间基本一致，也与中国大陆北方季风加强的时间基本一致。支持高原与约5～12Ma隆升并向周边扩展，引起西北季风加强的假说，但是不支持“陆陆斜向深俯冲消减模型”预测的祁连山南缘约11Ma隆升，北缘隆升时间晚于5Ma的预测。

英文摘要：

The onset time of Qilianshan uplift in the Late Cenozoic is an important parameter to constrain the Tibetan plateau continental dynamics and the climate feedback on the mountain uplift. The apatite fission track and （U-Th）/He dating for samples ftom northern Qilianshan suggest that the onset time of northern Qilianshan uplift is about 9.5 Ma, with a vertical thrust rate of （0.5 ± 0. 1 ） mm/a and a shortening rate of about （1.4 ±0.2） mm/a since the Late Cenozoic. The onset time of northern Qilianshan uplift presented in this paper is broadly consistent with the time predicted by ＂convective removal of lithospheric mantle＂ and ＂channel flow＂ models, and the time when the Chinese continent northwestern monsoon enhanced. Therefore, the onset time of Qilianshan uplift support the argument that the Tibetan plateau outgrowth during about 5 - 12 Ma. It does not support that southern Qilianshan uplift at 11 Ma and the northern Qilianshan uplift later than 5 Ma prodicted by the ＂oblique intra-continental subduction＂ model.