青藏高原东南部地貌边界带晚新生代构造运动

青藏高原是中国大陆最高一级地貌阶梯，其东南部地貌边界大致沿龙门山—大相岭—锦屏山—玉龙山—碧罗雪山一线分布。该文主要从青藏高原东南部地貌边界两侧的晚新生代地层记录来探讨晚新生代构造运动以及高原隆升。青藏高原东南部地貌边界带雏形出现于距今２．５Ｍａ左右，定型于１．２Ｍａ前的构造运动中，之后又在构造运动进程中不断得到加强，并最终形成今日之构造地貌格局。青藏高原从海变陆，并上升至平均海拔４５００ｍ以上，成为地球上最高的大高原，这是发生在晚新生代且主要是在第四纪最重大的地质事件。

LATE CENOZOIC TECTONIC MOVEMENT IN GEOMORPHOLOGIC BOUNDARY BELT OF SOUTHEASTERN QINGHAI XIZANG PLATEAU

The Qinghai Xizang Plateau is the highest geomorphologic step in China continent , and its southeastern geomorphologic boundary stretches along the Longmen Mts. Daxiangling Mts. Jinping Mts. Yulong Mts. Himalayas. In this paper, the Late Cenozoic tectonic movement and uplift of the Qinghai Xizang Plateau are studied and discussed based on the records of the Late Cenozoic strata that are distributed over the both sides of the geomorphologic boundary belt of the southeastern Qinghai Xizang Plateau. The boundary belt appeared in an embryonic form about 2.5 Ma B.P., and got further finalized through the tectonic movement during 1.2 Ma B.P.. Afterwards, the boundary belt has been continuously perfected in the course of tectonic movements, and the present tectonic geomorphologic framework formed at last. The Qinghai Xizang Plateau has been truned from sea into land and uplifted over 4 500 m in average altitude, and become the highest plateau in the Earth. It is the greatest geologic event happened during the Late Cenozoic and mainly Quaternary.