• 论文 •

### 西藏高原地貌的形成和演化

1. 中国科学院地理研究所
• 出版日期:1982-01-15 发布日期:1982-01-15

### THE FORMATION AND EVOLUTION OF LANDFORMS IN THE XIZANG PLATEAU

Yang Yichou, Li Bingyuan, Yi Zesheng, Zhang Qingsong

1. Institute of Geography, Academia Sinica
• Online:1982-01-15 Published:1982-01-15

Abstract: Landform on the Xizang Plateau is generally characterized by gentle rolling plateau surface. There are also a series of continous and towering mountains standing above the plateau surface, and these lofty mountains are the centres where both the ancient and modern glaciers developed. Numerous broad valleys and basins are inlaid in the interior of plateau surface. The upstreams of the exterior drainage system and most portions of the interior drainage system are meandering in the broad valleys while lakes dotted and spread all over the basins. The plateau surface is down cut by channels of middle and lower reaches of the exterior drainage system. In addition, karstie, aeolian and volcanic landforms have been developed on the plateau surface.The landform on the Qinghai-xizang plateau is a result of underthrust with a small angle of Indian plate into Eurasion plate. Since late Cretaceous, the Indian plate has, (due to the continous expansion of Indian Ocean floor,) pushed northward, approached and finally underthrust underneath the Eurasian plate. The different mountain-making movements of Hercynia, Indo-China, Yanshan and Himalaya acted upon Indian plate with horizontal movement and caused it disintegrated internally. As a result, the disintegrated smaller and younger plates, underthrusting along rift zones in stages underneath the Eurasian plate. The Yanshan movement exerted the greatest influence and laid the foundation of landforms of the plateau, while the early Himalayan movement finally made the plateau as an independent macromorphologic entity. The premitive plateau is thus formed. The ncotectonic movements, occurred since the end of Tertiary and acted upon the plateau, in the form of vertical movement have caused intense uplift of the plateau in stages, this open up the new era for the formation of the "World Koof". The strong uplifting of the plateau, coordinated with the global climatic cold-warm fluctuation created unique water-heat regime for the plateau. The complicated and homogeneous distribution and integration of the various land-forms are originated horizontally and vertically by many times of climatic alternation of glacial and interglacial periods.