page_title: Tibetan Plateau
section_title: Geology and geological history
hierarchical_section_title: Tibetan Plateau / Geology and geological history
caption_attribution_description: Lake Yamdroktso, Tibet Autonomous Region, China
context_page_description: The Tibetan Plateau, also known in China as the Qinghai–Tibet Plateau or the Qing–Zang Plateau or as the Himalayan Plateau in India, is a vast elevated plateau in Central Asia and East Asia, covering most of the Tibet Autonomous Region, Northwestern Yunnan, Western half of Sichuan, Southern Gansu and Qinghai provinces in Western China, Indian regions of Ladakh and Lahaul and Spiti as well as Bhutan. It stretches approximately 1,000 kilometres north to south and 2,500 kilometres east to west. It is the world's highest and largest plateau, with an area of 2,500,000 square kilometres. With an average elevation exceeding 4,500 metres and being surrounded by imposing mountain ranges that harbor the world's two highest summits, Mount Everest and K2, the Tibetan Plateau is often referred to as "the Roof of the World".
  The Tibetan Plateau contains the headwaters of the drainage basins of most of the streams in surrounding regions. Its tens of thousands of glaciers and other geographical and ecological features serve as a "water tower" storing water and maintaining flow.
context_section_description: The geological history of the Tibetan Plateau is closely related to that of the Himalayas. The Himalayas belong to the Alpine Orogeny and are therefore among the younger mountain ranges on the planet, consisting mostly of uplifted sedimentary and metamorphic rock. Their formation is a result of a continental collision or orogeny along the convergent boundary between the Indo-Australian Plate and the Eurasian Plate.
  The collision began in the Upper Cretaceous period about 70 million years ago, when the north-moving Indo-Australian Plate, moving at about 15 cm (6 in) per year, collided with the Eurasian Plate. About 50 million years ago, this fast-moving Indo-Australian plate had completely closed the Tethys Ocean, the existence of which has been determined by sedimentary rocks settled on the ocean floor, and the volcanoes that fringed its edges. Since these sediments were light, they crumpled into mountain ranges rather than sinking to the floor. The Indo-Australian plate continues to be driven horizontally below the Tibetan Plateau, which forces the plateau to move upwards; the plateau is still rising at a rate of approximately 5 mm (0.2 in) per year.
  Much of the Tibetan Plateau is of relatively low relief. The cause of this is debated among geologists. Some argue that the Tibetan Plateau is an uplifted peneplain formed at low altitude, while others argue that the low relief stems from erosion and infill of topographic depressions that occurred at already high elevations.
caption: Yamdrok Lake is one of the three largest sacred lakes in Tibet.
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