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Shri Ashtapad Maha Tirth - II
Byang-thang is thought to have been connected to the land southwest of the Red river region in Indochina (northern Vietnam, Cambodia, and Laos), and these regions may have joined Asia together. Another connection zone appears to run between Byang-thang and central Tibet, from Panggong lake in the far west, across Byang-thang, and along the Nag-chu river (Nu Jiang) in the east. Thus, the region of central Tibet south of the Nag-chu river and north of the gTsang-po seems to have joined Asia next. This land may also have been connected to Thailand and the Malay peninsula, and these regions may have moved together. The most recent surveys indicate that fossils south of the Nu Jiang connection zone are typical of the Indian subcontinent, sug-ftsTm; the region was associated with the Indian plate. As south China, Indochina, Byang-thang, and central Tibet joined Asia, the series of collisions and additions began to raise northern Tibet out of the water. The Kun-luns and the region east of the 'Bri-chu rose above sea level, followed by Byang-thangnorth of Gangs-ti-se, as well as the region north and east of the Xag-chu river: the modern area of Chab-mdo, Ri-bo-che, Tsha-barong, and Mar-khams. The plate motions are also thought to have produced great folding in older mountain ranges farther north, such as the Kun-luns and the Bayankara mountains. The Birth of The Himalayas The joining of the far southern part of Tibet to Asia is better understood, and discussions of India's northward drift can be found in encyclopedias as well as in geology texts. The 1980 symposium presented new details on this collision, giving a variety of hypotheses to explain the uplifting of the plateau. By 100 million years ago, the plate carrying India had begun to drift north from its location alongside Africa as rifts formed in Gondwanaland. This opening between India and Africa eventually became the Indian Ocean. As India moved north, ocean crust beneath the Tethys Sea was first to press against Asia. Sliding down beneath the continental land along the line now formed by the gTsang-po river, the ocean crust was remelted, and the sea began to shrink. The northward pressure and the remelting of crust created intense agitation. New volcanoes erupted in Gangs-ti-se and gNyan-chen-thang-lha, building these ranges higher. By 50 million years ago, the bulk of Mount Ti-se was built up. About this time the Rockies were forming in America and the Caucasus formed in Russia. North America was just now splitting away from Europe as the Atlantic Ocean continued to widen. By 45-40 million years ago, the entire crust of the Tethys Sea had descended beneath the Asian continent, closing the sea completely. The Indian plate carrying southern Tibet now collided with central Tibet along the zone of today's Indus and gTsang-po rivers. As land masses met head-on, the Himalayas began rising out of the sea. The last oceanic crust and sedimentary rock overlying ocean floor, as well as volcanic islands that had formed between the plates, were compressed and squeezed into huge folds that slid south over the Indian plate. The Himalayas continued to grow by a southward extension that occurred in several stages. As India continued to press north, the crust fractured, and about 20 million years ago, large faults developed in the new Himalayas. Along a fault 2000 kilometers long, known as the
Ancient Tibet
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