Published by: World Tibet Network News, Monday, August 5, 1996

BEIJING (Aug. 5) XINHUA - Chinese geologists say they believe that the fast growth of the Qinghai-Tibet Plateau is the result of isostatic adjustment of the plateau's crust and the expansion of terrestrial heat.

The theory was advanced today by Xiao Xuchang, a professor with the Chinese Academy of Geological Sciences, at the ongoing 30th International Geological Congress (IGC) in Beijing.

The plateau has risen about 10,000 m in the past two million years, and Qomolangma, or Mount Everest, rose 37 cm in the past 30 years.

As opposed to traditional theories of terrain collision and double crusts, the new theory is believed to be the most developed way to explain the plateau's swelling.

Xiao and geologist Li Tingdong separate the plateau's swelling into three periods: slow swelling of less than two millimeters a year from 65 million to 40 million years ago, moderate swelling of two to three mm a year from 40 million to two million years ago, and fast swelling of up to five mm a year over the past two million years.

They say they believe the motivity of the slow swelling period came from the collision of the Indian terrain. It is here where their view is the same as traditional terrain theory.

But about five million years ago, the terrain moved slower and slower toward the north. It moved 50 to 60 mm a year 65 million years ago, and five to eight mm a year over the past two million years.

The Qinghai-Tibet Plateau, at the same time, is growing faster and faster, indicating that terrain collision is no longer the major motivity factor, they explain.

Their studies show that terrestrial heat under the highlands plays an important part in the swelling.

Xiao explained the isostatic adjustment resulting from the weakening of the Indian terrain's collision by pointing to how a rubber ball will try its best to swell as soon as the power of a finger upon it is relaxed.