LATITUDINAL CONVERGENCE OF THE ASIAN CONTINENT, RISE OF THE QINGHAI-TIBET PLATEAU AND EXPANSION OF THE EAST ASIAN CONTINENT

The tectonic problem of East Asia is one of the focuses of the world's concern. In East Asia stand two magnificent plateaus —the Mongolia Plateau and Qinghai-Tibet Plateau —and between the two plateaus lie E-W-trending modern mountain systems such as the Tianshan-Yinshan and Kunlun-Qinling mountain systems, which consist of a series of shear-overthrusting tectonic systems, powerfully suggesting the occurrence of strong latitudinal convergence in the East Asian continent. East of the aforesaid region the general tectonic features show trends of expansion and divergence toward the SE. Southward they reach the Indonesia Islands south of the equator and eastward they might involve the Mariana island arc. A series of arcuate structures are tectonic belts formed by frontal compression, overthrusting, uplift and thickening of the overthrusting-extensional slabs and behind these arcuate structures there usually occur extensional and detachment-subsidence and thinning basins, which show the directions of movements of the continental crustal surface. The present tectonic features of the East Asian continent are the product of the Himalayan movement since the Cenozoic and this process is now still going on. It not only has exerted important influence on the geological structure and tectonics, distribution characteristics of earthquakes and resources and environmental problems, but also are closely related to the formation of the atmospheric circulation and climatic and environmental changes.