亚洲大陆的纬向汇聚与蒙古青藏高原的崛起及东亚大陆之扩张

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

东亚大地构造问题是世界瞩目的焦点之一。区内有蒙古和青藏两个雄伟的高原屹立,二者之间分布着天山—阴山和昆仑—秦岭等横亘东西的现代山系,它们由一系列剪切-推覆构造系统组成,有力地说明东亚大陆存在强烈的纬向汇聚。在此以东,总体构造面貌向SE呈扩张发散态势,南达赤道以南的印度尼西亚群岛,向东可能涉及马里亚纳岛弧。一系列弧形构造是推覆-拉伸构造岩片的前缘挤压逆冲推覆-隆起增厚构造带,后方常伴有拉伸滑脱-沉降减薄盆地,并显示着陆壳表层的运动方向。东亚大陆现今构造面貌是新生代以来喜山运动产物,这一过程迄今还在进行。它不仅对东亚地质构造和地震分布规律以及资源环境问题有重要影响,而且与大气环流形成及气候环境变化有密切关系。

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