中国大陆“十字构造”形成演化及其大陆动力学意义

THE “CROSS-TECTONICS” IN CHINA CONTINENT:FORMATION,EVOLUTION,AND ITS SIGNIFICANCE FOR CONTINENTAL DYNAMICS

东亚大陆是由许多分别亲劳亚或亲冈瓦纳的中小陆块经过复杂拼合而成的最为复杂的大陆,而中国大陆地处东亚的核心位置,是研究东亚大陆形成演化的关键。控制中国大陆形成演化的最主要的构造格架是“十字构造”,即东西向的中央造山系和南北向的贺兰—川滇南北构造带。前者自东而西包括秦岭造山带、祁连造山带和昆仑造山带,是南方和北方陆块群历经古生代—印支期拼合形成中国大陆主体的构造结合带,并遭受中新生代陆内造山改造,构成了中国大陆地质地理、生态环境、人文经济等南北分野;后者不同区段继承了前寒武纪板块构造记录,逐步转化为古亚洲洋或古特提斯构造域大陆边缘,尤其是新特提斯构造运动,形成青藏高原隆升—扩展变形的东部边界,控制了晚中生代—新生代中国大陆东西反转演化。以“十字构造”为坐标系,中国大陆四个象限的地质、地球物理结构、自然资源、生态环境、人文经济等存在明显差异。

The East Asian continent is the most complex continent which was formed by amalgamation of many small-to-medium-sized Laurasia or Gondwana associated blocks.The China continent is located in the core position of East Asia,and is the key to study the formation and evolution of the East Asian continent.The most important tectonic framework controlling the formation and evolution of main China continent is the“cross-tectonics”,that is,the EW trending Central Orogenic System and the NS trending Helan-Chuandian North-South tectonic belt.The former includes,from east to west,the Qinling,the Qilian and the Kunlun orogenic belts.They were formed by the subduction-collision between the southern and northern continental blocks during the Paleozoic-Indosinian period constituting the mainland of the China continent.Then,Central Orogenic System has been overprinted by the Mesozoic to Cenozoic intracontinental orogenic events,forming the north and south division of geological geography,ecological environment,and human economy.The latter inherited the Precambrian plate tectonic records,and was gradually transformed into the continental margin of the Paleo-Asian Ocean or Paleo-Tethys tectonic domain.Due to the Neo-Tethys tectonic evolution,it was evolved into the eastern boundary of the uplift and expansion of the Tibetan Plateau,controlling the late Mesozoic-Cenozoic reverse evolution of the western and eastern China.With“cross-tectonics”as the coordinate system,the four quadrants of China mainland have distinct characteristics of geological and geophysical structure,resources,geomorphology,ecology,environment,culture and economy.