中国东部及邻区大地构造演化的新见解

Some New Ideas on Tectonic Evolution of Eastern China and Adjacent Areas

中国东部及邻区诸陆块的聚合,曾经历了由“联而不合”的碰接到完全联为一体的焊合过程。中国东部几条造山带并不是简单的俯冲造山带或碰掩造山带,而是复杂的、多旋回复含造山带。燕山造山作用是中国东部占生代以来最重要的地质事件,它结束了蒙古—兴安、秦岭等造山带长期的多旋回造山过程,使中国东部及邻区诸陆块最终焊合为一个整体。亚洲大陆东部边缘曾经有过一个宏伟的燕山造山带。自中、晚白垩世以来,亚洲东部边缘发生大舰模裂斛,中国东部松辽、华北等裂陷盆地和西太平洋的边缘海就是有这一阶段陆续形成的。

The major tectonic units of eastern China and its adjacent areas include five Precambrian massifs and four Phanerozoic orogenic belts. The formet are characterized by relatively small size and great tectonic mobility except for the Siberian platform; the latter are composite systems made up of a series of small oceanic basins and microcontinents occurring as island chains except for the South China zone. The integration of the various massifs involved a complex process of collision and welding. The related orogenic belts are thought to be polycyclic collision-imbrication ones rather than simple subduction-type or collision-type ones. The Yanshanian movement is the most important geologic event since the Phanerozic in this region. It was due to the Yanshanian orogeny that the above belts eventually accomplished their long-continued and complicated polycyclic orogenic processes, and the continental blocks were finally welded as a unity, becoming a part of the giant unified Eurasian cration. In the Middle Cretaceous, eastern Asia entered a completely new stage of tectonic development——the disintegration stage of continent. The eastern margin of Asia is not an accreted margin, but a destructed or disintegrated one.