华北板内造山带的形成史

THE HISTORY OF FORMATION OF INTRAPLATE OROGENIC BELTS IN THE NORTH CHINA PALEOPLATE

本文从周缘环境的演变上论述了华北古板块板内造山带的形成史:T—J_2因相邻古板块之间碰撞和陆内俯冲,导致南北边部Ew向推覆造山带的形成;J_3—K_1由西太平洋活动高潮期形成的NNE向造山带波及古板块内部;K_2—R由于滨太平洋带的弧后拉张作用,形成板内陷落带和断块山,本文强调板内次级构造单元应按古板块碰撞的不同阶段和特征予以划分和厘定。

The history of formation of intraplate orogenic belts in the North China paleoplate is discussed from the evolution of the surrounding geological settings. East-west-trending orogenic belts with nappes on the north and south margins were formed by convergence and intracontinental subduction of adjacent paleoplates in the Triassic to Middle Jurassic. The NNE-trending orogenic belts formed during the mort active stage of the western Pacific Ocean from the Late Jurassic to Early Cretaceour affected the interior of the paleoplate. Intraplate depression zones and fault block mountains were formed by Circum-Pacific backarc extension between the Late Cretaceous and Tertiary.It is indicated from the above that the connotations of some of the conventional terms in geotectonics such as shield, axis and platform anticlise should be reconsidered or even these terms should be rejected. Second-order intraplate tectonic units should be classified and determined on the basis of different stages and their characteristics of paleoplate collision.