The Zoulang Nanshan Caledonian Subduct ion Complex in the Northern Qilian Mountains and Its Dynamics

作     者：Xu Zhiqin, Xu Huifen, Zhang Jianxin, Li Haibing, Zhu Zhizhi, Qu Jingchuan,Institute of Geology, Chinese Academy of Geological Sciences, BeijingChen Daizhang, Chen Jinlu, China University of Geosciences, Beijingand Yang KaichunNo. 2 Q ilian Geological Party, Bureau of Geology and Mineral Resources of Q inghai Province, Q ilian County, Q inghai 

作者机构：Chinese Academy of Geological Sciences Beijing China 

出 版 物：《Acta Geologica Sinica(English Edition)》 (地质学报（英文版）)

年 卷 期：1994年第68卷第3期

页      面：225-241页

核心收录：

学科分类：070904[理学-构造地质学] 0709[理学-地质学] 07[理学] 

基　　金：This research is a project (No. 4870127)supported by the National Natural Science Foundation of China 

主　　题：subduction complex accretionary terrane multiple structure retrotrench subduction dynamics 

摘      要：The front of the Zoulang Nanshan Caledonian volcanic island arc zone in the northern Qilian Mountains is a forearc accretionary terrane, composed of multiple accretionary volcanic island arcs, flysch accretionary wedges,high-pressure metamorphosed detachment zones and remnants of ophiolites. It resulted from the northeastward subduction of the Early Palaeozoic Qilan oceanic crust beneath the Alxa block. High-pressure metamorphism, which occurred during the subduction, progressed through three stages: the initial stage of medium T-high P,the main stage of temperature decrease and pressure increase, and the lag stage of pressure decrease and temperature increase. Finally the paper presents a retrotrench subduction dynamic model indicative of northward subduction of the central Qilian block and southward accretion of the Alxa block during the period of 450-500 Ma.