阴山地区早前寒武纪岩石构造分区及古元古地壳碰撞一伸展构造机制

阴山地区从东南到西北，依次划分为桑干麻粒岩区、集宁副变质岩区、乌拉山－大青山前缘构造区和色尔腾山岛弧过渡区。桑干麻粒岩区代表了中太古微古陆并经新太古强烈岩浆增生的太古地壳；集宁区代表基底之上新太古末期－古元古沉积盖层；乌拉山－大青山区是基底岩石构造剥露的前缘构造区；色尔腾山区主要由深部花岗岩和浅部绿岩构成的太古岛弧区，古元古时期北部古岛弧和南部古大陆碰撞汇聚，继后北东南面向伸展使阴山地区早前寒武纪岩石剥露。

TECTONIC DIVISION OF THE EARLY ROCKS IN THE YINSHAN AREA AND THE PALAEOPROTEROZOIC CRUSTAL COLLISION LATERAL EXTENSION MODEL

The two dinstict blocks-North Yinshan and South Yinshan blocks seperated by theWuchuan-Linhe Fault are recogniZed in the Yinshan area. From southeast to northwest fourterranes are divided. The Shanggan Granulite Terrane, dominantly granulite factes rnetamorphicorthogeisses and supracrustal rocks, interpreted as a meso-archaean microcontinent; the JiningTerrane, dominantly metasedimentary rocks and S-type granites; the Wulashan--Daqinshan FrontTectonic Belt, dominantly Palaooproterozoic reworking hasal granulites and sedimentary cover; theSe'erteng Termne, an archaean greenstone and gneisses belongiflg to the North Yinshan Block.Palaooproterozoic struture in the Yinshan shows two distinct lineation within co-planarfoliation. The earlier lineation trends to north in the Zhangjiakou and northwest in the Xinhe; thelater lineation trends to northeast-southwest which commonly developed in the Jining terrane.According to behaviour of metapelites under high temperature, It is proposed that the layerof metapelites within mid- to deep crust might be transferred to lateral extention during thecollision period. the lateral extension of the mid- to deep crust might result in the ewhumation ofthe Sanggan granulites.