内蒙苏尼特左旗地区构造演化初探

研究区位于内蒙功伲特左旗，其大地构造位置处于华北地台北侧的兴蒙海西－印支褶皱带内。发生于晚二叠纪－三叠纪的造山运动奠定了本区的构造格局，它使古生代地层发生了强烈的褶皱变形和绿片岩相变质作用，形成二连盆地的褶皱基底。早中侏罗世，本区形成了一些小型山间坳陷盆地；中侏罗世末期的燕山运动形成了走向ＮＥＥ的大型逆冲推覆构造，并伴有轴向ＮＥ的一期宽缓褶皱；

Study about the Tectonic Evolution in Sonid Zuoqi,Inner Mongolia

The study area is situated at Sonid Zuoqi,Inner Mongolia,and its tectonic position is located in the later Hercynian-lndonian fold belt which is located at the north of Huabei platform. The tectonic framwork is developed in the orogenic movement which took place in the later Permain-triassic.Thus, the Palaeozoic formations to be folded in the greenschist facies were metamorphizd,and the basement of Erlian basin were formed. Some smaller intermountain basins were formed during Early/Middle Jurassic period. The Yianshan orogenic movement in the late of Middle Jurassic formed the nappe structure and Juratype foIds. The study area was in extension stage since later Jurassic period,and a series of fault basins were formed.