内蒙古阿拉善地块北缘的构造单元划分及各单元的基本特征  

TECTONIC UNITS AND THEIR FUNDAMENTAL CHARACTERISTICS ON THE NORTHERN MARGIN OF THE ALXA BLOCK

作　　者：吴泰然 何国琦[2] 

机构地区：[1]中国地质大学地矿系 [2]北京大学地质系

出　　处：《地质学报》1993年第2期98-108,共11页Acta Geologica Sinica

基　　金：国家自然科学基金9487001项目子课题

摘　　要：阿拉善地块北缘是一个多构造单元的结合部,可以划分出以下4个一级构造单元:①不成熟岛弧性质的雅干构造带;②早古生代被动大陆边缘,到晚古生代转化为活动大陆边缘的珠斯楞-杭乌拉构造带;③成熟岛弧性质的沙拉扎构造带;④元古代造山带,在古生代演化成拉张型过渡壳的诺尔公-狼山构造带。上述各构造单元在沉积建造、岩浆岩组合、变质作用以及地球化学特征等方面都有明显的差异,单元之间以断裂作为界线。The northern margin of the Alxa block is the junction of the North China platform, Tarim platform and Siberian plateform and the foldbelts on their margins, There are four tectonic units with different sedimentary assemblage and magmatic rocks in the region, The Yagan tectonic belt is located to the north of the Yagan fault. It is an immature Early Palaeozoic island arc. The Zhusileng-Hangwula belt is between the Yagan fault and the Engger Us fault. Early Palaeozoic non-volcanic flysch shows that it is a passive continental margin. This unit turned in to an active continental margin in the Late Palaeozoic. The Shalazhashan belt is between the Engger Us fault and Badian Joran fault. It consists of some granite bathcliths with island arc features and back-arc basin sediments. The Nuru-Langshan belt is to the south of the Badian aaran fault. It consists of precambrian successions and granites. Rifting is the major event in the unit from the Late Proterozoic to Early Palaeozoic. The boundaries between the units are clear.

关 键 词：构造带 界线 岩石组合 阿拉善地块 

分 类 号：P544.1[天文地球—构造地质学]