摘要
出露于内蒙古呼和浩特北部的二道洼群 ,为一套陆源碎屑岩 碳酸盐岩夹中基性火山岩变质建造。岩石组合及其地球化学特征指示其形成于陆内裂陷槽或稳定陆缘盆地环境。研究表明 ,二道洼群是古元古代早期产物 ,2 4 50～ 2 4 0 0Ma开始接受沉积 ,大约在 2 2 0 0～2 10 0Ma之间开始褶皱回返 ,遭受了低角闪岩相变质作用 ,具有碰撞造山带的变质P T t轨迹。研究结果有助于华北陆台北缘古元古代的地壳演化研究 ,有助于乌拉山区二道洼群与孔兹岩系的相互关系的探讨。
The Palaeoproterozoic Erdaowa Group distributed in the north Hohhot, Nei Mongol is composed of metamorphic detrital sediment and carbonate with intermidiate basic volcanics. The rock assemblages and its geochemical characteristics indicate that Erdaowa Group developed in an aulacogen or an intracontinental basin. Erdaowa Group began to form at about 2 450 ～2 400 Ma and orogeny at 2 100～2 200 Ma, underwent low amphibolite facies metamorphism. The growth of metamorphic minerals and alternation of mineral assemblages show that Erdaowa Group has a metamorphic process of collision orogens with a clockwise P T t path. The results of study are conducive to probe the relationship between Erdaowa Group and Khondalite.
出处
《前寒武纪研究进展》
1999年第4期39-49,共11页
Progress in Precambrian Research
