白云鄂博矿区碱性基性岩-碳酸岩岩墙岩石学研究  

Petrological study of alkaline basic dyke and carbonatite dyke in Bayan Obo, Inner Mongolia

作　　者：郝梓国[1] 王希斌[2] 李震[3] 肖国望[4] 张台荣[4] 

机构地区：[1]中国地质科学院矿产资源研究所,北京100037 [2]中国地质科学院地质研究所,北京100037 [3]北京大学地学院,北京100871 [4]内蒙古白云鄂博铁矿地测科,内蒙古包头014000

出　　处：《岩石矿物学杂志》2002年第4期429-444,共16页Acta Petrologica et Mineralogica

基　　金：国家自然科学基金资助项目(4 9972 0 2 1)

摘　　要：白云鄂博地区广泛发育碳酸岩墙 -碱性基性岩墙,通过对其岩石学、矿物学、岩石化学、稀土元素、微量元素的系统研究表明,碳酸岩墙为火成碳酸岩,部分碳酸岩墙的REE含量高达14 6 75 %,与赋矿白云石碳酸岩体的REE含量(最高达 10 % )相近,两者均为富稀土矿石。矿区基性岩墙的K2 O +Na2 O含量( >5 % )高于普通基性岩石(4 % ),表明它们属于碱性岩类,是碱性基性岩墙。碳酸岩墙 -碱性基性岩墙的REE与微量元素的分配型式近似,Sr、Nd、Pb同位素特征亦相近,表明它们形成于一个比较特殊的、近似的源区,两者有一定的成因关系。Carbonatite dykes and alkaline basic dykes are widely distributed in Bayan Obo. A study on their petrology, mineralogy, petrochemistry, REE and trace elements indicates that carbonatite dykes are igneous carbonatite, and REE content of some dykes is 14.675%, similar to that of dolomite carbonatite, implying that the two kinds of carbonatite are both REE_rich rocks. K 2O+Na 2O content of basic dykes in the ore district is higher than that of general basic rocks, suggesting that these dykes are alkaline rocks and belong to alkaline basic dykes. Carbonatite dykes are similar to alkaline basic dykes in REE and trace element patterns, and they also have similar Sr, Nd and Pb isotopic characteristics. These features indicate that the two kinds of dykes were formed in a special and similar source area, thus genetically related to each other.

关 键 词：碱性基性岩墙 碳酸岩墙 岩石学 岩石化学 内蒙古 

分 类 号：P588.124[天文地球—岩石学] P58[天文地球—地质学]