中文摘要：

对白云鄂博铁矿石进行了分析,并将其划分为白云岩型、钠长岩型、钾长石型和混合型4种类型,不同类型的矿石其岩石化学组成明显不同,白云岩型镁钙含量高,钾钠铝含量低,其中P2O5明显较高;钠长岩型钠铝硅含量高,其中TiO2含量明显高于其他岩石;钾长石型特征是钾铝硅含量高;而混合型矿石,主要化学组成在上述岩石之间,大部分为角砾状矿石。各种矿石的微量及稀土元素地球化学特征与矿区内碳酸岩脉型矿石一致,显示为同一来源。矿石氧化系数与鞍山式铁矿类似,不同于岩浆热液交代型铁矿。元素氧化物R型聚类分析显示,REE与F,Ba,Fe2O3,TiO2组成一群,明显正相关,表明稀土矿化与萤石化白云岩有关,是表生氧化环境成矿。结合矿石矿物学研究,铁氧化物表现为高价赤铁矿与磁铁矿同时存在,两者在矿物结构上呈现出共结关系,研究认为,白云鄂博矿床属于典型岩浆来源特征,表生高氧环境富集矿床。

英文摘要：

The study mainly analyzed iron ore at the Bayan Obo deposit, and divided it into four types： dolomitic, albititic, K-felspar and mixed ores. Chemical composition of each type of ore was quite different. The dolomitic was high in Mg and Ca, low in K, Na and Al; but P2O5 was distinctly high. The albititic was high in Na, Al and Si, with TiO2 higher than other oxides. The K-feldspar-type was characterized by high K, Al and Si. The composition of the mixed was among the four types, but most were brecciated ore. Geochemistry of four types of ore was consistent to that of carbonatic dyke ore, indicating they are of the same origin. Oxidation coefficients of ores were similar to those of the Anshan iron deposit, but different from those of magmatic-hydrothermal replacement iron deposit. R-type cluster analysis of oxides also displayed that REE was grouped with F, Ba, Fe2O3, TiO2, and showed positive correlation, implying that REE mineralization was related to fluoritized dolomite and the deposit deposited in a supergenetic oxidizing environment. Mineralogical research implied that iron oxides exist in both high-valence hematite and magnetite, and display their coexisting relation. This study suggestsed that the Bayan Obo deposit is of typical magmatic origin, and is an enriched deposit under a supergenetic, highly oxidizing environment.