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白云鄂博碳酸岩型REE-Nb-Fe矿床是世界上最大的稀土矿床。稀土矿石产于整个白云石碳酸岩体和部分脉状碳酸岩中。对比世界上20余个火成碳酸岩地区的特征后发现,白云鄂博地区完全具备国外火成碳酸岩区的地质特征。在岩石、矿石组合上,本区也发育一套碳酸岩+超基性岩+碱性基性岩(含基性熔岩)+碱性岩+稀土矿石+铁矿石组合;在矿物组合上,以白云石为主,方解石次之,伴生一套碱性闪石、长石、霓石、磷灰石、萤石、磁铁矿、稀土矿物组合;在全岩化学成分、微量元素、稀土元素和Sr、Nd、Pb、C、O同位素上,这些岩石具有一定的亲缘关系,有着共同的来源;在岩体的形态与岩石组构上,它们以岩席、岩筒和脉岩的形式出现,并发育有强烈的熔离作用与流动构造;在区域构造上,发育隐伏穹窿构造、岩筒构造和巨型断裂汇聚构造。综合分析上述特征表明:白云鄂博地区具有中元古代破火山机构的痕迹,赋矿白云石碳酸岩体则是顺层侵入的火成碳酸岩体,东矿、主矿可能是一个火山颈构造控矿,而赋矿白云石碳酸岩体西南侧的苏木图矿床则是隐伏岩筒构造控矿。
The Bayan Obo carbonate-type REE-Nb-Fe deposit is the largest rare earth deposit in the world. Rare earth ore is produced in dolomitic carbonate rocks and some vein carbonates. Comparing the characteristics of more than 20 volcanic carbonate rocks in the world, it is found that the Baiyunebo region completely possesses the geological characteristics of the volcanic carbonate area abroad. In the rock and ore assemblage, a set of carbonate + ultramafic rocks + alkaline rocks (including basic lavas) + alkaline rock + rare earth ore + iron ore is also developed in this area. On the mineral assemblage, The main dolomite, followed by calcite, accompanied by a set of alkaline amphibole, feldspar, aegirine, apatite, fluorite, magnetite, rare earth minerals combination; chemical composition in the whole rock, trace elements, rare earth elements And Sr, Nd, Pb, C, O isotopes, these rocks have a certain genetic relationship and share a common source; in the form and rock structure of the rock mass, they appear in the form of mantle, rock tube and vein rock , And developed a strong melting effect and flow tectonics. On the regional structure, the concealed dome structure, rock tube structure and giant fault convergence structure are developed. Comprehensive analysis of the above characteristics shows that: the Bayan Obo area has the traces of the Mesoproterozoic caldera bodies, dolomite carbonate ore bodies are intruded into the carbonate rocks, the East Mine, the main mine may be a volcano neck structure control While the Sumu Tu deposit on the southwestern side of dolomite carbonate ore body is a hidden rock tube structure.