| 1 | 白云鄂博火成碳酸岩墙的研究显示文摘对白云鄂博稀土矿床附近的富方解石岩墙进行了阴极射线发光分析、x 射线萤光分析和电子探针分析。结果表明,该岩墙为方解石质的火成碳酸岩。其矿物组成有含锶锰的方解石、镁钠铁闪石、磷灰石、烧绿石、钾长石和黑云母。岩墙两侧有强烈稀士矿化,磷灰石和环带独居石较为发育,并经受多次次生蚀变作用。岩墙一侧的混合岩经受霓长岩化作用,变为镁钠铁闪石-钠长石岩石。白云鄂博的沉积白云岩(H8)主要由含锰、锶、稀土的铁质白云石所组成,并含有磁铁矿、磷灰石、独居石、萤石和带云母。通过微量元素和同位素分析结果看出,火成碳酸岩岩墙和沉积白云岩相似。这些证据支持了 H8是白云岩化火成碳酸岩中的凝灰岩观点。白云鄂博稀土矿化也显示出与火成碳酸岩墙的地球化学属性的相似性,提供了它们在成因方面的相互关系。 | M.J.Le Bas J.Keller 陶克捷 F.Wall CT.Williams 张培善 | 1992 | 地质科学1992，27，A12： | 10 |
| 2 | From mantle to critical zone:A review of large and giant sized deposits of the rare earth elements显示文摘The rare earth elements are unusual when defining giant-sized ore deposits,as resources are often quoted as total rare earth oxide,but the importance of a deposit may be related to the grade for individual,or a limited group of the elements.Taking the total REE resource,only one currently known deposit(Bayan Obo) would class as giant(>1.7×10~7 tonnes contained metal),but a range of others classify as large(>1.7×10~6 tonnes).With the exception of unclassified resource estimates from the Olympic Dam 10 CG deposit,all of these deposits are related to alkaline igneous activity- either carbonatites or agpaitic nepheline syenites.The total resource in these deposits must relate to the scale of the primary igneous source,but the grade is a complex function of igneous source,magmatic crystallisation,hydrothermal modification and supergene enrichment during weathering.Isotopic data suggest that the sources conducive to the formation of large REE deposits are developed in subcontinental lithospheric mantle,enriched in trace elements either by plume activity,or by previous subduction.The reactivation of such enriched mantle domains in relatively restricted geographical areas may have played a role in the formation of some of the largest deposits(e.g.Bayan Obo).Hydrothermal activity involving fluids from magmatic to meteoric sources may result in the redistribution of the REE and increases in grade,depending on primary mineralogy and the availability of ligands.Weathering and supergene enrichment of carbonatite has played a role in the formation of the highest grade deposits at Mount Weld(Australia) and Tomtor(Russia).For the individual REE with the current highest economic value(Nd and the HREE),the boundaries for the large and giant size classes are two orders of magnitude lower,and deposits enriched in these metals(agpaitic systems,ion absorption deposits) may have significant economic impact in the near future. | M.P.Smith K.Moore D.Kavecsanszki A.A.Finch J.Kynicky F.Wall | 2016 | Geoscience Frontiers2016，7，3： | 7 |
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