巴西与碱性岩-碳酸岩杂岩体相关的关键矿产成矿作用与规律

The strategic and critical minerals associated with alkaline and alkaline-carbonatite complexes Brazil

在巴西,与碱性岩-碳酸岩杂岩体相关成矿作用复杂,产出了世界上唯一的霞石正长岩型斜锆石矿床、全球最大的铌矿床以及巴西最大的铀矿和镍矿集区,资源储量丰富,具有重要的经济价值和战略意义,同时也是关键矿产成矿作用研究的殿堂。本文在前人研究基础之上,整理分析了35处与碱性岩-碳酸岩相关的关键矿产地质特征。根据成矿作用特征,划分了4个成矿系列:①霞石正长岩碱性杂岩相关的U-Zr-Mo-REE和萤石成矿系列;②碱性岩-碳酸岩杂岩(正长岩+辉石岩+霓霞岩+碳酸岩等)相关的Nb-P-Ti-REE和蛭石成矿系列;③阿拉斯加型超基性岩-碱性杂岩体相关的Ni成矿系列;④交代正长岩相关的U-P成矿系列。根据关键矿产资源时空分布规律,划分了5个成矿带:(Ⅰ)Lancinha-Cubatao碱性岩-碳酸岩相关REE-P-U-Zr-Ni-Mo-蛭石成矿带;(Ⅱ)Rio de Janeiro-Rondonia碱性岩-碳酸岩-金伯利岩相关的Nb-REE-Ti-Zr-P-金刚石成矿带;(Ⅲ)Ceara-Mato Grossodo Sul超基性岩-碱性岩-碳酸岩相关的Ni-U-P-蛭石成矿带;(Ⅳ)亚马逊地区碳酸岩相关Nb-REE-Th-Ti-P成矿带;(Ⅴ)巴伊亚地区与变正长岩相关的U成矿带。本文还详细介绍了典型矿床成矿地质特征和成矿条件,为走出去寻找关键矿产资源基地提供了理论支撑。

There are plenty of critical minerals deposits associated with alkaline and alkaline-carbonatite complexes in Brazil, such as the biggest niobium mine(Araxá)of the world, the world-only zircon deposit produced from nepheline syenite, and the biggest uranium and nickel deposit of Brazil. Economic geology related to alkaline and alkaline-carbonatite complexes are not only metallogeny interesting of critical metals, but are also economically important and strategic value. The main Critical Minerals deposits associated with alkaline and alkaline-carbonatite complexes could be divide into 4 metallogenic Series according the 35 representatives from the literature:①U-Zr-Mo-REE and fluorite matallogenic series related to agpaitic alkaline complexes;②Nb-P-Ti-REE and vermiculite matallogenic series associations alkaline-carbonatitic complexes;③Ni matallogenic series related to the Alaska-typemafic-ultramafic complexes;④U-P matallogenic series associations metasomatic "episyenites" and albitites.According to thetemporal spatial distribution, The Critical Minerals in Brazil also could be divided into 5 regional metallogenic belt:(Ⅰ) Lancinha-Cubatao REE-P-U-Zr-Ni-Mo and vermiculite metallogenic belt;(Ⅱ) Rio de Janeiro-Rondonia Nb-REE-Ti-Zr-P and diamond and 5 ore-concentrated area;(Ⅲ) Ceara-Mato Grossodo Sul Ni-U-P and vermiculiteMineralization zones;(Ⅳ) The Nb-REE-Th-Ti-Pmetallogenic belt in Amazon;(Ⅴ) The uranium ore-concentrated area of Bahia. This manuscripts also gives detail information of the typical critical ore deposit in Brazil, It would be helpful to find more strategic and critical Minerals resources in this area in the future.