投稿时间：2020-08-06
修订日期：2021-05-07
网络发布日期：2021-07-12
中文摘要:铌、钽矿是当今世界发展的战略性金属资源，巴西是世界上铌钽储量最为丰富的国家。研究者将巴西铌钽资源分为内生型和表生型2种类型。内生型包括伟晶岩型、花岗岩型、碱性岩型和碳酸岩型，典型矿床有Volta Grande、Madeira、Araxá；表生型为风化壳型（残坡积、冲积和红土型），典型矿床有Morro dos Seis Lagos。巴西铌钽资源以内生型矿床为主，并以碳酸岩型铌钽资源储量最大。巴西铌钽矿床主要分布在巴西中东部、南部，少量分布在北部地区，它们集中分布在戈亚斯-阿拉萨-蓬塔格罗萨、博尔博雷玛、米纳斯吉那斯、阿里克米斯、皮廷加、卡拉卡拉伊等铌钽成矿区（带）内。时间上，成矿作用集中在前寒武纪及古生代早期，少量发生在新生代。巴西铌钽成矿区（带）成矿时空分布具独特的成矿构造背景：花岗伟晶岩主要在巴西利亚造山褶皱带中，且在造山过程中发生铌钽成矿作用；碱性岩-碳酸岩主要在深大断裂带或裂谷区内，成矿物质具有深部幔源特征。文章认为巴西铌钽矿床找矿方向应该放在博尔博雷玛地区、中东部伟晶岩群密集分布地区，重点是要加强寻找高品位花岗伟晶岩型铌钽矿资源力度；另外，应在巴拉那盆地边缘等深大断裂带寻找类似Araxá等碱性-碳酸岩型铌矿资源。
Abstract:Niobium and tantalum are currently strategic metal resources for economic development in the world. Brazil has the world’s largest reserves of niobium and tantalum. Niobium and tantalum deposits there can be divided into endogenous and epigenic types. The endogenous types include pegmatite-type, granite-type,alkaline rock type and carbonatite type, such as deposits of Volta Grande, Madeira and Araxá, whereas epigenic types include weathering crust-type (residual,alluvial and laterite), such as deposit of Morro dos Seis Lagos. The main tantalum and niobium deposits in Brazil are of endogenous type, with the resources of carbonatite type being the largest. Tantalum and niobium deposits in Brazil are primarily distributed in central and eastern as well as southern Brazil with a small amount in northern Brazil. They are concentrated in such Nb-Ta metallogenic areas (belts) as Goiás-Araxá-Ponta Grossa, Borborema, Minas Ginas, Ariquemes, Pittinga and Cachoeira. The mineralization occurred mainly in Precambrian and Early Paleozoic with a small amount in Cenozoic. The temporal and spatial distribution of Nb-Ta mineralization areas in Brazil have unique characteristics of metallogenic tectonic background. The granitic pegmatite deposits mainly occur in the Brasilia orogenic fold belt, and Nb-Ta mineralization occurred during the orogenic process. However, the alkaline rock and carbonatite type deposits primarily are distributed along deep and large fault zones or rift areas, and the origin of ore-forming material has the characteristics of deep mantle. The exploration of high-grade granitic pegmatite niobium-tantalum deposits should focus on the densely distributed pegmatites in Borborema and central and eastern Brazil. The prospecting of alkali-carbonatite type niobium deposits (e.g., Araxá deposit) should be conducted along the edge of Parana Basin in southern Brazil.
keywords:geology niobium-tantalum deposit geological characteristics of the deposit resource distribution investment environment Brazil South America
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基金项目:本文得到“中国地质调查局地质调查项目（编号：DD20201157、12120115068301）联合资助
引用文本：
沈莽庭,郭维民,徐鸣,孙建东.2021.巴西铌钽矿典型矿床特征及其资源分布规律和找矿方向[J].矿床地质,40(3):603~624SHEN MangTing,GUO WeiMin,XU Ming,SUN JianDong.2021.Characteristics of typical niobium-tantalum deposits in Brazil and their resource distribution regularity and prospecting directions[J].Mineral Deposits40(3):603~624
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