投稿时间：2025-06-26
修订日期：2025-09-19
网络发布日期：2026-04-22
中文摘要:近年来，在辽宁鞍本地区富铁矿相关的蚀变岩中发现了具有工业意义的铌钽矿化。作为高场强元素，Nb、Ta元素在岩浆-热液体系中的地球化学行为一直是人们关注的焦点之一，故蚀变岩中铌钽矿物特征研究对其热液流体属性具有较好的指示意义。文章系统采集了弓长岭二矿区西北采区+50 m中段6穿剖面的富铁矿与蚀变岩样品，并对其岩相学、地球化学及铌钽矿物成分与结构特征进行了分析。结果表明，弓长岭富铁矿蚀变岩主要为不同含量绿泥石和石榴子石组成的石榴绿泥岩或绿泥石榴岩，并普遍伴有碳酸盐化；其内产出的铌钽矿物以重钽铁矿为主，含少量铌铁矿、钽铁矿和黑钨矿。重钽铁矿普遍发育裂隙与溶蚀孔，部分呈现出“内铌外钽”的环带结构，且与绿泥石等热液蚀变矿物紧密共生，应属热液成因。整个剖面中蚀变岩w(Nb)+w(Ta)不高且w(Nb)>w(Ta)，但局部超常富集部位则表现出Ta含量显著高于Nb，暗示可能存在后期富Ta流体的叠加。综合考虑铌钽矿物的成分、内部结构及其稀土元素特征，文章认为弓长岭富铁矿及蚀变岩中铌钽矿化可能经历两期热液作用的改造：早期流体交代BIF形成富铁矿雏形及蚀变岩中的弱铌钽矿化；后期富Ta流体叠加，最终形成富铁矿体及以重钽铁矿为主的蚀变岩型铌钽矿化。研究结果为鞍本地区富铁矿成因研究及找矿预测提供了一个新的视角。
Abstract:In recent years, industrial Nb-Ta mineralization has been discovered in the altered rocks related to the highgrade iron ore deposits in the Anshan-Benxi areas. As the typical high field strength elements, the geochemical behavior of Nb-Ta elements in magmatic-hydrothermal systems has long been one of the focuses of research. Therefore, the research of Nb-Ta mineral characteristics in altered rocks is indicative to their affiliate of hydrothermal fluid. In this paper, samples of high-grade iron ore and altered rocks from No.6 cross-section of on the +50 m level in the Northwest sub-mining area of the Gongchangling No.2 mining area were systematically collected,and their petrographic, geochemical, typical mineral composition and textural characteristics were analyzed. The results show that the altered rocks from Gongchangling area mainly consist of garnet-rich and chlorite-rich altered rocks composed of different amounts of chlorite and garnet, and are generally accompanied by carbonatization. The Nb-Ta minerals are mainly comprised of ferrotapiolite, with a small amount of columbite, tantalite and wolframite. The ferrotapiolite usually exhibits fractures and corrosion holes, and some show obvious“Nb inside and Ta outside”zonal structure, which are closely associated with hydrothermal altered minerals such as chlorite,implying that they are hydrothermal origin. The overall Nb+Ta content of the altered rocks in the whole sampling profile is not high and Nb>Ta, but the Ta concentration is significantly higher than Nb locally, suggestive of the overprinting of late-stage Ta-rich fluids. Considering the mineral composition, texture and the rare earth element characteristics of Nb-Ta minerals, this paper argues that the formation of the Gongchangling high-grade iron ore and associated Nb-Ta mineralization in altered rocks may have undergone two-stage hydrothermal superimposition: the early-stage hydrothermal fluids metasomatized BIF into the embryonic form of high-grade iron ore, and weak Nb-Ta mineralization in altered rocks; then the late-stage Ta-rich fluids overprinting ultimately led to the formation of the high-grade iron ore bodies and altered-rock-type tapiolite-dominated Nb-Ta mineralization. This research provides a new perspective on the genesis and the prospecting of high-grade iron ore in the AnshanBenxi areas.
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基金项目:国家重点研发计划项目(编号:2022YFC2903701);国家重点研发计划青年科学家项目(编号:2022YFC2905400)联合资助
引用文本：
徐盛,姚玉增,韦昌铭,刘静,付建飞.2026.辽宁弓长岭铁矿床蚀变岩中重钽铁矿特征及对富铁矿成矿的指示意义[J].矿床地质,45(2):375~390XU Sheng,YAO YuZeng,WEI ChangMing,LIU Jing,FU JianFei.2026.Characteristics of ferrotapiolite in altered rocks and its significance for genesis of high-grade iron ore of Gongchangling iron deposit[J].Mineral Deposits45(2):375~390
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