矿床地质2026，Vol.45Issue(2)：375-390,16.DOI:10.16111/j.0258-7106.2026.02.009
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
Characteristics of ferrotapiolite in altered rocks and its significance for genesis of high-grade iron ore of Gongchangling iron deposit
摘要
Abstract
In recent years,industrial Nb-Ta mineralization has been discovered in the altered rocks related to the high-grade iron ore deposits in the Anshan-Benxi areas.As the typical high field strength elements,the geochemical be-havior of Nb-Ta elements in magmatic-hydrothermal systems has long been one of the focuses of research.There-fore,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 al-tered rocks composed of different amounts of chlorite and garnet,and are generally accompanied by carbonatiza-tion.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 superimposi-tion: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 Anshan-Benxi areas.关键词
重钽铁矿/富铁矿/蚀变岩/弓长岭铁矿Key words
ferrotapiolite/high-grade iron ore/altered rock/Gongchangling iron deposit分类
天文与地球科学引用本文复制引用
徐盛,姚玉增,韦昌铭,刘静,付建飞..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,2026,45(2):375-390,16.基金项目
本文得到国家重点研发计划项目(编号:2022YFC2903701)和国家重点研发计划青年科学家项目(编号:2022YFC2905400)联合资助 （编号:2022YFC2903701）
