黔西北大方猫场硫铁矿床地球化学特征研究  

Geochemical Characteristics of the Maochang Pyrite Deposit in Dafang County of the Northwestern Guizhou, China

作　　者：李鑫正 杨瑞东[1,2] 罗朝坤 徐海 吉彦冰 汪龙波[1,2] 孙百川 LI Xin-zheng;YANG Rui-dong;LUO Chao-kun;XU Hai;JI Yan-bing;WANG Long-bo;SUN Bai-chuan(College of Resource and Environment Engineering,Guizhou University,Guiyang 550025,China;Key Laboratory of Karst Georesources and Environment of Ministry of Education,Guiyang 550025,China;College of Economics and Management,Tongren University,Tongren,Guizhou 554300,China)

机构地区：[1]贵州大学资源与环境工程学院,贵阳550025 [2]喀斯特地质资源与环境教育部重点实验室,贵阳550025 [3]铜仁学院经济管理学院,贵州铜仁554300

出　　处：《矿物岩石地球化学通报》2022年第3期547-556,共10页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：贵州省沉积矿床科技创新人才团队项目(黔科合平台人才[2018]5613);国家自然科学基金资助项目(U1812402);贵州省研究生科研基金资助项目(黔教合YJSKYJJ[2021]076)。

摘　　要：黔西北地区中二叠统茅口组灰岩上、峨眉山玄武岩下的黏土化斑杂状玄武岩中,广泛发育一层硫铁矿。为探讨硫铁矿的物质来源、成矿模式并评价伴生的三稀资源潜力,以贵州大方猫场硫铁矿为研究对象,对其开展了矿物学和元素地球化学研究。结果显示,硫铁矿层与峨眉山玄武岩在稳定元素二元相关性图解、稀土元素球粒陨石标准化配分型式等方面都具有明显的一致性,表明硫铁矿层的形成与峨眉山玄武岩密切相关。综合元素地球化学、化学蚀变指数(CIA)及化学风化指数(CIW)的结果认为,玄武岩的风化很可能为硫铁矿的形成提供了铁质来源。玄武岩风化释放的Fe被迁移到硫化-还原的海水环境中,以硫铁矿的形式沉淀从而形成硫铁矿床。此外,硫铁矿层中广泛富集Nb、Zr、REE等元素,也具有较大的开发利用潜力。A layer of pyrite has been widely developed in the argillaceous altered taxitic basalt between the floor of the Middle Permian Maokou Formation limestone and the roof of the Emeishan basalt in the northwestern Guizhou,. In order to explore the material source and discuss metallogenic model of the pyrite layer, and to assess the potential of resources of the associated rare earth elements, rare metal elements, and dispersed elements, in this paper, the mineralogical and elemental geochemical investigations of the Maochang pyrite deposit in Dafang County, Guizhou Province have been conducted. The results show that obvious similarities between characteristics in binary correlation diagrams of immobile elements and chondrite-normalized REE distribution patterns for samples of the pyrite layer and those of the Emeishan basalt indicate that the formation of pyrite layer was closely related to the Emeishan basalt. Meanwhile, combined with results of the elemental geochemistry, chemical alteration index(CIA), and chemical weathering index(CIW), it is believed that the weathering of basalt was likely to have provided iron for the formation of pyrite. Fe released from the basalt weathering was migrated into the sulfidation-reduced seawater environment and then was precipitated in the form of pyrite to have formed the pyrite deposit. In addition, samples of the pyrite layer are widely enriched in Nb, Zr and REE, etc. Thus, there is great potential for the development and utilization of those rare elements in the pyrite layer.

关 键 词：玄武岩 硫铁矿 成矿作用 物质来源 黔西北 

分 类 号：P618.31[天文地球—矿床学]