摘要
近年来赣南地区首次报道了变质岩离子吸附型稀土矿床的发现,为离子吸附型稀土的找矿提供了新思路。赣南地区新元古代变质岩大面积分布,风化壳也广泛发育。文章对30件稀土元素含量(>300×10^-6)高的变质岩矿物样品进行了详细的电子探针分析,旨在查明赣南新元古代不同类型变质岩中的稀土矿物种类及特征,探讨其成因、对全岩稀土元素含量的贡献以及离子吸附型稀土元素的成矿潜力。研究表明,区域上变质岩可大致分为6类,分别是变质凝灰岩类、板岩类、千枚岩类、片岩类、变砂岩类和变粒岩类,不同类型变质岩的稀土矿物组合不同,除了普遍存在的、难风化的独居石、磷钇矿和锆石外,部分岩性中出现易风化的褐帘石、含稀土元素绿泥石和含稀土元素金红石,及表生的水磷酸盐和磷铝酸盐等矿物。这些富稀土矿物贡献了全岩中大部分稀土元素,且部分矿物成因与后期流体作用相关,为成矿提供了良好的条件。文章总结分析认为,赣南地区广泛分布的变质岩中,片岩类、变砂岩类和变质凝灰岩类均具有相对易风化的稀土矿物组合,尤其变质凝灰岩类和变砂岩类,能为离子吸附型稀土成矿提供充足的物质来源,具有可观的离子吸附型稀土成矿潜力。
In recent years, the discovery of ion-adsorption rare earth deposits in the regolith of metamorphic rocks has been reported for the first time in southern Jiangxi Province, which provides a new idea for ion-adsorption rare earth prospecting. Neoproterozoic metamorphic rocks and the related weathered crusts are widely distributed in South Jiangxi Province. In order to ascertain the species, genesis, proportion of REE contribution to the whole rock REE content as well as the potential of forming ion-adsorption REE deposits of the REE minerals, the authors conducted detailed electron microprobe analysis on 30 pieces of high REE content rock samples. The results show that mainly 6 types of metamorphic rocks are distributed in the study area, i. e., metamorphic tuff, slate, phyllite, schist, blastopsammite, and granulite. REE minerals in these different types of rocks vary in composition;in addition to ubiquitous minerals such as monazite, xenotime and zircon, easily weathering minerals like allanite, REE chlorite, REE rutile and supergene minerals rhabdophane-(La) and florencite-(La) were also observed in some rock samples. Contributing most of the whole rock REE content, the REE minerals, some of which might be formed or altered by later fluid, are providing a favorable precondition for REE mineralization. To sum up, metamorphic tuff and blastopsammite in the study area both have easily weathered REE mineral assemblages, making them the most potential substances supplier for the ion-adsorption REE accumulation, and indicating that metamorphic rocks in South Jiangxi Province have the potential to develop ion-adsorption REE mineralization.
作者
王臻
陈振宇
赵芝
陈斌峰
邹新勇
WANG Zhen;CHEN ZhenYu;ZHAO Zhi;CHEN BinFeng;ZOU XinYong(MNR Key Laboratory of Metallogeny and Mineral Assessment,Institute of Mineral Resources, Chinese Academy of Geological Sciences, Beijing 100037, China;Geological Survey Party of Gannan, Bureau of Geology and Mineral Exploration & Development of Jiangxi Province, Ganzhou 341000, Jiangxi, China)
出处
《矿床地质》
CAS
CSCD
北大核心
2019年第4期837-850,共14页
Mineral Deposits
基金
中央级公益性科研院所基本科研业务费专项基金“赣南变质岩离子吸附型稀土矿成矿规律与找矿方向研究”（编号：YYWF201527）
“赣南变质岩离子吸附型稀土矿成矿机理研究”（编号：K1506）项目联合资助
关键词
地球化学
离子吸附型稀土矿
稀土元素
稀土矿物
变质岩
赣南
geochemistry
ion-adsorption REE deposits
rare earth elements
REE minerals
metamorphic rocks
South Jiangxi Province
