摘要
探讨稀土元素地球化学对多不杂铜矿床成矿物质及流体来源的指示意义。选择相关岩矿石及金属矿物样品,测试其稀土元素组成。研究表明,岩矿石及金属矿物均具有轻稀土富集的特征,这是地幔流体作用成矿的标志。由磁铁矿→浸染状黄铁矿→脉状黄铁矿→黄铜矿演化,δEu值逐步从大于1过渡为小于1,即由正铕异常→负铕异常演化,这是含矿地幔流体作用导致熔浆→热液演化,引发交代蚀变,促使壳幔物质混染叠加成矿的依据。从花岗闪长斑岩→变质砂岩→玄武安山岩,总稀土元素呈现出逐步上升的趋势;花岗闪长斑岩和变质砂岩均为含矿地质体,构成了接触带成矿体系,它们的δEu值分别表现为大于1和小于1,即分别呈现出正铕异常和负铕异常;玄武安山岩不含矿,无明显的铕异常。
The significance of geochemistry of rare earth elements on the origin of ore-forming materials and fluids in Duobuza copper deposit was studied. The samples of rocks and minerals were selected to test the REE composition. The results showed that the rocks and minerals are LREE enrichment. This is a sign of mineralization of man- tle fluid. The evolution from the magnetite to pyrite disseminated, then to vein pyrite and chalcopyrite, corresponds to 8Eu values gradually translate from more than 1 to less than 1, that is, from positive Eu anomaly to negative Eu anomaly evolution. This indicated that the ore bearing mantle fluids through metasomatie alteration resulted in evolu- tion from magma tohydrothermal ,and crust mantle contamination superposition mineralizations. The total rare earth elements show a gradual upward trend from granodiorite porphyry to metamorphic sandstone and basalt. Granodiorite porphyry and metamorphic sandstone are both ore bearing geological bodies, which form the metallogenic system of the contact zone. Their 8Eu values are more than 1 and less than 1, respectively, showing positive Eu anomaly and negative Eu anomaly. Basaltic andesite does not contain ore, no obvious Eu anomaly.
出处
《中国稀土学报》
CAS
CSCD
北大核心
2018年第1期122-128,共7页
Journal of the Chinese Society of Rare Earths
基金
国土资源部公益性行业科研专项项目(201011013)资助
关键词
稀土元素
地幔流体
多不杂铜矿床
西藏
rare earth elements
mantle fluids
Duobuza copper deposit
Tibet
