【摘要】 通过晚期与稀土元素矿化相关的萤石中流体包裹体岩相学、显微测温分析,以及萤石、矿石及碱性岩体的稀土及微量元素分析,系统地探讨了沙鄂博稀土矿床成矿流体的特征、成矿物质来源及萤石成因。与稀土矿化相关的晚期萤石中发育大量的熔体包裹体及流体-熔体包裹体,表明萤石归属于岩浆成因,同时表明成矿与岩浆作用有关。碱性斑岩体、晚期萤石和矿石的稀土元素具相似的配分模式,表现为向右陡倾的分配曲线。微量元素分析结果表明:含矿碱性岩体、晚期萤石和矿石均富集大离子亲石元素,并具明显的Ba, Th, Ce, Sr和Hf等负异常,微量元素蛛网图相似。含矿碱性岩体、矿石及与稀土矿化相关的萤石的稀土元素及微量元素的相似特征,表明成矿物质来自碱性岩体。通过包裹体、稀土与微量元素研究认为,干沙鄂博稀土矿床中萤石成因类型为岩浆成因非热液成因。更多还原

【Abstract】 Based on petrography and micro-thermometry of fluid inclusions in late ore-forming related fluorite and REEs and trace elements determination of fluorite, ore mineral and alkaline pluton, this paper discussed the characteristics of the ore-forming fluid and source of ore-forming substances, as well as genetic type of fluorite. A large amount of melt inclusions and melt-fluid inclusions, which attribute fluorite to be igneous origin, were found in fluorite, indicating ore-forming process is related to magma activity. Similar REs partition pattern, with the curve incline to the right sharply, was found in the alkaline porphyry, fluorite and ore mineral. Trace elements analysis showed that all of the alkaline porphyry, fluorite and ore mineral are rich in large ion lithophile element(LILEs), with similar spider diagram of trace elements and obvious negative anomaly of Ba, Th, Ce, Sr and Hf. The similarities of REEs and trace elements of the alkaline porphyry, fluorite and ore mineral make clear that the origin of ore-forming materials come from the alkaline pluton. Based on analysis of fluid inclusions, REE and trace elements of alkaline pluton, fluorite, and ores it suggests that fluorite in the Gansha-Ebo REE deposit can be classified as a magmatic type associated with alkaline porphyry rather than hydrothermal origin.更多还原