摘要
相山矿田邹家山铀矿床发育细小板柱状半自形-自形钛铀矿。应用显微镜、电子探针、LA-ICP-MS等分析手段,对邹家山矿床铀矿石中的钛铀矿开展化学成分特征研究,结果认为:钛铀矿具有较为稳定的U、Ti含量和Ti/U比值,钛铀矿的发育表明酸性成矿流体存在中高温阶段;钛铀矿富集U、Ti、K、Fe、Al、Ca、Pb、Zr、F、Y、Th、Yb、REE等元素,尤其富集Th、REE和Y,显示REE、Th、Y等元素与钛铀矿共沉淀,为钛铀矿快速结晶所形成,REE以类质同像形式赋存于钛铀矿中;钛铀矿稀土配分型式为轻稀土略富集、重稀土富集的平坦型,Eu中等负异常,指示铀成矿流体富含Cl、F、CO_2等挥发份,REE、U、Th、Y等元素主要以碳酸盐、氯化物和氟化物型络合物形式迁移;钛铀矿中稀土元素含量、配分型式与围岩存在显著差异,表明REE、U、Th、Y等元素不是来源于相山火山岩或其岩浆分异热液,也不是由基底变质岩、基性岩脉浸出,而主要来源于深部富铀地质体在地幔岩浆、热流体作用下部分熔融所形成的岩浆和(分异)热液,不排除部分来源于地幔。
Brannerite in subhedron-idiomorphic fine plate or columns developed in Zoujiashan uranium deposit, Xiangshan ore field. Applying the microscope, electron microprobe analysis, and LA-ICPMS analysis, the chemical composition characteristics of the brannerite was studied. Brannerite, with stable U, Ti content and Ti/U ratio suggest that the acidic ore-forming fluids had mid-high temperature. The brannerite is enriched in U, Ti, K, Fe, Al, Ca, Pb, Zr, F, Y, Th, Nb, Yb,REE, especially enriched in Th, REE and Y, which indicate that REE, Th, Y precipitated togetherwith brannerite crystallization rapidly, which indicated that uranium metallogenic fluids are enriched in volatile Cl, F, CO2 and so on, and REE, U, Th, Y is transferred mainly in the formes of carbonate, chloride and fluoride complexes. The content and distribution of REE of the brannerite is remarkably different from wall rock, which shows that REE, U, Th, Y does not root in Xiangshan volcanic hydrothermal or magma, or be lixiviated from the basement metamorphic rocks and the mafic dikes, while they may mostly come from magma and magmatic hydrothermal fluid which was generated from partial melting of the rich uranium geologic body altered by the mantle magma and thermal fluids which does not exclude that some of them may come from the mantle.
作者
胡志华
林锦荣
王勇剑
王峰
陶意
HU Zhihua;LIN Jinrong;WANG Yongjian;WANG Feng;TAO Yi(CNNC Key Laboratory of Uranium Resource Exploration and Evaluation Technology,Beijing Research Institute of Uranium Geology,Beijing 100029,China)
出处
《世界核地质科学》
CAS
2018年第2期63-70,共8页
World Nuclear Geoscience
基金
国家重点研发计划项目(编号:2017YFC0602600)
国家自然科学基金项目(编号:41573051)
中核集团科技示范工程项目(编号:地LCD116-3)资助
关键词
钛铀矿
地球化学特征
成矿意义
邹家山铀矿床
相山矿田
brannerite
geochemical characteristics
metallogenic significance
Zoujiashan uraniumdeposit
Xiangshan ore field
