Abstract：Abstract：Brannerite which presebts in lengrh platelike columns and subhedron-idiomorphic crystal developed in Zoujiashan uranium deposit，Xiangshan ore field. Applying the microscope，electron microprobe analysis，and LA-ICP-MS analysis，the chemical composition characteristics of the brannerite was studied. It is concluded that brannerite，with stable U，Ti content and Ti/U ratio， showthat the acidic ore-forming fluids had mid-high-temperature period. 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 precipitates together with brannerite crystallizing rapidly, and REE exists in brannerite by the isomorphic form; REE patterns of the brannerite was flat type with LREE enrichment slightly and HREE enrichment， and with that Eu is middle negative anomaly， which indicate 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 dose not root in Xiangshan volcanic hydrothermal or magma，or be lixiviated from the basement metamorphic rocks and the mafic dikes, while they mostly roots in magma and magmatic hydrothermal which .are generated from partial melting of the rich uranium geologic body altered by the mantle magma and thermal fluids, not excluding from that part of REE, U, Th, Y roots in the mantle.
2018, Vol. 35 
