中文摘要：

对粤北长江铀矿田赋矿花岗岩、蚀变花岗岩、铀矿石、沥青铀矿、黄铁矿、方解石和萤石开展了系统的REE，U与Th的地球化学研究，结果显示各类样品表现出类似的LREE相对富集、HREE相对亏损和Eu负异常的地球化学特征，表明样品REE特征具有一定的继承性，继承了赋矿花岗岩的REE特征。成矿早期钠交代作用对花岗岩中REE迁移较小，但对U有预富集作用，成矿期热液蚀变对花岗岩中REE迁移较明显，尤其是HREE，而Th表现出相对稳定的特征。从成矿早期到晚期方解石∑REE逐渐降低（EREE平均值由48．86×10-6→43．52×10-6→28．40×10-6），Eu负异常趋于减弱（8Eu均值由0．23→0．31→0．39），表明成矿流体向相对氧化环境演化。成矿热液中REE，U与Th活化、迁移具同步性和同时性。热液沸腾和去气作用是造成沥青铀矿、方解石和萤石相对富集HREE的原因。由成矿早期到成矿晚期，成矿热液向相对氧化的酸性流体演化。

英文摘要：

Geochemical study is carried out on the granite, altered granite, uranium ore, pitchblende and hydrothermal mineral （calcite,pyrite and fluorite） in the Changjiang uranium ore deposit of northern Guangdong Province. Various types of tested samples have similar REE characteristics, relative enrichment of LREE, relative depletion of HREE and obvious Eu negative anomaly,and have a certain inheritance for REE,derived from host ore granite. The migration of REE is not obvious in the Na-metasomatism at the early ore-forming stage but play a role in the early enrichment of uranium. The REE and U are obviously transported, especially the HREE,bring about remarkable enrichment of uranium in the mineralization stage. Thorium displays relatively stable in the hydrothermal activities. From the early ore-forming stage to late ore-forming stage, EREE of calcite become lower （∑REE average value： 48.86×10-6→43.52×10-6→28.40×10-6） ,and 3Eu become high （average value. 0.23→0.31→0.39）, suggesting that the hydrotherreal fluid evolved to relative oxidation fluid. REE and U are activated and migrated synchronously,and are transported together as soluble carbonate and fluoric complexes in the hydrothermal fluid. It seems that calcite and fluorite show more enrichment of HREE in the main mineralization stage than that in the later ore-forming stage. This phenomenon is related with the hydrothermal fluid boiling and CO2 degasification. The hydrothermal fluid gradually evolves to a relative oxidation acidulous fluid.