相山铀矿田特富矿成矿模式  

Ore-forming Model of the Extremely-rich Ores in Xiangshan Uranium Orefield,Jiangxi

作　　者：温志坚[1] 杜乐天[1] 刘正义[1] 

机构地区：[1]核工业北京地质研究院,100029

出　　处：《地质论评》1999年第S1期763-767,共5页Geological Review

摘　　要：相山铀矿田是我国最大的火山热液型铀矿田之一。大量的电子探针测试揭示该矿田特富铀矿体中普遍存在铀矿物与氟碳磷灰石紧密共生,对特富铀矿石的化学分析也显示铀含量与P_2O_5和CaO呈大体正相关关系。进一步研究表明磷、铀具有相似的地球化学特性并在热液条件下可以共迁移、共沉淀,据此作者提出:磷、铀胶体共沉淀是该区特富矿形成的主要机理。对采自相山盆地邻区地幔捕虏体研究证实地幔流体与相山矿田铀成矿热液化学成分具有相似性:即富含钾、钠离子和还原性气体。对相山铀矿田He、Ar同位素研究进一步证实该矿田铀成矿热液中有地幔流体参与。配合其他方面的研究,在本区首次提出特富矿铀成矿模式。The Xiangshan uranium orefield is one of the largest volcanogenic hydrothermal uranium orefields in China. A number of electronprobe tests indicates that francolite extensively coexists with uranium minerals. Chemical analyses also show that the uranium content is in approximately positive correlation with P_2O_5 and CaO. Further studies reveal that uranium and phosphorus have similar geochemical behaviors in hydrothermal condition, and may be transported and precipitated together. The authors propose that the formation mechanism of rich uranium deposits is originated from the colloidal co-precipitation of uranium and phosphorus minerals. Studies of mantle xenoliths reveal that mantle fluids are rich in reducing gases and K^+, Na^+ ions etc. , so do the hydrothermal fluids. He and Ar isotope analyses prove that the ore-forming hydrothermal fluids have been mixed with mantle fluids. On the basis of metallogenic features of this orefield, an ore forming model of extremely-rich uranium ores has been put forward.

关 键 词：相山铀矿田 富矿成矿作用 胶体共沉淀 地幔流体 成矿模式 

分 类 号：P619.14[天文地球—矿床学]