Geochemical evidence for contribution of ore-forming materials from peraluminous granite basement —— Taking Fucheng pluton and No. 6722 uranium deposit in southern Jiangxi Province as examples  

作　　者：章邦桐 陈培荣 杨东生 孔兴功 

机构地区：State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China[1] College of Geography Sciences, Nanjing Normal University, Nanjing 210097, China[2]

出　　处：《Science China Earth Sciences》2003年第3期296-304,共9页中国科学（地球科学英文版）

基　　金：This work was supported by the National Natural Science Foundation of China (Grant No. 49472107). The authors wish to thank Ni Xiuyi; chief engineer of Geological Team No. 264 for his assistance in field work. References

摘　　要：Using the induced fission-track method, mobile uranium leaching and lead isotope analysis, this work obtianed geochemical features of the peraluminous Fucheng granite basement and the host rock (shoshonite) of the No. 6722 uranium deposit in southern Jiangxi Province. (i) Uranium contents of the leucocratic rock-forming minerals (0.18 mg/g for quartz, 0.36 mg/g for feldspar) are lower than the uranium content of the whole rock (4.6 mg/g). Biotite and some ac-cessory mineral inclusions (zircon, monazite and uraninite) are the main uranium carriers of the Fucheng granite pluton. The fissure uranium in altered minerals (hydromica and chlorite) increased evidently. (ii) Leachable rate of mobile uranium in the biotite granite is 10.4%, while that in the al-tered granite increased to 31%. (iii) Caculation based on lead isotopes shows that during alteration the Fucheng granite lost uranium (DU = -37% — -65%), whereas the Caotaobei shoshonite gained uranium (DU = +37%— +58%). These features suggest that the ore-forming material of the No. 6722 uranium deposit was mainly derived from the altered peraluminous granite basement of Fucheng pluton.Using the induced fission-track method, mobile uranium leaching and lead isotope analysis, this work obtianed geochemical features of the peraluminous Fucheng granite basement and the host rock (shoshonite) of the No. 6722 uranium deposit in southern Jiangxi Province. (i) Uranium contents of the leucocratic rock-forming minerals (0.18 mg/g for quartz, 0.36 mg/g for feldspar) are lower than the uranium content of the whole rock (4.6 mg/g). Biotite and some ac-cessory mineral inclusions (zircon, monazite and uraninite) are the main uranium carriers of the Fucheng granite pluton. The fissure uranium in altered minerals (hydromica and chlorite) increased evidently. (ii) Leachable rate of mobile uranium in the biotite granite is 10.4%, while that in the al-tered granite increased to 31%. (iii) Caculation based on lead isotopes shows that during alteration the Fucheng granite lost uranium (DU = -37% — -65%), whereas the Caotaobei shoshonite gained uranium (DU = +37%— +58%). These features suggest that the ore-forming material of the No. 6722 uranium deposit was mainly derived from the altered peraluminous granite basement of Fucheng pluton.

关 键 词：PERALUMINOUS granite  No. 6722 URANIUM deposit  basement  induced fission-track  mobile uranium. 

分 类 号：P595[天文地球—地球化学]