An experimental determination of W,Nb,and Ta partition coefficients between P-rich peraluminous granitic melt and coexisting aqueous fluid  

作　　者：Yong Tang Hui Zhang 

机构地区：[1]Laboratory for High Temperature and High Pressure Study of the Earth's Interior,Institute of Geochemistry,Chinese Academy of Sciences

出　　处：《Chinese Journal Of Geochemistry》2015年第2期194-200,共7页中国地球化学学报

基　　金：supported by the Chinese National Natural Science Foundation(Project No.40273030);the Chinese Academy of Sciences through an innovation project (Project No.KZCX3-SW-124)

摘　　要：The partition coefficients of W,Nb,and Ta between the P-rich peraluminous granitic melt and the coexisting aqueous fluid were determined at 800-850 °C and 0.5-1.5 kbar.The experimental results showed that the partition coefficients D_w,D_(Nb) and D_(Ta)(D_i^(v/m) = C_i^V/C_i^m,where C_i^V and C_i^m denote the concentrations of an element,i,in the aqueous fluid and the melt,respectively) were less than 0.1.All partition coefficients were affected by pressure,but there was no evidence for the complexation of P2O5 with these elements in the granitic melt or aqueous fluid,except for with W in the fluid.The results showed that W,Nb,and Ta tended to partition into the granitic melt and,in the late period of crystallization of P-rich magma,they formed independent minerals.The partition coefficients of W,Nb,and Ta between the P-rich peraluminous granitic melt and the coexisting aqueous fluid were determined at 800-850 °C and 0.5-1.5 kbar.The experimental results showed that the partition coefficients Dw,D（Nb） and D（Ta）（Di^v/m = Ci^V/Ci^m,where Ci^V and Ci^m denote the concentrations of an element,i,in the aqueous fluid and the melt,respectively） were less than 0.1.All partition coefficients were affected by pressure,but there was no evidence for the complexation of P2O5 with these elements in the granitic melt or aqueous fluid,except for with W in the fluid.The results showed that W,Nb,and Ta tended to partition into the granitic melt and,in the late period of crystallization of P-rich magma,they formed independent minerals.

关 键 词：分配系数 实验测定 水流体 过铝质 熔体 NB 共存 钽 

分 类 号：P588.121[天文地球—岩石学]