100 MPa、850 ℃和800 ℃条件下锡在流体与富磷过铝质熔体相间分配的实验研究

利用江西宜春414岩体中的钠长石花岗岩作为实验初始物，制备含不同1〉20s含量（0．27％－7．71％）的实验玻璃，本次实验研究了100MPa、850℃和800℃条件下Sn在流体与富磷过铝质熔体相间的分配。实验结果显示，Sn在流体与熔体相间的分配系数（Dsofluid/mclt）变化于2．10×10^-4－1．36×10^3之间，指示Sn强烈趋向于在富磷过铝质熔体中富集。随体系中P2Os含量从0．27％增至1．91％，Sn在流体与熔体相间的分配系数逐渐增加，当体系中R2O5含量进一步增加时，Sn在两相间的分配系数呈降低的趋势。本次实验结果表明，P可能不是Sn以流体相形式进行搬运的主要络合剂。

Experimental study on Sn partitioning between phosphorus-rich peraluminous melt and coexisting aqueous fluid

The albite granite of Yichun stock, added with 0. 27%-7.71% P_2O_5, was chosen as the initial composition. The partition coefficients of Sn between the phosphorus-rich peraluminous granitic melt and coexisting aqueous fluid were determined at I00 Mpa and 800 ℃ and 850 ℃. The experimental results show that the partition coefficients (D_(Sn)~(flusd/melt)) ((D_(Sn)~(flusd/melt)) where C_(fluid) and C_(melt), are the concentrations of Sn in the aqueous fluid and the melt, respectively) vary from 2.10 x 10~(-4) to 1.36 x 10~(-3), indicating that Sn partitions preferentially into the hydrous melts. The partition coefficients of Sn increased with increasing P_2O_5 content from 0. 27% to 1.91%,but decreased when the P_2O_5 content further increased. According to our experimental results, P is probably not the main complexant for the transportation of Sn in fluids evolved from a granitic magma.