钨、锡液态分离成矿作用的新证据

NEW EVIDENCE FOR THE LIQUATION MINERALIZATION OF W AND Sn

花岗质岩浆体系中，钨、锡的流－熔分配和熔－熔分配实验结果为花岗质岩浆液态分离成矿作用提供了新证据，在实验范围内，钨、锡的流－熔分配系数和都很小，其最大值然而，钨、锡的熔－熔分配系数都大于１，其最大值分析估算表明，花岗质岩浆期后热液成矿作用难以形成大、中型钨锡矿床，而液态分离作用是形成钨锡矿床的主要途径。

New evidence for the liquation mineralizing processes has been presented using two se-ries of experimental results in the granitic magmatic system. These two series of experimentsinvolve(Ⅰ)partitioning of W and Sn between melts and fluids,and(Ⅱ)partitioning of Wand Sn between the immiscible phases. Within the experimental range,the fluid-melt parti-tioning coefficients are all rather small;the maximum values are 0.036.However,all melt-melt partitioning coefficients are more than 1;the maximum val-res are 4.18 and 3. 82.It is estimated that any large or middle-sized W andSn deposits are hard to be formed through granitic magmatic hydrothermal processes.On theother hand,liquation mineralizing process in granitic magmatic system is the major processof forming large or middle-sized W and Sn deposits.