华南花岗岩的岩浆与岩浆—流体包裹体及其意义

MAGMATIC, FLUID-MAGMATIC AND FLUID INCLUSIONS STUDIES ON GRANITES, SOUTH CHINA

对华南的壳源型重熔花岗岩，壳幔型花岗岩和碱性花岗岩的岩浆、岩浆—流体包裹体的研究结果，其岩浆包裹体可分为结晶质熔融包裹体、结晶质玻璃质熔融包裹体和玻璃质熔融包裹体３种。其均一温度的最佳值分别为８５０℃，９００℃和９２５℃。花岗岩的岩浆包裹体成分与该岩石的化学成分相似，且含有一定量的挥发组分。在华南花岗岩，特别是含稀有元素的花岗岩中发现了代表从岩浆衍生出岩浆热液的不混溶过程的岩浆—流体包裹体。按其成分可分为４种，它比一般的岩浆包裹体更富含挥发分和易溶盐，其均一温度的最佳值为７５０℃。结果表明，华南３类花岗岩均为岩浆熔融的产物，但其成分和温度不相同。

Tth magmatic (melt), magmatic-fluid and fluid inclusions in granites of south China have been examined. The results show that the magmatic inclusions in granites can be classified into three types: crystalline melt inclusion, crystalline-glass melt inclusion and glass inclusion. The homogenization temperatures of these ones range from 650 to 1100℃ with optimum value from 850 to 925℃. Chemical and electron microprobe analysis of composition of fmagmatic inclusion indicate that is similar to the bulk composition of the granite but rich in volatiles. The magmatic-fluid inclusion representing the process of a transition from magma to hydrothermal fluid have bee found. They consist of silicate melt and fluid in one or a group inclusions and usually it can be found in rare elements bearing granites with optimum homogenization temperatures of 750℃. The results explain that the granite driven from a partial melting of crustal or of crustal-mantle origin has difference in homogenization temperatures and composition.