庐山星子群变质流体的包裹体研究  

INCLUSION STUDY ON METAMORPHIC FLUIDS FROM THE XINGZI GROUP, LUSHAN

作　　者：唐红峰[1] 刘丛强[1] 倪培[2] 

机构地区：[1]中国科学院地球化学研究所,贵阳550002 [2]南京大学成矿作用国家重点实验室,南京210093

出　　处：《矿物学报》2000年第3期286-292,共7页Acta Mineralogica Sinica

基　　金：国家杰出青年科学基金!(批准号 :4962 5 3 0 4);科技部攀登计划预选项目!(批准号 :95 预 3 9)资助

摘　　要：庐山星子群沉积变质岩中发育平行区域片理的石英脉和长英质脉体 ,这些脉体的石英晶体内富含原生的流体包裹体 ,包括低盐度的含液体CO2 包裹体、液体包裹体、纯CO2 包裹体和高盐度含子矿物包裹体。它们与中生代伟晶岩脉体中包裹体在均一温度、盐度和CO2 密度等方面的明显差异和变质脉体中含液体CO2 包裹体的等容线位置 ,表明变质脉体石英中的流体包裹体是在变质作用期间被捕获的部分变质流体 ,进一步证实了脉体是与变质作用同期形成的。庐山星子群变质流体属于低盐度的H2 O -CO2 -NaCl和H2 O -NaCl体系 ,高盐度的卤水和纯CO2 体系的包裹体很可能是流体在运移过程中发生相分离的结果。Many quartz and felsic veins in parallel to the regional foliation occur in the Xingzi Group metasedimentary rocks. In the veins, quartz crystals contain a large number of primary fluid inclusions, including low\|salinity liquid\|CO\-2\|bearing, H\-2O\|NaCl, pure CO\-2, and high\|salinity daughter\|crystal\|bearing inclusions. The position of the isochors for liquid\|CO\-2\|bearing inclusions in the metamorphic veins, combined with the obvious differences in final homogenization temperature, salinity, and CO\-2 density between the inclusions in the metamorphic veins and those in the Mesozoic pegmatitic veins, suggests that the inclusions in the metamorphic veins are part of the metamorphic fluids trapped during metamorphism, hence lending further support to the conclusion that these quartz and felsic veins were formed during metamorphism. Metamorphic fluids in the Xingzi Group are the low\|salinity H\-2O\|CO\-2\|NaCl and H\-2O\|NaCl fluids. High\|salinity brine and pure CO\-2 inclusions probably resulted from fluid phase separation during migration of the metamorphic fluids.

关 键 词：变质流体 流体包裹体 星子群 庐山 变质岩 

分 类 号：P588.3[天文地球—岩石学] P578[天文地球—地质学]