高压超高压变质作用中的流体

文章强调了高压和超高压变质岩中流体包裹体的研究意义，重点论述了几个问题：（１）高压和超高压变质岩中流体包裹体的成分以含Ｎ２量高为特点，在大别山含柯石英榴辉岩中找到的高压榴辉岩阶段捕获的原生包裹体，其中气相组分含ＣＯ（摩尔分数）为１４％，表明流体来源于深部。原生流体包裹体的保存，要求在ｐ－Ｔ区间内的抬升轨迹与等容线近于平行。（２）在大别山高压和超高压榴辉岩中首次确认熔融包裹体的存在，由硅酸盐玻相和以ＣＯ２为主要成分的气相组成，并发现熔融包裹体中的玻相成分与主矿物相近。（３）高压和超高压变质期间的局部流体迁移可由榴辉岩中流体包裹体和矿物同位素成分（Ｈ－Ｃ－Ｏ）来显示。（４）高压和超高压变质中流体－熔体－岩石（矿物）相互作用是一个非常复杂的过程，并证实在榴辉岩相ｐ－Ｔ条件下岩石的部分熔融。（５）变质流体的成分与变质级之间存在着相关关系。

FLUIDS IN HIGH PRESSURE AND ULTRA HIGH PRESSURE METAMORPHISM

This paper emphasizes the significance of studies on fluid inclusions in high pressure and ultra high pressure rocks and several points have been discussed: (1) N 2 is present as a characteristic component in eclogites. Primary fluid inclusions found in coesite bearing eclogites from Dabie Mountains were traps in high pressure metamorphism stage. CO of 14 mol% was detected in gas component, suggesting fluids of deep seated origin. (2) Melt inclusions were first recognized in eclogites from Dabie Mountains. They are composed of sillicate glass phase and gas phase with the dominant CO 2 and the composition of glass phase close to that of the host mineral. (3) Fluid inclusion and mineral isotopic compositions (H C O) in eclogites as tracers of local fluid migration during high pressure and ultra high pressure metamorphism. (4) Fluid melt rock interaction in high pressure and ultra high pressure metamorphism is complicated and demonstrates partial melting at eclogite facies p T conditions. (5) Fluid inclusion data suggest a correlation between metamorphic grade and metamorphic fluid composition.