大别剪切构造带中榴辉岩的成分变异-体积变化和流体流动

研究了大别山区剪切构造带内榴辉岩在退变质阶段塑性变形过程中的成分变异、体积变化和流体流动特征，得到：（１）随着变形程度的增强，榴辉岩中除Ａｌ２Ｏ３，Ｐ２Ｏ５和Ｔｈ的含量基本保持不变外，其他组分或元素都发生了明显的变异；（２）ＳｉＯ２在超高压榴辉岩带中表现为明显的流失，而在高压中温榴辉岩带内表现为明显的获得；（３）从榴辉岩到榴闪岩再到榴云角闪片岩的退变质阶段变形过程中，岩石体积发生了明显扩容，其体积变化率为－３．５％～－２８％；（４）流体／岩石比值约为１～５０．１，说明了流体在高压超高压变质岩形成和抬升过程中起了重要的作用

COMPOSITION VARIATION,VOLUME CHANGE AND FLUID FLOW OF THE ECLOGITES IN THE SHEAR ZONES IN DABIE MOUNTAINS

Based on the study of the composition variation,volume change and fluid flow of the eclogites in the shear zones in Dabie mountains,the conclusions are summarizedas:(1)almost all of elements,except for A1,P and Th in the eclogites,had been varied in the shear zones during retrograde metamorphism processes;(2)Si was gained in the high-pressure and middle temperature eclogite zone,but lost in the ultra-high pressure eclogite zone;(3)the dilation,with the rate varying from 3.5% to 28% in volume,occurred from eclogites to amphibole schists in the shear zones during retrograde metamorphism processes and (4) the fluid flow and volume change are two key factors for the composition variation of the eclogites in the shear zones in Dabie Mountains.