Composition of Phengites in Eclogites and Their Retrogressive Derivatives of the Dabieshan Region: Implication for the Applicability of Phengite Geobarometre  

作　　者：顾连兴 杜建国 翟建平 范建国 赵成浩 张文兰 

机构地区：[1]Department of Earth Sciences, State Key Laboratory for Mineral Deposit Research,Nanjing University, Nanjing 210093, China [2]Anhui Academy of Geological Survey, Hefei 230001, China

出　　处：《Chinese Journal Of Geochemistry》2002年第1期52-56,共5页中国地球化学学报

基　　金：KeyProjectNo .95 0 110 2 0 4 0 1ofMinistryofGeologyandMineralResourcesandbyStateKeyLaboratoryofOreGenesis,NanjingUniversity

摘　　要：Phengites in ecologites of the Dabieshan region can be divided into three generations: primary phengite formed during ecologite-facies prograde metamorphism (Phe1), phengite formed during the late stage of eclogite-facies retrograde metamorphism (Phe2) and phengite formed during amphibolite- to greenschist-facies diaphthoresis (Phe3). Electron microprobe analyses show that the Si and Fe\+\{2+\}+Mg contents of Phe1 are unexpectedly lower than those of Phe3. Therefore, much caution should be exercised while using the Si content of phengite to estimate the pressure of a retrograde process.Phengites in ecologites of the Dabieshan region can be divided into three generations: primary phengite formed during ecologite-facies prograde metamorphism (Phe1), phengite formed during the late stage of eclogite-facies retrograde metamorphism (Phe2) and phengite formed during amphibolite- to greenschist-facies diaphthoresis (Phe3). Electron microprobe analyses show that the Si and Fe\+\{2+\}+Mg contents of Phe1 are unexpectedly lower than those of Phe3. Therefore, much caution should be exercised while using the Si content of phengite to estimate the pressure of a retrograde process.

关 键 词：榴辉岩 地球大气压力 大别山 多硅白云母 镁离子 铁离子 

分 类 号：P575[天文地球—矿物学]