皖中张八岭群“蓝片岩”中钠质角闪石及其变质p-T条件分析  

ANALYSIS OF SODIC AMPHIBOLES IN THE BLUESCHISTS' FROM THE ZHANGBALING GROUP ACROSS THE CENTRAL PART OF ANHUI PROVINCE AND ITS IMPLICATION FOR THE METAMORPHIC p-T CONDITIONS

作　　者：石永红[1] 朱光[1] 王道轩[1] 赵群[2] 

机构地区：[1]合肥工业大学资源与环境工程学院,安徽合肥23009 [2]安徽建筑工业学院,安徽合肥230022

出　　处：《矿物学报》2007年第2期179-188,共10页Acta Mineralogica Sinica

基　　金：国家自然科学基金项目(批准号:40672131)

摘　　要：对张八岭地区管店附近含角闪石片岩的岩相学、矿物成分分析和p-T条件的初步估计表明，该地区片岩中的角闪石为钠质闪石类的镁钠闪石，其中氧化物平均含量Al2O3=3.97%，Fe2O3=20.57%，相应的Al3＋，IV=0.54，Fe3＋=1.34，指示的变质温压条件为t=500-600℃，p≤0.3 GPa，显示了低压变质相系的特征。结合前人对张八岭地区的“蓝闪石”的研究资料，并对比作者等对天山昭苏、库车地区和西藏羌塘地区的蓝闪石分析数据，认为张八岭地区并没有真正意义上的蓝闪石存在，张八岭群中“蓝片岩”是否存在以及是否经历低温高压变质作用需要进一步的详细研究。On the basis of the petrology, mineral chemistry and p-t conditions of the amphibole-beating schists across Guandian, Zhangbaling, amphiboles in this schist belong to magnesioriebeckite, the average oxide contents： Al2O3 = 3.97%, Fe2O3 = 20.57% ,Al^3＋,Ⅳ = 0.54, Fe^3＋ = 1.34, and these magnesioriebeckites indicate that the p-t conditions are t = 500 - 600 ℃, p≤ 0.3 GPa, which display the characteristics of low pressure metamorphic facies. Combined with the data from early investigations for‘ glaucophane＇ in the Zhangbaling area, and contrasted to the data for glaucophane from Zhaosu and Kuche, Tianshan and Qiangtang, Tibet, no glaucophane appears certainly across the Zhangbaling area, and a detailed,study is necessary for the identification of blueschist and low-rand high-p metamorphism.

关 键 词：蓝闪石 镁钠闪石 张八岭群 蓝片岩 低温-高压变质带 

分 类 号：P578.955[天文地球—矿物学] P588.33[天文地球—地质学]