摘要
为查明安徽凤阳地区晶质石墨的矿物学特征,运用岩石矿物学、X射线粉晶衍射、能谱分析、扫描电镜及拉曼光谱等多种手段对凤阳地区晶质石墨样品进行成分、结构及性质的分析研究。结果表明,该区石墨已基本结晶成形,多呈鳞片状集合体;具典型的2H型石墨特征,轴长a为0.24599~0.24604 nm,c为0.67183~0.67202 nm,晶胞体积为0.03521~0.03522 nm^(3),晶胞体积随晶体结构中氧含量的增加而增大。石墨晶片厚度26.6~28.8 nm,石墨化度0.74~0.80,3R多型含量14.81%~16.69%,C原子含量69%~81%;石墨峰值变质温度估算成矿变质温度为410~430℃,属区域变质成因;δ;C值为-15.23‰~-24.90‰,均值为-19.91‰±0.2‰(n=6),与我国的柳毛、南墅、兴和等典型区域变质型石墨矿相当,表明石墨碳质主要来源为地层中同源沉积的生物有机碳。
To investigate the mineralogical characteristics of crystalline graphite in the Fengyang area,Anhui Province,in this paper,the compositions,structures and properties of crystalline graphite samples in the Fengyang area have been studied by using various methods of petrology and mineralogy,including XRD,EDS,SEM,and Raman spectroscopy.The results show that the graphite,which was basically crystallized,occurred mostly as scaly aggregates,with typical 2 H-graphite structure,unit cell parameters including a values varying from 0.24599 nm to 0.24604 nm and c values varying from 0.67183 nm to 0.67202 nm,and the unit cell volumes(V),varying from 0.03521 nm^(3) to 0.03522 nm^(3),which are increased with O contents of the crystalline structure of graphite samples.The graphite samples have wafer thicknesses varying from 26.6 nm to 28.8 nm,graphitization degrees varying from 0.74 to 0.80,3 R-graphite structure percentages varying from 4.84%to 16.69%,and C atomic contents varying from 69%to 81%.The estimated ore-forming temperatures vary from 410℃to 430℃based on the peak metamorphic temperatures of graphite samples.Therefore,the graphite was formed by the regional metamorphism.The studies of C isotopes of graphite samples show thatδ;C values vary from-15.23‰to-24.90‰,with the mean value of-19.91‰±0.2‰(n=6).They are similar to those of the typical regional metamorphic graphite ores in the Liumao,Nanshu,and Xinghe deposits.This indicates that the graphite carbon should be mainly sourced from the bio-organic carbon deposited homologously in the stratum.
作者
李小东
杜玉雕
徐波
潘宇观
田晶
张宜勇
徐刚
汪欢
LI Xiao-dong;DU Yu-diao;XU Bo;PAN Yu-guan;TIAN Jing;ZHANG Yi-yong;XU Gang;WANG Huan(Geological Survey of Anhui Province,Hefei 230001,China;State Key Laboratory for Mineral Deposits Research,Nanjing University,Nanjing 210023,China;Institute of Geochemistry,Chinese Academy of Sciences,Guiyang 550081,China;College of Earth Science and Resources,Chang’an University,Xi'an 710054,China;Yanduzhongshi Geological Analysis Laboratories Ltd.,Beijing 100089,China)
出处
《矿物岩石地球化学通报》
CAS
CSCD
北大核心
2022年第2期260-273,共14页
Bulletin of Mineralogy, Petrology and Geochemistry
基金
安徽省公益性地质工作项目(2018-g-8)。
关键词
安徽凤阳
晶质石墨
矿物学特征
晶胞参数
the Fengyang area of Anhui province
crystalline graphite
mineralogical characteristics
unit cell parameters
