Raman Spectroscopy of Nb,Ta-rich Cassiterite in Beauvoir and Montebras Granites,France  

作　　者：王汝成 吴劲薇 DUBESSY JEAN MONCHOUX PIERRE 

机构地区：[1]Department of Earth Sciences,Nanjing University,Nanjing,210008 [2]Centre de Recherches sur la Geologie deUranium,Nancy,France [3]Laboratoire de Mineralogic et de Cristallographie,Universite de Toulouse,France

出　　处：《Chinese Journal Of Geochemistry》1993年第4期353-360,共8页中国地球化学学报

摘　　要：Cassiterites from both the Beauvoir and Montebras geanited of France are typically rich in trace elements such as Nb and Ta, and contain quite a number of inclusions of columbite (dominantly manganocolumbite).Two thin sections of cassiterite crystals have been prepared for Raman microprobe analysis).The spectra obtained from different parts of the cassiterites show that the vibra-tion frequency of the A1g peak decreases with increasing Nb ,Ta,Fe and Mn atomic contents.It is worthy to note that a new peak (named the “An peak”) has been reported for the first time in the part with oriented columbite inclusions.The vibration frequency varies from 827 to 830 cm^-1.The presence of th enew peak may be attributed to structural changes of cassiterite due to the excess of Nb and Ta in the lattice and the exsolution of columbite inclusions in cassiterite.Cassiterites from both the Beauvoir and Montebras granites of France are typically rich in trace elements such as Nb and Ta,and contain quite a number of inclusions of columbite(dominantly manganocolumbite).Two thin sections of cassiterite crystals have been prepared for Raman microprobe analysis.The spectra obtained from different parts of the cassiterites show that the vibra- tion frequency of the A_(lg)peak decreases with increasing Nb,Ta,Fe and Mn atomic contents.It is worthy to note that a new peak(named the“An peak”)has been reported for the first time in the part with oriented columbite inclusions.The vibration frequency varies from 827 to 830 cm^(-1).The presence of the new peak may be attributed to structural changes of cassiterite due to the excess of Nb and Ta in the lattice and the exsolution of columbite inclusions in cassiterite.

关 键 词：拉曼光谱 钠 晶体结构 花岗岩 富铊锡石 法国 

分 类 号：P588.121[天文地球—岩石学]