法国Beauvoir和Montebras花岗岩中富铌钽锡石的拉曼光谱特征  

RAMAN SPECTROSCOPY OF Nb,Ta-RICH CASSITERITE IN BEAUVOIR AND MONTEBRAS GRANITES,FRANCE

作　　者：王汝成[1] Dubessy Jean Monchoux Pierre 

机构地区：[1]南京大学地球科学系 [2]法国南锡铀矿地质研究中心 [3]法国图鲁兹大学矿物学与结晶学实验室

出　　处：《地质论评》1992年第4期334-343,共10页Geological Review

摘　　要：法国Beauvoir花岗岩和Montebras花岗岩中的锡石都含有较丰富的微量元素,如Nb、Ta,并含有铌钽矿包裹体。将锡石晶体制成光薄片,运用拉曼探针,对不同部位进行的研究表明,锡石的A_(1g)峰的振动频率与其所含的Nb、Ta、Fe、Mn含量成反比。值得指出的是,在富含铌钽包裹体的部分,发现了一个新的拉曼光谱峰(定为An峰),其振动频率为827—830cm^(-1),对其进行的研究表明,该峰的出现与锡石晶格中(Nb,Ta)的过量和铌钽矿包裹体的出溶所造成的晶体结构的变化有关。The cassiterites from the Beauvoir granite and the Montebras granite (France)are typically rich in trace elements such as Nb and Ta, and contain many inolu-sions of columbite (manganocolumbite dominantly). Two thin sections of cassiteritecrystals have been prepared for the Raman microprobe analysis. The sepctra ob-tained from different parts of the cassiterites show that the vibrating frequancy ofthe A_(lg). peak decreases with increasing Nb, Ta, Fe and Mn atomic contents. It isworthy to note that a new peak (named as 'An peak') has been reported for thefirst time in the part with oriented columbite inclusions. The vibrating frequencyvaries from 827 to 830 cm^(-1). The presence of the new peak may be related to thechange of the cassiterite structure caused by the excess of Nb and Ta in thelattice of cassiterite and the exsolution of the columbite inclusions in cassiterite.

关 键 词：拉曼光谱 富铌 钽 锡石 花岗岩 

分 类 号：P588.121[天文地球—岩石学]