SPECTROSCOPIC RESEARCH ON MICAS FROM QIANLISHAN GRANITE AND ITS DERIVATIVE VEINS IN CHENXIAN COUNTY,HUNAN PROVINCE
Xu Ning ( IGMR, Nanjing)
This paper deals with the intrared features of micas from Qianlishan granite and its derivative veins in Chenxian County, Hunan Province. The result of infrared spectroscopic analysis shows that the micas belong to two different series: Li-Fe series and Li-Al series. All the infrared vibrational frequencies of the former are less than corresponding values of the later. The hydroxyl stretching vibration Is related to the content of octahedral (VI)A1 and the (Al)Si-O-Si stretching vibration to the content of octahedral (VI)Li. Whereas the Si-O bend vibration or O-Me(metal) stretching vibration is restricted by the content of octahedral (VI)Fe(2+). These relations of chemical compsition with infrared vibrational frequnecy sometimes have different regularities for the two series of micas. Accordingly, it its possible not only to make a general division of species of micas, but also to make a rough estimate of relative contents of their major compositions. Integrating with the occurrence of micas, the author considers that the two series of micas occured in different evolution stages of alteration of granite. This may have some special significance for approaching rock evolution and related metallogeny.