湖南郴县千里山花岗岩及其衍生岩脉云母矿物的红外光谱研究

湖南郴县千里山花岗岩及其衍生岩脉云母矿物系统的红外光谱分析结果表明:这些云母矿物分属于Li-Fe系列和Li-Al系列,前者所有红外光谱吸收峰波数均较后者相应的吸收峰值低;羟基伸缩振动与云母~(v1)Al的含量有关;(Al)Si-O-Si的对称伸缩振动与~(vl)Li~+含量关系密切;而Si-O弯曲振动或O-Me(金属)伸缩振动的频率变化则主要受~(vl)Fe~(2+)的含量制约。不同类型的云母有时其成分与红外光谱振动频率的关系有各自的规律,根据这一关系可以大致划分云母种属并粗略估计云母中某些主要组分的相对含量。结合云母产状的分析,两个系列出现于花岗岩蚀变的不同演化阶段,这对探讨岩体演化及矿化规律有一定的意义。

SPECTROSCOPIC RESEARCH ON MICAS FROM QIANLISHAN GRANITE AND ITS DERIVATIVE VEINS IN CHENXIAN COUNTY,HUNAN PROVINCE

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.