名义上无水矿物中水的定量方法及其优缺点:FTIR方法及其存在问题  

On the Quantification Methods of Water in Nominally Anhydrous Minerals: Their Strengths and Weaknesses, with Emphasis on FTIR Method

作　　者：严薇[1,2] 刘曦 YAN Wei;LIU Xi(Key Laboratory of Orogenic Belts and Crustal Exolution,Ministry of Education of China,Beijing 100871,China;School of Earth and Space Sciences,Peking University,Beijing 100871,China)

机构地区：[1]造山带与地壳演化教育部重点实验室,北京100871 [2]北京大学地球与空间科学学院,北京100871

出　　处：《矿物岩石地球化学通报》2021年第2期425-447,共23页Bulletin of Mineralogy, Petrology and Geochemistry

基　　金：国家重点研发计划项目(2016YFC0600408);中国科学院战略性先导科技专项(B类)项目(XDB18000000)。

摘　　要：构成地幔的主要物相多是名义上无水矿物(NAMs),如橄榄石、辉石等,其晶体结构中能赋存一定量的水。水能显著地影响矿物、岩石体系的物理、化学性质乃至地球深部的许多重要地质过程。为精确获取NAMs的水含量,科学家不断开发和改进水的定量分析方法,其中傅里叶变换红外光谱法(FTIR)是测定NAMs中水含量的最主要手段,但不同研究者的结果常有较大差异。本文就近年来NAMs中水的多种定量方法的研究进展进行综述,着重讨论FTIR方法及其存在问题,并初步谈论NAMs中水定量方法的未来研究方向。基于已有文献数据,本文进一步提出针对NAMs的新通用标定系数εtot=262.68(491)×[3644(94)-■],它既能弥补现有通用标定法建立于含水矿物、玻璃基础上的缺陷,又能较合理地体现吸收系数与频率的依赖性。Nearly all minerals in the mantle, like olivine and pyroxene, are nominally anhydrous minerals(NAMs), and capable of incorporating considerable amounts of water in their structures. Water can tremendously affect the physical and chemical properties of minerals and rocks, which is in turn of great significance to many important geological processes. In order to accurately constrain the water contents of the NAMs, scientists never stop exploring and improving water quantification methods. As the most commonly-used tool, Fourier transform infrared spectroscopy(FTIR) does not always lead to comparable results. With emphasis on the FTIR method, here we review recent progresses of various quantification methods, discuss existing problems, and tentatively explore the future directions of quantifying water in the NAMs. Based on the experimental results in the literatures, we also propose a new generic calibration for the IR absorption coefficients of water in the NAMs, ■. This is the first generic calibration, based on the NAMs and for the NAMs with different structures and compositions.

关 键 词：名义上无水矿物 水含量 定量方法 傅里叶变换红外光谱(FTIR) 羟基红外吸收系数 

分 类 号：P574.2[天文地球—矿物学]