沉积有机质的喇曼光谱研究

Raman Spectral Studies of Sedimentary Organic Matter

本文用激光喇曼光谱显微探针研究了选自广西、湖南和New Caldeonin(澳大利亚)的11个有代表性沉积变质岩样品中的沉积有机质。有机质有两个主要喇曼频率振动区域:1600cm^(-1)峰和1350cm^(-1)峰。文中对这两个特征喇曼谱峰的归属进行了说明,讨论了不同类型沉积有机质特征喇曼谱峰的差异和不同变质演化阶段有机质产生的喇曼光谱系统性变化规律,指出激光喇曼光谱显微探针技术是一种研究沉积有机质特征十分便利、有效的方法。

Organic matter of metasediments from Shixia,Longshui of South China and New Caledonia. has been studied by laser Raman microprobe. In all cases the Raman spectrum of two main bands at 1600cm-1 and 1350cm-1 having a bandwidth at half peak intersity respectively in the range 30 - 80 and 30 - 250cm-1 depending on thermal maturity. The spectra are similar to anthracite coals and heat treated industrial carbons. Three distinct types of organic matter originating in sapropelic kerogen can be recognized in the carbonaceous slates of Longshui; (a) indigenous. (b) hydrothermal metamorphis, (c) migration bitumen. There are differences on the intensities,positions and widthes of the Raman bands characteristic of these types of organic matter. Indigenous organic matter of a suite of metasediments from New Caledonia was examined to mdetermine changes in the Raman spectra with thermal maturity. As the reflectance of the canbon increases from R°max (%) = 2. 10 to 14. 9, the width of the 1350cm-1 Raman band decreases from 200 to 30 cm???? At the same time, the and separation deceases form 255 to 230cm-1, with increasing reflectance.while the ratio of band areas increases from 0. 38 to >1. 0.