利用U-1000型激光拉曼探针测定流体包裹体气体成分的研究

APPLICATION OF LASER RAMAN MICROPROBE (U-1000 RAMANOR) TO ANALYZING THE GAS COMPOSITIONS OF FLUID INCLUSIONS

本文利用U-1000型激光拉曼探针成功地测量出单个流体包裹体中H_2S、CH_4、CO_2气体成分,并讨论了包裹体中这些气体的拉曼谱峰位移与包裹体内压的关系,分析了影响激光拉曼探针定量测定包裹体气相成分的取面积和拉曼定量因子因素。

Gas compositions (CH_4, CO_2, H_2S) of fluid inclusions, which occur in quartz and fluorite from the Dongpo polymetallic ore field, were analyzed by laser Raman microprobe (U-1000 Ramanor). Samples were scanned by 514.5nm green laser (source power: 100 to 200 mW) with the objective magnification of 100×, monochromator slit of 500μm, and counting interval of 10 second/point (points spaced by 0.5cm).As a result of internal pressure of fluid inclusions, all spectral peaks shift from standard locations to lower wave numbers except 1285,0cm^(-1) ones for CO_2. It is thought that the estimates of internal pressures,based on the linear relationship between wave number shift of CH_4 Raman peaks and pressure increase, are less significant for fluid inclusion studies.Relative abundances of gas mixtures were measured with peak areas and Raman quantification factors, and the accuracy of final results is further discussed while using different area determinations for the same peak and different quantification factors.