| Summary: | 碩士 === 國立東華大學 === 自然資源與環境學系 === 100 === The Backbone Range of Taiwan is substantially composed of several types of meta-sedimentary rocks, including slate, phyllite, politic- and psammitic-schist, meta-sandstone and meta-conglomerate. It is difficult to particularly classify the metamorphic grades of the metamorphic rocks of the Backbone Range, due to lacking the index mineral to arrive at. However, the metamorphic rocks of the Backbone Range possess rich carbonaceous material, which exhibits the characteristics of irreversible reaction on structure and increasing crystallinity while heated, can be used to characterize the metamorphic rocks and record the strongest thermal event. It has been demonstrated that Raman spectroscopy is a suitable tool for the research of the rocks with rich-carbonaceous material, because it is sensitive to the change of structure of carbonaceous material and non-destructive measurement.
In this study, some slates are collected from the south drainage area of Taimali River, southern part of the Backbone Range. These samples were analyzed by micro-Raman spectroscopy to identify the degrees of the metamorphism, investigate the trend of temperature change and to portray the distribution of metamorphic facies. Based upon the results, further discussion on uplifting rate was accomplished.
The results show that the temperature of metamorphism can be calculated by the empirical formula proposed by Beyssac et al. in 2002. According to the models using the ratio of the peak-position difference and FWHM (full width at half maximum) of the Raman peak of graphite proposed by Chen and Chung in 1998 and 2011 respectively, the metamorphic grade of the analyzed samples are suggested to be greenschist facies. Additionally, the regional uplifting rates calculating by previous radioactive dating data of the neighboring areas is about 1.46~2.24mm/year.
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