R8: Metamorphic rocks and tectonics

[R8-07] New calibration of Raman spectra of Carbonaceous material thermometry using a deep UV micro-Raman spectroscopy

*Yoshihiro Nakamura¹, Koji U Takahashi¹, Hidetoshi Hara¹ (1. AIST)

Keywords:Carbonaceous material, Deep UV Micro-Raman spectroscopy

We demonstrated the structural evolution of carbonaceous material (CM) in rock chips using deep-UV micro-Raman spectroscopy. Raman spectra of CM show three prominent bands of the G, D, and T, depending on the peak metamorphism. The intensity of D and T bands gradually decreased with increasing metamorphism and finally disappeared. We found that G band FWHM and RBS (wavenumber _{G-D bands}) demonstrate strong linear relations (R² = 0.94 and 0.85) to peak temperatures. These parameters are a potential thermal indicator for very low to low grade metamorphic rocks (100~400 ℃).