UCSB Earth Science Raman Laser Spectroscopy Facilities

UCSB Earth Science operates a Bruker Senterra Raman Laser Microscope. The system includes:

                    - 532nm and 785nm lasers
                    - 1200 lines/mm  & 4000 lines/mm gratings for both lasers
                    - Spectral resolution of 3 cm-1.
                    - Reflected Light, Polarized Light and Fixed Analyzer 
                     - 100x Objective
                     - automatic calibration of the wavelength axis using built-in neon lamp

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This instrument is primarily used for the a range of thermobarometric and structural measurements, including:

 - Quartz-inclusion barometry,

- Raman Spectroscopy of Carbonaceous Material (RSCM)    
   thermometry (utilizing the reference standards and data     
   reduction protocols developed by Lünsdorf et al.,  (2017)

- Assessment of radiation damage in accessory minerals
   such as zircon

- rapid mineral identification

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Example of combining quartz-in-garnet (QuiG) barometry (measured by Raman) with titanium-in-quartz thermometry (via EPMA) from a Himalayan schist. Figure courtesy of Alex Johnson

Examples of Raman Spectra obtained from the South Tibetan Detachment zone. Position of the graphite G band and D group defect bands are indicated. For each spectrum, the value of the mean R2 ratio (R2 = D1/[G + D1 + D2] peak area ratio) obtained after 10 decompositions is given. Figure from Cottle et al., (2011).