Upgrading a Raman spectroscopic system for earth science studies

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In 2008, a Raman spectroscopic system was purchased for the Geofluids Lab in the Department of Geology, University of Regina. After 12 years of continual usage, the 514 nm laser is approaching the end of its expected life span, and the software and associated database also require upgrading. The in-situ, non-destructive nature of Raman spectroscopy makes it a versatile tool for various earth science fields. The upgraded Raman system will continue to support the analysis of geofluid and mineral compositions, mineral identification, and the characterization of mineral crystal structures. Data obtained from these studies can be used to inform various geological studies that span magmatic, metamorphic, sedimentary, hydrothermal, and surface environments. The Raman system in the Geofluids Lab has been used mainly by the principal applicant (Chi) to study fluid inclusions, particularly volatiles and solute composition, in combination with the heating-freezing stage. An innovative cryogenic Raman spectroscopy method has been established and applied to study fluid inclusions from different environments, including sedimentary, magmatic, and metamorphic environments. The upgraded Raman system will continue to be used in the study of fluid inclusions associated with mineralization, especially unconformity-related uranium deposits in the Athabasca Basin. This is in line with the principal applicant's main research focus that is supported by current and previous NSERC-DGs as well as NSERC-CRDs. The facility will also be used to study other critical and strategic metals (rare earth element (REE), Li, and Co), and their respective mineralization systems with a focus on those in Saskatchewan. This will include an emphasis on REE mineralization associated with uranium and those potentially associated with carbonatites. Additionally, studies of the crystal structures of graphite and pyrite, which may be used to estimate the P-T conditions of mineralization, will be supported. The upgraded Raman system will also be utilized by colleagues in the Faculty of Science, and the three co-applicants (Raharimahefa, Robbins and McBeth). It will be used by Raharimahefa to study the volatile composition and water content of fluid and melt inclusions in olivine. The Raman data will be combined with other geochemical and geophysical data to investigate Quaternary volcanism and deep processes in relation to the East African Rift System. Robbins and McBeth will use the facility for environmental studies. These studies may include characterization of mineral samples from lacustrine and marine sediments, microbial mats, mine wastes, identification of sulfidic and iron mineral phases around oxic-anoxic interfaces, and quantification of impurities within mineral phases. The Raman data will be integrated with other geochemical and microbiological data to provide a holistic view of biogeochemical cycling in the study environments.