Raman spectroscopy as a tool to unravel volcanic processes: applications to Earth and Martian volcanism
IPGP - Îlot Cuvier
Danilo di Genova
Raman spectroscopy represents a powerful technique for rapid and precise determination of assorted compounds distribution in heterogeneous samples. In volcanology has been successfully applied to the analysis of minerals, rocks, melt inclusions and silicate glasses and melts. This spectroscopic technique offers several advantages over other spectroscopic and analytical methods as little or no sample preparation is required, the technique has a non-destructive character and it allows to analyze extremely small sample volume with a sub-millimeter resolution (in the order of microns). Due to its intrinsic analytical capabilities, and its reduced cost, Raman spectroscopy it has also been used to perform remotely-controlled in-situ studies under extreme conditions such as volcanic and submarine environments. Moreover, Raman spectrometers will form a key component in the suite of analytical instrumentation for two forthcoming Mars missions [ExoMars (2016-2018) and Mars 2020 rovers], which are intended to both investigate geological processes and search for evidence of biological activity on Mars. In order to support and expand the applicability of Raman spectroscopy, to enhance our knowledge of the silicate structure and to shed new light on the type of magmatism and volcanic activity in our solar system, further spectroscopic investigations as a function of chemical composition, volatiles and oxygen fugacity of silicate glasses and melts are required. Here the state of art of the use of Raman spectroscopy in volcanology is presented together with a compositionally dependent database and models to estimate the chemical composition and oxygen fugacity of natural silicate glasses.