MSc Thesis Presentation: Quantification of MnO using the ChemCam LIBS Instrument and Comparison with the Alpha-Particle X-ray Spectrometer

MSc Candidate

Brent Wilhelm

Abstract

Manganese oxide (MnO) values exceeding 50wt% have been reported by the ChemCam (CCAM) laser-induced breakdown spectroscopy (LIBS) instrument onboard the Mars rover: Curiosity. These observations have raised speculation on the habitability of the early Mars environment. This work recreates the univariate calibration used for the quantification of MnO using CCAM spectra, and provides a novel comparison to the Alpha-Particle X-ray Spectrometer (APXS) also on-board Curiosity. Between instruments, systematic deviations of MnO values are found for groups of targets with a characteristic chemical and physical matrix. A multivariate calibration is introduced, which accounts for the relative abundance of SiO₂, TiO₂, Al₂O₃, FeO, MgO, CaO, Na₂O, and K₂O in the sample. The multivariate method corrects for impacts of the normalization to the manganese signal as well as chemical matrix effects, which reduces the MnO prediction error by a factor of >3.5 and agrees more favourably with the APXS in general.

Examination Committee

• Dr. Xiaorong Qin, Chair
• Dr. Ralf Gellert, Advisor
• Dr. Susan Glasauer
• Dr. Stefan Kycia