LIBS and raman spectral data in the qaidam analog

Biosignature detection is one of the most important goals in Mars missions. Since the Curiosity mission, the laser-induced breakdown spectrometer (LIBS) becomes an essential payload due to its convenience and versatility in profiling elemental chemistry. To test whether LIBS alone could filter potential biosignatures, a clastic quartz stone collected from a Mars analog setting, the western Qaidam Basin, was selected for LIBS analysis. Raman spectroscopy was used as an indicator of organic signals to support the presence of potential hypolithic communities and the dearth of epilithic biomass on the rock. A total of 344 LIBS spectra were determined and statistically analyzed using principal component analysis (PCA). Our results indicate that, with a sufficient sample size, PCA analysis can partially differentiate biotic and abiotic signals based on LIBS measures. This finding is significant since it indicates that multivariate analysis of LIBS data can be useful for biosignatures filtering on Mars exploration.