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.