Fig. 3: LIBS spectra and chemical compositions of selected VBF-ZR targets.
From: Aqueous alteration of the Vastitas Borealis Formation at the Tianwen-1 landing site
a Selected and normalized emission lines of Si, Fe, Mg, H, C, K, Na, Ca, and Al of six targets. b Major element concentrations in VBF-ZR targets, where the error bars are RMSEs of the multivariate model used in this study. c Cluster analysis using LIBS spectral line intensity ratios of the selected VBF-ZR targets and seven silicate cal-targets carried by MarSCoDe. The black line is a linear fit result using scatters of basalt, hypersthene, and norite cal-targets (R2 = 0.89). d Relative concentrations of eight major elements at four landing sites normalized to the average Martian soil compositions (data in Supplementary Table 7). The error bars are the ratios between error values and average Martian soil compositions.
