A) ROI identified on the CRISM FRT2992 PAN/NIR computed using as PAN the band at λ= 696 nm and for the NIR the band at λ = 938nm and similar in size to the one used in Fraeman et al. (2014), but optimised to enhance the 1000 nm absorption; B) ROI identified on the original Cassis PAN/NIR; C) ROI identified on the degraded Cassis PAN/NIR; D) Comparison between continuum removed mean spectra extracted from the ROI shown in panels A, B, and C, and panel D. In green, the CRISM spectrum resampled at the CaSSIS filter wavelengths. In black the original CRISM spectrum. In orange, the CaSSIS spectrum extracted from the original dataset. In light blue, the CaSSIS spectrum extracted from the dataset degraded to the CRISM spatial resolution (panel C). In pink and dark blue: CaSSIS spectra from ROIs Pb4 and Pb5.