Spectral analysis and geological mapping of the Daedalia Planum lava field (Mars) using OMEGA data

The great variety of morphologies observed in the Daedalia Planum lava flows (Mars) encouraged a detailed study of their spectral characteristics, in order to obtain information about lava composition and detect possible differences in the spectra of the flows. The OMEGA spectral data collected from the lava field appear rather similar, with absorptions between 0.8 and 1.4 μm and 1.8 and 2.5 μm, suggesting the presence of mafic minerals, which are typical primary mineral phases of volcanic rocks. Moreover, after the subtraction of the background absorption (continuum removal), we highlighted the presence of two classes of spectra both compatible with tholeiitic basalts but with different proportions of Ca in the pyroxene. Despite the similar absorption bands, Daedalia spectra show differences in albedo and spectral slope. By employing the average spectra of the different flow units as end-members, a SAM (Spectral Angle Mapper) classification was performed. The resulting spectral map reveals a relationship between spectral behavior and flow surface textures.

► The analysis of OMEGA data highlights variations of lava flow composition.
► Spectral analysis distinguishes two types of spectra on Daedalia Planum.
► Spectral maps of Daedalia Planum created with SAM classifier resolve new subunits.
► SAM map reveals a close relationship between spectral behavior and surface texture.
► Martian geological maps can be improved integrating morphological and spectral data.