Martian minerals components at Gale crater detected by MRO CRISM hyperspectral images

Gale Crater on Mars has the layered structure of deposit covered by the Noachian/Hesperian boundary. Mineral identification and classification at this region can provide important constrains on environment and geological evolution for Mars. Although Curiosity rove has provided the in-situ mineralogical analysis in Gale, but it restricted in small areas. Compact Reconnaissance Imaging Spectrometer for Mars (CRISM) aboard the Mars Reconnaissance Orbiter (MRO) with enhanced spectral resolution can provide more information in spatial and time scale. In this paper, CRISM near-infrared spectral data are used to identify mineral classes and groups at Martian Gale region. By using diagnostic absorptions features analysis in conjunction with spectral angle mapper (SAM), detailed mineral species are identified at Gale region, e.g., kaolinite, chlorites, smectite, jarosite, and northupite. The clay minerals' diversity in Gale Crater suggests the variation of aqueous alteration. The detection of northupite suggests that the Gale region has experienced the climate change from moist condition with mineral dissolution to dryer climate with water evaporation. The presence of ferric sulfate mineral jarosite formed through the oxidation of iron sulfides in acidic environments shows the experience of acidic sulfur-rich condition in Gale history.