MINERALOGICAL MAPPING OF THE OCCATOR QUADRANGLE
This work is focused on the mineralogical mapping of the Occator quadrangle, extending at latitudes from 22°S to 22°N and at longitudes from 214°E to 288°E. Mapping is based on VIR spectral data, in particular albedo at visible and infrared wavelengths, and depth of the bands at 2.7 um (due to OH [2]), 3.05 um (due to NH4 [2]), at 3.4 um and 3.9 um (due to carbonates [3]), as well on Ceres’ shape model.
The most peculiar feature of the quadrangle is the Occator crater, the brightest feature of the whole Ceres surface [3], presenting very shallow 2.7 and 3.05 um band with respect to the surroundings and very deep 3.4 and 3.9 um bands: this indicates a carbonates enrichment and a depletion of ammoniated phyllosilicates. On the contrary, the Occator ejecta are very dark and show very deep OH and NH4 bands.
The Lociyo crater also show a low albedo, and ammoniated phyllosilicates bands deeper than surroundings, whereas the opposite behavior (larger albedo a shallow bands) is observed on the Azacca crater.
A comparison between geological and mineralogical mapping is also part of this work, aimed at identifying possible correlations between composition and geological context.
References
[1] Russell C. T. and Raymond, C.A., 2011, SSR 163, 3-23
[2] De Sanctis M. C. et al., 2015 Nature, 528, 241-244
[3] De Sanctis, M.C. et al., 2016, Nature, in press, doi: 10.1038/nature18290