Ferric oxides in East Candor Chasma, Valles Marineris (Mars) inferred from analysis of OMEGA/Mars Express data: Identification and geological interpretation

Laetitia Le Deit (1) , Stéphane Le Mouélic (1) , Olivier Bourgeois (1) , Jean-Philippe Combe (2) , Daniel Mège (1) , Christophe Sotin (1) , Aline Gendrin (3) , Ernst Hauber (4) , Nicolas Mangold (1) , Jean-Pierre Bibring (3)

1 LPGN - Laboratoire de Planétologie et Géodynamique de Nantes [UMR 6112]
2 Bear Fight Institute
3 IAS - Institut d'astrophysique spatiale
4 DLR Institut für Planetenforschung

The mineralogical composition of the Martian surface is constrained by analyzing the data of the OMEGA visible and near infrared imaging spectrometer onboard Mars Express. Ferric signatures had previously been reported in Valles Marineris, Margaritifer Terra, and Terra Meridiani. Here we use three independent data reduction methods (Spectral Angle Mapper, a modified Spectral Mixture Analysis and Modified Gaussian Model) to detect and map ferric oxides in East Candor Chasma, a part of Valles Marineris. Ferric oxides in East Candor Chasma are concentrated in scattered formations. MOLA altimetry indicates that the ferric oxides are preferentially located in topographic lows. THEMIS, HRSC and MOC images show that the ferric oxide spectral signatures are systematically correlated with superficial deposits of low albedo, located at the foot of, or resting on Interior Layered Deposits (ILDs). This spatial distribution suggests that ferric oxides are genetically linked to ILDs. Gravity and wind‐driven remobilization of ferric oxides previously formed in the ILDs can explain their accumulation around the ILDs.

Domaines: Planétologie

Laetitia Le Deit, Stéphane Le Mouélic, Olivier Bourgeois, Jean-Philippe Combe, Daniel Mège, et al.. Ferric oxides in East Candor Chasma, Valles Marineris (Mars) inferred from analysis of OMEGA/Mars Express data: Identification and geological interpretation. Journal of Geophysical Research. Planets, 2008, ⟨10.1029/2007JE002950⟩. ⟨hal-02359935⟩