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

Research areas:
Year:
2008
Authors:
Journal:
JOURNAL OF GEOPHYSICAL RESEARCH-PLANETS
Volume:
113
Number:
E7
Month:
JUL 1
ISSN:
2169-9097
Abstract:
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.