Nature and origin of materials exposed in the Oxia Palus-Western Arabia-Sinus Meridiani region, Mars

Images and thermal data obtained by the Viking Orbiter over the Martian equatorial cratered terrain in western Arabia, eastern Oxia, and Sinuses Sabaeus and Meridiani, have been evaluated with a view to the identification, characterization, and mapping of local, bedrock-related materials. Three primary color/thermal units are discernible: (1) bright red dust storm deposits; (2) brown materials, which may be indurated; and (3) dark, but less red materials which may be composed of medium sand size-range lithic fragments. The surficial units exposed over the study area are judged to represent mixed eolian deposits, largely decoupled from the bedrock underneath.