Scoured Bedrock on the Floor of Eos Chasma

The scoured and scabby floor of Eos Chasma, located east of Valles Marineris, is covered with dunes or ripples and eroded craters. The reddish-brown color likely represents older, eroded basalt. Much of this erosion may have been accomplished by water.

An eroded crater exposes compositional differences below the surface: the bluish tones are probably fresher, boulder-rich exposures of basalt and the lighter-toned material near the base of the crater wall may have a different composition. The bottom of the crater is filled with material that is similarly-toned to the surface of Eos Chasma, and was likely eroded and transported there by the wind.
Written by: Sharon Wilson   (13 May 2009)

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Image: NASA/JPL/University of Arizona