This image shows the western half of a fan-shaped deposit in a small trough in the Valles Marineris system.
The fan is at the mouth of a smaller canyon, and may consist of material eroded from the canyon by flowing water in the distant past. The fan itself shows many layers, each likely corresponding to a different episode in the history of the system.
At the base of the fan, a series of light-toned layers are visible. Since these deposits extend beyond the base of the fan in addition to being different in color and texture, they may indicate a different type of sediment deposition before the fan was emplaced.
Written by: Colin Dundas (7 July 2011)
This is a stereo pair with ESP_030518_1650 .
More info and image formats at http://hirise.lpl.arizona.edu/ESP_022949_1650
Image: NASA/JPL/University of Arizona