This observation was taken in Miyamoto Crater in southwest Meridiani, an area near the equator of Mars. This image is located to the east of one of the potential Mars Science Laboratory landing sites and is near the contact between the hematite-bearing plains unit to the northeast (where the Mars Exploration Rover Opportunity is exploring) and the phyllosilicate-bearing unit to the southwest.
Aeolian (wind deposited) processes are active here, which are visible in dunes and ripples, most likely made of basaltic sand. The bedrock contains phyllosilicates (clay minerals), which form in the presence of water. Phyllosilicates have been detected in higher concentrations in other areas of Mars such as Mawrth Vallis and Nili Fossae, but detections of lesser abundance have been noticed in Meridiani as well.
Written by: Jennifer Griffes (23 May 2008)
More info and image formats at http://hirise.lpl.arizona.edu/PSP_008060_1770
Image: NASA/JPL/University of Arizona