This enhanced-color version of the central part of the HiRISE image shows colorful layers that may contain carbonate minerals.
Carbonates are commonly formed on Earth by marine organisms; the origin of these carbonates on Mars is unknown, but probably involved liquid water.
This image was taken along with the CRISM instrument, also onboard MRO, in what is called "ridealong" mode.
Photo credit: NASA/JPL/University of Arizona
Notes: This picture was taken in the Nili Fossae area to the northeast of Hargraves Crater. For the Spanish translation of this page, see Estratos de Colores en Nili Fossae.