This image covers the high plains about 25 kilometers (15 miles) south of Coprates Chasma, near the eastern end of the Valles Marineris canyon system. Here, the CRISM instrument on MRO has detected clay minerals, which imply substantial water-rock interactions in the past. These minerals often have a reddish- to yellow appearance in HiRISE images.

In this observation, the minerals appear concentrated along the boundaries of polygons up to 10 meters across. Perhaps the water-rock interactions at this site were most extensive within a network of pre-existing fractures dissecting the bedrock.

Rough, blue-to-purplish material appears to overlie the polygonal fractures in portions of the image. We also see lighter blue-to-green materials. While CRISM can provide a time constraint to the compositions of these varied materials, HiRISE shows us how they relate to each other and how such a colorful scene could have been assembled over geologic time.

Written by: James Wray (narration: Tre Gibbs)  (15 July 2021)