Light-Toned Materials along the Floor and Walls of Ius Chasma

Many of the Valles Marineris canyons, called chasmata, have kilometer-high, light-toned layered mounds made up of sulfate materials. Ius Chasma, near the western end of Valles Marineris, is an exception.

The light-toned deposits here are thinner and occur along both the floor and walls, as we see in this HiRISE image. Additionally, the sulfates are mixed with other minerals like clays and hydrated silica. Scientists are trying to use the combination of mineralogy, morphology, and stratigraphy to understand how the deposits formed in Ius Chasma and why they differ from those found elsewhere in Valles Marineris.

The map is projected here at a scale of 25 centimeters (9.8 inches) per pixel. (The original image scale is from 26.4 centimeters [10.4 inches] per pixel [with 1 x 1 binning] to 52.9 centimeters [20.8 inches] per pixel [with 2 x 2 binning].) North is up.

The University of Arizona, in Tucson, operates HiRISE, which was built by Ball Aerospace & Technologies Corp., in Boulder, Colorado. NASA's Jet Propulsion Laboratory, a division of Caltech in Pasadena, California, manages the Mars Reconnaissance Orbiter Project for NASA's Science Mission Directorate, Washington.