Wall Rock and Light-Toned Layering in Candor Chasma
Wall Rock and Light-Toned Layering in Candor Chasma
PSP_001390_1735  Science Theme: Sedimentary/Layering Processes
While the canyon walls that define Valles Marineris appear dark and blocky, the interior of the canyons can sometimes be filled with light-toned rocks that appear layered.

This observation shows the two geologic units in Candor Chasma, one of several canyons that make up Valles Marineris. At the center of the image is the wall rock that appears as a linear hill running east-west and composed of spurs and gullies.

Larger meter-size boulders can be resolved by HiRISE and indicate rock units consolidated from loose sediment that break down to produce these boulders which then roll downhill.

The light-toned layered deposits are visible in the lower portion of the image. They appear brighter than the wallrock and also have prominent layering, which is best seen near the bottom of the image where there is a steep exposure and dozens of layers are revealed.

Dark debris covers the layered deposits along this cliff face and forms debris aprons as material is shed downhill. The processes that emplaced the light-toned layered deposits are still being debated and include volcanism, aeolian (wind), and lacustrine (formed in a lake) origins. HiRISE images combined with multispectral data from CRISM (also on MRO) should help narrow down the possible origins.

Written by: Cathy Weitz  (6 December 2006)
Acquisition date
12 November 2006

Local Mars time

Latitude (centered)

Longitude (East)

Spacecraft altitude
263.2 km (163.5 miles)

Original image scale range
from 26.5 cm/pixel (with 1 x 1 binning) to 106.0 cm/pixel (with 4 x 4 binning)

Map projected scale
25 cm/pixel and North is up

Map projection

Emission angle

Phase angle

Solar incidence angle
57°, with the Sun about 33° above the horizon

Solar longitude
134.4°, Northern Summer

For non-map projected images
North azimuth:  97°
Sub-solar azimuth:  31.6°
Black and white
map projected  non-map

IRB color
map projected  non-map

Merged IRB
map projected

Merged RGB
map projected

RGB color
non-map projected

Black and white
map-projected   (348MB)

IRB color
map-projected   (289MB)

Black and white
map-projected  (155MB)
non-map           (142MB)

IRB color
map projected  (75MB)
non-map           (250MB)

Merged IRB
map projected  (104MB)

Merged RGB
map-projected  (106MB)

RGB color
non map           (233MB)
B&W label
Color label
Merged IRB label
Merged RGB label
EDR products

IRB: infrared-red-blue
RGB: red-green-blue
About color products (PDF)

Black & white is 5 km across; enhanced color about 1 km
For scale, use JPEG/JP2 black & white map-projected images

All of the images produced by HiRISE and accessible on this site are within the public domain: there are no restrictions on their usage by anyone in the public, including news or science organizations. We do ask for a credit line where possible:

NASA’s Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, Calif., manages the Mars Reconnaissance Orbiter for NASA’s Science Mission Directorate, Washington. The HiRISE camera was built by Ball Aerospace and Technology Corporation and is operated by the University of Arizona.