A Channel System and Patterned Ground near Hellas Basin

In this image, we explore the southwestern floor of a 50-kilometer diameter unnamed crater, about 100 kilometers northeast of Hellas Basin.

The crater’s rim is breached (see Google context image below) on both the north and south by a valley system that previously flowed across the crater floor, leaving behind an interesting array of channel patterns and deposits as it transported water and sediments into and out of the crater.

In this image, we see a portion of the channel system along the southwestern crater floor near where the valley breaches the southern rim. The darker-toned surface has a pattern similar to the texture of a basketball, and blankets the region both in the channel belt and in the basin below the cliffs. Superposed on this patterned surface are clusters of larger, circular mounds that may be related to the thawing and freezing of ice-rich sediment, which is unusual at this relatively low latitude. Extensional cracks and clusters of pits make this topography more complicated.

The southern part of this image reveals a prominent irregular scarp with light-toned layered deposits exposed along the margin beneath this textured surface. The light-toned layers look like an ancient mosaic in some areas as they are irregularly fractured and brecciated. Individual blocks and large boulders of this material are visible at full-resolution near the scarp, just about to fall and already lying on the debris slopes below the scarp. Some are brighter than the others: these may be dust-free, indicating that they have detached from the cliff more recently.

Written by: Henrik Hargitai and Ginny Gulick (audio: Tre Gibbs)   (1 July 2015)

This is a stereo pair with ESP_041036_1460 .

More info and image formats at http://hirise.lpl.arizona.edu/ESP_040601_1460

Image: NASA/JPL/University of Arizona