Ice-rich mantling deposits accumulate from the atmosphere in the Martian mid-latitudes in cycles during periods of high obliquity (axial tilt), as recently as several million years ago.
These deposits accumulate over cycles in layers, and here in the southern mid-latitudes, where the deposits have mostly eroded away due to warmer temperatures, small patches of the remnant layered deposits can still be observed .
Written by: Dan Berman (audio: Tre Gibbs) (22 February 2017)
More info and image formats at http://hirise.lpl.arizona.edu/ESP_048897_2125
Image: NASA/JPL/University of Arizona