Dunes fighting for survival

A Piece of Mars: Having a bad day? You’re in good company with these dunes in this 0.96×0.48 km (0.6×0.3 mi) scene. The gray barchanoid dunes are covered in ripples, as the wind valiantly tries to push the sand to the dune crests. But they are besieged by other processes at work. Dark scribbles show how dust devils have swept by, removing dust and probably scattering a little bit of the sand. The steep slip faces are not covered in dry avalanches typical of active dunes, but rather they appear eroded, as if some force locked the dune in place and started eroding the surface wherever ripples couldn’t rescue it. Splotches on the tan ground between the dunes, and narrow furrows attest to seasonal ice reworking the surface. And in this great battle, what I wonder is: can those dunes have formed like this amidst such turmoil, or are they relics of an older, windier, perhaps less icy age? (HiRISE ESP_050488_1150, NASA/JPL/Univ. of Arizona)