The martian climate and associated prevailing winds may have changed over time, as evidenced by the different orientation of yardangs in this multiply layered, eroded terrain. Note the crater (arrow) that formed before the erosion of the upper layer is now left behind on an erosional pedestal. The impact may have changed the material beneath it to be more resistant to erosion.
Location: Latitude 7.4°, Longitude 140.4°. Viking photograph 471S18, NGF orthographic version, clear filter.