First, with the caveat that I am neither a geologist or a Mars expert:

There are a few features in this area that appear similar to sand traps on a golf course, and your feature seems to be one of these. It seems depressions fill evenly with dust or sand that does not accumulate in great depth on flatter ground. The rock underneath the sand/dust that was swept away by the retracting airbags indicates that the geology of this place seems to be a flat layer of very interesting rock thinly coated by dust or sand, with rocks protruding. This would correspond to the pictures from orbit showing dark streaks where wind or dust devils have swept the surface dust away.