re: Odd looking stuff on Larry's Lookout - Spirit images
There's a lot of evidence from various "trenching" experiments that there seems to be lighter colored material just below the surface in a lot of places. Maybe some of that is blown to hilltops, somehow. Not sure how much of the Martian surface is "replaced" by winds, and how long that process takes. Is the top of the ground darkened by UV and other actions?
Would like input from some of the geology experts here.