A question.
How much of that material is "soil", manufactured by processes on Mars, and how much is like the lunar dust, micro- and meteorites drifting down from the cosmos and being blown hither, thither and yon?
It would seem to me that the cosmic dust would tell us about Mars the way lunar dust would tell us about Mars, with the exception that the weak atmosphere on Mars would burn some things up.
On Earth "soil" is the product of atmospheric, geological and life processes. Mars doesn't have the later two, and a weak atmosphere.
Just curious. I know there's a good answer out there, I just don't know it.
Arf