...because I think there are multivalent cations in the soil that can be oxidized by the thin atmosphere, and form a lighter crust than the soil below, which causes the 'skin' to fluff and breeze away. I don't know if there was water at first, to make these things, but I think that the "riverflows" are caused by this mechanical dust-like process. I would like someone to convince me that I'm wrong, because, of course, I would like to believe in an abundance of water in the history of mars.<br /><br /><font color="yellow">"You know what happens when you're proven wrong? They stop funding you."-Michael S. Phlegmbottoms, NASA 1966 </font>/safety_wrapper>