Your points about aeolian sediments are well taken. I have not ignored these possibilities. The Navajo Sandstone of the 4 corners region is up to 3000 ft thick. Portions have nice regular bedding. This is however, an exceptionally thick (thickest in world?) sandstone formation, and regional in extent. I would expect the thick (regional also?) series on Mars to be something like the Grand Canyon, a bit of all kinds of sediments, plus bedded volcanics. Why? Because tectonism must almost certainly have been occurring for sediments to form so thickly. While that does not implicate water, I think the satellite evidence for fluid flow in Mars Noachian periods is extensive. I believe that the Noachian and Cataclysmic eras stretched on a lot longer in time than the current paradigm models indicate due to interactions between the atmopshere and active lithosphere, such as the superabundance of hygroscopic minerals. I do not believe that the Opportunity Ledge rocks are altered basalts, but mid to deep marine sediments with large bioprecipitate input (but I see how you might have concluded that from what I wrote). I just brought this up as support for my theory about the past and current roles of Sulfuric acid.