re: Truely amazing
As a bit of a desert rat myself, I love those dunes. Beautiful. I hope they do a full 360 panorama pancam set before they start trenching.
Tom, I suspect the color variation is both light and composition. The "heavies" are gonna hang out in the troughs, mostly abraded "blueberries" and basaltic particles, I suspect. The rest may be the sulfate sand/silt.