in the foreground of the lower picture is the more interesting formation in the picture -- not that there's anything intrinsically uninteresting in the crossbedding.

The step-pyramid is interesting to me because it exactly mirrors, on a teensy-tiny scale, many of the interior layered deposits ("white rock") found in numerous equatorial and near equatorial craters.

It's always seemed to me that those mysterious deposits may be the result of material forced up from the interior of the planet. And the similar seeming deposits in Meridiani and elsewhere may have a comparable origin.

If so, neither the playa nor sabkha model would be truly analogous to what happened on Mars. The surface is hostile to fluid retention, you might say, and so even if the water table were ever so high, there would be little chance of forming such extravagant deposits from precipitation of solids and evaporation/sublimation. Not that it couldn't happen at all, just that it would be very difficult. Water would freeze/sublimate too fast, I think. But of course we've seen strong signs that water (in either pure or salty varieties) is NOT the operating fluid here. "Battery acid" is.

Which presents a whole other set of challenges to understanding.

My suspicion is that the formations we see at the surface actually formed subsurface, in a much more friendly environment to fluids. It could well be that these deposits are still being formed subsurface, and the layering we see now isn't actually chronological, or rather we aren't properly attuned to the chronology we see. (Of course so much of the exposed layering is so jumbled up, it's hard to draw any conclusions yet.)

Still, it's a grand adventure!

If only we could go play there in person!

Cheers, BR