The original Magic Carpet section was posted on Sol2 (it's now posted as a Black and White thumb image at the rover site). JPL's Planetquest site posted it in color when it came out link.

I'm wondering WHEN the image that they showed today was taken, if it was part of that Sol2 batch. The reason why I'm asking is that the image that they posted today has a slighty different angle (the sun is higher) than that of Sol2, obviously granted, BUT, the cohesive material looks the same. Whatever is keeping the grains together seems to take a long time to sublimate and the 'sand' is not settling back in the cracks where rocks were moved. I can understand frost beneath the surface melting or sublimating upon exposure and acting as a binder with the grains/sand, but if these images were taken at different times, it must take a looong time for things to dry/sublimate on Mars. CO2 would be long gone by now, right?

I keep thinking salt because it keeps water from freezing.

It's really a captivating image. :)