Just like a bathtub ring, you can trace those pale layers across the whole crater. Interestingly, in some places there are two white stripes, in others only one, and they are not flat either - they are palaeosurfaces. This should answer some of the questions about the large-scale geometry of the sulphate deposits. At first glance they look more like surface crusts than lake deposits, but let's wait for more pics and more time to analyse them carefully...

As for questions about the scalloping - we saw hints of this in the other craters. It probably shows a pattern of softer and more resistant zones in the rock, maybe related to the original sulpohate mineralisation or the large-scale fracture pattern.