Dissolution
Ya know, Marvi, I've left that door open. Sometimes, it opens wider. We've seen structures that might be related to dissolution, and there are some things about this crater that remind me of collapse (ie- assymmetry of dip- the crater is almost an asymetrical graben). But it could be the rheology of the rocks in response to oblique impact...evaporites are fairly plastic...and/or subsequent dissolution.