Re: More on White Rock.
The THEMIS scientists appear to want to have it both ways. In the caption accompanying the visible light release they say it is not brighter than the terrain outside of the crater itself:
White Rock (Released 19 April 2002)
http://themis.la.asu.edu/zoom-20020419a.html
Then to explain its darkness in the infrared image they say it is brighter than the terrain outside the crater.
I would not consider a duricrust explanation to be mundane. That would mean it formed as a sedimentary deposit involving liquid water, therefore raising the possibility of life.
Bob Clark