No mention in the article that the Kimberley Diamond mine is located within the confines of a 300-500km impact crater (Reitz Ring)?

No mention in the the article that the ancient crusts may have been uplifted and exposed to the surface by this putative impact event?

Such would certainly change their hypothesis.

http://www.scienc...chtype=a

Uh, possibly because there's scant literature on the Reitz ring. Makes for alternate hypothesis, of course, that an ancient impact prompted upwelling etc that spawned kimberlite pipes...