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Re: Double impact at K-T boundary ?



 > Typical DML reaction!  Loads of discussion on whether Ukraine should
 or should not be preceded by "the".

 Absolutely no discussion, apart from the usual "is Shiva really an
 impact?", on whether this satisfies Gerta Keller's double impact
 theory.

That's because many of us are very, very skeptical about Keller's double-impact hypothesis in the first place. The identification of the supposed Cretaceous foraminifera in the Chicxulub crater has been questioned, and if it's correct, it's still possible that the rock they're in has fallen in from the walls of the primary crater. (Impactors of that size produce a hemispherical crater that is, IIRC, 20 km deep or some other such insane number. Its walls, vertical at the top, then collapse, leaving a much shallower and much wider crater. In other words, Cretaceous rock with Cretaceous foraminifera in it _must_ have fallen into the primary crater and _must_ be present inside the present crater; maybe Keller has found some of it.)