Re: The K-T boundary in Nanxiong

[John Bois <jbois@umd5.umd.edu>]

On Wed, 12 Jun 2002, David Marjanovic wrote:

> > Does any hypothesis predict total, instant, annihilation?
> 
> When "instant" means "between a few days and a few 1000 years", then an
> impact does predict that this is fully possible.

So circular!  Anything that happened is predicted by bolide, therefore
everything that happened was caused by the bolide.  

Bolide hypo accepts no burden.  For example, what firepower:angle of
attack:terrestrial substrate:latitude of impact combination would be
required to remove neornithines as well as enantornithines?  What range of
megatonnage would leave no dino alive, yet leave mammals, birds, crocs to
carry on?  Is this a broad range--such that a strike is likely to fall
into that range?  Or, is it a very narrow range such that dinos were
incredibly unlucky?  Or, is it: "Whatever the range is, that was what the
bolide delivered because that was what went extinct?"

I'm really not trying (or succeeding?) to be smart with this.  I have an
intuition that the suggested ecological surgery was too clean to be
real!  I fully agree that I might be wrong.  But, as it stands, I perceive
such surgery to be very unlikely in every valley, forest, island, cave,or 
antipodean refuge.