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Re: Isotopic Evidence for the K - T Impactor and Its Type

-----Original Message-----
From: Stanley Friesen <sarima@ix.netcom.com>
To: dinosaur@usc.edu <dinosaur@usc.edu>
Date: Wednesday, November 11, 1998 12:03 PM
Subject: Re: Isotopic Evidence for the K - T Impactor and Its Type

>At 12:51 PM 11/10/98 -0500, RAY D STANFORD wrote:
>    The authors report that high-precision mass spectrometric analysis of
>chromium in sediment samples from the K - T boundary, to quote,
>"...coincident with the extinction of numerous organisms on Earth...", from
>Stevns Klint, Denmark, and from Caravaca, Spain, "...is different from that
>of Earth and indicates its extra-terrestrial source".
>Actually, this doesn't address my remaining issues with the simple impact
>scenario.  I do *not* deny an impact happened at that time.  Thus evidence
>that the impact occurred does not in any way change my views.

Stanley makes the necessary point that one cannot prove the impact caused
the extinction of the dinosaurs.  I would like to know how this could ever
be proved.

However, the magnitude of this strike cannot be underestimated.  The
crater's size and shape as well as debris is reasonably clear cut evidence
of the size of the comet and therefore the amount of energy released.  This
has to lead to some reasonable estimation of the damages.  A comet striking
at the necessary angle to create the crater would release enough energy to
have global impact.  It is unreasonable to argue against this (and I know
you aren't Stanley).

Whether it caused, hastened or even contributed to the dinosaurs demise is
conjecture.  However, it is not unreasonable to think it played a role.  (I
personally think it created havoc, but what do I know).

What is the latest paleobotanical changes before, during and after the

Michael Teuton