Re: Sundry responses of Bois

[Stanley Friesen <sarima@friesen.net>]

At 08:28 PM 5/28/00 -0400, Dinogeorge@aol.com wrote:
> In a message dated 5/28/00 5:38:20 PM EST, jbois@umd5.umd.edu writes:
>
> Chatterjee & Rudra have noted K-T boundary clay through the middle of the
> Deccan Traps, with plentiful dinosaur remains below and none above. They
> attribute the boundary clay and extinction to the asteroid impact that caused
> the so-called Shiva crater, but it could simply be from the Chicxulub impact.
> Or, if there really was a Shiva impact at the same time, to both.

I have two problems with this paper.  One is that I find the argument that 
the "Shiva" feature is an impact crater unconvincing.  Given its provenance 
I think it more likely to be related to the hot-spot plume.  (It is not 
even clear it is a *crater*).

Second, given the nature of the sedimentary record in the Deccan Traps, the 
time resolution on issues like extinctions is, to say the least, 
lousy.  Intertrappen beds are so few in number, and so thin, that all one 
has is a few tiny snapshots of the fauna.

Now, the data do establish that dinosaurs were still around well after the 
beginning of the Deccan emplacement, and gone before the end.  But that is 
still a rather broad span of time.

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May the peace of God be with you.         sarima@ix.netcom.com