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Re: Sundry responses of Bois



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