Bits and pieces about Re: Re siberian (Deccan) traps

[David Marjanovic <david.marjanovic@gmx.at>]

Original Message by Tim Donovan
Thursday, 2 January 2003 12:38

> Ken Carpenter wrote:
> >Everyone's criticism of Frank's statement have all focused on his last
> >hyperbole, rather than his criticism of the sloppy thinking behind some of
> >the stories about impacts. One has only look at David Raup and the impact
> >periodicity as a classic example of seeing what you want. As has been
> >pointed out several times, there is no periodicity, even in Raup's own
> >data.

Not even in his own data? Really?
Not to mention that the implication is false. Impact-induced mass extinctions 
and periodicity of same are not the same thing. The first can exist without 
the other.

> >OR that there was an impact in what he calls the Shiva Crater off the west
> >coast of India. He even states that this crater is larger than the
> >Chicxulub. How can he know the size of the crater if he isn't even sure it
> >is one?

That's the easy part, obviously. Chatterjee finds some unusual features in 
India and the Seychelles*, connects them into a teardrop shape of 600 x 300 
km**, calls that the Shiva crater, and then other people come and say it 
isn't a crater at all.

* These two continents ripped apart 63 Ma ago or so. The Seychelles 
themselves are just coral islands, but they stand on continental bedrock.

** Figure from The Rise of Birds.

>    I understand Koeberl doubts it is.

Yeah. After a talk on impacts, with a bit about mass extinctions, Köberl 
called the Shiva crater "science fiction". I've never seen a paper about 
this, but I don't read much geological literature. Just for the record, 
Köberl is convinced about the K-T and apparently the Tr-J impact-induced mass 
extinctions -- one more reason to reject the speculation that widespread 
acceptance of spectacular hypotheses is an American phenomenon. :-) Even 
though the vertebrate ERRRR cave bear paleontologists in the same house de 
facto regard spectacular hypotheses as wrong by definition.

In case someone is interested (there's not much information there): 
http://www.univie.ac.at/geochemistry/koeb.html
English version at the bottom. If you are interested in the publication list, 
start from its bottom, too, where the most recent and list-topic-related 
papers are.

I don't understand how "evolutionary drift" is supposed to cause a mass 
extinction. Can someone explain? Thanks in advance.

Oh, while I am at it: I'm sure racial senescence wasn't American either. In 
the mid-20th century it was common to write "the Persians had passed their 
full bloom and were getting old, while the Greeks were a young, rising 
people, therefore (apart from the details) the Greeks won the Persian Wars... 
and then the Greeks were getting old and the Romans were young... and so on".