# Permian-Triassic extinction - again



## Brian G Turner (Nov 22, 2003)

We've covered this topic before, but it requires it's own thread now as advances in analysis create new data to work with.

In simple terms, it is believed that fragments of an extraterrestrial impact body have been found - in the form of chondrites in Antartica.

This follows closely on the notion of the Dinosaurs being wiped out 65 million years ago by an asteroid striking the earth - though in this instance, any impact crater is believed to have been long removed from the geological record by plate tectonics:

http://news.bbc.co.uk/1/hi/sci/tech/3223708.stm

excerpt:



> *Scientists have found new evidence that the greatest extinction in the Earth's history was triggered by an asteroid. *
> 
> 
> About 250 million years ago, something unknown wiped out most of the life on the planet.
> ...


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## John #17324 (Jan 9, 2004)

I said:
			
		

> We've covered this topic before, but it requires it's own thread now as advances in analysis create new data to work with.
> 
> In simple terms, it is believed that fragments of an extraterrestrial impact body have been found - in the form of chondrites in Antartica.
> 
> ...


 what about gamma rays from a supernova? for the P-T mass ext.


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## Brian G Turner (Jan 10, 2004)

It's certainly a possibility - but I have a nasty feeling that there's too much emphasis on finding a "sole cause". My personal interpretation of the K-T boundary event is that there is a far more complex series of events in play, and that a strange tendency to single answer apocalyptic generalisations are winning out over reasoned and considered theories.

Oh - and welcome to the chronicles-network, John #17324.


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## BAYLOR (Jun 19, 2022)

A Chain of Volcanoes  in what is Siberia began long phase of eruptions , Caused the temprature of the earth to rise, the sea acidify About 90 percent of everything that lived on Earth died.  It need  The dimetrodons and the entire pelycosaur line and lots of other land animal species. In the oceans much of the marine life perished including the trilobites  which hd sever other previous extinction events, but not this one.  The temperate o the went went up to 170 degrees in most places  and this castoephe went on for about 100,000 years. Had the temperature gone up a few degrees more, Earth would have turned into a runway green house  planet like Venus. it took  Earth about 10  millions of years to recover.


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## BAYLOR (Sep 25, 2022)

The scary part is such a mass extinction event could occur again.


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