Permian-Triassic Extinction?

[Gawdzilla Sama]

Impact event or no? Whatcha got?

[FBM]

I've got a vague memory of reading something about it several days ago. How's that? IIRC, the scientists involved are still slapfighting about it.

[Gawdzilla Sama]

I've got a vague memory of reading something about it several days ago. How's that? IIRC, the scientists involved are still slapfighting about it.

Of curse they are, that's how you get papers published.

"Yeah!"
"Oh yeah?"
"Hell yes, yeah!"
"Yeah yourself!"
ETC.

[Dory]

I doubt it's a gradual environmental change-- that'd leave room for adaptations. Impact event seems more likely...but who knows.

[Pappa]

Bacterial takeover.

[Gawdzilla Sama]

I doubt it's a gradual environmental change-- that'd leave room for adaptations. Impact event seems more likely...but who knows.

The reason I'm asking is a scientist has claimed to have found a candidate impact crater in or about northern Oz. You upside-downers heard about this?

[Thinking Aloud]

I doubt it's a gradual environmental change-- that'd leave room for adaptations. Impact event seems more likely...but who knows.

The reason I'm asking is a scientist has claimed to have found a candidate impact crater in or about northern Oz. You upside-downers heard about this?

No, but I have. Though there's another speculative crater somewhere else too - I forget just now (ah- East Antarctica and possibly the Gulf of Mexico according to Wiki). There are also the staggeringly massive Siberian Traps, and apparently odd CO2 values around the time which some say suggest a huge outgassing of methane hydrate from the ocean floor. All of which could be related, of course, and maybe even connected to an impact event. (Some suggest that the Deccan Traps were emphasised as a consequence of the K-T impactor.)

[JimC]

I remember reading in New Scientist suggestions that both impacts and vulcanism may be involved, as the right sort of impact can trigger massive eruptions...

[Gawdzilla Sama]

I've seen/heard:

1. Big impactor.
2. Big impactor with Traps.
3. Traps alone.
4. Traps and mega-continent.
5. Mega-continent alone.
6. Bacterial take-over? (But so far only from Pappa.)

[Thinking Aloud]

I've seen/heard:

1. Big impactor.
2. Big impactor with Traps.
3. Traps alone.
4. Traps and mega-continent.
5. Mega-continent alone.
6. Bacterial take-over? (But so far only from Pappa.)

2.5. Big impactor with Traps leading to methane hydrate outgassing...

[Gawdzilla Sama]

I've seen/heard:

1. Big impactor.
2. Big impactor with Traps.
2.5. Big impactor with Traps leading to methane hydrate outgassing... (For got the methane. )
3. Traps alone.
4. Traps and mega-continent.
5. Mega-continent alone.
6. Bacterial take-over? (But so far only from Pappa.)

Was there enough methane around at that point?

[Thinking Aloud]

I've seen/heard:

1. Big impactor.
2. Big impactor with Traps.
2.5. Big impactor with Traps leading to methane hydrate outgassing... (For got the methane. )
3. Traps alone.
4. Traps and mega-continent.
5. Mega-continent alone.
6. Bacterial take-over? (But so far only from Pappa.)

Was there enough methane around at that point?

Buried in ocean sediments? Sure. Ocean crust doesn't usually last more than 200MY, so there's plenty of time to accumulate stuff before the P-T.

[Gawdzilla Sama]

Okay then, we'll throw that one in the bucket with the rest. Plenty of suspects, and a supporter or supporters for each one.

[klr]

May I recommend When Life Nearly Died by Michael Benton?

There was also a BBC documentary based on the book, but the book is naturally more detailed.

http://www.amazon.com/When-Life-Nearly- ... 050005116X

[Gawdzilla Sama]

Thanks Kev!