Undersea volcanoes caused mass extinctions

[Drachir]

Interesting article covering mass extinctions of sea life 93 million years ago. I also like the fact that the scientists were from my Alma Mater. I find it significant that the discovery also has a connection with modern day global warming.

Underwater Volcanoes Blamed for Mass Extinctions - Science - redOrbit

 

[HardScienceFan]

these,I suppose,are the clams the article talks about.
They are called rudists,became very large(up to 1 metre)and formed large accumulations,
'reefs' if you will.
One valve is lid-like,and was probably originally translucent.*
*diagenesis has often altered the original mineralogy.
It is assumed at least some rudists formed symbioses with zooxanthellae-like algae,making them good indicators of the photic zone.
the Mg/Ca ratio of the valves(again,for diagenetically unaltered specimens)is a proxy for ambient seatemperatures.

and foraminifera were NOT wiped out,of course

 

[TheEndIsNigh]

HSF: Well there's another possibility - I'll add to my list. I wonder if anyone has looked for Yellowstone like super bulges under the oceans. I know abot the Naples area but there's a lot of ocean out there. Ah well...

On the other hand maybe we were lucky here. It would appear they had developed a rudimantary currency system so maybe had they not been killed off we wouldn't have got here.

 

[HardScienceFan]

given the current state of seismic reflection and refraction profiling and its resolution,i suspect something would have turned up by now.

ah
gas hydrates,you mean?
and call me Ben please,End

 

[Dave]

Also interesting is that the vast majority of our Oil reserves come from the warmer period that followed.

 

[HardScienceFan]

ah,you may guess who have a longstanding interest in rudist bio-accumulations,and the Cretaceous in general

especially the Mid-Cretaceous

the rudist 'reefs' of Oman and Saudi Arabia are EXTREMELY well studied

rhymes with boil companies

 

[TheEndIsNigh]

Ben: No I was meaning extremely large super bulges (as opposed to hot spots Hawaii etc) The oil people found the meteor collision site of Mexico ages before anybody realised it's significance. It didn't interest them at the time. It was only later that someone made the connection.

By the way, people tend to call me Tein.

 

[HardScienceFan]

Tein:i take it you don't mean the evidence for superwells/mantle plumes?

 

[TheEndIsNigh]

Ben: Yes though I've just read that the Hawaii hot spot is considered to be similar to Yellowstone which as I understand it when it goes of will be good night Vienna for the lot of us. However I wondered if any of the undersea ones never send up volcanoes and are just lurking there, waiting their time for a monster eruption.

 

[Sephiroth]

With undersea volcanos, the magma is hot, fluid and basic, which means they tend not to be explosive eruptions. Hawaii is a good example of this: the lava that comes out is runny, and not so gaseous.

It's silica-rich continental material that makes for the really big booms, which is why you're unlikely to see a super eruption happen underwater (unless it's on drowned continental crust, that is).


In the instance mentioned by Drachir, there was over 20,000 years between the initial eruption event and the correlated mass-extinction, IIRC.