Great Unconformity: Evidence for a geologic trigger of the Cambrian explosion

[Tank]

Great Unconformity: Evidence for a geologic trigger of the Cambrian explosion

(Phys.org) -- The oceans teemed with life 600 million years ago, but the simple, soft-bodied creatures would have been hardly recognizable as the ancestors of nearly all animals on Earth today.

Then something happened. Over several tens of millions of years – a relative blink of an eye in geologic terms – a burst of evolution led to a flurry of diversification and increasing complexity, including the expansion of multicellular organisms and the appearance of the first shells and skeletons.

The results of this Cambrian explosion are well documented in the fossil record, but its cause – why and when it happened, and perhaps why nothing similar has happened since – has been a mystery.

New research shows that the answer may lie in a second geological curiosity – a dramatic boundary, known as the Great Unconformity, between ancient igneous and metamorphic rocks and younger sediments.

"The Great Unconformity is a very prominent geomorphic surface and there's nothing else like it in the entire rock record," says Shanan Peters, a geoscience professor at the University of Wisconsin–Madison who led the new work. Occurring worldwide, the Great Unconformity juxtaposes old rocks, formed billions of years ago deep within the Earth's crust, with relatively young Cambrian sedimentary rock formed from deposits left by shallow ancient seas that covered the continents just a half billion years ago...

Great Unconformity

Life starts to effect ocean chemistry on a global level which in turn effects life on a global level. A feedback loop that is posited to underpin the Cambrian Explosion.

[Velma]

Wow!  I had no idea.  I'll have to read it again later, when it's not 3:38 am after a tough day at work.

[Tank]

Wow!  I had no idea.  I'll have to read it again later, when it's not 3:38 am after a tough day at work.

I was completely unaware of this as well. Very interesting.

[OldGit]

This is when the earliest proto-Asmodean emerged:

[Tank]

This is when the earliest proto-Asmodean emerged:

Where the hell did you find that? 

[OldGit]

In some ancient rocks . 

[Buddy]

This is when the earliest proto-Asmodean emerged:

Oh hey, I know the show where that came from.

[Tank]

This is when the earliest proto-Asmodean emerged:

Oh hey, I know the show where that came from.

Well do share 

[Buddy]

I think it is the Discovery Kids version of The Future is Wild. I was babysitting once and it was on. I don't think they show it anymore though.

[Tank]

I think it is the Discovery Kids version of The Future is Wild. I was babysitting once and it was on. I don't think they show it anymore though.

I've had a look at that now. Couldn't find a specific episode though. There's quite a few clips on YouTube.