EARTH'S GEOLOGIC HISTORY IN TEN SITES THAT REMAIN TO THIS DAY

Another treat for geology fans (I'm one too).

 

Earth is 4.5 billion years old, and during that time it's been through a lot of dramatic changes — as well as enormous disasters that reshaped the oceans and continents. 

 

io9 website provides you with ten images with explanatory notes that reveal the grandeur of Earth, as seen from the perspective of deep geological time.

 

Three samples:

1.  The Burgess Shale -  It rises up out of the Canadian Rockies in British Columbia. 500 million years ago, it was a rich seabed at the base of an enormous reef system that teemed with life. Really, really weird life — including many creatures unlike anything alive today — whose fossils were preserved in a pristine state due to lucky chance when the reef crumbled.

 

This area gave scientists their first window onto the so-called Cambrian Explosion, when evolution went nuts and produced a wide variety of body types in a short period of time. Think giant shrimp and lots of tentacles.

 

The Burgess Shale reveals an era when multicellular life became the norm, and is in many ways the cradle of life as we know it.

 

2.  Shark Bay - It hosts some of the oldest life forms on Earth, stromatolites, who make their home in this site on the western coast of Australia.

 

Those knobby-looking rocks are actually sand-encrusted layers of algae and bacterial mats, very similar to ones that lived here over 3 billion years ago. Indeed, geologists have discovered the oldest fossilized life forms in the world here.

When you slice open an ancient stromatolite sphere, you find layers of billion-year old algae in it that look like tree rings. This is a view onto what Earth life might have looked like just a billion years after our planet was born.

 

5.  Siberian Traps, Russia  - 250 million years ago, a massive volcanic rift opened up in the area now known as Siberia. At the time, it was at the northern tip of a massive supercontinent called Pangaea.

 

The volcano oozed lava and noxious gasses for roughly 1,000 years, eventually releasing as much as 7 million square kilometers of lava, and covering an area roughly the size of western Europe.

 

The emissions from the volcano were so toxic that almost 95 percent of all the species on Earth went extinct (many more than the asteroid impact drove extinct 65 million years ago).

 

Today, the Siberian traps are what remains of this massive, world-destroying volcano. It's about 2 million square km of basaltic rock or hardened lava. It looks peaceful and lovely today, but 250 million years ago it was a sea of poison.

Read more and see pictures - http://io9.com/earths-deep-geological-history-revealed-in-10-strikin-1290830007

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