Posted on 01/01/2019 7:48:02 AM PST by rktman
The Grand Canyon is a gigantic geological library, with rocky layers that tell much of the story of Earths history. Curiously though, a sizeable layer representing anywhere from 250 million years to 1.2 billion years is missing.
Known as the Great Unconformity, this massive temporal gap can be found not just in this famous crevasse, but in places all over the world. In one layer, you have the Cambrian period, which started roughly 540 million years ago and left behind sedimentary rocks packed with the fossils of complex, multicellular life. Directly below, you have fossil-free crystalline basement rock, which formed about a billion or more years ago.
So where did all the rock that belongs in between these time periods go? Using multiple lines of evidence, an international team of geoscientists reckons that the thief was Snowball Earth, a hypothesized time when much, if not all, of the planet was covered in ice.
According to the team, at intervals within those billion or so years, up to a third of Earths crust was sawn off by Snowball Earths roaming glaciers and their erosive capabilities. The resulting sediment was dumped into the slush-covered oceans, where it was then sucked into the mantle by subducting tectonic plates. (Heres what will happen when Earths tectonic plates grind to a halt.)
(Excerpt) Read more at nationalgeographic.com ...
Good one :)!
*ping*
I just followed your link and found out the moraine I live on is named after our small town. Who knew? I mean other than geologists. Neat.
It starts in the third sentence: "the thief was Snowball Earth, a hypnotized time..."
An entire geological era was "hypnotized"? Give me a break. Immaturity abounds everywhere.
Let’s look on the bright side. Man has destroyed all the glaciers. Therefore we have stopped more of the crust from going missing.
What if their entire theory of geological uniformity is wrong? Easy. Invent "snowball earth"!
The science described is rather refreshing and I can look beyond the author’s creativity to make a rather boring subject (rocks) palatable for layman readers.
Without regard for the mocking of the delivery, the article outlines some very sound science and its application in study of a genuine geological mystery.
Now only if the same methods were used in archaeology & climate sciences...
Maybe the method they’re using for dating is incorrect.
Hard to believe sediment would only go to the ocean.
I missed that one. We are indeed getting dumber as a people.
Details on that erosional event can be found in Genesis 7-8
My sediments exactly.
Trump’s ‘fault’!
tech, tech, tech.....
Everybody knows that Gaia was making pre cambrian sandwiches one day and cut off the crusts
Could have been the Earth Mother. I knew a kid whose mom would always remove the crusts..
Bring on globull warming.
God is wondrous!
Agreed!
Ginormous? Splediforous!
Imagine if the Moon tipped over!
Well, don't keep us in suspense, where do you think it should go?
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