Earth is missing a huge part of its crust. Now we may know why. (Thieves?)

nationalgeographic.com ^ | 12/31/2018 | Robin George Andrews

[rktman]

The Grand Canyon is a gigantic geological library, with rocky layers that tell much of the story of Earth’s 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 Earth’s crust was sawn off by Snowball Earth’s 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. (Here’s what will happen when Earth’s tectonic plates grind to a halt.)

[rktman]

Not cactuses? WTH?

[Rurudyne]

Ginourmous: Jazz the Autobot approved

[faucetman]

I know where the crust went!

Myself, I don’t like crust. My dogs LOVE it! I give it to them.

Where is the crust? ... Out in my front yard.

[rktman]

In an altered form no doubt. 🍕💩

[M Kehoe]

Hi. Laz stole the chunk of crust...

It was back when we were all posting stone tablets on a wooden message board.

It took JimRob for ever to get all the posts up.

There wasn’t a White House basement then.

5.56mm

[EVO X]

Here is another article on missing continental crust.

“What we found is that half of the mass that was there 60 million years ago is missing from Earth’s surface today,” said Miquela Ingalls, a graduate student in geophysical sciences who led the project as part of her doctoral work.

https://www.sciencedaily.com/releases/2016/10/161005084321.htm

[NorthStarOkie]

In the middle of flat Iowa, there is an east-west line of hills that mark the edge of the last glaciation.

---

There is a moraine in Minnesota that is at the latitude of the “wart” on the west boundary of Minnesota. It was formed when the glacier slowed its retreat toward the North. Rivers north of that moraine tend to flow northward. Example: Red River of the North. Rivers south of the moraine tend to flow southward. Example: The Minnesota River. It is interesting that the Mississippi River flows northward for a number of miles before turning to flow to the Gulf of Mexico.

There is a triple-divide a short ways north of Duluth. Rivers flow to Hudson Bay, the Atlantic Ocean and the Gulf of Mexico. Rains that fall on Triple Divide mountain in Glacier Park flow to the Pacific, Arctic Ocean and the Gulf of Mexico.

[timestax]

bttt

[Eagles6]

Possibly, if we are actually warming.

We are technically in an Ice Age, ina warming period between glaciations.

[justa-hairyape]

Dang chem trails. Every time. We need a base on Mars fast. Lol.

[Yaelle]

Yeah, we took your freakin crusts, wanna make something out of it??”

[unlearner]

“I still get irritated by the fact that we can’t be bothered to use the word ‘cacti’ as the plural of cactus.”

There was a band called Cacti, but just like the word, they seem to have disappeared into oblivion.

https://www.youtube.com/watch?v=jlxjVi66TTw

Back for More

It’s like a dance
The way that you
Shake your head
In full denial of the truth

When it was knocking on your door
Nobody got in
Now when your screaming for a hand
Nobody’s listening

Didn’t get a chance
To say it loud
Your secrets kept you
Pushing down, disavow

...

Makes me think of liberals. They never learn. If they did, they wouldn’t be liberals any more.

[Abathar]

I was looking for Martinsville, but at least Paragon made it, close enough I guess.

[Red Badger]

The crust is the best part!......................

[Red Badger]

It was the Wurst off-times, it was the Best of Tymes................

[central_va]

[ProtectOurFreedom]

Congratulations! You scored 100%. You’re hired!

[Rebelbase]

‘It would take quite a subduction zone to transfer all of that into the mantle.’

A few teaspoons a day over a billion years and your talking a lot of moraines.

[refreshed]

👍 The Martinsville area is nice.

[colorado tanker]

Not eating the crust makes pizza a low carb meal.

Well, that's what I tell myself.