Quebec sure does have a lot of wierd circles...

[Pds314]

A map of Quebec.

 

A map of Quebec, with (some of the) wierd circular features highlighted...

 

The Quebec shield rock is like... 3 billion years old or something. What are the odds that more than a few of these came from giant meteorite impacts?

[ThatGuyWithALongUsername]

"Odds" nothing. Quite a few of those are actually confirmed impact craters!

It's always interesting to be able to see these on Earth, a good reminder that Earth is just another planet. Love this kind of thing- I've even tried looking them up and marking them on Google Earth in my spare time. Eventually, after enough boredom, it should have all visually identifiable craters on Earth.

 

Most interestingly, the double lakes are BOTH confirmed craters, BUT evidence shows that they're from different time periods. Their proximity is merely a coincidence, as opposed to an asteroid breaking up. https://en.wikipedia.org/wiki/Clearwater_Lakes

 

Here, have this: https://en.wikipedia.org/wiki/List_of_impact_craters_in_North_America

Edited February 29, 2020 by ThatGuyWithALongUsername

[Scotius]

Pretty good. Old, solid plate means there wasn't much volcanism going on over the millennia. But... not every circular geological structure is an impact crater. There are processes that create such things without burning rocks falling from space.

[DDE]

42 minutes ago, Pds314 said:

The Quebec shield rock is like... 3 billion years old or something. What are the odds that more than a few of these came from giant meteorite impacts?

Not every circle is an astrobleme.

Meet the Kondyor massif on Russia's Pacific coast.

Not an astrobleme - just a magmatic extrusion. Looks like a part of the Aldan Shield, too.

 

Edited February 29, 2020 by DDE

[kerbiloid]

Spoiler

 

 

[ThatGuyWithALongUsername]

9 hours ago, ThatGuyWithALongUsername said:

Love this kind of thing- I've even tried looking them up and marking them on Google Earth in my spare time. Eventually, after enough boredom, it should have all visually identifiable craters on Earth.

I didn't bring that up just to sound like a smug idiot, I said this so I could show this map!- the red circles all mark visible, exposed, confirmed impact craters

Took me a while because this thread motivated me to just go ahead and finish all of Canada. Even the parts not visible in this screenshot. Yep. Right now.

(I may need help)

I am not a geologist, but I'm guessing the reason there are so many here is that they've been preserved under ice sheets. Sure, they eroded basically the entire landscape, but I guess big enough depressions were fine- and sediments covering them weren't as much of a problem because the glaciers were transporting sediments away from those areas? Idk, again I don't know what I'm talking about here

(EDIT: I told you I don't know what I'm talking about lol)

 

And no, the giant thing off the Hudson Bay is probably not an impact crater, though apparently that's debated?

Edited March 1, 2020 by ThatGuyWithALongUsername

[Pds314]

8 hours ago, ThatGuyWithALongUsername said:

I didn't bring that up just to sound like a smug idiot, I said this so I could show this map!- the red circles all mark visible, exposed, confirmed impact craters

Took me a while because this thread motivated me to just go ahead and finish all of Canada. Even the parts not visible in this screenshot. Yep. Right now.

(I may need help)

I am not a geologist, but I'm guessing the reason there are so many here is that they've been preserved under ice sheets. Sure, they eroded basically the entire landscape, but I guess big enough depressions were fine- and sediments covering them weren't as much of a problem because the glaciers were transporting sediments away from those areas? Idk, again I don't know what I'm talking about here

 

And no, the giant thing off the Hudson Bay is probably not an impact crater, though apparently that's debated?

I very much doubt the glaciers have too much to do with crater preservation, although crater visibility is another question entirely. Remember, these glaciers are 2.5 million years old and only exist intermittently. The rock is >2.5 billion years old and exists permanently, as do any craters that have formed in it in the last 2.5 billion years. Obviously there were other ice ages besides the present day one (though they were pretty different than the present day one), but continents were in different positions then anyway. Looking up the age of clearwater west to be 286 million years ago, I found that Quebec was basically tropical at that point. I can't imagine ice sheets during the early Permian anywhere, let alone in Quebec, which was entirely withing 17 degrees of the equator.

Edited March 1, 2020 by Pds314

[Pds314]

9 hours ago, DDE said:

Not every circle is an astrobleme.

Meet the Kondyor massif on Russia's Pacific coast.

Not an astrobleme - just a magmatic extrusion. Looks like a part of the Aldan Shield, too.

 

Switzerland would love that terrain.

[ThatGuyWithALongUsername]

18 minutes ago, Pds314 said:

I very much doubt the glaciers have too much to do with crater preservation, although crater visibility is another question entirely. Remember, these glaciers are 2.5 million years old and only exist intermittently. The rock is >2.5 billion years old and exists permanently, as do any craters that have formed in it in the last 2.5 billion years. Obviously there were other ice ages besides the present day one (though they were pretty different than the present day one), but continents were in different positions then anyway. Looking up the age of clearwater west to be 286 million years ago, I found that Quebec was basically tropical at that point. I can't imagine ice sheets during the early Permian anywhere, let alone in Quebec, which was entirely withing 17 degrees of the equator.
 

Yeah, I was wrong lol. Guess it's just because it's really old crust, then?

[HansonKerman]

I cannot science for my life. But that is weird and cool

[farmerben]

I was looking at this a while back in relation to the younger dryas impact hypothesis.

What would happen if a giant comet made of ice crashed into a continent covered my enormous glaciers?  How do we date that giant feature on the Hudson Bay?

Randall Carlson lays out very strong evidence that the North American glaciers turned to floods of mind boggling violence. 

If true it helps explain why the Atlanteans split up going to Egypt and Peru.  It also helps explain why the Mormons and Paiutes both told stories of an ancient flood.  

[Wjolcz]

20 hours ago, farmerben said:

If true it helps explain why the Atlanteans split up going to Egypt and Peru.  It also helps explain why the Mormons and Paiutes both told stories of an ancient flood.  

HMMMMMMMMMMM...

[DDE]

On 3/29/2020 at 3:54 AM, farmerben said:

Randall Carlson lays out very strong evidence that the North American glaciers turned to floods of mind boggling violence. 

Hypervelocity impacts have a tendency to shatter or vapourize objects on impact, not melt them.

[Nightside]

On 3/28/2020 at 5:54 PM, farmerben said:

 

Randall Carlson lays out very strong evidence that the North American glaciers turned to floods of mind boggling violence. 

There is substantial geologic evidence that melting glaciers caused catastrophic floods. These events occurred at the end of ice ages, as glacial dams broke, releasing immense reservoirs of liquid water from mountain valleys across the landscape below.

Perhaps the best studied example are the Missoula Floods of Columbia River in the Pacific Northwest. The southern tips of the glacier would create lakes in the mountains (blue areas). At the end of ice age cycles, the depth of the lake would increase, eventually the hydrostatic pressure would float the dam out of place and the resulting flood would scour what is now eastern Washington state (red zones on the eastern side of the Cascade Mountains), completely removing stripping the topsoil down to bedrock in huge areas (and even plucking out huge chunks of bedrock). 

The flood followed the path of the Columbia River through the Cascade Mountain range (threading between several large volcanoes), cutting the dramatic landscape of the Columbia gorge, with waters several hundred feet deep.  These floods deposited all that rock, gravel and silt in layers hundreds of feet thick in the Portland and Willamette Valley regions of Oregon (red areas west of Cascade Range).

This flood is an exciting geologic story because it is a rare case of something actually happening fast. We are trained to think of the earth changing slowly over "geologic time", but a few events, like the floods, and comet/asteroid impacts are truly catastrophic, fast occurrences. 

On 3/28/2020 at 5:54 PM, farmerben said:

If true it helps explain why the Atlanteans split up going to Egypt and Peru.  It also helps explain why the Mormons and Paiutes both told stories of an ancient flood.  

My usually acute irony detector is failing me now, @farmerben, are you serious? This Randall Carlson is not a geologist, but a storyteller. He is bringing together lots of dramatic and interesting material to help prop up a quasireligious fantasy about Atlantis. In light of current events (such as other conspiracy theorists like Alex Jones selling poison as coronavirus cures), please try to decouple science from fantasy, and understand the difference between scientists and hucksters. Our lives and our prospects after this pandemic depend on it! The history of geologic and planetary events is interesting enough on its own, there is no need to dilute it with somebody's selfserving fiction.

Edited April 1, 2020 by Nightside

[Arugela]

It's so you know that they are holier than thou!!

Edited April 1, 2020 by Arugela

[farmerben]

9 hours ago, Nightside said:

 

My usually acute irony detector is failing me now, @farmerben, are you serious? 

Joke...   If I were selling explanations of mythology, I wouldn't lead with the most preposterous.