The Great Lakes of Canada; Why they Occur Along a Straight Line

[@zGJungle]

A video on Komatiite what conditions make it unique would be nice ? I've not heard of this before until this video.

[@andreasmanique113]

kzbin.info/www/bejne/e2m8lnqvaqaebs0

[@Dragrath1]

He did a video on this topic already kzbin.info/www/bejne/e2m8lnqvaqaebs0 Basically the lava was a hotter cousin to basalt incorporating minerals that have already cooled and crystalized out of basaltic melts which was possible back when Earth's interior was hotter than it is today. The youngest example of this kind of lava was related to hotspot volcanism in Africa some 90 million years ago if I remember correctly.

[@lorrinbarth1969]

I agree, Komatiite is a high temperature lava. As I understand it, the unlikelihood of a Komatiite eruption today is due to a cooler mantle.

[@zGJungle]

@@Dragrath1 thank you

[@markharder3676]

If I recall correctly, komatiite is a lava that originated in the mantle of the earth with ultramafic minerals like olivine and pyroxene in it. Compared with basalt, komatiite has a high melting temperature, higher than those produced in the shallow mantle today, because Earth was hotter than it is today and the more recent geological eras. So, komatiites will not form in today's volcanic events, an exception to the general pattern in which geological processes we see today also took place throughout Earth's history. I think they're one of the more interesting phenomena of geology, and one of the reasons I like studying the field as an amateur.

[@nothanks3236]

Ok so before watching I'm going to predict: it has something to do with ice age processes, glaciation. Edit: Yep I was wrong.

[@xiphosura413]

The glaciation is what put the lakes there, but why the lakes ended up where they did is due to the underlying geology. So in a way, both are correct assertions.

[@conradnelson5283]

That’s what I thought

[@johnpembroke9869]

Egyptologist say they were dug out using stone tools and ramps.

[@Eyes_Open]

@@johnpembroke9869 There is a reason why Egyptologists talk about certain tools in ancient Egypt.

[@johnpembroke9869]

@@Eyes_Open what reason would that be?

[@cbl1199]

There is also the fact that due to the last ice age melting, which because of the thickness of the ice crust (Iirc, as an exemple, there was about 2 km of ice over the Laurentides, the region I live in in Eastern Canada, and is now way below the modern arctic region), resulted in incredible amount of erosion due to the displacement of surface water. So by the time the flow hit the ground, it was so strong that it effectively carved into the bedrock and swept away huge multi-tons boulders like they were pebbles (you can still find to this day huge smoothed boulders in the middle of forests, or just below the surface, right in the middle of forests or elevated area that obviously never were river bottoms), causing the formation of fjords all over the land, as many of the rivers that cover the area have a form reminiscing of more evident jfords like those found in the Scandinavian peninsula (if you were to take a cross section, it would be shaped like a T, where the shores are shallow but the middle has great depth which hide a great flow of water, which make them especially dangerous to swim in if unprepared). Even a simple walk in the forest can show you parts of the bedrock still visible, as the accumulation of biological matter has yet to recover the land in dirt in many places. I wouldn't be surprised that the difference in height between the Canadian shield and the western mountain ranges funeled the flow, with the areas now known as the great lakes to be the result of interaction with water soluble rocks and the aforementioned ice age melting water flows, creating pockets of water whereever the flow was throttled due to the local bedrock composition. As an end note, I'd really like to hear you speak of the odd geological formation found within the Hudson Bay, the Nastapoka arc, as its almost perfectly circular shape always piqued my curiosity, and has been a source of debate among geologist for ages. Its as if something just took a planet sized cookie cutter and stripped away a whole chunk of the landmass, with despite its shape insinuating its origin to be an impact crater, geological analysis found no shatter cones or melted rocks whatsover. I'd like to hear your take on the matter.

[@ssansu]

He did a video on the Nastapoka arc.

[@cbl1199]

@@ssansu My bad, thanks for the heads up!

[@cbl1199]

@@ssansu My bad, thanks for the heads up!

[@hamletksquid2702]

The parts of Ontario I've lived in were almost all composed of glacial debris with no discernible pattern to it. I grew up on the Oak Ridge moraine and now live on the bottom of a former glacial lake just south of the edge of the Shield. There are escarpments from sea shores when the land was depressed under the ice, and we get the occasional earthquake because the land's still rebounding. We're basically the dump where the glacier dropped everything it scraped off the Shield.

[@gingerlyglasses444]

I'm on the bruce peninsula which is on lake Huron. Behind my old house there's a massive granit Boulder that was in the shape of a ball and taller than me. In that area there's like 30-60 centimeters of top soil and that's it

[@MonkeyspankO]

The geology of Canada, and the shield specifically, is fascinating. Both for the features it does and does not have. Guess the great ice sheet is still making waves (pun intended). Would love more content like this about my neck of the woods.

[@GeologyHub]

Also, due to the uniformly old age of the majority of the Canadian Shield, it has mineral deposits which could best be described as unusual due to the hotter mantle at the time they formed.

[@рената_цехановецкая]

it really is ! I've had the pleasure of visiting a national park in Ontario Called Beausoleil Island, which is located right on the edge of the shield, with a very clear transition, and it's so interesting to see. Many of the best hiking experiences i've ever had were on sheild terrain !

[@thezood]

Check out Lake Vättern in Sweden. It's a deep, narrow lake that was formed as a grabben along the Protogine zone. The geological map along this zone is really interesting.

[@composthis]

It's cool to see a video about these types of larger, continent-scale geologic features and forces and their geologic histories. Would love to see more videos covering larger features and their changes over geologic time, like the Wester Interior Seaway or the Tethys ocean, or the assembling of western North America. You condense complex topics down so well into small bites. Thanks for your great work.

[@Backroad_Junkie]

Not to shade GeologyHub, but there's a 3 part Nova called, "Making North America", hosted by Kirk Johnson. It does an excellent job of describing the major events on how North America was formed (geologically and inhabitation) in less than three hours. I was very impressed with that series...

[@AtarahDerek]

Straight line? I always thought it looked more like the distinctive arc one would expect at the edge of an ice sheet.

[@gordonrichardson2972]

The type of lava at 3:32 is pronounced Komati-ite, named after the region it was first identified in South Africa.

[@stevejohnson3357]

Until about age 9 I lives in Kenora at the northern end of lake of the Woods. There is farming to the west in Manitoba but right there it's bare rock, small trees and muskeg. No farming but a great area for picking wild berries.

[@jrv128]

Lake of the Woods is another good example of this lake type

[@highenergyog]

I live along Lake Ontario and I’ve been to Great Slave Lake as well as Great Bear Lake , I have been subscribed for a while and I always look forward to seeing your next upload. Best regards as always from Lloyd somewhere here in southern Ontario Canada 🇨🇦.

[@Foxxorz]

Nice to see the Canadian great lakes get some recognition.

[@huttboynz4422]

Flying from Ireland to NZ on my return trips to catch up with family etc. I’m often amazed at the share size of Hudson Bay when flying over. Some Bay!!

[@leechjim8023]

Watch out, you,r flying over Russia. They are murderers!

[@dennisenright7725]

Eight million square kilometers of some of the oldest and hardest rock on the face of the earth. Scraped clean of topsoil by repeated glaciations. Cape Cod and Long Island as well as the highest points of a half dozen midwestern states are apparently the terminal moraine that glaciers scraped off the region

[@jakedemedeiros9978]

Big fan of the work you put out, I never miss an episode Canadian geology is fascinating, I was wondering if you could do a video on glacial erratics, particularly the abnormally large glacial erratic I grew up nearby to called “The Big Rock” in Okotoks, Alberta Also, and this isn’t a problem just so you know for the future, Winnipeg is pronounced “win-uh-peg” not “whinnie-peg” Cheers, keep it up!! 👍👍

[@countrykids6483]

The "Whinnie-peg Jeets"

[@ssansu]

I thought it was pronounced "winter-pig" 😉 Just kidding. Winnipeg is a nice city even if it is a tad chilly in the winter.

[@denisenilsson1366]

@@countrykids6483 🤣🤣🤣

[@SunsetLynxx]

Winnipeg is the cesspool of Manitoba. Always hated going there lol

[@hamletksquid2702]

@@SunsetLynxx - I've been around it, but never in it. Hitchhiking in the 70's, that was like the gateway to civilization when going East. After days of flat nothing with pickups swerving onto the shoulder to scare you and beer bottles flying out of car windows at you, you pass Winnipeg, and the trees start and the wind ends.

[@gosselinkfinecarpentry9786]

I was literally googling the largest lakes in the world last night and saw many in canada. As a new resident to canada I wondered why there were so many. Thank you. Now how about a video on nittilling lake? I enjoy these geologic videos as much or more than the videos on volcanoes.

[@MG-cu6ny]

Love the Canadian shield. So much to look at with all the rocks. And you can find nice crystals in the veins.

[@saukhaven]

I would enjoy hearing more about what created the craton itself. Thanks for such great videos and Happy New Years!

[@earthknight60]

The lakes also occur because the vast continental glaciers scoured the Canadian shield down the the bedrock and then dug down even deeper into the softer terrain just off the edge of the Canadian shield.

[@ticksunbs4944]

I saw a vid about the ‘NA’s forgotten great lakes’ some weeks ago thanks for the follow up

[@beyerdr]

I would love to hear more about Komalite and why it can no longer erupt on earth. That sounds fascinating!

[@coolnewpants]

So why do cratons tend to be smooth rather than jagged?

[@Blaqjaqshellaq]

Parts of the Canadian Shield are in the USA, including Michigan's Upper Peninsula and the Adirondack Mountains.

[@gigibluestockings5168]

I've heard of the Canadian Sheild but I've never known what or where it is. Thank you for that knowledge.

[@thecryingshame]

I'd love to see a video on the unconformity in SE Ontario & Western Quebec. Keep up the great work!

[@Me3stR]

I thought before the most recent Ice Age, the Missouri River emptied into the Hudson Bay in an Amazon-esque fashion. But the Glaciers advanced, and redirected the waters towards the Mississippi and Mackenzie. My understanding was those Lakes were remnants of the vast river system that existed so long ago.

[@georgechord5376]

Thanks for this post. I have been fasinated by this area - the Canadian Shield - and these lakes for years. I knew they were in a line but never made the connection.

[@stevespyder]

Finally a video that talks about Bear and Slave lakes. These are part of the rift that is slowly forming as Canada is slowly being pulled apart by tectonic action.

[@jasonstinson1767]

Mr Hub, Could you please explain the formation on flint (in chalk) and chert (limestone)? Sincerely , Jason, a Knapper in Kentucky

[@rexstuff4655]

Concise and to the point. I wish many more YT videos were like this.

[@DennisCambly]

As a note the Great Lakes are connected to each other. The water flows from northern and northwestern Ontario into Lake Superior down the other lakes to the Atlantic Ocean. The other lakes you mention in western Canada flow to the Arctic Ocean.

[@bukboefidun9096]

Fascinating! Good stuff GH

[@AmazingPhilippines1]

I make a trip with a friend to Winnipeg and Winnipeg Lake decades ago. My friend, a French major in college, wanted to practice his French in that area of the city. Interesting geology in the area.

[@iciajay6891]

I live on the shield. In something called 'The escartment'. Were ancient mountains are worn down to large hills. I can see it every direction in my small but sprawling city. My sister moved to BC. I could not handle the stress of earthquakes so i wil stay on the shield thnx. XD

[@seanrodgers1839]

In high school geography, I once ask the teacher why were these lakes were in a line. He didn't have an answer, but I knew there must be one. I had figured this was the reason, but it's nice to have it confirmed.

[@paul6925]

I grew up right on that line north of Kingston by Lake Ontario. It was really obvious - abruptly going from cottage country exposed granite to limestone farmland whenever we travelled into town. There was a small ski hill right on the line because of the huge change in elevation.

[@thesilentone4024]

Can you do a video on all the active volcanos that are venting gas and how much gas there letting out mybe let us know what kinds of gas if tells you.

[@filonin2]

Humans emit 60x more co2 than volcanoes per year, so not much.

[@djblackprincecdn]

A video on the how and why the ground is rebounding around Hudsons Bay would be great.

[@jonathanellsworth21]

So I see you left Minnesota’s Arrowhead and Mesabi regions out of the Canadian Shield, does the international border actually follow the edge of the craton, with NE MN geologically different? Or was it omitted just for simplicity?

[@erikzered7945]

No he just left out the parts of the shield not in Canada, Which also includes the Adirondacks in New York btw.

[@user-gi3oc1kv5m]

I saw a video of yours one night while surfing youtube for content to soothe me to sleep. Your voice and how you break down the information hooked me to subscribe. While a lot of the things mentioned I have no idea about - and I rewatch them several times to wrap my head around them - it's still exciting and intriguing to learn about, and I've always enjoyed learning about Geology. I appreciate your time and the content you put together. I look forward to your future videos! Thank you!

[@GeologyHub]

I am glad that you enjoyed my content. Thank you for your support :). Do you have any geology topics that you want to request?

[@brian8410]

Telling someone that they are a cure for insomnia can sometimes be taken the wrong way.

[@user-gi3oc1kv5m]

@@brian8410 hmm, I wasn’t aware in my comment that I said they cured my insomnia… It started off as a night I needed help sleeping and it turned out to be a wonderful find, so now I actually watch these videos to learn instead of helping me sleep. Happy learning, take care :)

[@fantomfang1100]

Can you cover the Wallupa gap feature in Washington? Love your videos!

[@Misterwhistle]

I live in northern Saskatchewan Canada. It is bedrock and part of the Canadian Shield as you call it. This is the first time I have heard the term Canadian Shield and have always known it as the Precambrian Shield. Have I been wrong all this time or are they one in the same?

[@andrewclayton4181]

I heard the term Canadian shield decades ago. Maybe it's more common outside of Canada.

[@gordonrichardson2972]

Precambrian is an age term (> 600 Mya), and many Shields/Cratons are similarly ancient. Canadian Shield is location specific.

[@erikzered7945]

As an Ontarian I've known the term for most of my life but usually just call it the shield anyways. Your case is probably just what the locals call it rather than the scientific term

[@filonin2]

Same reason French Fries aren't called that in France.

[@ColePenner]

Grew up in ‘Berta and we are taught that it was called the Canadian Shield in our textbooks

[@scottj4641]

I feel I learned a number of things from this video, including why the lakes formed along the shield's boundary, but not why in a straight line rather than in an arc.

[@derrickstorm6976]

I binged some older videos that were almost-volcano related history just like this, and were hoping for more to come :D

[@Backroad_Junkie]

Actually, this may explain why all the border lakes around the Minnesota Arrowhead all seem to run East-West. (They were the border routes for the fur trapping trade...) I've canoed a few in the Boundary Waters... Can you explain why all these border lakes run East-West? Was it cracking around the edges of the Canadian Shield?

[@BackYardScience2000]

Now I'm extremely curious, I'd like to suggest that we need a video on this lava that can no longer erupt on earth. If you don't already have one posted to KZbin, that is. If you've already made one, if I find it I'll share it as a reply to my comment. I'm pretty busy, so if someone beats me to it, then by all means. Lol 🙂

[@BackYardScience2000]

Found it. Can't believe I never saw this.... kzbin.info/www/bejne/e2m8lnqvaqaebs0

[@Dragrath1]

He did a video on it before kzbin.info/www/bejne/e2m8lnqvaqaebs0 It was a higher temperature lava type than basalt as in contained stuff that has already precipitated out of basalt. The most fascinating thing about it is its low viscosity which made it flow more like water than modern lavas

[@iver7473]

really interesting! thank you

[@NocturneSMT3]

Please make a >10 minute video on the cascadia subduction zone.

[@kevinbyrne4538]

I'd never wondered about this; nevertheless, I did find it interesting. Is the "Canadian shield" also called "Laurentia" on some maps of plate tectonics?

[@jeffclarkofclarklesparkle3103]

I live near the canadian shield border and found a crystal in the middle of a rock that both have some pretty cool features. A geophysisist (not sure how to spell that my bad) looked at it and said it is called an Augen Gniess and formed about 1.5 billion years ago by sheer tectonics movement. The crystal inside the middle can be almost any hard crystal. I beleive it is a feldspar type but it's hard to tell. But it has rainbow shiller effect lines, which i found spectacular, otherwise the crystal looks like a dull greyish colour. I tried extracting the crystal but had no luck as the surrounding rock is very hard and full of different types of crystal much like granite that has been fused together to be even harder. Augen is the german word for eye, because the feldspar on the outer portions of rock have been melted slightly and stretched giving them the look of a half closed human eye. 😁💖 i love canadian geology

[@leechjim8023]

Good enough!🙂

[@roosjen]

I loved this and would love to learn more from you about cratons. I visited Karijini National Park in Australia and stood on a rock surface that was over 2 billion years old. Beautiful surroundings there, and great experience. I believe the park is part of the Vaalbara craton. Not sure about the name, but the other half of it is stuck in South Africa. I bet you know the one I mean 😅 Thanks for all your great content!

[@SunsetLynxx]

I like it when my country get mentioned. I learn so much! But now I must know more about Komatiites please!

[@jrv128]

Lake Athabasca is on 2 significant unconformities. The unconformity of the crystalline basement rocks of more typical Canadian Shield on the north shore and the 1.5 billion unmetamorphosed sandstone of the Athabasca Basin. Also the unconformity of the shield and the Western Interior Seaway sediments. You can see the sand dunes from the erosion of the sandstone on the south shore of Lake Athabasca. They are the northern most active sand dunes. The Athabasca Basin is by far my favourite part of the shield, it is unique for many reasons.

[@zilvoxidgod]

very cool video!

[@fimbulsummer]

I really want to know about Komatiite now!

[@Nemodog]

Please do a video on komatiite. I've never heard of this and I'm very interested! Why aren't circumstances on earth allowing for this kind of lava flow at this time? Really hope you follow up on this! Thanks! Love your videos and watch every one!

[@xoxo2008oxox]

We used to joke that the shape of the Canadian shield is the same spot where the moon left from the Earth... if you are one for that theory....

[@grokeffer6226]

Interesting observations.

[@michigannative2951]

Neat summary. Have a question do you think that the radius of the graphic you used could be a foot print from a meteor strike. The sudden shock could have melted ice rock and there’s recently been a miner in Canada? I think that’s been finding mastodon tusks and bones, not the point but it could explain it better why the animals herd and and ultimately died. They say the Great Lakes formed as result of volcanic tubes being crushed by glacier’s forming over the top and eventually collapsed and they filled in with water. Might explain the copper and gold found.

[@mengatur]

Please discuss about gede-pangrango stratovolcano its contain 2 caldera maybe it have vei 6-7 eruption

[@BriansAdventuresAndGaming]

I think a good topic for a future video would be about the US Great Lakes. I was watching something one time where it said I think Superior has basalt in it which means there has been some lava present in there at one time.

[@Dragrath1]

Yeah the great lakes of North America are ancient rift lakes associated with an extensive failed Mesoproterozoic rift complex. They had for most of the planets history become filled in by sedimentation and eventually sedimentary rocks but during the Pleistocene they were once again excavated by glaciers as the less resistant sedimentary rock layers were carved away.

[@Backroad_Junkie]

Look up the "Mid Continental Rift in North America." Apparently, it was so large (It extended all the way into Kansas) it almost ripped (what was to become) North American in two. If @Geologyhub hasn't done a video on it, he should...

[@BCRandom69]

I'd like to request a video on Mount Garabaldi and "The Barrier" in Southwestern British Columbia near the town of Squamish

[@OMGitshimitis]

My guess before seeing this. Something to do with the time the American tectonic plate tried to rift.

[@sofiav4353]

Would love to hear more about the Canadian Shield. I live in southern Ontario, and often find tonnes of tiny seashells and coral fossils in driveway gravel that has been sourced locally. I wonder how old they are. I've also heard that it is very hard to find any other "big" fossils because of this.

[@alexilonopoulos3165]

Wow, this is something I’ve actually always wondered about! Great video!

[@Slothery]

Wow that was so we'll described in such an easy way to understand. Fascinating stuff!

[@mfreel1657]

Thank you for answering that question. I notice the line as well and wondered about it many times. One less shower thought.

[@62Cristoforo]

For years I’ve wondered about this very thing. And then this video appears.

[@Rancid-Jane]

Thank you. I have always wanted to know why.

[@chasemclain6235]

Can you go into detail of why some lavas can’t erupt anymore?

[@Deeplycloseted435]

There is some cool geology in the upper midwest from glaciers. If you guys like this kind of stuff, search for geologic points of interest near where you live. There is always something that will surprise you. Email a professor nearby, and I bet they could give the best list. Then get outside, see some geology, and enjoy the world. You don’t have to go to school forever to be an enthusiast in ANY science field.

[@Thanksabunch]

Thanks! Really enjoyed this one!

[@Nightscape_]

I didn't even know these lakes existed and I live in North America! I want to know about the formation of cratons now.

[@jackjones9460]

I understood you saying Cratons had generally straight edges but I don’t see how that explains the Canadian and US Great Lakes existence. I’ve often wondered if the land east and west of the lakes pulled apart creating the deep cavities the lakes seem to be covering. Can you tell us what processes most likely formed the lakes as opposed to my guess? I appreciate you making the videos. I have in fact wondered how all the Great Lakes formed but never had an opportunity to ask anyone before. Thank you!

[@herenowjal]

The elephant in the room (and seldom discussed) are the periodic pole shifts that occur throughout earth history. It’s been suggested that a previous pole shift (concurrent with a earth crustal displacement) moved Hudson Bay from its position as the former North Pole, to its present location. This accounts for it being the center of the Laurentide Ice Sheet during the Last Glacial Maximum (LGM). Would this account for massive ice coverage over North America - as compared to ice coverage in Eastern Asia ?

[@zaynecaspersen4455]

On the Canadian Shield, in the province of Quebec, the west side in the Hudson Bay looks like an extremely large crater, which I know isn't quite the case, but why does the area have such a round looking edge to it

[@joshhancock3163]

Can you do a video on the Oregon coast range? It seems like I've heard it has some volcanic origin but not entirely sure

[@charonsiouxsie949]

His is bloody fascinating

[@sylver369]

Lakes and ponds occur along rivers, streams and brooks in lowland areas. They are not really in a straight line, they are close enough together you could draw a line through them though.

[@DaFlyingFox]

Very interesting topic, thanks.

[@rogerdudra178]

Greetings from the BIG SKY. Most interestings, thanks.

[@diskdrive123]

I haven't looked it up; but I'm guessing those other lakes aren't very deep and in general more narrow/stringy, so by sheer water capacity they probably don't even compare.

[@ElBantosClips]

Why does Canada, Alaska and even some areas in Russia all have what seem to be thousands of small lakes all running the same sort of direction? Are they ancient markings of ice sheets? Or just simple tectonics?

[@TheDanEdwards]

Ice.

[@SailorGreenTea]

1:40, time for a change.

[@KhaoticDeterminism]

Thanks! I always wondered this

[@dainisozols1213]

Lake depressions are made by glacial erosion where softer bedrock occur. Baltic Sea is very similar to Great lakes and is made mainly by glacial (and glaciofluvial) erosion.

[@SB-qm5wg]

The rift-lines under Lake Ontario are pretty cool. Not part of the failed rift of Lake Superior. No one knows why they are there.

[@allixkirchhoff7857]

I love the videos! keep it up! i hope maybe more lake videos in the future this was great thank you!

[@alecity4877]

I'd love a video on the Guiana shield tbh.

[@PaulSteMarie]

I'd be interested in seeing a video on komatiitie why it no longer erupts on Earth.

[@sheikchilli8670]

considering that the earth is not a perfect sphere and is flattened at the poles, is there evidence of deformation of tectonic plates caused by them moving north/south?

[@richardupcott9026]

Why is Hudson's Bay in the center of the Shield? As if the Shield is a bowl, high rim but a low center. Also, is James Bay a crater?

[@jrv128]

Hudson Bay was the most depressed part of where the ice sheet was. It compressed so much that it is below sea level. It is shield underneath all the marine sediments for sure though.

[@barbburns2122]

Great information

[@riverAmazonNZ]

Extremely interesting!

[@TexasTimeLord]

It's amazing how the Great Lakes formed right on the border of the US and Canada dividing themselves in half

[@leechjim8023]

I think you got it backwards!

[@crinkly.love-stick]

Topic idea: how did lake inferior form? It's a giant lake, hidden underneath lake superior.

[@CJFreeza]

Fantastic video

[@rorymacintosh6691]

Wonderful, thanks!

[@gbrown9273]

How about the possibility of a fault line causing the lakes to run in a similar line?

[@AstonMartin427]

GeologyHub, can you do a video outlining the creation of Cape Cod and the islands?

[@labexperiment2260]

Thank you.