This really helps me grasp how old the earth is. Continents moving about the speed my fingernails grow and that they have broken apart and come together many times. It’s amazing

@GEOGIRL

4 күн бұрын

That is so true! I never thought about it like that, but actually fingernail growth is probably a bit faster than continent movement haha ;)

Even supercontinents have problematic breakups.

Thank you for another great video! I’ve now been a channel member for two years!!! And I’ve always been impressed by your knowledge, skill and passion for the amazing subject of geosciences, Dr. Geo Girl! One thing that I’ve been curious about concerning Gondwana is its existence as a coherent landmass both before its fusing with Euramerica to form Pangea AND after Pangea’s breakup. That makes me wonder if the rocks in orogenic provinces are much more broken and weaker than in the more stable cratons. So in general when continental rifting begins, it’s much more likely to occur in areas like the Central Pangean Mountains than in continental shield areas. (And maybe that’s why the Midcontinent Rift System failed to break apart North America?) Do you know more about this? Thank you again for your wonderful and talented work!!!

@GEOGIRL

12 күн бұрын

That is a great question! I don't know for sure, but I have always assumed exactly like you said that the non-craton parts of the continents are always the weak zones that are liable to future rifting and breaking apart, but I will have to look further into this to really understand the mechanisms behind why :D Thanks so so so much for your amazing support as a channel member (and virtual friend

Your videos have become more enjoyable for me as you've gotten more experience making them.

@GEOGIRL

4 күн бұрын

Thank you so much! I continue to try to improve each one :)

Thanks for another great video! Your star is shining brighter and brighter!

One of your best, this one. I hope your future plans include the writing of books. You'd be good at it. There's nothing that holds the attention quite so well as enthusiasm on the printed page.

The possible extinction of mammals? What a cliffhanger ending!

@toweypat

4 күн бұрын

I'm against that!

I swear I could listen to this for hours, amazing work breaking it down!

Loved your video! I recently got down a rabbit hole reading about the supercontinent Rodinia and the Great Discontinuity in the geological record

@duhduhvesta

4 күн бұрын

Godwana is my jam

Rachel ⛳, Solid work ⛏️. That was well constructed and super interesting! 👏👏👏👏👏

@GEOGIRL

13 күн бұрын

Thanks so much! I am so glad you enjoyed it :D

@urrywest

5 күн бұрын

@@GEOGIRL You do tons of good works. Like the Steve Keen of geology...

You really deepened my understanding of the supercontinents and the mass extinctions around them. I still don't have knowledge of every detail but I have a better foundation to draw on in my readings. Thaks a bunch!

Howdy Rachel, thanks for another interesting topic. Back in my academic days I only remember Pangea and Gondwana being discussed, and plate tectonics only then being more globally accepted. And in my career expanding back to Columbia/Nena. But I suspect Vaalbará might have been larger than we might be able to prove because of continental mass being re-incorporated into the mantle. Look forward to seeing the model of the future Supercontinent. Who will take over after mammals? Birds?

Thanks, very nice presentation

Whaast? I didn't know about the first five at all! Why didn't anyone talk about them before? Seems you're the first here, Rachel! Thank you for my weekly dose of geology 😅🌺

THANK YOU! I've wondered about how continental drift affects life for a few years, and you summed it up very nicely. What hypotheses do we have for WHY the continents drift the way they do? Why wasn't continental drift occurring for the first billion years or whatever of Earth's history? What drives them together, and then apart again? Does the mantle have a 250 million year cycle of sloshing back and forth somehow? I look forward to future vids!

Your videos were helpful to clear iit jam geology exam, so thank you

Love this. I have a Ph.D in geology, but my topic didn’t cover a lot of earth’s history. I appreciate that you don’t glaze over details that a wonk like me requires. :-)

Always brightening up my day 🌻

Geo Girl is a super KZreadr! Keep these awesome videos coming! ❤🎉😊

@GEOGIRL

4 күн бұрын

Thank you!

Thanks , I spent the whole video thinking will she talk about the future. Well now I have even more reason to wait on the next episode!

Wow I didnt know there were several super continents, and Pangea is the most recent one. Thanks for this awesome video

@toweypat

4 күн бұрын

Same here.

What a fascinating topic!

Absolutely terrific video. Thank you.

@GEOGIRL

4 күн бұрын

Thank you so much!

Dang, I can hardly wait for the video about the next supercontinent! But at least I don't have to wait the whole 200 million years to see it in real life.

I would be very interested in a video discussing what (little?) is known about some of the earlier proposed supercontinents, especially in the later Archean and early Proterozoic. My understanding is that the earliest land masses were probably a result of mantle plumes, but that at some point before plate tectonics developed there was a lid tectonic regime and there might have been one or more supercontinents during that phase.

Thanks for making this really informative video!!! Can you please make a video about Vaalbara, Ur, Kenorland, Arctica (?) and Columbia/Nana? I've looked for more information about these first contents but i haven't been able to find much info (as you have mention). Maybe you could discuss the evidence for these continents, and alternative theories? Also, in the past when reading about these early continents, i have assumed that they were created by plate tectonics, but thats really interesting that they formed before plate tectonics started (you video with Steve was super interesting btw! ). One thing im wondering now is why would these first continents form all together instead of all of the lighter continental material raising to the surface through differentiation equally across the early earth? Please make a video about this, it would be super interesting 😀

Thank you for the video about supercontinents. This is something that has sparked my interest. I was researching the black diamond called the enigma that Richard Heart unethically purchased through Sotheby's. Back when Rodinia was a supercontinent there may have been a meteor shower and it's why black diamonds are typically found in Brazil and Central Africa which made up Rodinia. Rodinia is Russian meaning motherland. I thought that was pretty cool 😎. Then your channel show up on my homepage, even cooler 😎. Peace and Ahev

As a Kiwi Gondwana for ever.

Fun fact: the Caspian Sea, while considered a "lake" since its landlocked, it's actually the last remnant of the Tethis Sea, as Eurasia closed in around it. It's bottom is oceanic crust, rather than continental crust, like other true lakes

@mrbyzantine0528

6 сағат бұрын

What about the Black and Mediterranean Seas?

I was really in search of this video. Thank you

That was all very interesting. Thank you.

There was a time before plate tectonics? I'm going to have to watch your earlier videos to find out about that!

Thank you Dr Phillips.

@_andrewvia

5 күн бұрын

I hadn't thought through the process before: when India met EurAsia and started to push into it, the land was flat at first, then hilly. It took a few thousand (million?) years for the mountains to pile up. Animals could venture back and forth for quite a while before the mountains blocked their travel. That's very interesting. Thanks for sparking a new connection in my old brain.

@GEOGIRL

4 күн бұрын

Yes! Millions of years! Glad you enjoyed that bit :)

There is a new paper out, that proposes that the fresh water cycle a.k.a. weathering started earlier and might also have accelerated the beginning of life earlier than thought. I'm curious how you think about this and if you would lecture us about that 😃

Yaaaaay! Thank you

An amazing collection of videos. I wonder if there are descriptions of how the oceanic crust or ocean floor has changed over the millenia? The changes might have significant effects on the ocean, climate and life. For example, the ocean bowl in the atlantic has a resonant frequency near the lunar 12 hr cycle which greatly affects the tide heights up and down the american east coast.

@barbaradurfee645

Күн бұрын

Oooo Rachel, this is worth looking into! Free advice from Mom 😊❤

Very Informative, GEO-Goddess!!!

I'll look forward to the next one then. Thanks!

Thanks for another great video. I'm from the West of UK in the area called Avalon (Avalonia) but at the moment I am in Agadir Morocco, just where the CAMP break up was located. It's really old rock here. Think it's called the West African Craton (WAC) There are fossils in the garden here and this is where the Atlas mountains drop down to the sea. Looks like the mountains just got cut up with a big knife! Thanks for the wonderful channel.

@MrSiwat

2 күн бұрын

Correction! The WAC is further south from here in Agadir. This area is an Orogeny. The High Atlas are here and the WAC starts down in the Low Atlas. There's a place called Tafraoute surrounded by very beautiful mountains. That's on the WAC! The Sahara is scary big when you look south!!.)

Excellent video. I have some questions though... 1. Rather than a super continent, or any continent; could the first land on Earth have been more like islands (bits of continent forming here, there, and thither), which then coalesced into the first actual continent(s)? 2. I see a lot of rain "events" these days and the flooding that inevitably follows; could that be weathering and erosion that will lead to increased carbon burial? (Hopefully not burying too many people in the process) 3. The most hopeful thing I've learned, from you, about mass extinction events; is that even the worst ones don't seem to wipe out life completely. So, I do you think that means the formation of a future super continent, and any mass extinction will behave the same way? (I sure hope something survives.)

So you take an entire continent, you move it along on the mantle-lithosphere boundary, you bang it into other continents, and then you have a supercontinent, until it heats up in the middle and breaks up into smaller continental sized fragments again. Then, you so this again and again over the course of the Earth's 4.6 billion year history and-Voila! (Mind blown.)

Interesting that, of all the displayed supercontinents, only Pangea and, to a lesser extent, Gondwana had plants and animals living on them.🤔

@GEOGIRL

4 күн бұрын

Well, plants and animals did not evolve on land until about 400-300 million years ago. Before that, there were some marine animals but only back to about 600 million years. Rodinia and earlier supercontinents were before land animals and plants were a thing :D So crazy to think about!

It is also possible the massive expenses of desert contributed to bio diversity via isolation. Members of the same species that were seperated by newly expending deserts could have speciated.

If all of the super continents came together at the same time would they form a Justice League?

Pangea is my favorite 'cause i know what it is!

Does desertification (like in the case of Pangaea) predictably occur whenever landmasses become large enough?

@GEOGIRL

4 күн бұрын

It seems like it based on the evidence we have. And in fact, the future supercontinent I hinted at in the end of the video is thought to potential cause the mass extinction of mammals in large part due to this desertification of land effect!

Can you elaborae how weathering of rocks sequesters carbon in the ocean? I thought snowball earth was caused since this weathering released nutrients into the ocean, accelerating the growth of photosynthesizing algee---- Great video overall

@GEOGIRL

4 күн бұрын

It does both! First, silicate weathering (the weathering of silicate rocks which are the most common ones in Earth's crust) induces the transport of CO3 and cations like Ca and Mg to the ocean where they form carbonate rocks like CaCO3 and Ca,MgCO3 (limestone), and this sequester carbon from the atmosphere (because the CO3 originally comes from H2CO3 in acid rain which resulted from the reaction between CO2 and H2O vapor in the atmosphere). And second, continental weathering transports nutrients to the ocean, just as you said, increasing the algal or photosynthetic blooms or activity in the photic zone of the water column, which increases the production of organic carbon (the body mass of the algal or bacterial bloom) and subsequently the burial (sequestration) of that organic carbon in the ocean sediment as the dead bodies of those organisms eventually fall to the sea floor. So, it is somewhat indirect, but a very powerful carbon sequestration mechanism. Hope this helps! ;) If you want to hear a better explanation of this in video format, I recommend this video (specifically, the section on silicate weathering about 11 minutes in): kzread.info/dash/bejne/lZdorc-zhtS7aLg.html

@HereIAmThereIWas

4 күн бұрын

@GEOGIRL this is great! Thank-you so much!

Great video! I'm surprised by the map of the future super-continent. I get that Africa is moving North, but will in squeeze between North America and Europe, or continue to crash into Europe closing off the Mediterranean? Also, I thought Australia was moving North, so shouldn't it eventually crash into Asia the way India did? And North America has already crashed into far-eastern Siberia, so won't the Bering sea eventually close up? I would expect that the next super-continent would be made up of Africa, Eurasia, Australia and North America, with East Africa, Antarctica and South America being the remaining smaller continents.

@GEOGIRL

4 күн бұрын

Well there are mulitple potential scenarios of future supercontinent configurations and I will go through the 4 most likely ones in that next video that I mentioned, which will come out in about two weeks! :D Hope you will come back to check it out!

If there are any metalheads in the comments section I highly recommend "Valbaara" by ERRA. The song is fantastic and has some neat geologic/Mesopotamia references!

I was a Navy brat(a kid born to a Navy personal). Naval officer's move around every two years, while enlisted move every four years. Well, we ran into this one family around my high school times after we had met long before. Like when we were playing in sand boxes. I don't know how else to describe that. We'd spend the Summer playing RISK, and . . . Imperium Galacticum - A space empires, exploration and conquer game. This was back in floppy disks time. I'd always call my empire "Pangea!"

@oker59

5 күн бұрын

Oh yes, I saw a disproof of oxygen as the reason for life to become multicellular - there was a Cambrian explosion before the Cambrian explosion. I forget what it was called.

❤👍❤

Ur is a play on words with one of the oldest cities in history Ur in Mesopotamia (according to the Bible also Abraham's birthplace), and the German syllable Ur meaning "origin" as in "Urkontinent" (paleocontinent) or "Urmensch" (early hominid). So I would pronounce it like "oor".

@barbaradurfee645

Күн бұрын

Thank you!

That looks to be a most uncomfortable chair you have in the background. I do hope that those with the means will contribute to a better one. If not , perhaps a roadside collection🤗

@GEOGIRL

4 күн бұрын

Haha, it is not too bad, but my cat, Hope, absolutely loves it, so it has become her chair anyway ;)

is it not the case that each mass extinction has resulted in a reduction of body-plan diversity? it has certainly reduced the total number of phyla on the Earth. so is it actually accurate to say that these breakups led to "diversification" if each event actually reduced the variability (and diversity) of macroscopic animals?

The pointy finger saga IS OVER!

Not floating? Continental crust is kept up by the fact that its density is less than that of the mantle, isn't it? The stresses involved are large enough to deform rock, whether by faulting of lithosphere or plastic deformation of asthenosphere, so it seems to me as though it should count as floating even though the material involved is solid.

@GEOGIRL

4 күн бұрын

Absolutely! I just think most people assume I mean floating on water or on magma or some type of liquid when I use the word 'floating' so I didn't want to give that misperception through using that word, but yes, you are absolutely right that it is kind of floating, just on a solid instead of liquid! ;D

Ur looks like a diving penguin. Such a cool name too, Ur!

Is it possible that when the glaciers melt the pressure at the equator from liquid water and less pressure at the poles (no ice) the faults float differently? Is there correlation between global temperature and continental drift?

I got the impression that you're saying the movement of the continents caused extinction events, with hardly any mention of vulcanism. The Siberian Traps caused massive extinctions ~250 Ma, the Indian Traps wiped out life ~35 Ma, and the Atlantic Rift between NA, Europe and Africa caused a lot of extinctions. I'm sure the continental masses and their location on the globe had an effect on life. But I think vulcanism affected it more.

Look! Down on the ground! It's a crust--it's a mantle--it's Supercontinent!

If the breakup of supercontinents like Pangea leads to species diversification via isolation, does the formation of supercontinents lead to a loss of diversification due to previously-isolated species competing for the same niches? Or does the associated climate change disrupt existing niches anyway?

😊

😎

So are your videos part of your teaching curriculum, Rachael?

i have a carbonaceous meteorite i wanna do isotope oxygen ,can u help for finding where to do it thx ,

So, Rachel, if you had a time-machine which part of Pangea would you love to visit and more importantly which time period would you visit?

Can an astronomical impact object (meteorite) puncture through the crust and initiate a new plate boundary?

Isn't the unclarity of the Pannotia situation i little bit like what we have today? Since there is a continental connection spanning the Bering straight, all major continents except Australia are connected. This should satisfy the criteria for being a supercontinent, but most geologists seem to think that it isn't. (And wasn't that also part of why the whole "previously disjointed continents form up..." addition?) I would prefer that there would be a tangible criterion, such as one that could be at least indicated in the geological record, rather than than this "yeah, but..." situation. But it is what it is, I guess.

Case in point: Tuatara.

I suppose that afer millions of years of species being separated, man has come and made a kind of homoginization of ecosystems by introducing the strogest species in each land mass to the other land masses.

What about Eurasia?

Reunite Pangea!

Sorry your text is overlapping important figures. Unable to see pics.

@GEOGIRL

4 күн бұрын

Thanks for letting me know! I'll try to fix that in future videos ;)

"the extinction of mammals" *SAD POGGLE NOISES*

All this talk of subduction & orogenous zones is making a bulge in my magma chamber.

"Ur" should be pronounced "ooh-r". It comes from a German prefix meaning "original". If you hear English speakers pronouncing it like "your", they're probably misreading it because they're so used to the texting abbreviation "ur" for "your"/"you're".

@GEOGIRL

4 күн бұрын

Thanks! This is very helpful! :D

everyone is forgetting the continent of "Longoland". how do i know you asked. trust me bruh.

Another boring about definition if or not a super-continent. The importance of big landmass is * they are so big so have a fully locked inside area without rain * there mein position like equator or pole, to trigger another world wide climate. Over this definition discussion we forget over the important impacts of size and position.

Meh. At 57% of the world's land area, and 85% the size of Gondwana, Afro-Eurasia is more than enough to be the sixth supercontinent to me.

Sooner or later people are going to have to face the fact that the continents broke apart in the days of Peleg, 100 years after the global flood. * It’s the reason for the glacial striations stamped on top of bedrock like a gigantic broken seal in South America, Africa, India and Australia from glaciers that were moving from south to north from the time when they were all still connected to Antarctica at the South Pole. Of course this was after the sediment layers from the global flood were deposited. * It’s the reason fossils and sediment layers line up between South America, Africa, Madagascar, India and Australia. (The fossils and sediment layers were deposited first and then the continents broke apart, 100 years after the global flood.) * It’s also the reason there are many frozen animals and forest ecosystems buried by tsunamis from the rise of sea levels in North America and Siberia as the continents were being shoved into the Arctic from the centrifugal force after the earth broke apart, possibly due to hardening of the sediments and other factors. * It’s the reason animals made it to South America from Africa and humans did not since they were still trying to build the Tower of Babel before the breakup of the continents. Jaguars were separated from leopards, greater grisons were separated from African honey badgers, tapirs were separated from …tapirs, otters were separated from otters and all of the other animals arrived at various places around the world before the breakup of the continents. * It’s the reason why the lifespan of humans was cut in half a second time since the global flood from a less than 500 year lifespan to a less than 250 year lifespan. * It’s the reason why the meaning of the word Peleg in Hebrew that meant “divided” turned into “as (where) the waters flow” in the later Aramaic form of Hebrew. That’s quite an impressive change in meaning. * It’s the reason people isolated into family groups and began speaking their own language. (Everything that happens is of course by the power of God.) *Last but not least, it’s the reason penguins never made it to the Arctic since there was no land there for them to breed in the Arctic. …And now you know the rest of the story, the whole story.

@TheDanEdwards

4 күн бұрын

"Sooner or later people are going to have to face the fact that the continents broke apart in the days of Peleg, 100 years after the global flood. "

@judychurley6623

4 күн бұрын

Well, no, just the opposite. Genesis is not history, not geology. It doesn't work, trying to shoehorn data to fit an idea from Bronze Age goat herders of a young earth that has had no physical evidence and a lot of fossil and geologic and astronomical evidence against it

_"Pea an Geea"_ ? 🤣 {:o:O:}

@AtomikNY

4 күн бұрын

In most North American and Australian dialects of English, the vowel /æ/ breaks to /eə/ when it comes before /m/ or /n/.

@ansfridaeyowulfsdottir8095

4 күн бұрын

@@AtomikNY I've never heard that. And it's not a North American or Australian word. It's an English word. It doesn't even have a diphthong after the "p". Pangea. Pan gee-a Not "Pee-an-gee-a" {:o:O:}

@AtomikNY

3 күн бұрын

​@@ansfridaeyowulfsdottir8095 All English words get pronounced in the regional accent of the person speaking, no matter what the etymology of the word. Any English word with a short A /æ/ coming before an /n/ or /m/ is going to be pronounced that way in North American and Australian accents. All accents have their own sound changes that they historically underwent, which is why we have different accents. This allophonic change happens to be a natural feature of North American and Australian English, and it's part of why they sound different to the English of London. English is a language where vowels vary a lot by region and the vowels somebody uses are very informative for identifying where they come from. In North America and Australia, "pan" is [pʰeən], as opposed to Britain where it's [pʰan], New Zealand where it's [pʰɛ̝n], or Ireland where it's [pʰæn]. In all these places the "Pan" in "Pangaea" sounds the same as the word "pan". Also, "Pangaea" is composed of two Greek words, "Pan-" meaning "all" and "Gaia" meaning "Earth", and it was coined by a German guy. So if you're going to be a stickler for an etymological pronunciation, it'll have to be a German or Ancient Greek one. And you're mishearing the vowel here, it's not "Pee-an-gee-a", it's [ˈpʰe(j)əndʒijə] ("PAY-an-gee-a").

@ansfridaeyowulfsdottir8095

3 күн бұрын

@@AtomikNY Irrelevant. She's saying _"Pee-an-gee-a"._ It's not _"Pee-an-gee-a",_ it's Pan-gee-a. She often mispronounces things and always acknowledges it, so butt out, no one is talking to you. Crabs with pinchers instead of pincers, "pick-shure" instead of "picture", and various scientific words which I forget atm. {:o:O:}

Why is Afro-Eurasia not considered a supercontinent?

Thank goodness the CO2 levels were much higher then…to support all the life that was existing on the planet!

Some dude is going to be lucky enough to marry this woman!