Pangaea - Assembly and Fragmentation of a Supercontinent | Tony Doré, Ph.D.

Ғылым және технология

Tony Doré is the Global Chief Scientist and Senior Advisor to the Director of EGI. This Webinar occurred on March 7th 2024.
The supercontinent of Pangaea - its formation, its consequences and its break-up - are fundamental issues in the history of the planet, of importance to geologists in both the industrial and academic worlds.
I will show new ideas and research on Pangaea, addressing the following key questions: Is the Supercontinent Cycle real, or is the plate tectonic process less repetitive and more chaotic than hitherto recognized? What are the reasons for the devastating volcanism affecting the Pangaean interior, including the most extensive known volcanic episode in Earth’s history? Is the extreme sedimentary flux in the Arctic - forming the world’s largest known delta - part of a more widespread, global phenomenon?
I will discuss the possible reasons for Pangaean fragmentation, and its tectonic signature. I will attempt to show that this process is not simply a manifestation of the concertina-like opening of oceans and closing of orogens, but also significantly related to the exploitation of continental-scale strike-slip zones. Finally, I will discuss how these modes of break-up were manifested, in different ways, in today’s deep water ocean margins.

Пікірлер: 30

  • @Bloodknok
    @Bloodknok10 күн бұрын

    Very informative visual commentary - thank you.

  • @Randy778
    @Randy778Күн бұрын

    41:10 the sediment content isn´t that suprising? It´s more about the sheer load those rivers discharged. On the other hand it´s the consequence of a massive increase in water vapour resulting from a huge increase in atmospheric CO²? Gigant storm systems formig over the 2/3s of the globe spaning tropical ocean- that´s kind of what a tempest tossed sea looks. Atmospheric rivers forming equaly elaborate "deltas"... Thanks for pointing out even the rocks themselfs can exprience sudden drastic regime shifts and everything flows in this strange river of time.

  • @GhostScout42
    @GhostScout423 күн бұрын

    Questions: doest the mid oceanic ridge look much more like a tension crack than spreading? also, where does the force to subduct all the material come from, where does the material go, and how does the process of subduction overcome the friction of the mass being subducted, addionoally, how does the mass being subducted not break due to having its compresisive strength fail? also, doesnt it seem like the continents line up better with mid oceanic ridge than the other continents themselves?

  • @katsmeow2775

    @katsmeow2775

    Күн бұрын

    I think it is a tension crack as much as anything else. You need a good video on subduction. Gravity makes the heavier ocean crust subduct under the lighter continental crust into the mantel. The subducting crust is quickly affected by growing heat and pressure changing its properties, making it more ductile until melting it. The mid-ocean ridge is a breaking point in a previously continous plate, often loosely based on a previous breaking point. Tear a piece of paper in half. The best fit of the two pieces is along the tear.

  • @Geologynut37
    @Geologynut37Ай бұрын

    I think another factor related to the breakup of Pangea could be Organic Collapse. The weight from the mountains caused the crust to be pushed into the Mantle. Together with melt from the slab break off could have caused an enormous amount of magma. Crustal delimitation from the weight of the Appalachian Mountains along with slab break off slowly started to find cracks as the Appalachian Mountains eroded, lessening crustal thickness.

  • @grindupBaker

    @grindupBaker

    15 күн бұрын

    Wouldn't the lithosphere get in the way a tad of "the crust to be pushed into the Mantle" ?

  • @grindupBaker
    @grindupBaker15 күн бұрын

    I wandered into a Public Lecture either London 1964 or Toronto 1974 and some bloke was lecturing about the moving geomagnetic North Pole with a diagram and I asked him in the end questions where it was going and whether there was a formula or predicted track and he just looked at me "funny" and said it was random and I ran away. Maybe the Tuzo Wilson bloke at Ontario Place Toronto Island Cinesphere 1974 with the Missus & daughter I think, the name's familiar. What's been unclear to me is whether the lithosphere is crust that got plasticized to mush by mantle heat, or is liquid mantle that got plasticized by cooling from nominal 1,300 to nominal 600 degrees. Just realized maybe I could figure that by using 0.085 w/m**2 heat loss for 4.6 billion years, but I'll probably not bother.

  • @warpdriveby

    @warpdriveby

    Күн бұрын

    I can't pretend to know the entire answer to the question at the end, I'm only an interested amateur, I studied neuroscience, but I did soak up all the geology lectures and outings I could get into. The lithosphere's and mantle's plastic behavior under stress, is due to heat, and the pressure found deep in the earth. There's a ton of heating that occurs as a result of radioactive decay in the mantle, not just the core, though the heavier and frequently less stable elements should be concentrated along with Ni and Fe in the inner and outer core. If our current ideas are roughly correct, the top half of the mantle has been almost fully "contaminated" with the remains of subducted old oceanic crust. Another idea is that the old crust falls deep into the mantle and gets piled up into lumps, as an attempt to account for the south Atlantic geomagnetic anomaly. I'm not sure they'd need to be exclusive, but they may not be the best information we end up having either so it's hard to say how much "one became the other" to kind of paraphrase your question. It's certainly possible their state today results from lighter crust being recycled back in? Interesting idea. The simpler part is that materials you know well and are predictable at "normal" temperatures and pressures (0-100c and .5-3 Atmospheres) behave very strangely at 4000c and many many tons per in². In experiments, ceramics can be made hard as steel, or if you can believe it, flexible. Glass as well, I'm sure you've seen new flexible glass displays? I don't think they need such extremes now to make them, but geological information certainly aided in the development of it. That's the bit I know.

  • @davidwilkie9551
    @davidwilkie95513 күн бұрын

    "Precision is not Accuracy", so Observable Precision is not necessarily an accurately described explanation when it's "not even wrong" relative-timingat all scales and distance distribution holography-quantization simultaneously. Why should it be? Superimposed QM-TIME Chemistry bonding probability is complicated and messy superposition, as is inadvertently shown by this video of crustal ages and supposition. Interesting geological surveys.

  • @dancingnature
    @dancingnature3 күн бұрын

    There’s some weird statements in the comments . Creationist fantasy explanations and former but now refuted scientific theories

  • @ossiedunstan4419
    @ossiedunstan44192 күн бұрын

    Never explained how north American Pangea fossils are found in Tasmania

  • @amantedar123
    @amantedar1232 күн бұрын

    It always occured to me that Pangea looks like a perfect circle. I do not know why nobody else made this connection. Remember we are seeing these maps on a flat surface not on a globe. Some maps show the round shape more than others. One has to add another continent near where the Tethys sea is depicted. As to why this is so I have no idea. Maybe it may have formed when the moon separated from the Earth leaving a bulge, like when you separate a piece of dough from a larger piece.

  • @dennissalisbury496
    @dennissalisbury496Ай бұрын

    The Expanding Earth Theory and Abiotic Oil must be considered to understand Plate Techtonics. What is the proof that Earth has always been the same size?

  • @Anatoly-Cherep

    @Anatoly-Cherep

    Ай бұрын

    The Earth is definitely expanding. The "plate tectonics theory" is a poor fantasy. The continents do not occasionally float or drift. In fact, the continents move apart forever after the break of Pangea about 160-170 mln years ago. To know the truth, two global programs should be carried out on a planetary basis: 1) accurate and adequate measurements of the Earth size; 2) accurate measurements of the gravity acceleration. And we will know the proper answer in ten years or so!

  • @grindupBaker

    @grindupBaker

    15 күн бұрын

    Absolutely ! Abiotic Oil must be considered for pretty much everything, including hair styling, because of the huge money & taxes involved. Huge factors in Earth's lithocrusty movements. Always Remember "It's not you ! It's not CO2 ! It's the Sun !" or if you're into some popular Religion then "It's not you ! It's not CO2 ! It's the Sin !". Top-notch physical science.

  • @GhostScout42

    @GhostScout42

    3 күн бұрын

    it was not always the same size. we lost a considerabe amount of mass and water to space during the flood. and fossil fuels are definitley real, but theres oceans of oil in our solar system not on earth, so there is obviously an abiotic component to it as well. Hydroplate theory explains our world much better than uniformitarianism and traditional plate tectonics. I think its crazy we base our worldview off uneducated 1800s peoples theorys

  • @GhostScout42

    @GhostScout42

    3 күн бұрын

    @@grindupBaker i wonder if people in the medieval warm period or little ice age blamed sin or c02? its crazy what peoples religions will make you think, though i freely admit i believe in catastrophism over uniformitarianism remember all the fear mongering in the early 2000s, how miami would be gone now? well, even before then in the 70s, all the fear mongering was for the next iceage. the more things change the more they stay the same

  • @standingbear998
    @standingbear99815 күн бұрын

    just a theory

  • @grindupBaker

    @grindupBaker

    15 күн бұрын

    So similar to reality. Perhaps it doesn't exist. There's only a bunch of "Lines of Evidence" that anything exists. I dunno the evidence for Earth's age 4.64 billion years and not interested enough to study that for no audience, but if volcanic activity, the Earth interior stuff farting & flowing out, averaged for 4.64 billion years what it has the last few thousand years then obviously the stuff farting & flowing out of volcanoes has totalled a layer of volcanic material covering Earth averaging 1.4 billion millimetres thick, which is 1,400 km thick of sedimentary layers laid down over Earth's life but the crust sedimentary layers are a lot thinner than 1,400 km so either the surface is somehow getting shoved back inside where it all came from or the sedimentary layers are melting on the underside (or both) and those are the only 2 possibilities.

  • @Anatoly-Cherep

    @Anatoly-Cherep

    14 күн бұрын

    If you mean "plate tectonics", it's not a theory. It's a poor fantasy. Meanwhile the Earth is expanding. And its mass is growing also.

  • @danieljayfrank7276
    @danieljayfrank72766 күн бұрын

    Thesis: If you look at the division of Pangea into the different continents, we think from the perspective of our solar system, in which all planets are held in gravitational orbits, which existed around 100 million ago. Years ago there was an event that briefly decoupled the Earth from these attractive forces for...reasons, the Earth rotated around itself at high speed, so the lava detached itself from viscous continents, later the Earth oscillated back into its orbit and the rapid rotation stopped, then, due to this massive braking, South America slid onto North America, so the Andes mountains were formed, Antarctica also stuck to South America with its viscous mass, due to the impact, South America folded apart from North America! You should make a visual animation about centrifugal forces that set the planet with viscous mass in the form of Pangea in rotation and slow down when it collides with each other and then separates again and unfolds! Since this event the continent and our poles have been moving steadily!

  • @pgypg
    @pgypgАй бұрын

    An asteroid with a diameter of approximately 300 km to 500 km falls in the Democratic Republic of Congo and collides with Earth! The asteroid falls at an angle of 48 degrees and passes through the Earth. As it passes through the Earth's mantle, two donut mantle convection currents occur. One is an underwater mountain range (rift valley, ridge) that extends from the Indian Ocean to the Atlantic Ocean. The second is the Pacific submarine mountain range (oceanic ridge, rift valley). Donut mantle rises due to heat! So, when it meets the crust, the crust separates. The remaining submarine mountains (rift valleys) are caused by two donut mantle convections following the Himalayan asteroid impact. In other words, the asteroid fell into the sea east of South Africa (now Tanzania). As it pierced the Earth and passed through the Ural Mountains, two donut mantle convection currents occurred. The angle fell at an angle. The first donut mantle convection created underwater landforms from the Australian South Sea, underwater rift valleys (undersea mountain ranges), and from the Philippine Sea to New Zealand. The second donut mantle convection gave rise to Arctic ocean ridges and rift valleys. In other words, two giant asteroids will fall and the continent will split (split)! Other large asteroid impacts have pulled or stretched convection currents in the otherwise circular donut mantle, causing the African continent to become uncircular! For reference, the primary vortex (donut mantle convection) of the asteroid that fell in the Democratic Republic of Congo, Africa, was cut off by the asteroid impact in the Himalayas. The tip of the cut donut mantle rose to become the island of Iceland.

  • @grindupBaker

    @grindupBaker

    Ай бұрын

    "passes through the Earth|" Does it leave a bigger hole on exit after going through both cores and mantle twice ? Same as a bullet exit wound ? Did it damage the asteroid at all passing through Earth's mantle, through the core, through the core, through the core, and through Earth's mantle ?

  • @pgypg

    @pgypg

    Ай бұрын

    @@grindupBaker If the asteroid is about 100 kilometers in diameter, it has a core of its own. That's why doughnut mantle convection occurs twice. Once as the outer shell is shed, and twice as the core travels through the mantle! The Democratic Republic of Congo asteroid impacted Earth at an inclination of about 48 degrees. So it didn't hit the Earth's outer core!

  • @liamhickey359

    @liamhickey359

    27 күн бұрын

    Where did you get this from.

  • @grindupBaker

    @grindupBaker

    15 күн бұрын

    @@pgypg At inclination of 48 degrees it would pass through outer core unless it was turned by ploughing through 3,000 km of mantle. Is that what your scientific reference indicates ? How far from the penetration wound was the exit wound as the sphere of approximately 500 km diameter "passes through the Earth's mantle".? What does your published geologic analysis indicate ?

  • @GhostScout42

    @GhostScout42

    3 күн бұрын

    we know now from NASA's DART mission that asteroids are a collection of ice and loose rubble (creationists predicted this) they also say the mid oceanic ridge was created when the water under the continents burst forth, it was created in one go, thats why it circumnavigates the earth and meets itself what you are not considering in your statement is magma crossover depth. at a certain depth magma sinks because it compresses more than solid rock around it.

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