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Really nice breakdown of the history and development of research into supercontinents.

Like the enthusiasm, but, as a writer, I'm bothered by the "uhms." Even my level, undergrad lib arts, we rid ourselves of those before graduating.

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Very interesting!

so glad i found these seminars on this channel! especially this one. thank you for posting and please please keep them all up!

That’s awesome! It’d be cool to find evidence of sponges earlier than Otavia

l love your work and I love this channel. Please keep posting. Vox loco et solo clamantis est in deserto. The comparison of the Superior circular structures to those on Venus seems to imply (perhaps unintentionally) the notion of stagnant lid processes for Earth in the late Archaean. I believe we were way past stagnant lid at the time of these events (2.73 Ga). My own sense is that if we ever had stagnant lid, it was Hadean and it is ALL gone. The Acasta Gneiss might be trying to tell us any such regime ended quite early. Even Pilbara doesn't seem to fit my notion of stagnant lid. I instinctively view Stagnant Lid to imply horizontally "stagnant mantle", characterized by vertical pinpoint plume motions with attendant smaller scale lateral displacements to accommodate the rising plume material. The Venusian domes are then just igneous blobs formed at the surface by plume burps. (That's if we can conclusively rule out their origin as bolide punctures.) They erupted onto some crust about which I know nothing, but they don't appear to be foundering. Might be that crust is thick. Venus' mantle could be monominerallic for all I know. In that (unlikely) scenario, magma and source rock are the same composition; density differences arise only from temperature and pressure, not fractional melting and crystallization. That would make for a lot less action. I don't care who you are, that's funny. What we're seeing in the granite/greenstone terranes is straight up lava lamp action generated without hemispherical scale lateral motions of the mantle. Hans Ramberg had it all back in '67. The lava lamp model obviously needs to be extended to incorporate polyphasic rocks subject to repeated episodes of partial melting, melt extraction, and large scale chemical differentiation in addition to diapiric rise and cold foundering. Rocks from this era are commonly highly deformed by what appear to horizontal forces, and if not plate tectonics, then what? Tectonics done it alright, just not "plate" tectonics. Perhaps most of what we argue about could be simply settled by allowing for small plates. Early cratons might have had no connection to their adjoining oceanic slabs, instead just pushing them around and possibly forcing them under the cratons (underplating) instead of descending into the mantle slab graveyard. Oh, BTW, if anyone can tell me how the craton is attached to the plate at its edge, I'm all ears. How does slab pull drag a craton around? Bob? Kent? Watch video of slag circulation on molten metal, and see how it changes over time if the charge is allowed to cool in the crucible. Tectonics in real time, baby! I think we're looking at a phase between a presumed stagnant lid and modern Paleozoic-style tectonics. We need a name for this regime: I'll suggest we call it the "Rambergian Phase". It pretty much corresponds to the Archaean. All of the data you've presented, (which by the way is great, great work) coupled with everything else we know seem to indicate a vigourously convecting mantle, but with a stronger vertical component relative to the horizontal. All I'm getting at is that the Venus comparison is kinda tenuous. Sorry. Now for the real fun. The graphic of the plume ponding under the SCLM and then working its way upward along the upward tapered bottom of the SCLM had me jumping! If I was a plume, that's exactly what I would do. I can never figure out if the igneous rocks we see are the plume material itself or SCLM melts produced by the plume heat. Either way I believe they behave and rise in the same manner: Plume causes rifted margin; rifted margin is multiply intruded along the normal faults by gabbroic magmas. But, importantly, a rifted margin is not a simple hard break. The edge of a rifted craton is a broken mess of fault blocks often extending hundreds of kilometers across strike. There's plenty of room for complexity as to where the intrusions will emplace. Your description of the plume material rising under the cratonic edge is how I picture the anorthosites formed, particularly the Grenville series. Thus the Anorthosite line is a rough approximation of the cratonic edge location after it was rifted apart. My best guess is that most of what we see in these mafic intrusions are melts derived from the SCLM and not the rising plume material itself. I wonder if HREE depletion in OPX could inform us on that question. I also guess that at the depth of the craton here, 75 through about 25 kilometers, plagioclase floats. After it rises to shallow emplacement depths it becomes mildly negatively bouyant and sinks. What neither I nor anyone else can explain is why Anorthosites (massif-type) are confined to the late Proterozoic. Best guess is that the phenomenon of plumes rising under the edge of a craton has been going on since cratons first went into business for themselves, but the petrological manifestation has evolved over time. First it's them damn greenstones, then it's your garden variety ultramafics, and then for a very short window, Anorthosites. All corresponding to gradual earth cooling and thickening of the lithosphere. Happy.

Still fascinating

I find it hilarious that a distinguished scientist, who searches the globe for biological truth, feels compelled to play along with the latest social psychosis de jour by feeling it necessary to announce that he's a "he/him". Too funny.

Thank you for a very interesting presentation. I am in my 70's but a beginner in Geology, so although my questions are roughly about silica and maybe 'off topic' (and seem very basic) I would value a knowledgable reply based on accepted uptodate papers etc. Questions At what time during the Hadean? would we start to see sand appearing? My understanding is that rocks need time and erosion to break down crust via weather/climate/wind? to silica forms like sand. Or is there any other reason ? e.g. is the early bombardment also depositing a water buildup and the cause or increase of erosion . I guess I am also curious about why today there's not red seas from the huge amounts of early pyrite, and not what i see today a sedimentary sand in the oceans often pale or yellow.. Sorry about my ignorance but I would value you straightening me out. Thanks

"You don't need to compete with your neighbours if you're sharing resources", in other words, Karl Marx was right.

Is there a systematic bias againat the preservation of shallow-water ecosystems of "Avalon" age? Do you think there was there a genuine absence of "White Sea"-type animals living in shallow water during that time, or do you expect that the faunas overlapped with each other?

Another winner!

almost no rail road on some big island Sir

"Promo sm" 😌

Booyah! I'm the Duce, love fresh brain nutrition.

Great data presentation and volume of data as well.......Just not really strong enough to connect the dots. Serious. Am disappointed at weakness when conclusions are attempted to be made.

Excellent.

Always fascinating and thought provoking to listen to Teras.

And I thought I was not interested in sedimentology..... Haha. Great talk!

I have an example from the gasconade formation in dent county Missouri. It has several types of tubes, some plated some not. There's also a silica gastropod or two. And quartz replacement of soft tissue.

Truly enjoyed this lecture. Thank you for all the work you do illuminating the Ediacaran, a particularly fascinating and underappreciated period of Earth's biological history.

I have found a few specimens of charnia in cherty flint from the thames foreshore in london,maybe they would be interesting to you.all english flint is Cambrian or is that now rong?

From an amateur eye, I think you are looking at the results of the Frankenstein progression. For billions of years there wasn't oxygen and single cell organisms could clone and prosper. The accumulation of oxygen became toxic to them, and through cloning they passed on the oxygen deformation to the clones decreasing the clones life span. Which is why sexual reproduction evolved through cells splitting only half their code and requiring a second partial code from another in order to break the oxygen deformation inheritance. Anyways there's banded iron formations from several events prior and throughout the time you are looking at. The constant fluctuating oxygen levels and the struggle for evolution to adapt in altering conditions left it grasping at every direction and likely some blue prints just didn't last. You should consider volcanism, hydrothermal vents and meteor impacts as a combination of environmental services influences and failed biological attempts to adjust. You can't have worms with no mouths or buttholes surviving through energy created by ancient bacteria inside them without major influences on a variety of magnitudes. Scientist need to broaden their time focus and understand geologic time in ancient history is all relevant to any particular time period. There wouldn't be a tsunami recorded in the early Cambrian bonneterre formation of Missouri if there wasn't geologic driving forces involved. Earth's evolution and life's evolution are hand and hand. Y'all have proven that much. There was a great struggle when oxygen formed in the water and the over oxygenated material of the ocean occured before the atmosphere. Everything had to overcome that and when it did, it had it's oxygen stripped away.. repeat that a few times while trying to recode and evolve. The answers are out there. And everything is evidence. Cold, hot, oxygen fluctuations, continental formations, ancient bacteria from asteroid impacts deep in oceanic crust mixing with evolved bacterias in the sub sedimentary ocean layers, it's endless. Great start to piling evidence and pushing for more answers ❤❤❤

Can please someone explain why Eu and Ce anomalies of seawater are recorded in carbonates and Fe-Mn BIFs? Shouldn't they be opposite? If you could redirect me to some resource it will be highly appreciated

There's a tsunami in the rock record above the great unconformity in Missouri. I think much is lost in the understanding of the Ozarks, prior to the Ouachita. Personal I think this part of the key to figuring more details. I also believe there was hydrothermal activity, ancient volcanism, shoreline rifting etc. Stories of part of Texas and Oklahoma trying to rift apart, and failing like the older rifting in the great lakes

Really an amazing video. Thanks to all involved!

Hello Mitchell, thank you for sharing your deep knowledge.

Do you what was Charnia's life span? Was it due to viruses and/or pathogens? Thanks! Samuel Varela.

Great work and very well explained! Thanks!

Thank you for sharing this knowledge, Professor Moyen! I am a great admirer of your work

Great discussion!

nice group management Alex!

Wow! Great presentation! Where can I read more about the Great Dike?

Paul Hoffman was a REAL CHARACTER, it's too bad we didn't record more of his lectures

Could it be any oxygen produce was used by aerobic microbes? Just curious.

i am so amazed by this presentation! thank you for your organization! do you think cap carbonate could be a result of microbial activity as well?

Fabulous overview by a leading modeler in the field.

Excellent lecture! Thank you!

The viewers may be interested in a model I have published for the emergence of siphonophores during evolution. The zooids would have emerged during the Late-Proterozoic Snowball Earths, when they would have lived on heat (not food nor light!): i.e., while the oceans were covered by ice the zooids would have lived on primary production based on the thermal gradients above submarine hydrothermal vents. Higher metazoan animals would have descended from the siphonophores after the Snowball Earths ended and the colonies could live on food resulting from primary production by the reemerged sunlight. 1. ISSOL 2008 conference. Poster: DOI: 10.13140/RG.2.2.33734.01609 2. June 2009 Publication Animal emergence during Snowball Earths by thermosynthesis in submarine hydrothermal vents Nature Precedings 4 DOI: 10.1038/npre.2009.3333.2 3. February 2012 Book chapter Life Explained by Heat Engines

To the guys question about predation: could have been that bilaterian predation pushed the ediacarans into areas of sea with less oxygen that the predators couldn't enter? I feel that is where he was trying to go. For example, you have filter feeding predators like Auroralumina attenboroughii that have poor preservation and representation. The could have been eating all the baby vendobiotes.

I still use information circular 14.

Laurentia as the geological key to open the box of exciting new discoveries and better understanding of deep time continents vagaries.

Friggin dope, thank you. Enhanced my geo knowledge ten fold!!!

How could life in shallow water and in terrestrial settings in the archean thrived when there was no ozone layer to absorbs ultraviolet light from the sun?

This is groundbreaking. I can't get enough of this ediacaran knowledge. Hoping they get even more details about this mysterious time

So rare in that field that such beautiful lady give a lecture. I love the informative content!

good morning all!!

*FARHAT*

Interesting. NOTE PROPAGANDA COMMENT BY GOOGLE-RUclips ON ANTHROPOGENIC FRAUD "CLIMATE CHANGE "