The Tortured History of Earth's Oldest Rocks w/Jesse & Chris from PlanetGEO! (PT 1)

Check out their YouTube channel @planetgeopodcast !

Video Chapters:
0:00 Oldest Rocks on Earth!
0:21 Planet GEO Podcast!
2:22 Why Do We Care?
7:01 Our Oldest Rocks
9:10 Why is Earth Older Than its Rocks?
12:32 Where & What Are The Oldest Rocks on Earth?
17:17 How Do Zircon Grains ‘Escape’ Metamorphism?
24:41 How to Account For Initial Daughter Isotope
28:12 C Dating Misconceptions
29:45 Zircon Grains w/Multiple Ages
32:42 What These Rocks Tell Us About Ancient Earth

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[Meatwad]

I don't know how the algorithm guided me to this video and channel, but it's rekindling that love of geology from college!

[wadehines]

Nerd tidbit. Long ago (80s) I worked in a mass spectrometry lab that had a special solid one-piece hammer that had been used to smash up moon rocks. It was special because it was machined out of a special no-carbon steel so that it could not contaminate the moon rocks with carbon. It was just randomly kept in a tool chest at that point. Looking back, and knowing it has likely been lost/discarded, I kinda wish I had "collected" it for my grandkids.

[Grumpyoldman]

Why do we want to know about earths oldest rocks? In all of your conversations, you overlooked one important reason: its fun! Keep up the great work, Geo!

[r.kellycoker]

My inner nerd enjoyed this whole podcast. All of you are so interesting to listen to. Kudos to all of you!

[barbaradurfee]

I smiled all the way through this conversation, so fresh and interesting. Thanks to all three of you!

[joecanales]

Thanks Rachel, great conversation. It makes it seem my college days were in the dark ages. Glad to be expanding my interests with such wonderful teachers. Thanks!

[robinredbeard]

I would argue that there is no other reason needed to study the Earth (or anything) than because humans are curious and discovery enriches our lives in uncountable and often in yet to be know ways. Yes, if funding is coming from a source that wants to commodify information, you have to give them a reason. But so much basic understanding of our universe comes form someone asking, "'what's that?", "What's over there?", "What causes that?", "How does that work" and other questions of curiosity.

[bernard]

That Acasta was a really gneiss present. You guys are so nerdy - it's very cool 🙂

[erikziak]

24:25 100% agree. It is a marvel of our understanding of nature, that we, collectively, can do this. Many fields of science came together to make this possible. We should be humble and grateful for all the work our predecessors made. All those discoveries, and yet still so many for us to find.

[pocketlama]

I had a massive blind spot to the number of different ways y'all find the ages of rocks. This helped me see some things in a much clearer way. Thank you, I'm looking forward to part two.

[neotericrecreant]

These are some of the most intuitive explanations I've seen on these subjects.

[nicospeaksintongues]

the vibes in this video are immaculate + the info is helpful for someone who has no understanding of geology

[Zeldafan]

It still blows my mind that the ground you stand on every day is unfathomably old. Even "Recent" sedimentary rock is older than the existence of human civilization. You can pick up any rock of granite or basalt and imagine just how much that it's gone through, from the steady rise of mountains to the flooding of oceans and countless thousands of different species emerging and disappearing while it just sits still, idling the time away until a person can walk up to it so it can be admired. Mind Blowing!

[MT-urdp]

Great to see the connection being made to planet formation. I come from the astronomy side btw.

[VoIcanoman]

Fascinating discussion. I hope that, in addition to the part 2 upcoming, you keep on this particular road and discuss the Nuvvuagittuq rocks in greater depth, covering how they're different than the other kinds of extremely old rocks in the world, how they are dated differently (due to their inconvenient lack of zircons, a fact shared by most mafic rocks on Earth), and why their status as the potential "oldest rocks in the world" is debated to this day. Maybe you could even get Dr. Jonathan O'Neil to come on as a guest; thanks to his team's groundbreaking work (which started with his PhD research, and continues still, at least as far as I'm aware), we now know that there could be a new oldest rock in the world. And since he made one of the boldest claims the geological community has seen in the 21st century, scientists from all over the world have been busily working in a VERY isolated part of Québec to study these rocks and perhaps find evidence disproving their "oldest" provenance...or find additional evidence confirming that they're exactly as old as claimed by O'Neil.

Before this work was conducted, the rocks at Nuvvuagittuq were known to be pretty old - at least 3.8 billion years old based on infiltrated magma bodies that bisect the greenstone, which DO have zircons for scientists to study (which sounds old - and it is - but as a rock-loving kid in Canada, I routinely collected and played on and around granitic rocks in the 2.8-3.2 billion year old range...so 3.8 is impressive, but not THAT impressive). But there's a fascinating debate now about neodymium-142, and whether it is native to those rocks (having decayed from samarium-146 in situ), or was incorporated into them at a later date. And the discussion could even proceed beyond that debate, to the insane possibilities that open up if we truly have HADEAN oceanic crust that is accessible for scientific study. It may even be possible to prove that plate tectonics started earlier than we believe right now, or to find evidence old life forms within these rocks. But most importantly, such a discussion would shed light on how science progresses. Because regardless of whether Acasta, or Nuvvuagittuq, or even some other rock entirely, is the oldest in the world, research like this has significantly improved isotopic methods of dating rocks, which will help geologists better characterize rocks from all over the world, not just northern Canada.

[Bones_and_Stones]

I have been interested in geology and rocks for a long time. Both Planet Geo podcast and Geo Girl videos are treasured resources for introducing and gently explaining complex aspects of geology to people without a science background.
Migmatite and gneiss of Lower Silesia Sudety mountains (Poland) were the first rocks that got me intrigued as a child with their wild patterns. It's great to find out more about those tortured creations!

[IanBourneMusic]

They sent you an old rock. That's adorable.

[barbaradurfee]

Thanks! Take Tyler & Suki out for a treat

[magictrades]

Love geochronology and Archaean age or older geology. This was one of my favourite topics in my undergrad geology degree so love to see this on your channel

[rickmoore]

Fantastic! Such a great discussion. As a layperson I feel like I'm getting bathed in important knowledge. Eye opening stuff for me.