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Meteors+Dinosaurs+Geology = Extinction! · PlanetGeo: The Geology Podcast

• 0:03
  SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:14
  SPEAKER_01: Welcome to season two of Planet Geo.
• 0:17
  SPEAKER_01: We've been going for about a year and a half now, so you know it's not quite season two, but we're calling it that.
• 0:22
  SPEAKER_01: So whatever.
• 0:23
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• 0:30
  SPEAKER_01: If you know anything about search algorithms, you know that those reviews and five-star ratings are the best way to help us out.
• 0:36
  SPEAKER_01: Also, Chris and I recorded this episode that you're about to hear while sitting together in the same room over holiday break.
• 0:42
  SPEAKER_01: So the audio isn't necessarily as clean as we normally like to have, but hey, we needed some FaceTime together.
• 0:47
  SPEAKER_01: Hope you enjoy the episode.
• 0:49
  SPEAKER_01: Please reach out with any questions, all the social medias at Planet Geocast and send us an email, planetgeocast at gmail.com.
• 0:56
  SPEAKER_01: Enjoy.
• 1:04
  SPEAKER_00: Amazing chapstick holders.
• 1:06
  SPEAKER_00: We've got I got ideas.
• 1:08
  SPEAKER_01: You you got ideas about stuff.
• 1:10
  SPEAKER_00: I got ideas.
• 1:10
  SPEAKER_00: Cheers, man.
• 1:11
  SPEAKER_01: Cheers, man.
• 1:12
  SPEAKER_01: Cheers.
• 1:12
  SPEAKER_00: Are we recording right now?
• 1:13
  SPEAKER_01: We're recording.
• 1:14
  SPEAKER_01: We're live.
• 1:14
  SPEAKER_01: All right.
• 1:14
  SPEAKER_01: We're live.
• 1:15
  SPEAKER_01: Okay.
• 1:17
  SPEAKER_01: Okay.
• 1:18
  SPEAKER_01: So this is a this is a Chris Bolis led episode.
• 1:20
  SPEAKER_01: What are we doing, Chris?
• 1:22
  SPEAKER_00: Uh well, we're gonna talk about the end of the Cretaceous mass extinction event and the story that leads up to like how this was all put together.
• 1:31
  SPEAKER_00: It's such a cool story.
• 1:33
  SPEAKER_01: So you you know, you pitched this to me like many of our episodes.
• 1:35
  SPEAKER_01: You pitched it to me.
• 1:36
  SPEAKER_01: I was, you know, a little suspicious at first, maybe.
• 1:39
  SPEAKER_01: You have it in Hawed for sure.
• 1:41
  SPEAKER_01: But but we came down to something pretty cool, I think.
• 1:43
  SPEAKER_01: I think so, yeah.
• 1:44
  SPEAKER_01: So where are we going?
• 1:44
  SPEAKER_01: Like, can you give us the sort of outline, high-level outline of where we're going today?
• 1:48
  SPEAKER_00: Yeah.
• 1:48
  SPEAKER_00: So we're gonna just begin by talking a little bit about what a mass extinction is, and you have some things to say about that, and then we're gonna talk about the like, and to me, this is like the meat of the story is the discovery process.
• 1:59
  SPEAKER_00: Yeah, how all of this was put together from many different people all over the world, and it's just a cool story.
• 2:07
  SPEAKER_00: And then we're gonna wrap things up by talking about there's a a little bit of a debate, or at least there was a debate that was going on, not so much anymore.
• 2:15
  SPEAKER_00: Totally, and again, you have some some things to to bring to the table on that, and then we're gonna really wrap it up by this uh this paper that came out in 2019, or was it 2015?
• 2:25
  SPEAKER_01: Uh, it was a series of things, but yeah, 2019 was the first peer-reviewed publication, and there's been some since, yeah.
• 2:31
  SPEAKER_00: And just some really interesting things that came about that kind of play into this story.
• 2:36
  SPEAKER_01: Totally.
• 2:37
  SPEAKER_01: It kind of shows, you know, where really cool, very sort of rare fossil records are really important.
• 2:43
  SPEAKER_00: Right.
• 2:43
  SPEAKER_00: Yep.
• 2:44
  SPEAKER_01: So let's start with the N Cretaceous, like the in what a mass extinction really kind of is.
• 2:50
  SPEAKER_01: We're talking about a time period around about 65, 66 million years ago, and this is kind of the end of dinosaurs, right?
• 2:56
  SPEAKER_01: Right.
• 2:56
  SPEAKER_01: But let's kind of put that into context a little bit.
• 2:58
  SPEAKER_01: What is a mass extinction, I guess?
• 3:01
  SPEAKER_00: Well, this was when anywhere from 60 to 80 percent of life on our planet died up, and it died out rather quickly.
• 3:09
  SPEAKER_00: That is the well, that's the that's the most recent mass extinction event.
• 3:14
  SPEAKER_01: Sure.
• 3:14
  SPEAKER_00: Correct.
• 3:15
  SPEAKER_01: Yeah, for sure.
• 3:15
  SPEAKER_01: And this and this was a um, you know, a major shift in the sort of life story of Earth, which is, you know, for the last, I don't know, 650, 560 million years, which we call the Phanerozoic time period, the most recent like fifth of Earth history, is kind of broken up into three chunks.
• 3:33
  SPEAKER_01: The Paleozoic, the Mesozoic, and the Cenozoic.
• 3:36
  SPEAKER_01: And those are kind of defined by the life forms on Earth in that time period.
• 3:41
  SPEAKER_02: Right.
• 3:42
  SPEAKER_01: And so this dinosaur sort of dominated area um of of Earth history is kind of the Mesozoic.
• 3:49
  SPEAKER_01: Well, you know, that's the broad generalization, but reptiles sort of the reptiles.
• 3:55
  SPEAKER_01: The age of the reptiles, this Mesozoic, about 250 million years ago to about 65 million years ago.
• 4:00
  SPEAKER_00: Let's go back, because really, in this this since the Pre-Cambrian time period of the Earth, you have the Cambrian, which is broken up into three time periods.
• 4:10
  SPEAKER_00: Right.
• 4:10
  SPEAKER_00: The Paleozoic, the Mesozoic, and the Cenozoic.
• 4:13
  SPEAKER_00: And they're really the the div the divisions are based upon the life that predominated on the planet.
• 4:20
  SPEAKER_00: So the Paleozoic, that was early life, and most of it was marine life.
• 4:25
  SPEAKER_00: Then you have the Mesozoic, which is the age of the reptiles or the age of the dinosaurs, it's often referred to.
• 4:30
  SPEAKER_00: And then the at the end of that, the end of the Mesozoic, that's what we're talking about, was this time period called the Cretaceous.
• 4:38
  SPEAKER_00: And so we're going to be talking about the Cretaceous mass extinction event.
• 4:42
  SPEAKER_00: Anyway, when the dinosaurs died out, that gave way to the Cenozoic time period, which is the age of the mammals.
• 4:50
  SPEAKER_01: That's right.
• 4:51
  SPEAKER_01: And when we say the sort of life, we mean multicellular life, complex multicellular life, which came about around 560, 580 million years ago, sometime around then.
• 5:00
  SPEAKER_01: There was life on Earth before that, but it was uh sort of relatively simple.
• 5:04
  SPEAKER_01: So, yes, we're talking about this transition between when dinosaurs existed and then when mammals became the sort of main life form that dominated many of the biomes on Earth, the terrestrial biomes.
• 5:15
  SPEAKER_01: So now we're gonna get into this sort of scientific story, right, Chris?
• 5:18
  SPEAKER_01: And you know, warning to the listener.
• 5:23
  SPEAKER_01: This is a Chris Bullheis storytelling.
• 5:26
  SPEAKER_01: This might get a little bit old man ranty.
• 5:29
  SPEAKER_01: We'll try and rein them in.
• 5:30
  SPEAKER_01: We'll try and rein them in a little bit here.
• 5:32
  SPEAKER_00: Part of me dies every time we say that.
• 5:35
  SPEAKER_01: It's a good story.
• 5:36
  SPEAKER_01: It's a good story.
• 5:37
  SPEAKER_01: Uh, you know, just try and stay awake.
• 5:39
  SPEAKER_00: Oh, come on.
• 5:41
  SPEAKER_01: So before we get into it, you are Chris Bullheis, nationally recognized earth science teacher, my former high school teacher.
• 5:46
  SPEAKER_01: You taught me intro to geology, intro to earth science, field geology, a whole bunch of stuff.
• 5:51
  SPEAKER_01: You've taught generations of uh of high schoolers the basic principles of geology and stuff like this.
• 5:56
  SPEAKER_00: I don't know about generations, but anyway.
• 5:59
  SPEAKER_00: Oh well, well, well, multiple, four generations deep, probably.
• 6:02
  SPEAKER_00: Four, okay.
• 6:03
  SPEAKER_00: All right.
• 6:03
  SPEAKER_00: Well, anyway, you are Dr.
• 6:04
  SPEAKER_00: Jesse Rymanck.
• 6:05
  SPEAKER_00: As you said, one of my former students.
• 6:07
  SPEAKER_00: You went on to get your PhD in geoscience, and now you're a professor of geoscience at Penn State University.
• 6:12
  SPEAKER_00: And we are coming to you in person.
• 6:15
  SPEAKER_01: In person, we're sitting across from each other.
• 6:17
  SPEAKER_01: Yeah, this is fun, not over Zoom.
• 6:18
  SPEAKER_00: So, yeah, we're stink gear.
• 6:20
  SPEAKER_00: We're not having Zoom beers, we're having actual beers like uh, you know, face to face.
• 6:24
  SPEAKER_00: And so if you do notice anything like a little different with the audio, it's because we are in person, not recording separately.
• 6:31
  SPEAKER_01: Yeah, that's our we're we're sitting across from each other, which is great fun for us.
• 6:35
  SPEAKER_01: All right, this Chris, the story, the lead up, the scientific discovery process, go.
• 6:39
  SPEAKER_00: You can't just say go.
• 6:41
  SPEAKER_00: All right, it's it's not this.
• 6:43
  SPEAKER_01: No, no, no, we've got to have a big lead-in.
• 6:45
  SPEAKER_00: No, not really.
• 6:46
  SPEAKER_00: But this is the meat of what we're doing today.
• 6:50
  SPEAKER_00: To me, anyway, the why we're doing this, the compelling part of it is is how the science was actually all put together.
• 6:58
  SPEAKER_00: So when you say go, I'm just gonna start with like how this whole idea that a meteor from space caused the extinction of the dinosaurs, which led to a pretty hot debate for a long time and has I think rather cooled off.
• 7:15
  SPEAKER_00: And I think I think you'll understand why the debate has cooled off when we're done with today's episode.
• 7:21
  SPEAKER_01: Exactly.
• 7:21
  SPEAKER_01: And this is a kind of an interesting lesson in sort of how the scientific process works on the ground and how debates sometimes get resolved by fantastic discoveries.
• 7:31
  SPEAKER_00: Yeah, I mean, you know, you and I talk about that sometimes with your uh research, you know.
• 7:36
  SPEAKER_00: You you sometimes wonder about, you know, what's what does all this mean?
• 7:41
  SPEAKER_00: You know, I'm gonna devote a major chunk of my career to this.
• 7:44
  SPEAKER_00: And today it really kind of highlights, well, you don't really know what this means, and you don't know really, you don't really know how what you what you come to understand throughout your research is gonna be used by somebody else.
• 7:57
  SPEAKER_00: For sure.
• 7:58
  SPEAKER_00: And today really highlights that.
• 7:59
  SPEAKER_02: Absolutely.
• 8:00
  SPEAKER_00: Okay, so we're gonna start off um by going to the the what this these sedimentary layers in Gubbio, which is this place in Italy.
• 8:09
  SPEAKER_00: Okay, and and what we're talking about is this sequence of limestone strata, okay, limestone layers.
• 8:17
  SPEAKER_00: And in the middle of these limestone layers was this clay layer that uh, well, the guy has a pretty famous last name.
• 8:24
  SPEAKER_00: His last name is Alvarez, okay.
• 8:27
  SPEAKER_00: And so Walter Alvarez was studying this, the limestone, and then eventually, which led to this clay layer that was really interesting in the middle of it.
• 8:36
  SPEAKER_00: And what he found were these vast differences in what are called foramidiferum or forams.
• 8:43
  SPEAKER_01: And these are single-celled, uh, what are they, algae kind of things that live in the ocean, you know, things that live suspended in the water color.
• 8:51
  SPEAKER_00: Yeah, and they also make this shell, okay.
• 8:54
  SPEAKER_00: And the shell is made out of calcium carbonate, which is the building block for the rock limestone.
• 8:58
  SPEAKER_00: So these pretty diverse set of organisms that all had shells were living, and then they would die and they would just settle down onto the bottom of the ocean, forming these limestone layers.
• 9:11
  SPEAKER_00: Okay, and so this is what what Walter Alvarez was studying in Gubbio, Italy.
• 9:17
  SPEAKER_01: So he's looking at these this clay layer, this interesting clay layer in the middle of a big limestone package, and notice that there's differences in the forams, the style of 4Ms, and the the amount of the well, the difference of 4A's above and below this clay layer.
• 9:31
  SPEAKER_01: So something in this clay layer changed the types of 4Ms that were being, well, that were living in the ocean, and then therefore that were falling to the ocean bottom.
• 9:40
  SPEAKER_01: So something happened associated with this clay layer.
• 9:43
  SPEAKER_00: And there was a noticeable difference in the diversity of the forams below this clay layer and above the clay layer.
• 9:50
  SPEAKER_01: That's right.
• 9:51
  SPEAKER_00: A vast difference.
• 9:52
  SPEAKER_00: And so that's kind of where we're gonna start was with that.
• 9:55
  SPEAKER_00: And then at the roughly the same time this was going on, another geologist named Jan Schmidt in Zumaya, Spain, which is this is 1,500 kilometers away from Gubios.
• 10:07
  SPEAKER_00: So this is a long ways away, and that's kind of the point of today, is we're gonna just be bouncing all over the planet, really, in terms of the evidence.
• 10:13
  SPEAKER_00: Um, he was also studying these layers of limestone, and it was it's actually the longest set of continuous strata in the world, and he found the same clay layer.
• 10:25
  SPEAKER_00: Okay, now he didn't know it was the same clay or uh clay layer that Alvarez had discovered, he just he found this clay layer.
• 10:31
  SPEAKER_00: And Smith, Jan Smith, was also studying these forams, and it like everything was consistent.
• 10:38
  SPEAKER_00: The foreams were consistent, the limestone was consistent for over a million years, from the bottom to the top, and that's what we do in geology.
• 10:46
  SPEAKER_00: We always work from the bottom to the top because in sedimentary layers, the bottom is the oldest, and so we're just we're kind of reading a book from beginning to end.
• 10:55
  SPEAKER_01: So when you say the longest set of continuous strata, it means that this is a continuous record of sediment being deposited on the seafloor.
• 11:02
  SPEAKER_01: So we have this time consistent continuous time record in the sediments.
• 11:07
  SPEAKER_01: And so if we look at the foreams in there, what happens on this clay layer here in Spain, Chris?
• 11:12
  SPEAKER_00: Below the clay layer, Jan Smit was studying over four dozen species of foreams.
• 11:19
  SPEAKER_00: Okay, and they were they were big, they were small, and everything in between, they were very diverse in the type of foreams because this is kind of a broad category of organism.
• 11:28
  SPEAKER_00: And then above the clay layer, there were just a few species.
• 11:33
  SPEAKER_00: They were much, much smaller.
• 11:35
  SPEAKER_00: It's really, really noticeable.
• 11:36
  SPEAKER_00: I've seen like video segments of this under the microscope.
• 11:39
  SPEAKER_00: So he did.
• 11:40
  SPEAKER_01: Oh, cool.
• 11:40
  SPEAKER_00: Yeah, so with what he did is under the microscope, he would he separated the forams out of the limestone, and so he puts them all in like this this petri dish and and sticks under a microscope and then just sifts through it with a needle.
• 11:53
  SPEAKER_01: Oh, cool.
• 11:53
  SPEAKER_00: Yeah, and it's amazing what you see below it is just this.
• 11:57
  SPEAKER_00: You can it doesn't take a uh somebody that studies forams for a living to see, wow, that's a diverse set of organisms there.
• 12:04
  SPEAKER_00: And then samples from above it are just strikingly different.
• 12:09
  SPEAKER_00: Okay.
• 12:09
  SPEAKER_00: Again, much smaller and a lot less diverse.
• 12:12
  SPEAKER_01: So you know, the the clay layer becomes kind of interesting, and you know, why is this big difference?
• 12:18
  SPEAKER_01: What's in the clay layer that separates the differences here?
• 12:21
  SPEAKER_01: And so, you know, we have to bring in some chemistry and uh and some potentially astrophysics.
• 12:26
  SPEAKER_01: So this Walter Alvarez brings in his father, who is an expert in astrophysics, and let's look at the clay.
• 12:32
  SPEAKER_01: And in the clay layer, chemically, there is this massive amount or relatively large amount of iridium, which is an element.
• 12:42
  SPEAKER_01: And uh our Geo Short talks about why iridium is unique and why iridium is useful for detecting things like meteorite impacts, but basically it's massively elevated, 30 times the background level in this clay layer compared to all the other surroundings.
• 12:59
  SPEAKER_00: What do you mean?
• 12:59
  SPEAKER_00: What do you mean is when you if you look at the rocks around the clay layer above it and below it and so on, and pretty much anywhere over the planet, it has 30 times less the amount of iridium in it than this clay layer does.
• 13:14
  SPEAKER_00: This clay layer is usually only like a around an inch thick.
• 13:18
  SPEAKER_00: So this is not a a massive, very noticeable layer of rock, you know, at any on any scale.
• 13:26
  SPEAKER_01: Right.
• 13:26
  SPEAKER_01: And there are a couple potential reasons why you might have iridium in something like a clay layer.
• 13:31
  SPEAKER_01: Most of them involve extraterrestrial additions.
• 13:34
  SPEAKER_01: So things outside of our Earth, because all of Earth's iridium, which we talk about in our Geo Short coming up, is is mostly in the core.
• 13:41
  SPEAKER_01: So things like a supernova that you know pushed a lot of uh cosmic rays or c uh particles into Earth could have deposited this.
• 13:49
  SPEAKER_01: Other things like an asteroid um could have done this.
• 13:52
  SPEAKER_01: But with a supernova, you would expect other chemical features to be in there that we could predict, and you don't see things like plutonium-244 that would potentially be present if a supernova deposited this iridium.
• 14:04
  SPEAKER_01: So, you know, something came in and brought material from outside of our planet in and deposited it in this layer.
• 14:12
  SPEAKER_00: Not only that, Louis Alvarez, who's a very famous astrophysicist, he calculated that that was a one chance out of a billion for it to be a supernova explosion that would be that close to our solar system.
• 14:27
  SPEAKER_00: Right.
• 14:27
  SPEAKER_01: So very, very improbable.
• 14:29
  SPEAKER_01: And so you if you calculate how much iridium there is, you can do some rough back of the envelope calculations on what the size you might expect for a meteorite to bring in that amount of iridium.
• 14:42
  SPEAKER_01: So you can kind of calculate, oh, we know there's this concentration of iridium, but what size of meteorite must have brought that in, and you get a fairly large size.
• 14:50
  SPEAKER_00: Okay, but first of all, why would it have been like laid down like that?
• 14:55
  SPEAKER_00: Why why was this assumption made?
• 14:59
  SPEAKER_00: Well, a meteor impact that would be of this magnitude, right, would have sent debris all over the world, and it would have gone into space and it would have enveloped Earth, and then it would have fallen back to Earth.
• 15:11
  SPEAKER_00: And so that's kind of that blanket analogy, right?
• 15:14
  SPEAKER_00: That this would have came down on Earth all over the planet, in the oceans, on the terrestrial land, all over the place, as this relatively uniform blanket.
• 15:25
  SPEAKER_00: Okay, and it formed this clay kind of material that was rich in iridium.
• 15:31
  SPEAKER_00: So that's the blanket kind of analogy.
• 15:33
  SPEAKER_01: Yes, right, right.
• 15:34
  SPEAKER_01: That's how you get from the meteorite into this sort of blanketing, for sure.
• 15:37
  SPEAKER_01: So this, you know, the calculation is is uh something quite large, and uh we should see a very large impact crater because of that, because you need such a massive meteorite to deposit this much iridium in this large expanse of a of a clay layer.
• 15:52
  SPEAKER_01: You know, this would also be theoretically a catastrophic event if a meteorite this large hit Earth, it would have sent material up into space and then it sort of rained back down, shut off photosynthesis, cooled the earth, blocked sunlight, a very traumatic event that would have disturbed Earth's operations and life on Earth, too.
• 16:12
  SPEAKER_00: So you're saying then that based on the concentration of iridium in that little tiny clay layer found all over the planet, he was able to calculate then that the meteor had to be roughly this size, right?
• 16:27
  SPEAKER_00: Is that is that what happened?
• 16:28
  SPEAKER_01: Yes, something on the order of 10 kilometers in diameter, which is as large or larger than Mount Everest, is sort of sort of the mass of things.
• 16:36
  SPEAKER_01: This would make a huge crater, 200 kilometer diameter crater if a a meteorite that size hit Earth somewhere.
• 16:43
  SPEAKER_01: So 66 million years ago, it's a long time ago, but we have a lot of rocks preserved from 66 million years ago.
• 16:50
  SPEAKER_01: We might expect to see this crater somewhere.
• 16:52
  SPEAKER_01: That's a big crater, right?
• 16:53
  SPEAKER_00: Well, I mean, to put it in perspective, too, this would be the amount of energy given off by a meteor this large would be a hundred million nuclear bombs all going off at the same time.
• 17:06
  SPEAKER_00: Massive catastrophe.
• 17:07
  SPEAKER_00: It'd be a bad day to be on Earth.
• 17:09
  SPEAKER_01: Really, really not so fun.
• 17:10
  SPEAKER_00: Yeah.
• 17:11
  SPEAKER_00: Anyway, so you know, Walter Alvarez brings in his dad, right?
• 17:14
  SPEAKER_00: Who's an astrophysicist, not a geologist.
• 17:16
  SPEAKER_00: He comes up with this really kind of revolutionary idea that, hey, maybe a meteor did this, okay, wiped out the dinosaurs.
• 17:25
  SPEAKER_00: This was not a widely accepted thought at the time.
• 17:28
  SPEAKER_00: In fact, I mean it was it was pretty violently or vehemently rejected.
• 17:34
  SPEAKER_00: There's a paper that was, I think it ran in the New York Times.
• 17:38
  SPEAKER_00: It was called The Debate Over Dinosaur Extinction Takes an Unusually Rancorous Turn.
• 17:44
  SPEAKER_00: Okay, this came out.
• 17:46
  SPEAKER_00: I said that right, didn't I?
• 17:47
  SPEAKER_01: Yeah, yeah, no, no, I'm laughing at the use of the word.
• 17:49
  SPEAKER_01: That's very funny.
• 17:50
  SPEAKER_00: This came out early in 1988, and it this the bottom line is that this thought really riled up the geologist of the time because geologists are used to deal with things in millions or tens of millions of years, and and now this this outsider comes in and says, wait a second, the dinosaurs were wiped out in a matter of months to years, not not tens of millions of years.
• 18:12
  SPEAKER_00: So yeah, it didn't go over real well.
• 18:15
  SPEAKER_01: So the the you know, we're trying still trying to find evidence for this thing, and we predict, you know, that there's this massive meteorite that him hits Earth.
• 18:22
  SPEAKER_01: It should produce this massive crater, which given the relative youth of this event, we might be able to find that crater somewhere.
• 18:30
  SPEAKER_01: But well, that'd be kind of hard to miss, wouldn't it?
• 18:32
  SPEAKER_01: You would think so.
• 18:33
  SPEAKER_01: 200 kilometers, that's a that's a big ass crater.
• 18:35
  SPEAKER_00: It is, but also 66 million years is uh in geology, we kind of lose sight of that sometimes, I think.
• 18:43
  SPEAKER_00: We lose sight of how vast that time period really is.
• 18:48
  SPEAKER_01: Right.
• 18:48
  SPEAKER_01: It's it's a very long time period.
• 18:50
  SPEAKER_01: A lot of uh a lot of stuff's happened since then.
• 18:52
  SPEAKER_01: We have continental interiors that are stable for billions of years, but you know, there's a lot of ocean that that thing could have hit, that we could have wiped out the the record of that meteorite impact.
• 19:02
  SPEAKER_01: So the search is kind of on.
• 19:03
  SPEAKER_01: And what they found next was was really interesting and sort of helped validate this impact hypothesis.
• 19:09
  SPEAKER_00: Right.
• 19:10
  SPEAKER_00: I mean, two big things that were pretty consistent is Jan Smit, we talked about him earlier, he found these spheroles.
• 19:18
  SPEAKER_00: And what these are uh from impacts like this, the rock around the impact site gets vaporized and thrown up into the air.
• 19:26
  SPEAKER_00: Okay, so they become streamlined, right?
• 19:28
  SPEAKER_00: They're they're like uh imagine uh a glob of lava ejected from a volcano.
• 19:34
  SPEAKER_00: It's not gonna be blocky and angular, it's gonna be rather teardrop shaped and you know, so or spherical because of the friction and so on.
• 19:41
  SPEAKER_00: So these this vaporized rock gets thrown up into space, some of it goes into orbit, and then it begins to all rain back down.
• 19:49
  SPEAKER_01: It's like hail, except instead of being made of water, it's made of liquid rock.
• 19:53
  SPEAKER_01: So, you know, it's it's hailing little tiny pieces of liquid rock that were vaporized, formed little drops of magma, and then cooled on their way down.
• 20:02
  SPEAKER_00: And then revaporized or re-melted on their way because of the think of a meteor, right?
• 20:08
  SPEAKER_00: Streaking through our atmosphere at at thousands of kilometers per second.
• 20:12
  SPEAKER_00: That's what happened to these, is they were raining back down.
• 20:15
  SPEAKER_00: They upon re-entry, they melted again.
• 20:18
  SPEAKER_00: And so Earth was getting peppered all over the place, all over the globe, from these little tiny globs of molten rock falling from the sky.
• 20:29
  SPEAKER_01: So that's evidence one.
• 20:31
  SPEAKER_01: What's evidence two?
• 20:33
  SPEAKER_00: Yeah, it's something called shocked quartz.
• 20:35
  SPEAKER_00: It's really an important thing.
• 20:37
  SPEAKER_00: So quartz is a land-derived mineral mostly.
• 20:40
  SPEAKER_00: Yeah.
• 20:41
  SPEAKER_00: Okay.
• 20:41
  SPEAKER_00: And so, well, first of all, we need to describe, let's paint a picture for what shocked quartz is.
• 20:46
  SPEAKER_01: Yeah, so it's basically uh, you know, it's if you put something under a lot of pressure, it's gonna crack.
• 20:52
  SPEAKER_01: And if you put a lot of mini, you put minerals, mineral grains, which are usually pretty solid things, and quartz is one that's actually pretty solid.
• 20:59
  SPEAKER_01: Quartz actually likes to flow, it likes to deform plastically, so it kind of likes to flow under high heat and high pressure.
• 21:07
  SPEAKER_01: But if you put quartz under high pressure without the heat, it's going to just kind of fracture, it's going to break, and it's going to form this very diagnostic or very characteristic pattern of shock that it has these parallel bands in it.
• 21:21
  SPEAKER_01: And you can usually see it under a microscope.
• 21:23
  SPEAKER_01: It's more rare to see it in a hand sample.
• 21:26
  SPEAKER_01: So you usually need a microscope to see it.
• 21:27
  SPEAKER_01: But you can see these very characteristic shock features.
• 21:30
  SPEAKER_01: And it's basically you put this under a lot of pressure, it's like a mini earthquake, put it under a lot of pressure, and it deforms slightly in this very planar pattern.
• 21:38
  SPEAKER_01: And a lot of minerals have this shock feature to them.
• 21:42
  SPEAKER_01: A lot of minerals can record this shock deformation to it, but it is diagnostic of a meteorite impact.
• 21:47
  SPEAKER_00: Have you ever seen those vases that you can buy at the store that they're they're made of glass, but they have cracks running all through it?
• 21:55
  SPEAKER_01: Oh, yeah, yeah.
• 21:56
  SPEAKER_01: Yep.
• 21:56
  SPEAKER_00: That's kind of how I envision what shocked quartz looks like.
• 22:00
  SPEAKER_01: Yep, for sure.
• 22:02
  SPEAKER_00: It's still a solid microcrystal, but it's got fractures crisscrossing it all over the place.
• 22:08
  SPEAKER_01: Exactly.
• 22:08
  SPEAKER_01: And very sort of systematic fractures.
• 22:10
  SPEAKER_01: So we find this thing and it's a meteorite impact, and you find shocked quartz in these layers that are these clay layers or these layers around the world that we we we thought were potentially meteorite impacts.
• 22:22
  SPEAKER_01: So there's evidence for a big meteorite impact in the spheroles, the melted vaporized rock bits that drop back down, and the shocked minerals that are in this layer.
• 22:31
  SPEAKER_00: Yeah.
• 22:32
  SPEAKER_00: And um you also we also see these shocked quartz with um test nuclear bomb sites.
• 22:38
  SPEAKER_01: Yeah, and we see these things.
• 22:39
  SPEAKER_01: I I just submitted a paper looking at um shocked looking for shocked minerals.
• 22:43
  SPEAKER_00: Well Dr.
• 22:45
  SPEAKER_00: Rymank just submitted a paper.
• 22:47
  SPEAKER_00: So sit back, grab a beer, and uh you're in okay.
• 22:50
  SPEAKER_00: What was your paper, Dr.
• 22:51
  SPEAKER_00: Ryman?
• 22:52
  SPEAKER_01: We're not gonna get into it because I don't want to say because it's probably gonna get rejected, and then I'll feel bad about it.
• 22:56
  SPEAKER_01: But but uh please let me know.
• 22:58
  SPEAKER_01: We're looking for shocked feet shock features in very old mineral grains to try and look for meteorite impacts a very long time ago.
• 23:04
  SPEAKER_00: Anyway, all of my dogs are clicking around.
• 23:05
  SPEAKER_00: Yeah, you can hear them click, click, click, be, click, click, clack.
• 23:08
  SPEAKER_00: Yeah, hold on.
• 23:09
  SPEAKER_01: Dogs are moving from couch to bed.
• 23:11
  SPEAKER_00: You shouldn't just bring them down here with us.
• 23:12
  SPEAKER_00: They could they would just lay on the floor and go to sleep.
• 23:15
  SPEAKER_00: They might snore.
• 23:16
  SPEAKER_01: Yeah, that they'd be getting a little bit old there.
• 23:18
  SPEAKER_00: Will you please tell me though, if your paper gets rejected?
• 23:21
  SPEAKER_01: Yeah, we'll give you an update in like five or six months.
• 23:23
  SPEAKER_01: That's how long it takes.
• 23:24
  SPEAKER_01: Well, sometimes.
• 23:25
  SPEAKER_00: To reject a paper by Dr.
• 23:26
  SPEAKER_00: Rymink takes five months?
• 23:28
  SPEAKER_01: Well, no, usually it takes a day, so I'm shocked it hasn't happened yet.
• 23:30
  SPEAKER_01: To reject a paper for me.
• 23:32
  SPEAKER_01: But you know, we'll have to get an update.
• 23:35
  SPEAKER_00: This gets peer-reviewed.
• 23:37
  SPEAKER_01: Well, sometimes it doesn't go out to review.
• 23:39
  SPEAKER_00: Sometimes the editors Why are my dogs walking around?
• 23:41
  SPEAKER_00: Because I want to actually I want to get into this, but I want my dogs to they need to lay down.
• 23:45
  SPEAKER_00: I don't know what's got them all excited right now.
• 23:47
  SPEAKER_01: They're very excited.
• 23:48
  SPEAKER_01: All right, they're coming.
• 23:50
  SPEAKER_00: All right, so anyway, like how does the a paper of yours get rejected?
• 23:55
  SPEAKER_01: Well, I mean, a paper could get rejected by the editor saying, Oh, this is not quite right for this journal, or it could go out to review and reviewers don't like various aspects of it, um, and and then the editor makes a decision that says, Well, too many reviewers didn't like it, so it's not going to be accepted.
• 24:12
  SPEAKER_01: Okay.
• 24:13
  SPEAKER_01: Or it can go re go, you know, we could take those reviews and improve the paper and resubmit it, um, and and then that's the path towards potential acceptance.
• 24:22
  SPEAKER_01: So we'll see.
• 24:23
  SPEAKER_01: We'll give an update on this paper later.
• 24:26
  SPEAKER_00: Is that what you're saying?
• 24:26
  SPEAKER_00: Yeah.
• 24:27
  SPEAKER_00: Yeah, exactly.
• 24:28
  SPEAKER_00: It can it can be quite frustrating sometimes.
• 24:30
  SPEAKER_00: I'll keep the uh I'll keep the listeners informed.
• 24:32
  SPEAKER_01: All right, so we're moving on.
• 24:33
  SPEAKER_01: We're we're finding uh uh we're going to Texas now, right, Chris?
• 24:36
  SPEAKER_00: Yep, yeah.
• 24:36
  SPEAKER_00: It's called Texas on the Brazos.
• 24:38
  SPEAKER_00: It's a river, it's a it's a river basin, okay.
• 24:41
  SPEAKER_00: And um, there's this geologist, Alan Hildebrand, um, who did like this, he was pretty important this whole process.
• 24:47
  SPEAKER_00: Um, he was studying this area that was all underwater in this basin 66 million years ago.
• 24:54
  SPEAKER_00: Okay, and it was basically seven million years, which is a long time, okay?
• 25:00
  SPEAKER_00: Yes, seven million years of what he calls boring mud, which I I get it.
• 25:06
  SPEAKER_00: It's shale and and mudstone is not all that like exciting.
• 25:10
  SPEAKER_01: That's a lot of mud.
• 25:11
  SPEAKER_01: Yes, seven million years worth.
• 25:13
  SPEAKER_00: Suddenly, as you work your way through from bottom to top in these mud layers, um, something big happened.
• 25:21
  SPEAKER_00: The mud it showed signs of a big event.
• 25:24
  SPEAKER_00: The mud got ripped up.
• 25:26
  SPEAKER_00: If we studied like a modern day tsunami, it looked like that.
• 25:30
  SPEAKER_00: Okay, where you had this the mud was rolled up.
• 25:34
  SPEAKER_00: Uh, think of like a snow plow going through like wet snow and how it kind of pushes and rolls the snow bank away.
• 25:42
  SPEAKER_01: So, what you're describing is the mud being moved before it turned into a rock, and then now we're looking at the rock that is the result of the mud that got moved and then turned into a rock.
• 25:52
  SPEAKER_01: So we're looking at what's called soft sediment deformation.
• 25:55
  SPEAKER_01: So exactly this is stuff before the rock is actually formed, it's the sediment moving around.
• 25:59
  SPEAKER_00: And you had these huge boulders that were in the middle of this mud, which you know that doesn't happen because mud is deposited in a very specific environment.
• 26:10
  SPEAKER_00: This is like really calm, quiet, shallow marine kind of deposition, right?
• 26:15
  SPEAKER_00: Because um, that's the only kind of water that is gonna allow like fine silt and clay or dust-sized particles to settle down to the bottom of this basin.
• 26:24
  SPEAKER_00: So boulders do not belong in this.
• 26:26
  SPEAKER_00: They do not, they don't belong.
• 26:28
  SPEAKER_00: And so, and we see the same kind of deformation with tsunamis, right?
• 26:32
  SPEAKER_00: Um, but an asteroid would also cause a tsunami-like event.
• 26:39
  SPEAKER_01: If that asteroid hit in the oceans, right?
• 26:43
  SPEAKER_01: Or potentially if it was big enough hit on land, it could cause a tsunami, but especially if it hit an ocean, you're gonna create a massive tsunami with that, just moving water out of the way of that thing.
• 26:52
  SPEAKER_00: Right.
• 26:53
  SPEAKER_00: Um, and so but what you would expect then is to have this ejecta from the impact site to come to rest.
• 27:00
  SPEAKER_00: And that's what this was was this was ejecta that came to rest, got ripped up and came to rest with this deposit.
• 27:08
  SPEAKER_01: Yes, right.
• 27:08
  SPEAKER_00: This boring mud.
• 27:10
  SPEAKER_00: So from from Texas now, let's go to Haiti.
• 27:14
  SPEAKER_01: Yeah, so what was going on in Haiti, Chris?
• 27:17
  SPEAKER_00: There was a report of these strange volcanic rocks.
• 27:20
  SPEAKER_00: Okay.
• 27:22
  SPEAKER_00: But when when people went there and and actually looked at this, these volcanic rocks were actually ejecta that were full of shocked quartz and those spheroles that we talked about before.
• 27:33
  SPEAKER_01: And there's a thing called tectites, which are these sort of impact-related melt rocks.
• 27:38
  SPEAKER_01: So basically you melt the rocks, what is called the target rock, a meteorite comes in, it hits the land.
• 27:43
  SPEAKER_01: That land, whatever that land is, is melted almost immediately.
• 27:47
  SPEAKER_01: Part of it's vaporized, part of it's melted, and it forms this molten rock, which we call tectites, which is a magma formed by a meteorite impact, basically.
• 27:56
  SPEAKER_01: And so there was evidence of a strike somewhere near the Gulf of Mexico, somewhere around the region of Haiti, that would form a lot of shocked courts and a lot of these tectites to form this sort of weird, strange looking kind of volcanic E rock, but not really volcanic.
• 28:12
  SPEAKER_01: It's actually a meteorite impact rock.
• 28:13
  SPEAKER_00: Yeah, exactly.
• 28:14
  SPEAKER_01: So it's something is nearby, is kind of the clue there.
• 28:17
  SPEAKER_00: That was again strong evidence.
• 28:18
  SPEAKER_00: You have this this Texas event, okay.
• 28:21
  SPEAKER_00: Now you have this Haiti event suggesting something in the vicinity big happened, right?
• 28:28
  SPEAKER_00: Right, and that's what that's what this is all about.
• 28:30
  SPEAKER_00: So we still don't have the crater, okay?
• 28:35
  SPEAKER_00: We we're we're now kind of zeroing in on it, though.
• 28:38
  SPEAKER_00: We know that it's somewhere close by because of what we saw in Texas, what we saw in Haiti, and so on.
• 28:44
  SPEAKER_00: And what happened here?
• 28:46
  SPEAKER_00: How did this come about?
• 28:47
  SPEAKER_01: Well, you know, it relates to sort of the petroleum industry and hunting for for uh petroleum deposits, and a lot of what the petroleum industry does is look for gravitational anomalies.
• 28:57
  SPEAKER_01: So they look at the gravity field, which is talking about sort of the the topology and the density of rocks underneath the surface and underneath the water.
• 29:06
  SPEAKER_00: So w what he found was this these gravitational anomalies, okay, and which which suggested no, actually, it didn't suggest, it showed this buried crater.
• 29:17
  SPEAKER_00: But he wasn't looking for that, and he didn't know that that's what he was looking at.
• 29:21
  SPEAKER_00: So the the Hildebrand, Alan Hildebrand, followed the data, and lo and behold, there's this roughly 200 kilometer-wide caldera, the same size, the same age, the same type that was predicted by Louis Alvarez off the Yucatan Peninsula.
• 29:39
  SPEAKER_01: So this is we've kind of zeroed in on the crater, right?
• 29:43
  SPEAKER_01: This is potentially the cause.
• 29:44
  SPEAKER_01: And the benefit of something hitting uh in the ocean and remaining preserved as a crater is you can kind of date the crater pretty well because sediments will keep being deposited after this crater event happened.
• 29:56
  SPEAKER_01: It sits down in the in the ocean and sediments will keep being deposited on top of it.
• 30:00
  SPEAKER_01: And actually, there's just a very large drilling program in 2016 to drill into, drill out into the ocean, drill down into the sea floor to drill through that new sediment, through the impact crater, down into the sort of crater, um, the sediment record within the crater, which sort of produced some interesting results.
• 30:19
  SPEAKER_01: But I just want to put this into a little bit of context.
• 30:21
  SPEAKER_01: The clay, let's go back to the initial clay.
• 30:23
  SPEAKER_00: I gotta go, I want to ask you something, actually.
• 30:26
  SPEAKER_00: So you date rocks.
• 30:28
  SPEAKER_00: Yes.
• 30:28
  SPEAKER_00: Okay.
• 30:29
  SPEAKER_00: I would think that then dating these tectites or spheroles would be pretty straightforward too, right?
• 30:35
  SPEAKER_01: Yes.
• 30:36
  SPEAKER_01: It it it is.
• 30:37
  SPEAKER_00: Tell us why that's the case.
• 30:38
  SPEAKER_00: Why why would dating these things be pretty straightforward?
• 30:41
  SPEAKER_01: Well, because you you uh you can date, you can look at the chemistry of these things and you can figure out when they formed pretty easily because they kind of get reset.
• 30:48
  SPEAKER_01: The chemistry of them gets reset due to the usually uranium-led systematics of these things.
• 30:53
  SPEAKER_01: Um, but you can also date the sediment layers above and below it, and especially the tectites, they're basically a magma that crystallizes, and so it is easier to date igneous rocks or things that crystallize from magma than it is to date sedimentary rocks.
• 31:06
  SPEAKER_00: So, as we've said before, like when if you melt something and then it crystallizes, becomes hardened, that's when the clock starts counting, right?
• 31:14
  SPEAKER_00: So if you dated these spheroles or tectites, uh they're gonna date back to that 66 million year event.
• 31:22
  SPEAKER_00: Exactly.
• 31:23
  SPEAKER_01: And so we've zeroed in on this thing, and we've kind of gone through this scientific sort of lineage as we get closer and closer to the event.
• 31:30
  SPEAKER_01: But I want to jump back to the clay a minute and talk about how that clay actually is formed, the stuff in Italy and Spain.
• 31:35
  SPEAKER_01: This is kind of an ash fall deposit, right?
• 31:38
  SPEAKER_01: So this is didn't really see this massive tsunami necessarily, but there was ash in the atmosphere that got deposited to form this clay layer in here, and that ash is the result of this big meteorite impact.
• 31:51
  SPEAKER_01: So, kind of to come full circle to the global implications of this.
• 31:54
  SPEAKER_00: Right.
• 31:54
  SPEAKER_01: So, you know, that that's the impact.
• 31:55
  SPEAKER_00: Right.
• 31:56
  SPEAKER_00: So let's go on to just uh to round out kind of this evidence in this whole story is you know, the dinosaurs.
• 32:03
  SPEAKER_00: There no dinosaur ever in the world has been found above this what we call the boundary clay or this KT boundary, this Cretaceous tertiary boundary.
• 32:14
  SPEAKER_00: Okay, no dinosaurs have ever been found above it.
• 32:17
  SPEAKER_00: Um, and you know, kind of like what you were saying too, is that this this fell is this kind of ash from above, included in the clay.
• 32:25
  SPEAKER_00: Uh you had the the shocked quartz, um, the spheroles, you have all kinds of soot, which suggests fires all over the place, which which go along with this kind of boiling atmosphere.
• 32:41
  SPEAKER_00: Imagine all these fireballs falling from the sky from this ejector that was blown up into space, cooled off, then reheated and re-melted upon re-entry into our atmosphere, falling all over the planet.
• 32:55
  SPEAKER_00: And essentially, you know, we we talked about this a lot with Dr.
• 33:01
  SPEAKER_00: Ian Miller.
• 33:02
  SPEAKER_00: He did a great discussion.
• 33:03
  SPEAKER_01: Yeah, that was a really fun interview.
• 33:05
  SPEAKER_01: So go back and listen to that if you want to hear.
• 33:06
  SPEAKER_01: He gives it, paints a very vivid picture of of this event, basically.
• 33:11
  SPEAKER_00: Yeah, and and so it really it didn't matter where you were, you could have been on the other side of the planet uh from this meteor impact.
• 33:18
  SPEAKER_00: You were still gonna be basically broiled alive.
• 33:20
  SPEAKER_01: Yes, and then after that event happens, you have 60% less diversity.
• 33:26
  SPEAKER_01: Uh, ferns actually took over.
• 33:28
  SPEAKER_01: So it's basically imagine, you know, a forest fire where all the big old trees get knocked down, and then you have this like new growth forest, except imagine that on a global scale.
• 33:37
  SPEAKER_01: And so fern spores can germinate, then uh, you know, so ferns take over first, and we basically have to regrow the world's forests from scratch and the world's life forms, basically.
• 33:48
  SPEAKER_01: And mammals start to dominate.
• 33:50
  SPEAKER_01: Mammals kind of recover quicker and dominate all of the biological niches after this point in time.
• 33:56
  SPEAKER_00: Right.
• 33:56
  SPEAKER_00: And that was an important part of the interview with Dr.
• 33:58
  SPEAKER_00: Miller is the discovery right outside of Denver, the Corral Bluffs discovery, where they found the first million years after this KT boundary event.
• 34:09
  SPEAKER_01: Yeah, so this is really interesting.
• 34:11
  SPEAKER_01: And, you know, before we move on, I want to sort of interject because this is where um, you know, when I was in graduate school, this was still kind of a debate.
• 34:18
  SPEAKER_01: The the cause of the death of the dinosaurs was was up for debate a little bit.
• 34:24
  SPEAKER_01: And um it has since resolved itself, I think, you know, since about 2012 or 2015.
• 34:30
  SPEAKER_01: Things have progressed a lot in the last 10 years on this topic.
• 34:33
  SPEAKER_01: But there were other options, there are other things in Earth that can generate, it could cause mass extinction events.
• 34:40
  SPEAKER_01: And one is volcanism, these large, huge volumes of uh volcanic outpouring, lots of basalt erupted onto the surface, and there is actually a big volcanic eruption in this exact time period that could fit the description, and this is what's called the Deccan Traps.
• 34:57
  SPEAKER_01: And these are a huge expanse, like one million cubic kilometers of basalt that was erupted in a window around about a million years, in a window of a million years in India, and usually sometimes these big volcanic eruptions they always produce a lot of CO2 and mercury, push a lot of that into the atmosphere, which can change climate enough to generate mass extinctions events a little bit.
• 35:20
  SPEAKER_01: So there was a a bit of a debate, well, actually quite a bit of a debate, about whether dinosaurs died because of these big volcanic eruptions over a long time period, or whether the mass extinction and the death of the dinosaurs was really driven by this meteorite impact.
• 35:33
  SPEAKER_00: All right, so I'm just asking, because this is not my field.
• 35:37
  SPEAKER_00: Uh do the scientists that study the Deccan traps then, these massive basaltic flows, eruptions, do they still believe that that caused the extinction?
• 35:49
  SPEAKER_01: No, I think, well, there was just a review of uh the sort of evidence about this event.
• 35:55
  SPEAKER_01: And the consensus view is very much that the meteorite impact was the main driver, the main cause of this extinction event.
• 36:01
  SPEAKER_01: So I don't think there's many people who who would argue aggressively that the Deccan traps in this volcanic eruption is the only thing that uh drove the extinction event.
• 36:11
  SPEAKER_00: But maybe the Deccan eruptions or the Deccan traps made it ripe before an event?
• 36:19
  SPEAKER_01: I think that's exact I think that's kind of the discussion where the discussion is at.
• 36:23
  SPEAKER_01: I mean, we might need to go search out an expert on this particular time interval to sort of have a an in-depth discussion.
• 36:30
  SPEAKER_01: But from what I can see, it looks like the discussion is very much like you said, is it ripe?
• 36:35
  SPEAKER_01: Did the Deccan traps kind of set the climate stage such that dinosaurs were already on the decline, life was already kind of in limbo or having a rough go of it, and then the meteorite impact came in and just finished it off completely, right?
• 36:47
  SPEAKER_02: Okay.
• 36:48
  SPEAKER_01: Because there are meteorite impacts in other times in Earth history that didn't cause mass extinction events, and there are other volcanic eruptions like the Deccan traps that probably did cause mass extinction events at other time periods in Earth history.
• 36:59
  SPEAKER_01: So I think let's get so let's go find somebody to interview who who wants to sort of elaborate on this.
• 37:03
  SPEAKER_01: I'm no expert on mass extinction events, but it'd be fun, it'd be a fun discussion to have for sure.
• 37:08
  SPEAKER_00: I think so too, because I was listening to a podcast that that the the podcaster was interviewing Jan Smith.
• 37:14
  SPEAKER_01: Oh, okay.
• 37:14
  SPEAKER_00: And he referred to the Deccan Traps and um just he let's just say that he didn't think that was the reason.
• 37:23
  SPEAKER_00: That's a good reason.
• 37:24
  SPEAKER_00: Yeah, yeah, no, for sure.
• 37:25
  SPEAKER_01: I think that's the that's more the that's definitely the consensus view.
• 37:27
  SPEAKER_01: But it's an interesting like look at how sort of the the scientific ideas evolve through time and how these like debates get resolved with a bit of a spectacular discovery in some ways, which I think we're gonna go into next.
• 37:38
  SPEAKER_00: Well, let's go into this rather new thing then, 2019, but I think this started actually in 2015, didn't it?
• 37:46
  SPEAKER_00: Yeah, there was this paper that documented fish in Wyoming.
• 37:50
  SPEAKER_00: Yes, and it's it's in this place called Tannis, North Dakota.
• 37:54
  SPEAKER_00: It lies within the very famous Hell Creek Formation.
• 37:57
  SPEAKER_00: Actually, it's near the top of the Hell Creek Formation, and this is really famous because the Hell Creek is renowned for dinosaur fossils.
• 38:06
  SPEAKER_01: Right.
• 38:06
  SPEAKER_01: Is this this is the one that's in like the Badlands?
• 38:08
  SPEAKER_00: Yeah, um North Dakota, South Dakota, Montana area.
• 38:12
  SPEAKER_01: Yeah, so it's this big deposit that has, for whatever reason, a lot of dinosaur uh bones preserved in it, a lot of fossils everywhere, right?
• 38:19
  SPEAKER_00: Yeah.
• 38:19
  SPEAKER_00: So I actually uh when I was teaching my field class um this number of years ago, um, we were doing a road cut in South Dakota, just uh putting together the geologic history of this road cut, right?
• 38:31
  SPEAKER_00: It's pretty interesting.
• 38:32
  SPEAKER_00: There's some faults and folds and so on.
• 38:34
  SPEAKER_00: It's pretty cool.
• 38:34
  SPEAKER_00: This guy pulls up in a pickup truck and he's like, Hey, you from Hudsonville?
• 38:39
  SPEAKER_00: And I'm like, Yeah, look that you know, I got a group of students around me.
• 38:42
  SPEAKER_00: He's like, I'm from Rockford.
• 38:44
  SPEAKER_00: Hey, I what are you guys doing?
• 38:46
  SPEAKER_00: I said, Well, we're just geology field course.
• 38:47
  SPEAKER_00: I explained what's going on, you know.
• 38:49
  SPEAKER_00: And the guy's like, I got about 1,500 pounds of dinosaur bones in the back of my truck.
• 38:54
  SPEAKER_00: You guys want to look at them?
• 38:56
  SPEAKER_00: Wow.
• 38:57
  SPEAKER_00: So he um he was a lawyer from Rockford, and he paid to paid a guide to take him dinosaur collecting.
• 39:08
  SPEAKER_00: Wow, bone collecting.
• 39:09
  SPEAKER_00: And so he was very cool.
• 39:10
  SPEAKER_00: So he was given dinosaur like fragments of dinosaur bones to the kids and everything.
• 39:15
  SPEAKER_00: That's awesome.
• 39:16
  SPEAKER_01: Wow.
• 39:16
  SPEAKER_01: So okay, yeah, this is a good thing.
• 39:17
  SPEAKER_01: And he got them all out of Hell Creek, yeah.
• 39:19
  SPEAKER_01: Yeah, okay.
• 39:19
  SPEAKER_01: That's all the Hell Creek Formation.
• 39:21
  SPEAKER_01: All right, so we've got this this you know sequence of rocks called in the place called Tannis, North Dakota, top of the Hell Creek Formation.
• 39:28
  SPEAKER_00: Yeah.
• 39:29
  SPEAKER_00: So the what they found is evidence of a tsunami deposit.
• 39:33
  SPEAKER_00: Okay, the same kind of stuff that we talked about before, right?
• 39:36
  SPEAKER_00: Um, but it also the the rocks had three very distinct types of fish fossils in it.
• 39:42
  SPEAKER_00: Uh there were paddlefish, sturgeon, and ammonites.
• 39:44
  SPEAKER_00: Okay.
• 39:45
  SPEAKER_00: And it they these are saltwater and freshwater creatures.
• 39:51
  SPEAKER_00: So why is that important?
• 39:53
  SPEAKER_01: It's important because the deposit itself is not a saltwater deposit.
• 39:59
  SPEAKER_01: Like the rocks themselves are not formed in a saltwater environment.
• 40:02
  SPEAKER_01: They're formed in a freshwater environment, like a river system, like a river channel is sort of what the sediments themselves are formed in.
• 40:09
  SPEAKER_00: So the implication is an event.
• 40:11
  SPEAKER_00: How the hell big ass event mixed these things together.
• 40:15
  SPEAKER_01: And if you look at the pay, what's called the paleotopography of the area, so you look at the sedimentary rocks and try and figure out where was the ancient shoreline, 66, 65 million years ago.
• 40:26
  SPEAKER_01: This is kind of along the shoreline, but not that close to the shoreline.
• 40:30
  SPEAKER_01: So this is like a river system, a river mouth that's flowing into the ocean, but it's not in the ocean.
• 40:35
  SPEAKER_00: It's not a part of the delta previous.
• 40:37
  SPEAKER_01: Exactly.
• 40:37
  SPEAKER_01: Exactly.
• 40:38
  SPEAKER_01: So it's upstream, but it's it's near the ocean.
• 40:40
  SPEAKER_01: It's an area which would probably be susceptible to a big tsunami.
• 40:45
  SPEAKER_01: It would be inundated during a big tsunami.
• 40:48
  SPEAKER_00: So the author of this paper also found these tectites, these spheroles in the deposit that he dated to 66 million years ago.
• 40:58
  SPEAKER_01: I mean, what's spectacular is this is just one of these incredible fossil localities.
• 41:03
  SPEAKER_01: Like fossils are always kind of a rare thing.
• 41:05
  SPEAKER_01: Like most things that die don't form fossils.
• 41:09
  SPEAKER_01: Right.
• 41:09
  SPEAKER_01: And so having multiple fossils in one area is kind of spectacular.
• 41:13
  SPEAKER_01: Having all of these fish fossils in one area is even more spectacular, but they're all lined up, they're all sort of arrayed in a manner that looks like the fossils were deposited in this kind of flowing water environment, right?
• 41:26
  SPEAKER_01: Which is weird for fossils.
• 41:27
  SPEAKER_01: And then also there are tectites, tiny little molten pieces of rock in the fish gills.
• 41:34
  SPEAKER_01: So these things were swallowing these while they were still alive, as the fish were dying.
• 41:40
  SPEAKER_01: Not so much normal behavior for fish, right?
• 41:43
  SPEAKER_01: So this is a this is you know evidence that these fish were killed during this meteorite impact, or in the immediate aftermath of this meteorite impact.
• 41:53
  SPEAKER_00: But think about that a second.
• 41:55
  SPEAKER_00: I that's amazing that he took these fossils, extracted the tectites out of the gills.
• 42:02
  SPEAKER_00: Like that's that's pretty cool stuff.
• 42:04
  SPEAKER_01: It's amazing.
• 42:05
  SPEAKER_01: The discovery, and and there's also dinosaur bones in this thing, in this sort of deposit, this tsunami deposit.
• 42:12
  SPEAKER_01: So dinosaurs were most likely alive at this point, at least some of the dinosaurs.
• 42:16
  SPEAKER_01: And so it's just this like really spectacular, well-preserved, just an exceptional deposit.
• 42:22
  SPEAKER_01: Like you can gain a lot of information from this one area that for whatever reason preserves these rocks.
• 42:28
  SPEAKER_00: Not to put you on the spot again, but didn't the dinosaurs suffer some sort of bone uh issue because they were inhaling this ash at the time that they were alive?
• 42:39
  SPEAKER_01: That's a good question.
• 42:40
  SPEAKER_01: I don't know.
• 42:41
  SPEAKER_01: I don't know that.
• 42:41
  SPEAKER_01: Okay.
• 42:42
  SPEAKER_01: I don't know that I thought you would.
• 42:43
  SPEAKER_01: No.
• 42:44
  SPEAKER_00: Um sometimes I give you too much credit.
• 42:47
  SPEAKER_01: Most of the time you give me too much credit.
• 42:49
  SPEAKER_00: Actually, no.
• 42:51
  SPEAKER_00: There's one of those rare instances when I gave you too much credit.
• 42:54
  SPEAKER_01: So the this is, you know, this just speaks to this amazingly traumatic time to be alive on Earth.
• 43:01
  SPEAKER_01: And basically, you have no chance of survival here.
• 43:03
  SPEAKER_01: The energy from these tech dykes, like falling back to Earth, so all this molten rock is thrown up in the atmosphere, some of it cools, it gets reheated as it falls to earth, it is radiating heat away, it is heating the surface of the earth to boiling temperatures, and this would have been enough to kill most animals and plants on the surface, created all these forest fires that you were talking about, Chris.
• 43:23
  SPEAKER_01: Um, just a completely traumatic event.
• 43:25
  SPEAKER_01: And we have now evidence that there was a lot of death and destruction during this event.
• 43:30
  SPEAKER_00: Yeah, I would encourage anybody listening to this podcast to Google search something like animation or simulation of the dinosaur extinction event or the dinosaur extinction impact.
• 43:45
  SPEAKER_00: Yes.
• 43:45
  SPEAKER_00: You do that, you're gonna you're gonna get a pretty clear picture as to what this probably looked like.
• 43:51
  SPEAKER_00: Yes.
• 43:52
  SPEAKER_00: It's it's amazing.
• 43:53
  SPEAKER_00: It really is.
• 43:53
  SPEAKER_01: It is uh very, very graphic.
• 43:56
  SPEAKER_01: Graphic.
• 43:58
  SPEAKER_01: Not a time to be alive.
• 43:59
  SPEAKER_01: Let's not be Alive when that happens, right?
• 44:01
  SPEAKER_00: Right on.
• 44:02
  SPEAKER_01: So what do you think?
• 44:04
  SPEAKER_01: Yeah, I think that I mean, what a cool story.
• 44:07
  SPEAKER_01: There's I think so.
• 44:08
  SPEAKER_00: That's the thing for me.
• 44:10
  SPEAKER_00: Why I wanted to pitch this to you is You've convinced me.
• 44:13
  SPEAKER_00: I don't I don't get to I don't get to look into your world very often.
• 44:18
  SPEAKER_00: You know, we hit we live in very, very different worlds, okay, with what you do and what I do, and the just kind of the how the research of one person and one part of the world and and another person from another part of the world and how all of it came together to paint this beautiful picture, really, is is really interesting to me.
• 44:37
  SPEAKER_00: And so yeah, and it's it's really interesting.
• 44:39
  SPEAKER_01: I I always like these stories of sort of how uh consensus scientific consensus is kind of made, you know.
• 44:46
  SPEAKER_01: Like how do you get a whole bunch of people who love to argue about these really weird details all to agree on something?
• 44:51
  SPEAKER_01: And you know, it takes a lot of effort, takes a lot of different pieces of evidence that all kind of agree with one story for everybody to kind of buy into it.
• 45:00
  SPEAKER_01: Um so it's a really interesting story of sort of scientific discovery, I think, for sure.
• 45:03
  SPEAKER_00: It's very I think so too, because from me on the outside, looking into your world, when you look at the evidence for this event, everything that we went through, it's really hard for somebody like me to s to to question that.
• 45:16
  SPEAKER_01: Sure.
• 45:16
  SPEAKER_00: You know, um, I don't know if that's healthy or not.
• 45:19
  SPEAKER_00: Like, I don't know.
• 45:20
  SPEAKER_00: I've I haven't thought about that, but I look at it and say, wow, that is really a compelling story.
• 45:25
  SPEAKER_01: Yes, and I think that's that's the consensus view at this point.
• 45:29
  SPEAKER_01: There's very little uncertainty about the main driver of the extinction, you know, that this was a meteorite impact, catastrophic, you know, reset the biological environments on Earth.
• 45:39
  SPEAKER_01: I think there's probably still a little bit of a debate about, you know, was the Earth, like we said before, kind of primed for an extinction event?
• 45:45
  SPEAKER_01: You know, why is this one unique?
• 45:46
  SPEAKER_01: There's something unique about this big meteorite impact.
• 45:48
  SPEAKER_01: There's also some interesting um suggestions that maybe this was uh several meteorite impacts that all hit kind of consecutively, or there's there's sort of all one body that broke up and there's a bunch.
• 45:59
  SPEAKER_00: That pretty much happens with a meteor because the gravity holding the meteor together is overcome by the gravity of Earth and it tears them apart into smaller fragments.
• 46:10
  SPEAKER_00: Exactly.
• 46:10
  SPEAKER_01: So maybe a big asteroid came by and a bunch of pieces of that all you know got got got caught in Earth's um in gravity well.
• 46:18
  SPEAKER_01: So, you know, there's still some some details to be worked out, but deposits like these spectacular uh fish deposits from Tannis, North Dakota will be very valuable in helping to figure all this out.
• 46:30
  SPEAKER_00: So, yeah, I guess in summary, I I would say go back, listen to the Dr.
• 46:34
  SPEAKER_00: Ian Miller interview.
• 46:35
  SPEAKER_01: Totally.
• 46:35
  SPEAKER_00: Because it's awesome, and it really kind of goes hand in hand with what we talked about.
• 46:41
  SPEAKER_00: We we're kind of talking about the the event itself, and he talks about what happened after the event, but he paints a really vivid picture of the event.
• 46:48
  SPEAKER_00: Totally.
• 46:49
  SPEAKER_00: Um anyway, and then also look up a simulation.
• 46:52
  SPEAKER_00: Yes, yeah, absolutely of the meteor mass extinction event.
• 46:55
  SPEAKER_00: It's pretty cool.
• 46:56
  SPEAKER_01: And Cretaceous Mass Extinction, very, very cool.
• 46:59
  SPEAKER_01: All right, Chris, with that, let's wrap it up.
• 47:01
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• 47:02
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• 47:08
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• 47:09
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• 47:10
  SPEAKER_01: That's right.
• 47:11
  SPEAKER_01: Planet Geo.
• 47:12
  SPEAKER_00: That's the biggest thing to me.
• 47:12
  SPEAKER_00: Yeah, that's the best thing.
• 47:14
  SPEAKER_01: You know, recommendations by people is great.
• 47:17
  SPEAKER_01: Cheers.
• 47:18
  SPEAKER_01: All right, peace.