Dr. Jesse Reimink: Well, this is, uh, this is a good one because this is a wrap basically on our plate tectonics question list, which you got, uh, very worked up about what was it, September or something like that. I guess this was a long time ago that we started this whole process. Maybe, than September.

Chris Bolhuis: September, October. Yeah, it was, it was right away. But the beginning of the school year.

Dr. Jesse Reimink: so this is, I mean, we'll probably come back to this with part eight in, you know, next year or that. But, but, uh, this [00:01:00] is part seven,

Chris Bolhuis: Eight through 10.

Dr. Jesse Reimink: eight , eight through 10 or 15, however many we get But, this is a big topic and, and this is a big episode too. I think this is a really important episode. So we, we kind of have to cover it and we want to end on it.

Chris Bolhuis: let's say what this is. This is about rocks and climate. can we determine what earth's ancient climate was when we look at ancient rocks, that's really what this is all about today. And.

Dr. Jesse Reimink: Let me add one thing to that, Chris, cuz I think we're, we're gonna kind of come from this, I think we, we sort [00:01:30] of have to come from this

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: how do rocks interact with climate? Like we should, we should at least touch on that briefly, how rocks interact with climate, which sets the stage for how can we use old rocks to understand climate as well. Like those are kind of two sides of the same coin. interaction.

Chris Bolhuis: this was kind of my idea, this episode It came from one of my students actually in my astronomy class. yeah, she was doing a presentation, like a 15 minute presentation that I have. All the kids do. They get to [00:02:00] pick the topic that they want, that is, astronomy related. Right. And she chose this one and I was amazed by it. I had, I'd actually never thought about. in this way about how rocks are affected by the atmospheric composition. And so, This episode is tied to plate tectonics. You know, how, how the atmospheric composition affects the rocks, but then there's parts of it that are not directly tied to plate tectonics. this is a perfect way to end [00:02:30] this series.

Dr. Jesse Reimink: Yeah, I, I agree completely. And so I think Chris, maybe the best way to start out here is to just kinda level set from. How this happens today, how do rocks interact with atmosphere today? And, and sort of a little brief thing about how that affects climate or really how it is the thermostat of Earth, which is a, a term that's been used before. but we talked about this going back to one of our really early episodes on, uh, hard water and

Chris Bolhuis: Hmm

Dr. Jesse Reimink: cycle, the long [00:03:00] term carbon cycle basically. and so I think, should we start there? Should we just kind of give five minutes? Background here.

Chris Bolhuis: Sure. Uh, I'm not sure exactly what you, what direction you want to go, so go ahead. Just throw something my way.

Dr. Jesse Reimink: so I, I guess what I'm thinking of is , let's talk about co2 cuz we're gonna really talk about CO2 and oxygen and how they interact with rock. So can we just give the, the intro level. geo level style of how do rocks [00:03:30] interact with co2, or how do rocks impact the Americ CO2 content?

Chris Bolhuis: Well, that's a huge topic, Jesse . Oh my gosh, really? Okay. Uh, I mean, We have, I, we have to do this, we have to spend a couple of episodes and talk about this carbon cycle, the fast carbon cycle, the slow carbon cycle. But the bottom line is, is that y you know, carbonates and carbon dioxide is, drawn out of rocks through weathering, and it's brought then to the oceans. And then,[00:04:00] I don't know, Jesse, if we want to get, do you want to get into the geochemistry or, that was actually a really dumb question here that I asked a geochemist. If you want to talk about, Geochemistry. But,

Dr. Jesse Reimink: obviously, I mean, it's the best, but, uh, no, I, I

Chris Bolhuis: I mean

Dr. Jesse Reimink: to go into too much detail here. I, I think you've covered it. Uh, basically like, you know that CO2 is pulled outta the atmosphere by weathering. I think weathering is the key, the key thing here. That is exactly what we're, we're looking for.

Chris Bolhuis: Okay. Hold on though Jesse cuz You said something that I want to [00:04:30] ask you about and I do want you to explain it because I think you skipped a couple steps. You just went from, from one to the other, right? You said that carbon dioxide is drawn out of the atmosphere by weathering. Okay. But I think you need to walk us through that step or the steps that are in between there.

Dr. Jesse Reimink: sure. And this is a really big and important topic, which you're exactly right. We should dedicate many episodes to, and we should

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: who maybe are part of these startup companies who are trying to do this as a, uh, carbon [00:05:00] sequestration mechanism. But, Basically what happens if you take ultra meic rocks, which we've talked about before, this is the interior of the earth. This is pretty tight high in magnesium and iron and calcium. Those things, those types of rocks break down easily at the surface, meaning they're weathered chemically and physically very easily. They're not happy at the surface. So when they

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: low temperature, they're unhappy minerals, stay breakdown. What happens then is calcium. Very importantly, also magnesium and iron to some degree.

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: The term is solubilized, [00:05:30] but basically they're picked up in water and they're carried into the ocean. And when they're carried into the ocean, what they do is they bond with an acid, a CO2 bearing acid. Usually it's HCO three or one of these acid types, but CO2 goes into the ocean and is a little acid in the ocean and they bond calcium. Plus the CO three bond together to form calci. The mineral calci in that instance, or dolomite or any these

Chris Bolhuis: Y

Dr. Jesse Reimink: organisms can do this. It's biologically mediated, uh, today. But [00:06:00] basically, so the minerals break down these ultra meic minerals, we put them on the surface. They basically through weathering the. are transported. They interact with co2, gas and orga. They interact with CO2 that's been dissolved in water and they form minerals, and then they're locked up for millions and millions of years in those very stable minerals Calci or reaganite or dolomite.

Chris Bolhuis: And not to nitpick at all with you, but how is this carbon dioxide drawn out of the atmosphere through this process?

Dr. Jesse Reimink: Yeah. So that's [00:06:30] sort of a partitioning, that's something that is, is basically they're in equilibrium. The atmospheric CO2 and the oceanic CO2 are gonna be in equilibrium. if we take more bicarbonate ions out of the ocean, the ocean will start to suck up CO2 outta the

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: kind of maintain this chemical equilibrium at the surface of the ocean. So that's how this happens. But I. Tie this off at Plate Tectonics. Let's bring it back to plate Tectonics a little bit because a, a big cycle. There's a, actually a paper published by some colleagues of [00:07:00] State University recently, just this year that got a lot of, uh, press actually, and the title here is How Temperature Dependent Silicate, weathering Acts as Earth's Geological Thermostat. I mean, it's a cool title, geological

Chris Bolhuis: Yeah.

Dr. Jesse Reimink: it's a good one. And, but basically that co2, it does not go down all the way into the mantle and stay there forever. Those carbonate minerals, those come back up in volcanoes,

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: millions and millions of years. So this is, you said it earlier, Earth's long-term carbon cycle.

Chris Bolhuis: Okay, [00:07:30] Jesse, bringing this back to Plate Tectonics. Okay. Let's just simplify this cuz I think you, you went into the weeds a little bit and I'm gonna bring it back a little bit is basically plate tectonics. is the force that lifts things up, right? And, and so as that happens, that accelerates the weathering and erosion process, which accelerates the removal of carbon dioxide. And

Dr. Jesse Reimink: Exactly

Chris Bolhuis: that's kind of how these gases, atmospheric gases are tied to plate tectonics. The rate of [00:08:00] removal, the rate at which things happen is tied to elevation.

Dr. Jesse Reimink: That's exactly right Chris, and, and I just want to double click on that because you're exactly right. The, the faster things go up, the more CO2 is gonna be drawn

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: Also, what happens is the hotter things get more CO2 gets drawn back down because hotter temperatures, faster reactions, faster chemical weathering,

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: that are drawing down CO2 happens faster. So over really long time scales. Kind of goes up and down and is modulated [00:08:30] like a thermostat where, you know, it goes up and then turns off and then goes down and then turns on. and this is how this works over really long timescale that I think brings us nicely into the discussion of the early earth and comparisons with up. Planet like Venus, which Marty Gilmore, who is amazing and we were lucky enough interview a while back. She called it Earth's toxic twin. Which,

kind of brings us back home to this paper that I think you wanted to center this discussion around a little bit about [00:09:00] ancient rocks and climate.

Chris Bolhuis: That's right. talking about our neighbors Mars and Venus Earth is PE. we're Mars and Venus their atmospheres, although very different, right? Venus has an extremely thick atmosphere everything about Venus has to do with the atmosphere. I mean, it's, it's such a harsh, harsh place because of this. But Mars has a very thin at. Comparatively, and, and so, but they have very similar atmospheric compositions. They [00:09:30] are dominated both of them by carbon dioxide. And then the second most abundant gas being, nitrogen, on the order of two to 3% nitrogen, so 96 to 97% CO2 and then nitrogen. Okay. Earth is very peculiar in this because we're dominated by. It's like 78% of our atmospheric composition. Then oxygen comes in at 21%. And then we have, although very important, [00:10:00] our carbon dioxide concentration, we're talking about things on the order of like 415 to 420 parts per million. know, it, it's a, it's a. Hugely important gas, but a very small constituent of our atmosphere. So Earth is really, really peculiar in this situation, but we don't think it was always that way. And that's what comes back to plate tectonics and, and this whole paper.

Dr. Jesse Reimink: And we kind of, we've talked about this a little bit before. We talked about this in, I think, part four of [00:10:30] this plate tectonic series, which is when did plate tectonics start on earth? We talked about this in part three of this with planetary tectonics. What is the tectonic regime of other planets? And is part of the big question about the early earth is what type of tectonics was going on on the early earth? Was it plate tectonics? Was it different? and Venus and Mars are extremely different right now, both in plate tectonics and in atmospheric composition? The question is, were they always different? There's pretty good evidence that Mars had [00:11:00] water. , we don't really know what Venus had going on in the atmosphere over the last four and a half billion years, so, a really problem and deeply tied to plate tectonics because as we just started out talking about plate tectonics influences climate and influences the atmospheric composition of a

Chris Bolhuis: Okay, so let's start talking then about what we think our early atmosphere was like. can we do that now? All right so first of all we think that we probably had two [00:11:30] atmospheres in ancient earth. One was when Earth began, you know, when it formed 4.54 billion years ago. Our at. Whatever it was at that time, it went away because we got smacked by a Mars size object, Thea. that process formed our moon and that that violent collision would've also dazed earth. I mean, we lo our atmosphere would've been blown into space at that point. So whatever our earliest composition [00:12:00] was, that went away, but then it started over again because of this process. Right. I mean, you know, when that event happened, earth was entirely resurfaced. It was molten again. And then that ocean of magma was. Degassing and creating a new atmosphere. that's really what this is about today is what do we think that atmosphere was like and how can the rocks tell us about that

Dr. Jesse Reimink: I just want to [00:12:30] paint a little bit of a visual here, Chris, cuz I want to. Across the point of how violent these things are. I mean, the planet is melted and in order for the planet to be molten for any period of time for the the top the planet to be molten at any period of time, we have to have like a thick atmosphere. You can't just be exposed outer space cuz the thing will solidify if the temperature at the surface of this magma pond is. Space temperature, it's gonna cool down and crystallize really, really quickly. But if you have an atmosphere on top [00:13:00] of that, you can kind of insulate this much like Earth is insulated and it can stay warm for longer. But this is like an atmospheric composition that right after this impact you have silica in the atmosphere. So you have like, basically this is a, a, a rock dust atmosphere. It's like a volcanic eruption, you know, it's just

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: of particles and gas it's so hot. That stuff that should not be gas is gas.

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: it's an extreme atmospheric composition in that first stage that you're talking about.

Chris Bolhuis: Okay, let's talk [00:13:30] about this then. Like what kind of research is being done know, the, papers are saying that we think our early atmosphere was similar to what Venus and Mars have today in terms of like overall percentages. In other words, we were dominated by carbon dioxide , than probably nitrogen. Okay. what's being done? How, how in the world. Can ancient rocks? Tell us about the chemistry of our atmosphere.

Dr. Jesse Reimink: Yeah.

Chris Bolhuis: Let's, go in that direction. I think this is like, [00:14:00] I mean, you, you live in this world a whole lot more than, than you do. So what's going on? Because I think this is just fascinating. This is so,

Dr. Jesse Reimink: so, okay. There's a whole bunch of different ways to do this, and I think this is actually a really nice leading one because we're gonna have an episode coming up in the next month or so here on banded iron Formations. And Banded

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: are a sedimentary rock type that. Don't exist on the modern earth or don't form on the modern Earth, but they formed a lot back in early Earth. And tells us that Earth's atmosphere [00:14:30] was different. So we know for sure Earth's atmosphere is different. For instance, there was no oxygen or barely any oxygen in Earth's atmosphere prior to two and a half billion years ago. , we can use sedimentary rocks that kind of record this interac. They record the climate . Conditions a little bit, or they record certain aspects of the climate conditions. We can also look in minerals that are formed with fluid around, so things like quartz inclusions, sometimes quartz has little gas bubbles in it, and quartz can [00:15:00] form near the atmosphere and it can crystallize, and there might be some atmospheric gas around. And so there's really old quartz crystals that, people argue have. of a record of the early atmosphere, or at least something to the early atmosphere

Chris Bolhuis: really interesting. can I interrupt you a second? Don't lose your train of thought. But that does bring up a point too, that we're talking about going back billions of years and looking at atmospheric composition. We're able to go back maybe hundreds of thousands of years by looking at little [00:15:30] bubbles that are trapped in ice cores. Okay. You know, we have the Greenland ice sheet, we have the Antarctic ice sheets, and, These are basically time machines for us. You know, the deeper that we drill down into the ice and we are able to analyze these little bubbles of, tens of thousands of year old, atmosphere. So we can do that. That's not what we're talking about today. We're talk, we have to go back much further in time

And we have to look at rocks then.

Dr. Jesse Reimink: We have to also, [00:16:00] Not really the atmosphere. Like when a quartz crystal grows, it's usually growing. It's not growing right at the surface like ice does. You know, it's not

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: a piece of the atmosphere. It's maybe some gas that's in chemical communication with the atmosphere, but is modified, uh, you know, maybe a couple hundred meters down in the earth. Like the gas is different than the atmosphere. So it's not a perfect sample of atmospheric gas. Uh, but. You know, we can make a relationship. There's a relationship between the composition of this little bubble in courts and the [00:16:30] actual atmospheric composition. But, those samples are few and far between. The other thing that we can do is look at rocks, as we've talked about here, and as. Sort of we're centering this conversation on, and people have looked at rocks and basically what this comes down to is looking at the chemical composition usually of iron, sometimes of other elements. Uh, for instance, Ercan has some chemistry in it that can get at broadly the composition of the atmosphere, but it's not perfect. Um, but [00:17:00] usually of iron. . And the key here is that rock composition a little bit to do with the atmosphere. Certain rocks have a little

Chris Bolhuis: That's

Dr. Jesse Reimink: the atmosphere.

and so let me just ask you a question here, Chris. If

I was to

Chris Bolhuis: Uh

Dr. Jesse Reimink: through

Chris Bolhuis: Uh

Dr. Jesse Reimink: pressure's on Yeah. Perk up exactly. Uh, yeah. Straighten up. Here we go. Uh, so if I was to say I want you Chris to go find me a rock type. As a record of an interaction with the atmosphere, what [00:17:30] broad, general category of rock would you be most likely to select? I'm you know, the, the

Chris Bolhuis: Okay. Yep

Dr. Jesse Reimink: physical Geology categories

Chris Bolhuis: All right, so I am, I'm gonna look for something that's meic or ultra meic because I'm gonna be looking for something that is loaded with iron. You just got done talking about the importance of iron basically we're looking, did I get that right? By the

way,

Dr. Jesse Reimink: I actually, I want to go

one .I want to go, I want to go 1, level deeper though.

Like what?

Chris Bolhuis: the rock?

Dr. Jesse Reimink: Well, [00:18:00] I'm thinking how, like where is this rock found what would this rock have experienced? I mean, are you, are you looking for a ga, you looking for, uh, you know, meic intermediate composition, but can

Chris Bolhuis: I'm looking for a rock that was extrusive at the time that it formed.

Dr. Jesse Reimink: Perfect.

Chris Bolhuis: Right. I mean, because we wanna have something. Well, I feel so good. Like the pressure's off me now. Um, we want to have something that was directly interacting with our atmosphere. Right? And so, what [00:18:30] we're basically talking about is what happens to iron. Everybody knows this. Iron rusts. Okay. And this is if we were talking about this in a chemistry context, that's the oxidation of iron. But there are various different oxidation states that can happen. And by looking at the the oxidation state of iron, then we can determine what the composition of the atmosphere was that was interacting with that rock at the time that it.

Dr. Jesse Reimink: [00:19:00] Right, I think, a good way to sort of set this stage. And so what we're talking about here is how much oxygen is. In the atmosphere , so think of it this way. You have iron and iron is hanging onto electrons on the outer shell and oxygen really loves to grab electrons. Oxygen super loves electrons and so oxygen's gonna strip away electrons and make iron lose electrons and iron can lose two electrons. That's iron two. So it becomes two plus cuz it lost two

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: iron can [00:19:30] become three plus and it lost three electrons. And when it becomes three plus, that's the oxidation, oxidation state of iron. it means that there's more oxygen around because more oxygen is grabbing more electrons, basically. I mean, a really rudimentary sense. That's what it means. But

Chris Bolhuis: That's right. And, uh, can I just interrupt you a second? So what that would form then with an abundance of oxygen is it's gonna form f E 2 0 3 as opposed to when you [00:20:00] have less oxygen, it'll form a one-to-one ratio, cuz it only lost two electrons. It'll form f e o.

Dr. Jesse Reimink: so you're exactly right. But I think people might get lost in the numbers there. Can you balance those equations? Because I just said f e three plus gets formed more oxygen, and then you said f e 2 0 3, so why, why the numbers here? Can you just explain

Chris Bolhuis: I think so. Um, so when ions combine, when they come together, the electrical nature of matter, opposites attract. So the, the iron, which is f e three plus [00:20:30] in this situation is gonna bond with. Oxygen in the negative state, but they have to come together to form a neutral charge. So if I have two irons, F E two, that gives me a total plus six charge, right? I need three oxygens. Each of those are negative two, and then I have a negative six, and I can put 'em together then in that . Ratio. So it's f E 2 0 3, that forms a neutral compound. But in order to do that, [00:21:00] in order to do that, you have to have an abundance of oxygen.

Dr. Jesse Reimink: So I think if we just back up really quickly here, because if we take Iron Three Plus, so we've got a lot of Iron Three Plus, which as you said, two of those plus three oxygen, two. Two minuses makes an even thing. If you have some iron two plus around, you can't just stuff that in the same mineral because you're gonna have too many oxygen. So you have to make a different combination, a different recipe to get a neutral bond here. So the of iron in a rock will tell us [00:21:30] something about the state, the amount of oxygen around when that rock formed. That's really what we're talking about here, right? Chris?

Chris Bolhuis: absolutely. We're looking at whether or not we have F e O which means there was less oxygen in the atmosphere that was interacting with the rocks or whether we have f e 2 0 3, which means there was more oxygen. So let's just cut to the chase. What do we find with these ancient rocks? What kind of oxidation state are [00:22:00] we finding?

Dr. Jesse Reimink: Well, we're finding pretty low state in most of the, uh, ancient rocks because again, we've talked about the fact that there's less free oxygen, less oh two the early atmosphere than there is today. So by today's standards fairly low, but, uh, that's not necessarily totally low, I guess , right?

Chris Bolhuis: All right. So Jesse, um, before we get into some of the other details, I, do want to ask something that hopefully [00:22:30] you can clear up.

Dr. Jesse Reimink: oxygen

Chris Bolhuis: talking about the

Dr. Jesse Reimink: electrons from

Chris Bolhuis: oxidation state of iron, so what kind of oxygen are we referring to? Is this just free oxygen in the atmosphere, or can this be oxygen that's tied to carbon in the form of, let's say carbon dioxide or a carbonate,

Dr. Jesse Reimink: Yeah. Uh, it's a really good point, Chris, because free

Chris Bolhuis: I

Dr. Jesse Reimink: is, is what everybody thinks about when we're having this discussion about grabbing iron, but it's not just free oxygen oh two that we're talking about because a lot of the molecules we have in our atmosphere have oxygen in [00:23:00] them. H two O co co2, they all have oxygen in there. And so those things have higher, what are called oxidation there is more oxygen around, there's more potential for auction to grab some electrons from iron. so oxygen fuga. F O two is the term we use. Oxygen FGA or oxidation state. That's a really complicated thing. That depends on the certain combination of gases you have in your atmosphere, like what the oxidation state of the atmosphere is can [00:23:30] depend on a lot of different stuff. Co2, co, H two o, H two, c4, four, and two. All that stuff goes in

Chris Bolhuis: It can come from all the oxygen that's available. Right. That's what you're saying. Okay. So let's talk about then this experiment, because in order for them to make conclusions about what our early atmosphere was like, we have to be able to do this in lab, right? I mean, and so you said earlier there are a lot of different ways this can be done, but let's talk about what was done with the paper that, we kind of read. As a [00:24:00] primer to get us ready thinking about this episode. So bottom line is, I'm gonna try to paint a picture of what this was like, and I'm, I'm really simplifying this a lot, but the, basically in the lab they use the laser. And they melted the Rock Tite. Okay. And Tite is, this is ultra meic, which just means this is a rock that is loaded with iron. A lot of magnesium too. But we're talking about oxidation state of iron. So, and then they used. A variety of, [00:24:30] gases, different compositions, different ratios of the gases that are meant to kind of simulate what our early atmosphere was like. Okay. And this is the part that I found interesting and weird, and maybe, I don't know what to think of it, but they were actually able to levitate this.

Dr. Jesse Reimink: Yeah.

Chris Bolhuis: in the gas. In other words, they melted the rock And it was levitated inside this chamber. So the gas was available all around the melt, not just the [00:25:00] surface of it. It was actually all around. is that a problem with this experiment? D Like why, why does that necessary? Is it just so they can do it faster you think?

Dr. Jesse Reimink: I think it's partially to do it faster. And also I think, um, I mean, I'm not an experimental. Person. So I, I don't exactly know how these experiments are done or what the limitations of other types are, but with this thing you can quench this thing super quick. So it's basically think of a little tiny bead of prototype that's being melted and levitated [00:25:30] up in space,

Chris Bolhuis: know

Dr. Jesse Reimink: there's atmosphere kind of swirling around it. You can cool that down instantaneously, and that's really valuable because while you. Bigger experiments. think of like, little glass vial full of liquid magma that takes longer to cool down. And when stuff cools down, it changes the composition. And what we're after is the composition of magma and atmosphere in equilibrium when it is magma at super high temperatures, not what happens after it cools down with all those back reactions that might [00:26:00] happen and, perturb that in the experi.

Chris Bolhuis: And so what they did is the, you know, the variable in the experiment was the composition of the gas. They kept changing the composition until the rocks oxidized in the way that we see ancient rocks. Does that make sense?

Dr. Jesse Reimink: For sure. I mean, it's a, it's a really, uh, uh, certifi, you know, we're coming at this from the experimental way because as we've talked about, rocks preserved

Chris Bolhuis: uh

Dr. Jesse Reimink: early and earth history, [00:26:30] and most of the rocks that are preserved are completely altered. So if we went back, it found a 3.8 billion year old basalt, which do exist. There are

Chris Bolhuis: Like

Dr. Jesse Reimink: old, very few of them, but those things have been altered so much that any gas, little bubbles that were entrapped, think vesicles or think anything that could be gas in that rock when it formed 3.8 billion years ago. That's all been overprinted by later

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: we rely on this sort of experimental approach to say what is. Possible on the early earth. And then [00:27:00] compare that. Compare the oxidation state, which is hard to perturb. Compare the oxidation state of iron, uh, to what we see on Earth. So,

Chris Bolhuis: And so bottom line is what they found to get to replicate the oxidation state in lab with what we find in ancient rocks. Our atmosphere was similar then to what? It's what it is on Venus and Mars today. In other words, we're talking about. Upwards of 97% carbon dioxide, about [00:27:30] 3% or a little bit less N two or nitrogen gave us the proper oxidation state in the lab. And so that's the same basically as what we have on Mars and Venus today. So this brings us full circle then back to Plate Tectonics. So if this was Earth's early atmosphere, where did all the CO2 go? We're obviously very very different then, and that comes [00:28:00] back to a massive part of carbon dioxide removal is tied to plate tectonics, right? You know, so over time we've removed carbon dioxide because of our oceans and because of plate tectonic.

Dr. Jesse Reimink: Yeah. And it's a really important question of where is this stuff all tied up in? Where does it exist? , we know there's diamonds down in the mantle. Some of those diamonds have a record of surface carbon down there probably was CO2 at some point. So, you know, there could be loads [00:28:30] of carbon stored in diamonds. there is loads of carbon stored in carbonate rocks. So think any limestone or mar. You have marble countertops. If you have a limestone out your back door, that's a lot of CO2 stored in that baby right there. And

Chris Bolhuis: Mm-hmm

Dr. Jesse Reimink: those rock types on Mars or Venus necessarily that we know of. we might find some later, which gives us a record of ancient Mars or Venus, what that might look like. But I dunno, Chris, it kind of highlights for me the most interesting data point we could ever get from our solar system would be a rock from Venus because we could do these [00:29:00] same sort calibrations, these. Experimental tests on a rock from Venus. If we had a sample from Venus in a lab here at home on Earth, be able to tell a lot about the history of Venus, which I think is a really important comparison. We'd be able to kind of test this model, maybe even

Chris Bolhuis: And that's not gonna happen, at least not in the foreseeable future. You know, we're not gonna get a rock back from Venus. We're gonna go to Venus, you know, go back to our Marty Gilmore interview, which was amazing. And we're gonna put a probe on the surface [00:29:30] again for the first time in decades, but we're not coming back with. it's just going to, give us as much data

Dr. Jesse Reimink: from

Chris Bolhuis: here, right? It's gonna give us as much data as we can possibly glean from that little bit of time that it's gonna be able to survive on that harsh, uh, surface. But yeah, we're not gonna get a rock back anytime soon anyway, one other thing, right? Because you know, we talked about how plate tectonics is tied to carbon. Dioxide and the carbon cycle. Right. But [00:30:00] there's another part of that carbon cycle too, and that, that has to deal with our oceans. Okay. And so , why is Earth unique that we still have water? mean, we know Mars had water at one time. It lost its oceans. We really think Venus had oceans as well. It lost them. Why is earth able to retain. such a long time, it's oceans.

Dr. Jesse Reimink: great

Chris Bolhuis: I

Dr. Jesse Reimink: and very important question. About, which I don't think there's a [00:30:30] huge amount of consensus, lots

Chris Bolhuis: It

Dr. Jesse Reimink: ideas about it, but it might have something to do with the distance from the sun. You know, it's not our oceans, our atmosphere is staying intact or as is staying in this really, uh, Goldilocks, , habitable zone. Habitable zone where it's not getting blown away. It's not getting too thick, it's not burning off cuz the planet gets too hot. There's a lot of, uh, potential reasons. A magnetic field, you know, lots of potential reasons for that, um, that that could exist. But it's a very important one. [00:31:00] Or it could be plate tectonics. You know, water is cycling lot and plate tectonics. There's, this is sort of a chicken or the egg argument. Some people would like to think that water makes plate tectonics possible. Some people would like to think that plate tectonics makes our oceans, uh, long-lived.

Chris Bolhuis: and hey, funny thing, it all comes back to plate tectonics, Jess. It just

Dr. Jesse Reimink: it does, it does .

Chris Bolhuis: go round, you know?

Dr. Jesse Reimink: So fun. Well, I think Chris, that's a good place to wrap up our plate tectonics series here. This was a fun exercise [00:31:30] um, as hard as it was to convince me that it was a good thing

Chris Bolhuis: Like

Dr. Jesse Reimink: you were totally right and, um, this was really fun

Chris Bolhuis: Thanks. I, I will say this, that we might not be done yet because we might have office hours coming your way about

Dr. Jesse Reimink: covered

Chris Bolhuis: questions. We've gotten a lot of

Dr. Jesse Reimink: us

Chris Bolhuis: questions, emails about tectonic related issues, so we might not be totally done with it yet, but

Dr. Jesse Reimink: us

Chris Bolhuis: in terms of like our series, yeah, that's a, that's a wrap for that, but we'll, we'll definitely be coming back to [00:32:00] tectonics related issues for.

Dr. Jesse Reimink: Absolutely. And that's a great point, Chris. So if you have questions about anything we've in Plate Tectonics or otherwise, send an email. We are planet geo cast gmail.com. You can follow us on all the social medias. You can hit up there with dms as well. We are. Planet Geo cast on all the social medias. Go to our website, planet geo cast.com, and there you can like, follow, subscribe, and support us. And Chris, what else?

Chris Bolhuis: And the only thing I would add, Jess, rate us, give us a rating. Um, that really [00:32:30] helps us out a lot. Helps the algorithms and searchability and we like that.

Dr. Jesse Reimink: We love it. All

Chris Bolhuis: Yeah.

Dr. Jesse Reimink: peace.

Jesse Reimink

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