PlanetGeo: The Geology Podcast
PlanetGeo: The Geology Podcast
Field Observations - a How-To
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Dr. Jesse Reimink and Chris Bolhuis share their firsthand experiences and insights from recent fieldwork. The episode delves into their fascinating observations and discussions about various geological features, including lava inflation structures, such as tumuli and inflation pits, the stunning landscapes shaped by fjords in Iceland, and the deposits of eskers in the Northwest Territories. They highlight the importance of careful, methodical analysis in geology and discuss how to draw conclusions in the field accurately. Additionally, they emphasize the complexities and challenges of fieldwork, as well as the beauty and excitement of discovering geological phenomena in remote locations. The episode concludes with practical tips for supporting their work and engaging with further educational resources through their Camp Geo app.
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Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you. Okay.
SPEAKER_03Hold on, I'm not done. I'm not done clicking around, Jesse.
SPEAKER_00You're not done clicking around and you're not done sucking on that orange that you just literally inhaled. Are you hungry, Chris? You just smashed that orange.
SPEAKER_03Jesse, nobody eats an orange because you're hungry. You just eat them because they're delicious. Okay. Fair enough.
SPEAKER_00Fair enough. Well, let me tell you something, Chris. You just ate that orange like you were ravenous.
SPEAKER_03So well, I was I'm thirsty, so I have I have an orange in front of me. I have a big glass of water in front of me, and I have a beer in front of me.
SPEAKER_00So you're just ready to podcast, man.
SPEAKER_03I'm getting hydrated.
SPEAKER_00You are ready to. That's a podcasting setup if I ever heard one.
SPEAKER_03Speaking of which, you took a drink of something, and it it's shocking. You took a drink of something called liquid death. Yeah. Well, I don't I don't understand. That does not fit Jesse Rymanck's personality. Dr. Jesse does not drink liquid death.
SPEAKER_00So this is uh some insight into me. Um, this is liquid death, which is like it's just water, it's carbonated water. But I saw it in the gas stations a bunch, and I was it's in like the energy drink section, which I do not like energy drinks at all. Like have always hated energy drinks, but it's always in that section. And then I was listening to the podcast How I Built This, where he interviews people who make who start companies, and the founder of Liquid Death was on and explained it as he wanted to make water that looked like an energy drink and looked like Red Bull because he was like on tour and saw the Red Bull, like Red Bull sponsored skateboarders, and they were drinking out of a Red Bull can, but they just put water in the Red Bull can because they were like sponsored by Red Bull, but they didn't want Red Bull, they wanted water. So he made this thing anyway. I was like, oh wow, that's interesting. So I decided to try Liquid Death Water from the grocery store from the energy drink section.
SPEAKER_03Well, there you go. Now it all makes sense.
SPEAKER_00The world the world came back together with a long story about that, but it does, I think it still fits the vibe. Carbonated water.
SPEAKER_03It does look like an energy drink. Yeah, that fits the vibe for sure. Yeah, are you like a bubbly or lacroix kind of guy?
SPEAKER_00I mean, LaCroix's a little fancy, but yeah, the the discount brand of bubbly water for sure.
SPEAKER_03They leave me wanting, you know, like if you take a look at the beer. These no, but they're fruity, right? They have lemon, lime, and you know, grapefruit, right? And that flavor hits you, and then you drink it and it's gone before it should be gone. And so it just leaves me like, uh.
SPEAKER_00You want more.
SPEAKER_03I want more flavor. Yeah, right.
SPEAKER_00Yeah, yeah, yeah. I get it. I get it.
SPEAKER_03It's always so disappointing. Every sip is a disappointment for me.
SPEAKER_00So I wouldn't I don't quite frame it that way, but I see what you mean. I see your point. Yeah, yeah.
SPEAKER_03It's like, oh, this is gonna be so good.
SPEAKER_00Uh, it's not well. Hopefully, this episode is not like that, Chris. I think this episode is this is good, and it just keeps getting better and better and better because this episode, you pitch this idea. This is again, you're on fire right now. A couple of really good episode ideas. This is just field observations. We've both been out in the field. You you know did summer science, but you went to Iceland. I think that's probably where your most interesting observations, because that's a new place for you. I did field work up in northern Canada. I went along with some colleagues who had money to go to the Acasta Nice complex where I worked during my PhD. So it's kind of like going home for me in a way, academically and and sort of geologically. So we went there and we did some some stuff I hadn't done before. And so I don't know, we're just gonna talk about field observations, cool things you see in the field. And maybe, Chris, we could also talk about I don't know, the thought process as you're working through new things you've seen in the field, or how you like you know what I mean? Like how how do you think about it?
SPEAKER_03That's right. We kind of talked about that when we approached columnar joints. What would their thought process be? What questions would they have sitting there looking at these exotic, like atypical columnar joints?
SPEAKER_00Yeah, and I think that would be useful maybe is to do these kind of things, but more from the expertise, like flip it instead of saying here's a really common feature, the person who doesn't know anything about geology, how do they think about it? How about we are pretty good geologists who are seeing new stuff, new geological features. How do you approach new stuff as you're learning about it, or something like that? Kind of flip the script a little bit. So I'm curious because you're one of your topics is stuff I've never seen before, and I'm guessing things you never seen. No, you have though.
SPEAKER_03You have. So you were just young, you've seen this. I was a baby. Um, yeah, you were just a baby. It was it was uh pre-doctor, pre uh college, Jesse Remink. Creators of the moon. We saw some of this stuff.
SPEAKER_00Oh, okay. All right, yeah, fair enough. Fair enough. We uh actually saw that on our field school, um, our field camp, the Penn State field camp, like two years ago that I went on um at leading it. But we didn't Creators of the Moon was just a side trip, like it was a sort of a vacation. You didn't spend a lot of time there, yeah. No, we just went, it was like a tourist day for the students. There was no exercises, it was all just kind of like ooh and ah. So you're right though. I have seen that.
SPEAKER_03Well, hey, before we get into like everything, let's just a rundown of what we're gonna talk about today. We're gonna talk about lava inflation and the features that you typically or you might see when this kind of phenomenon happens. This is like a big lava flow field and the associated features with it. We're gonna talk about fjords, so we're gonna talk about those, why they're so beautiful and and how they form and why they're significant and important. And then you're gonna talk about some rocks that you saw in the Northwest Territories. What what do you want to talk about with those a little bit?
SPEAKER_00Yeah, I guess two things. Like one is sort of more philosophical, just it really struck me that these rocks, the Acostanized complex, which I studied for many, many years, tons of people have studied for the last several decades. We still don't know a lot about them. Like, there's some basic stuff we do not know. And it kind of struck me that if we don't know this basic stuff about these rocks, like, man, there's a lot of work to be done yet. So that was one. That was kind of, I don't know, theoretical, philosophical, something like that.
SPEAKER_03You know, it's interesting because you were with Dr. Mike Ackerson from The Smithsonian, and it seems like every time we talk about that's right, and we're gonna get him on here again soon.
SPEAKER_00We have to, yeah, absolutely.
SPEAKER_03Yes, we have to. But it seems like whenever you talk with him or about him, you talk about these things that we just don't know that we should know that seem so basic. It's you know, like what is a magma chamber, you know, or how does granite form?
SPEAKER_01You know, these things that's a really good point. This is uh elementary geology, yeah, yeah, yeah.
SPEAKER_00Mike and I Mike and I are are nerds of the same ilk, you know, that worry about the same, you know, bait I don't know, what seem to be basic problems that are still problems. So that was one. And then the second one is we were sampling some eskers and we were up in the Northwest territories, and it kind of struck me how amazingly cool and valuable these escher trains really are. So that kind of links to the fjords. So, Chris, before we get into it, really quickly, let's just advertise our Camp Geo app. If you are looking for ways to support us, you can click on the first link in your show notes. Takes you to our Camp Geo mobile app. There we have loads of free content. We have basically, Chris, your intro to geology class. It's a college level class you teach the high school students. My intro to geology at the Penn State level, the first class you take in a college-level geology course or curriculum. We have that for free there. And we also have audiobooks you can purchase. So download the Camp Geo app and the first link in your show notes and leave us a rating and a review. If you see something you like, go ahead and purchase it. That helps support us. So, Chris, uh, why don't you take it away here and uh talk about I've like we said before, rarely seen these magma inflation features. Is that a good categorization for what you saw and what you want to talk about here?
SPEAKER_03Yeah, the first thing that that struck me, and I've seen these in three different places because I did my field work in New Mexico, and I saw these same kind of features there that we're gonna talk about today. Craters of the moon has some of them. I don't I don't know if they have all of the features I want to talk about. And then of course, I just got back from Iceland and it was towards the tail end of our trip, maybe the last week we were on a three-week trip, and the the tail end of that trip, we just drove across this expansive lava flow, and you saw all these really interesting features to the point where Jenny sitting next to me is like, Chris, what's that? What's going on? And so we'd pull off and take a walk on the lava field and and you know, just verify that, yep, that's what we're looking at. It was really, really cool stuff. So lava inflation. I don't know. I think the name is kind of intuitive. What Jesse, you're not really familiar with this kind of stuff. Do you know anything or what do you think lava inflation would be?
SPEAKER_00Lava inflation or magma inflation?
SPEAKER_03Lava inflation. Lava inflation.
SPEAKER_00Yeah. Okay, yeah, this is interesting because uh, you know, I know as much about volcanoes as like your average undergraduate, uh advanced undergraduate. Uh, my guess would be that it's lava's flowing, the top gets crystallized and and is sort of solid, like I think a lava or pohohe lava. The the bottom is still flowing and liquid, and so it kind of flows up and down, and it's kind of like a river system with a solid top to it. Is that what we're talking about? Like the the sort of topic. Exactly.
SPEAKER_03It's exactly right. Okay. Think about a lot like a think about a basaltic or mafic lava flow, which is going to be very thin and runny and low viscosity, and it has a solidified crust. It's out of the lava tube and it's it's starting to sprawl and expand, right? And you get this solidified crust, but it's still being injected with fresh material. And so what happens, right? It has this solidified crust, and so it just inflates up toward the crust because that's the path of least resistance. Imagine the lava flow that's taken a big deep breath, you know, how like how you take a deep breath and your chest expands and it heaves, and that's what's going on with lava inflation. That's I guess that's my best way of kind of simplifying this whole process.
SPEAKER_00So, two two questions for you. One, what are the features that you saw that were related? How how does this represent itself on the surface? Like you're driving across this lava field. What is Jenny pointing out and saying, Chris, what's that? What are the features? What are the category of features, maybe?
SPEAKER_03So I want to start by talking about a feature that's called tumuli. Tumulus is the singular and tumuli is the plural version of this. It's spelled T-U-M-U-L-U-S for tumulus. These are prominent, they're fairly obvious because on top of this lava flow, this mafic lava flow, you have these like dome-shaped structures. I guess typically less than like 10 meters high or you know, 30 to 33 feet uh high at the most. We didn't see any that were that big. But when you have lava inflation, you have building pressure and it causes the lava flow to kind of buckle upwards, and molten magma can be squeezed out through these pipes or through fissures. That's how you get this tumuli. So think about like on top of a relatively flat lava flow, a domal structure, maybe 10 meters high at the most, and it just kind of looks like it was a pipe where lava extruded out of that dome.
SPEAKER_00Okay, cool. Does that make sense?
SPEAKER_03It's totally so it's this it's this pressure building up, the lava then is finding the path of least resistance, and it just exploits that. So what we saw in Iceland was this expansive, relatively flat lava flow with all of these domal structures on top of it.
SPEAKER_00Okay, very cool. And how I mean, how many? If you're looking out, if you're sitting there in your car and you're looking out, how many are you seeing at one time? That's a good question. Or like one or two.
SPEAKER_03Oh, yeah, dozens, dozens to they are all over Jesse. Uh in this one area. I mean, we did a drive, and you know, it was a few hours long. We were going from one place to another, and we probably saw hundreds of these tumuli.
SPEAKER_00Yeah, oh, very cool. Okay. All right. Um, that's one.
SPEAKER_03And then another feature that we came across were these what are called inflation pits. Um now, when I think of like an inflation pit, I kind of I don't know if the name is a good name because it is it's it's kind of like this. So if you have this lava flow that encounters an obstacle, the lava then gets squeezed around the obstacle, right? So it kind of like thickens in front of the obstacle and then gets thin around it. Does that okay? Does that make sense?
SPEAKER_00Yeah, yeah, yeah, yeah.
SPEAKER_03So here's what they look like. These inflation pits, they look like a collapsed lava tube, but they're not. Okay, so it's like this thinner area that cooled faster because the lava was being kind of squeezed around an obstacle in its way. So you had this thinner area that just cooled faster than everything else around it, if that makes sense.
SPEAKER_00Yeah, yeah. It's like uh a river flowing around a rock. Sometimes, you know, it'll kind of dip down first and and the as the water's flowing around there, something along those lines, kind of roughly.
SPEAKER_03Imagine a dried up river valley, except it's all lava, you know, mafic basaltic lava flow, and that's what an inflation pit looks like.
SPEAKER_00Okay, yeah, yeah, yeah.
SPEAKER_03And I think like a lot of people, in fact, I heard this once when we were out in Iceland. Somebody was saying, because there are lava tubes all over the place in Iceland, too. Somebody was saying, I think that this is a collapsed lava tube, and and it's not. I can see where somebody would make that deduction. It does look like that.
SPEAKER_00Yeah, interesting.
SPEAKER_03Okay, cool. And then the other thing that we saw tons of were these inflation clefts. And this is where you kind of get this this inflation builds the pressure up below, and you get this kind of ridge that cracks on the top like a fissure. And those, to me anyway, resemble because they're kind of like the long and skinny shaped, you know. They're that's why they're called inflation clefts. They resemble a lava tube. But again, they're not.
SPEAKER_00They're not. Okay, because they're not hollow inside, they're not they're not hollow inside, absolutely.
SPEAKER_03This was a part of a relatively flat, very expansive lava flow that then inflated because of the solidified crust. So instead of getting the tumuli, you get not a dome, but a ridge that is split on the top, and those are called inflation clefts. And so we saw tons of those in Iceland on this trip, you know. And I like I said, I've seen them too in um craters of the moon in Idaho, which is a very, very cool place and geologically very interesting, and then also in New Mexico.
SPEAKER_00Uh, but probably not, I'm guessing I've got so many questions now. Probably you haven't seen these on the same scale as what you saw in Iceland. I'm guessing. Is that would that be accurate? Like, are they just bigger or more prevalent in Iceland?
SPEAKER_03Okay, so that's a very hard question to answer. And and the reason is because we traveled so much in Iceland. I mean, the amount of driving that we did to get from place to place, we didn't do a lot of sleeping, you know. We're like our motto was we can sleep when we get home. And so we just wanted to it's it's going well.
SPEAKER_00How's the sleeping when you're home?
SPEAKER_03It's it's good, but I did tell you we just got a new puppy. Yeah, okay.
SPEAKER_01So yeah, yeah, yeah. Okay.
SPEAKER_03So kind of last night was the first first full night. Yeah, so but now she's doing great. So it's hard for me to say because craters of the moon is big. That whole national monument is massive, but the you know, they don't have the infrastructure to traverse all this stuff in a way that you that I could do in Iceland. So I don't know how to answer it. It's a really good question, but my guess is not nearly as big. Yeah, okay.
SPEAKER_00Just because Iceland is what was my other question? Oh, another question for you. Sort of back to our conversation earlier. What are you thinking? You've seen this stuff before, you're in a new place. Stuff always looks different in a new place. In a different place, they all look different, the same features will look different. How do you I don't know, I'm trying to visualize the conversation. How do you start to think about it? What is going through your mind when either Jenny asks you, Chris, what is this, or you're just driving and you're like, oh, that's obviously something I need to, you know, spend some time thinking about. How are you parsing through this?
SPEAKER_03I'm parsing through it by most of the time I know what I'm gonna see before I see it because I've done my research before I got there. And so I'm so different than you in that I learned the geology and then I go see it. And so I'm I'm relying upon what other people have done, if that makes sense, you know.
SPEAKER_00Um so how does that work with your terrible memory? Do you like get there and you're like, oh, I forgot I read about this, but I don't remember what they said?
SPEAKER_02How does that never happen?
SPEAKER_03Yeah, that has happened. But you know, Google's a wonderful thing.
SPEAKER_00That's true. Yeah, okay, fair enough. Fair enough. But more like, okay, maybe stuff that I'm sure you saw stuff that you didn't know. So how if you come across something, your Jenny asks you something, it's not obvious. What do you I think our listeners would would really find this conversation valuable? Like, okay, you know what you're supposed to be seeing, but it doesn't really doesn't really match. How do you work through it to explain it to your wife, who's very smart and very curious, but not a geologist.
SPEAKER_03So I I know exactly what you're talking about because I can think of a couple of specific situations when we were backpacking on day one and yeah, walk us through those.
SPEAKER_00This would be really interesting. Walk us through one of those. Like that'd be great, I think.
SPEAKER_03So Iceland has rhyolitic lava activity in addition to semanticitic and and a lot of mafic stuff, right? We talked about that, I think, during the summer on our summer break, if you will. We had an episode that we preloaded. So we were hiking across this, and I came across a rock that I didn't readily know, like, oh my gosh, that's what this is, right? It wasn't just that's rhylite or that's obsidian. We saw tons of obsidian too in the highlands. And I'd pick it up and and look at what kind of rock is it. I had to literally take a step back and think about what kind of rock am I dealing with here? Is this igneous? Is this sedimentary? It's not metamorphic, but is it igneous of sedimentary? And the and to be honest with you, it looked sedimentary. There were a couple reasons for that. One is there were some lahar deposits that we came across that was confusing for a minute. If that does that make sense, you don't expect you just don't expect to see that. You got these massive mountain peaks around you. In addition to the to the Lahar deposits, you also had some volcanic breccia that was there. These are not common rocks.
SPEAKER_00Not common anywhere and uh and maybe unexpected in Iceland too.
SPEAKER_03So you come across these and and I think you just have to kind of take a step back and say, all right, what what can I see in this rock? First of all, like what kind is it? Let's get that out of the way, and then go from there. So start like really, really broad and then try to narrow it down from there and and and just you know, process of elimination is important.
SPEAKER_00No, what'd you end on? I mean, what was the do you think you're confident in your ending evaluation or decision?
SPEAKER_03Well, we definitely came across some Lahar deposits. We definitely saw some breccia, some volcanic breccia, not sedimentary breccia, which is the maybe the more common kind of breccia. And then also, you know, we came across some ignimbrites and other more obscure kind of igneous things. But I was able to kind of draw upon this is rhyolytic volcanism, and what are the some of the things that you can get with rhyolytic volcanism? I mean, you could these are massive peaks, Jesse. I mean, this it's so so impressive. But I have not, to be honest with you, have not done any further looking into what we saw. And this is obscure areas. I mean, we're backpacking here. So this is you, you know, you have to be one or two days away from any kind of civilization at all.
SPEAKER_00So they've been mapped maybe once by a geologist or maybe twice, you know. Maybe, yeah. These are areas that that geologists have walked across, but maybe not that specific outcrop or or something. These are not well traveled uh areas with with road signs explaining the geology.
SPEAKER_03Kind of similar to you, you know, you your area that you go to in the Northwest Territories is there aren't a lot of boots that traverse that on a year-to-year basis.
SPEAKER_00Yeah, that's right. That's right. So, I mean, just a couple thoughts. I think that's exactly the right way to go about it. I think if people have a flaw in their thinking, I think they they start from a place of like fantastic discovery. You know, if you find a piece of mica, a little flake of mica, you think it's gold. You don't think it's mica. Your mind goes to the the most fantastic version of the story that you could possibly have. Instead of like starting, as you said, very broad and then narrow down in a kind of a conservative manner, what's the simplest explanation? What's the most reasonable explanation for what I'm seeing? I've got a, let's say, I don't know, you've you've got a volcanic breccia in your hand. You're thinking, holy crap, is this a sedimentary breccia? Like that'd be amazing to find on Iceland and so weird. If your answer is it's so weird, maybe you should kind of set that one aside and say fantastic discoveries require fantastic evidence. And I don't have that yet. So, like, you know, kind of work from the simplest thing forward. I that sounds totally reasonable to me, but it is hard. Like, even somebody who is an amazing geologist in the Northwest Territories of Canada would not be able to go to Iceland and pick it up super easily because the rock types are different, the geology is so totally different. It takes a while to get tuned in to specific regions, you know, and the rock types in that region. So hence this is why geologists become specialized in certain rocks and certain areas and certain, you know, mapping types. So that's right.
SPEAKER_03There were other times when we would just see strange stuff and we're driving down the road, let's say, and Jenny would say, Chris, what's that? I have no idea. When I'm not really familiar with an area that I haven't been to again and again and again and again, I can't do roadside geology at 75 miles an hour. Just it, you know, I'm not that good. You know, I don't know. If you really want to know, then we gotta stop and we gotta get out and we gotta go look. And maybe I can tell you something about what we're what we're looking at. Maybe not though.
SPEAKER_00You can make a more educated guess than than the average person, but also no guarantee it's right. You know, I mean it it's an educated guess, still the same. So yeah, I think that that maybe that's a good transition point, Chris. To the first thing that I that stuck out to me when we talked about okay, field observations. What observations do you make in the field? The one thing that stuck out to me is I'll sort of set the stage a little bit. You know, there's Mike Ackerson, two postdocs, myself, and we're flying up to the Castanice complex. So this is get yourself to Yellowknife, which is a a little town or a little city, depending on what you call it, of 20,000 people. It's kind of the end of the road in the Northwest Territories. You can't go much further north on any road of any of any type. And so from there you're in float plane country. So we take off from the float base and we're in a small float plane, and we land up two hours north on the Acosta River system on a beach, and we set up camp and the plane takes off. And now we're in the Acosta Nice complex. This really sort of storied thing. We we have an audiobook on Earth's oldest rocks that is in our Camp Geo app that we have a couple chapters on the Acosta Nice complex. So check that out if you're interested in this, in more of the science behind it. But the Acosta Nice Complex has been studied since the late 80s and and has been known to be really old, has four billion-year-old rocks up there. I did my PhD up there, so I've spent four months of my life, or more than that, maybe even camping in this location. So I've been there a bunch, you know, many other people for decades have been up there. It's a place where geotourists go as well. Random geologists will come visit for a day because they want some samples. So it's one of these, it's remote, but it's Can I interrupt you, Jesse?
SPEAKER_03Because I want to paint a picture for what this looks like. I mean, you're talking about an area that's so remote, it's north of the Arctic Circle. I think the tree line is what, 400 feet, Jesse? Is that about right?
SPEAKER_00Oh, I don't know where tree line would be, but we're we're near there's not much elevation gain. I mean, we're like there's not much elevation change. I mean, there are hills, what I would call big hills, or here in Pennsylvania we call them mountains, but low hills around, yeah.
SPEAKER_03A lot of like inland lakes and things like this, lots of water. Yeah. The trees are not very big. No, they're scruffy if you have them. You have to cook, you have to cook in a different area than you sleep, right? Because the brown bears and and so on. Do you carry bear bangers with you?
SPEAKER_00Bear bangers and bear spray on you all the time, even if you're just walking around camp. So yeah, it's that it's that kind of thing. It's very flat. It's like um, you know, Montana on steroids, that sort of big sky feeling because there's the trees are really scruffy. Once you get up into the we're right on the edge of what's called the Barrens, where you get into the barrens, there's no trees and there's very little vegetation. So you get up there and it's like why it's big sky, like wide open sky country, and the you know, long daylight because we're at Acosta, we're right near the Arctic Circle, but we're not in the Arctic Circle. This is super remote, but being that remote, it's quite highly trafficked because it's a very old area and people have studied it for a long time. So we're four PhD level geologists on the outcrops, like talking about them. None of the other three had been there, and I was the only one who'd been there. So I was kind of like touring a little bit, you know, saying, Here, here's what this looks like, here's here's a different outcrop, here's what's been studied on this one. Let's go to these outcrops over there and look at those ones. Here's how they're different. And what I took away from those conversations was you know, the other geologists with us were asking really reasonable first order questions. Like, what is the age of that little mafic area of the outcrop as compared to the other mafic unit on the other side of the outcrop? So walk to the other side of this in an outcrop, is maybe the size of a room in your house. So in that corner of your room, you've got a mafic rock, on the other corner of your room, you've got another mafic rock. What are the ages? And the answer is we don't know. Like, we don't know. Oh, do they cross-cut one another? We've talked about cross-cutting relations, and you know, if something is cross-cutting another unit, it must be the youngest one, and then the other one's the older one. Cross-cutting relationships up here get really hard to actually tease apart because the rocks have been stretched. Think of like toothpaste, you stretch them into kind of parallel paths, and it's hard to tell what's cross-cutting what, and you just can't work it out in the field. So those are really like first-order basic fundamental things that we don't know. And the answer was we don't know. And so we're having this conversation in a place that's had 50 years of you know high-level research done on it, and there's a lot we just don't understand.
SPEAKER_03So I have some I have a question about that. Then why can't you just knock off a sample of each of the metamorphic rocks and then take it back to your lab at Penn State in a radiometric datum?
SPEAKER_00So that's a very good question. We could, for sure. But here's where it becomes like a cost-benefit analysis, which is okay, we're up there, we've got these two rocks right next to each other. How much do I care? It's a really basic first-order thing, but the question is how much do I care about the age difference there? Because we spent 30 grand at a minimum to get up here with four people, it's probably more. Taking those samples back is gonna cost us a bunch, shipping it back, doing the geochemistry, doing the geochronology, it adds up pretty quick. So you gotta care. That's gotta be a really important question. And so part of it is that no one's really cared enough. There are some people who've gone in different outcrops, like and said, Okay, there's an outcrop over here, we're gonna rip it apart and do all the detailed stuff on that particular outcrop. But there's a handful of them. I did that on a particular set of outcrops in one area, but but landing at the camp, this is where everybody camps, and there's an outcrop right there, and nobody's done it on that outcrop. You're kind of like, what the heck?
SPEAKER_03So this was more of just a philosophical thing where you're like, I can't believe we don't know this, but we could.
SPEAKER_00We could potentially, with a lot of work on one little room-sized outcrop.
SPEAKER_03Did this lead to a discussion, you know, sitting around at night after dinner and talking about geology and stuff we don't know that we maybe should know or could know?
SPEAKER_00And yeah, it led to a couple things that you know, certainly those kind of conversations like why don't we know this? How important is this question? How would we answer it? Kind of laying out a roadmap for how would we answer it and and should we pursue that path? It also led to so Mike Ackerson, his one of his primary goals was to collect samples for the Smithsonian research collection, because they don't have a suite of acostanized samples, and it's a really famous location, so they thought we should have some for the Smithsonian research collection so that other researchers could use it however they want for the next century. So part of the goal was to do that for him. And they had a really cool idea, which was you're visualizing it. We're on this beach, it's maybe a couple hundred meters, several football fields long, this beach on an island, and then you're looking out in this kind of this beach is in the interior of a bay, and on the right side and on the left side, the left side in particular, is a series of cliffs. I mean, they're low cliffs, they're not more than a hundred feet tall, but right along the water, there's these cliffs, and you kind of walk around, and those are kind of the discovery ones. So, Mike's idea, the rocks are kind of you look at the cliff, they're tipping into the ground away from you. They're kind of tipping, they're tipping up into the right, and then also back into down into the ground past you. So they're kind of the rock layers are dipping away from sitting on the beach. And Mike's idea, which is really a good one, was to take the boat, a little we had a little inflatable zodiac boat, and just collect a sample every five feet along that whole peninsula, and you kind of end up getting because the rocks are dipping away from you, as you go along there, you'd kind of end up getting kind of like a drill core through the sequence.
SPEAKER_03You kind of get getting younger and younger and younger rocks as you go further.
SPEAKER_00Or these are layered and tilted, so it's not clear entirely clear which way is up, but it it's you would get different ages as you go through. You get kind of an average, and you'd be able to do this detailed work if somebody wanted to. I mean, his goal was to sample for a collection, and if somebody wanted to do that type of work, they could and wouldn't have to spend a bunch of money to get up to the Casa Nice complex. So something like that is a really, I think, great idea, like a really valuable sample set to have and to generate um being at the Smithsonian. So it's one of these like lessons that I think it'll it'll go with me, this lesson or this sort of idea of just how little how hard it is to extract a lot of information from rocks. It can be different. Okay, all right.
SPEAKER_03That's a really interesting point. Because I think how many times have I picked up a rock and just been blown away by what that rock tells me in 10 seconds? It's an incredible amount of information, right? What a story that's locked up in that rock. And now you're saying kind of just the opposite, which I find to be really interesting.
SPEAKER_00Yeah, I think okay, let's maybe uh tease that apart. I think it's probably really easy to be 50% confident. You know what I mean? Like it's really easy to say this is a shale, so it means this broadly about the earth at this point in time. I think it's really hard to get to a hundred, it's like nearly impossible to get to a hundred percent confidence and say this is a shale with this particular sequence of fossils in it, or this particular like, I don't know, depositional setting, and really paint a very, very specific picture. So it gets harder the closer you get to a hundred percent information. And in the case of the Acosta Nice complex up here, because you have to do geochronology and all this stuff, it gets really hard to get over 50% of the information out of the rock. So it's easy to point to and say that's gotta be old, that's pretty old because it's metamorphosed multiple times and it's really deformed and it's sitting in this old terrain. So it's easy to say that's a pretty old rock, which is a lot of information out of it, but it's hard to get to that really certain area. I I don't know, that's just a off the coat.
SPEAKER_03That's interesting. So you you said it's really easy to be 50% confident. You know, you got a little long-winded there, and while you were doing that, I just looked up um the Lahar deposits. I just looked up the Lahar deposits in Iceland. There are two fairly prominent Lahar deposits in Iceland, and both of them we traversed them when we went on the Lagovegar Trail backpacking. One is a volcano called Hecla, it's like 3,900 years ago. And then of course, the other one, uh you know, I'm gonna really butcher this because it's Icelandic. Aya Fialeka. That's horrible, but anyway, the volcano that erupted in 2010 disrupted travels in Europe and so on.
SPEAKER_01Well, there you go.
SPEAKER_03So we traversed both of those I think. That's a really good way of putting it. It's easy to be 50% confident, you know.
SPEAKER_00But uh, before you looked that up, you would have probably put what 90% confident in your assessments in the field before looking it up and sort of and then now you're probably like 98% confident after looking it up, or you know, that the right I felt good about it because I went through this, you know.
SPEAKER_03I went through the process of all right, what am I looking at here? Because this is really weird. So I I went through that kind of mental process of all right, process of elimination, keep it big, work small, keep going smaller, keep going smaller. This is what I think we're dealing with right here.
SPEAKER_00Yeah, that's great. Okay, fjords. We're getting long in the tooth here a little bit, but I want to hear, let's do a quick five minutes on fjords, five minutes on uh on eskers, quick.
SPEAKER_03Yeah, so a fjord is a basically it's a flooded U-shaped valley. So where you have a continent that meets the ocean during the ice ages, sea level was lower. The continent was bigger during that time, just by default, because sea level was lower. Glaciers then had further to go to get to the oceans. When the glaciers melt, the climate warms up, glaciers melt, sea level rises, and it floods those U-shaped valleys, and those are called fjords. So you have this really long finger of oceanic water that reaches up into the continent that's surrounded by a land peninsula on each side of it.
SPEAKER_00And really they are steep-sided. I mean, U-shaped valley, you're talking about steep-sided erosion, really deep cliffs diving right into the. I mean, the visual I always think of is if you just picture Norway in your head, any photo you've seen of Norway, that's probably what your a photo of of Norway is, is like steep-sided things diving into water. That that's so cool.
SPEAKER_03Jesse, uh we spent a lot of time on the peninsulas around the fjords, driving up to the end of the peninsula and around again and crossing over the mountains and so on. A lot of time doing this. And because in in Iceland you can disperse camp. And so basically, as long as you're not on like private property or farmland, and you know, you can just camp. And so Jesse, the views that we camped at, because we would just drive and be like, I don't want to go any further right now. This is too beautiful for me. And we would just stop right there and either pitch a tent or car camp, and it was uh just amazing. And so we did that almost always on a beautiful fjord.
SPEAKER_00I mean, so pretty. That's just so cool.
SPEAKER_03We also this is where we saw we in one of the fjords, we saw puffins. Jenny had to see the puffins, and I'm really glad we did because we were able to get so close to them, like literally two feet away from puffins, like they were just all over the place. At this same place in the fjord, uh, we saw three humpback whales. So that was and really, really close. We walked out onto a rock outcrop, and I looked down, I'm like, oh my gosh, Jenny, there's a whale right there. And sure enough, it was just so I'd never seen that before, and so that was that part of the biology excited me.
SPEAKER_00Yeah, as it should, as it should, despite our you know, sort of disrespect in some ways for biology. That should excite you. That's a good one. I mean, that's cool. Fjords are just spectacular.
SPEAKER_03Um, you had some glacial features too, right? That yeah, like so.
SPEAKER_00We I mean we're up in the still on the Gaunton, obviously, but where the we're dealing mostly with erosional features in the glaciers. Well, it scraped the land clear and flat, but then we have the as the glacier retreated, you have these depositional features. And we were interested in sampling eskers because eskers are really good at sampling the rocks upstream of the glacial field. So in Acosta, the Acosta area, the eskers are flowing east to west because the glacier was flowing east to west there. Let's set the stage on what an escher is, Jesse. Oh, yeah. Okay. So Esker is it's a landscape feature, and when you see it's basically a long low hill or ridge of sand and gravel, and it's a depositional feature. It's a stream that was coming out of a glacial front, so a continental scale glacier. As it's melting, the front edge of that glacier is melting out, and as it's melting, it's producing water. That water's got to go somewhere. It aggregates into streams, you know, a bunch of streams coming off the front of a glacier, and they will carry stuff with them and dump them out, and it'll dump out sediment. And that sediment ridge that's left behind is what's called the escher. And so there are. That's right.
SPEAKER_03So this is this is a stream that is on top of a glacier, or it's even within a glacier, within the the vertical column of the glacier itself. But glaciers are dirty, they have lots of sediment in them, so these rivers are picking that sediment up. A river in a glacier or on a glacier has everything else that any other river has. It's got stream banks, it's got a stream bed, and basically then this sediment is sorted because it's deposited by running water or just happens to be associated with ice. And as the glacier melts, it just kind of sets this stuff down on the glacial deposits that were deposited previously.
SPEAKER_00That's exactly right. And these eschers are kind of winding, they're described as sinuous. They're winding sinuous features on the landscape. They can go for hundreds of miles as a consistent escher system. However, there's a bit of debate about whether that was one continuous sort of glacial river segment or whether it kind of was broken apart. And we're interested in eskers because that sediment that is aggregating the eskers is really kind of formed from the basement, the bedrock that's exposed underneath the glacier upstream. So we're kind of using the eskers as a sort of a sampling tool to figure out what's upstream. So they're amazing features. And the way to think about this is you got a big glacier that's like kilometers thick, and then at the leading edge of it, it's melting out. That's where the glacier is melting. And so the river will form on the surface typically, and then it kind of runs down slope towards the nose of the glacier. And at the nose of the glacier, where it really starts to melt, it starts to break apart. The glacial ice breaks apart. And the river, as soon as it hits one of those fractures, will dive down to the base of the glacier, and that's where it starts to pick up the sediment. So it'll be like clear, perfect water that goes down a crack and then is running at the base of the glacier, picking up all the sediment and aggregating it. Anyway, esskers, we should do a whole episode on eskers, I think, because they're just amazingly cool. They're great tools for exploration. And if you go back and listen to our interview on the diamond mining, Eskers were really, really instrumental in discovering the diamond deposits up in the Northwest Territories. And so Mike and I were in the float plane. We were going up to sample this esker system up in the Arctic Circle. We landed on this beautiful, amazing, huge lake that you could see 30 feet down, crystal clear water. It's just stunningly beautiful landscape up on the barrens. We landed near an escher, and we're like, Oh, we're gonna go sample that escher. We park on a little rock slope, sort of outcrop dipping into the water, park the plane. We jump off, and Mike immediately goes, Oh, this is a Kimberlite. And Kimberlite's this really rare rock that brings up diamonds. It's volcanic eruption that brings up diamonds from the deep mantle. And it's what if you're looking for diamonds up there in the Northwest Territories or anywhere, you're looking for Kimberlite pipes, and it's a totally rare rock. And he could he identified it like a snap. And and I've I've seen Kimberlite, but not like he has. He's seen the Smithsonian collection of Kimberlites, and so it's just a rare rock that Chris, if like you or I, if if I wasn't with Mike or if I landed on it not knowing, it'd be easy to walk across this and think, oh, this is some weird Breccia thing. But it's a Kimberlite. We landed on a Kimberlite. Is it an ultramafic rock? They're typically ultramafic and they usually have these classes in them, but they can be it. This Kimberlite was a relatively big one, several hundred meters to a sort of a kilometer wide. It varied a ton. We were walking for maybe a hundred meters along the shore, and it varied a ton. The the just the type of the Kimberlite material, it looked so different. It still looked like a brecia of some kind, but totally different across there.
SPEAKER_03So they get is that because it was the Breccia part is because it was ripping stuff up the walls as it came from deep down?
SPEAKER_00The magma itself is pretty pretty limited amount, and it just come brings up everything with it. And it turns out that we had landed on a Kimberlight pipe, that or very near one, and De Beers had looked for diamonds around there. There's an old De Beers camp, exploration camp, you know, a couple miles from where we landed that we flew over on the way back. Like, oh, that's a De Beers camp. Okay, that's the one that was on the map. Anyway, so two things. It was an amazing experience sampling eskers in the Arctic. Beautiful day, beautiful weather, like landed there. It's just stunningly cool to think about these escher systems, how they're working, the continental scale glaciers that deposited them, and also how valuable they were for the diamond prospecting and any sort of economic mineral prospecting as a tool. And then we landed on the Kimberlite. The other thing that struck me was we landed on the Kimberlight, and Mike immediately could identify it. And I took a little bit because he's again seen the rock collection, the Smithsonian Kimberlite collection, which is a great way to get your eye tuned in. So even really good, really practiced geologists, you got to tune your eye into the rocks that you're looking for or looking at, because they're not entirely obvious without that. So especially these kind of rare rock types that we've been talking about.
SPEAKER_03It speaks to what I've said before, but the best geologist is the geologist that's seen the most rocks. It's true. It's true. In work through. There's some truth to it.
SPEAKER_00That is definitely true. Exercise that muscle of seeing something you don't know and working through maybe not to the correct answer, but towards the correct answer. You know what I mean? Like you could have identified the rocks you saw as something close to it. Even if you got to this is not basalt, this is probably uh felsic rock. You're going in the right direction, at least, right? And you got to do that over and over and over, and then the closer you get to the right answer in a new area when you're coming across something new.
SPEAKER_03And I had to think this through also because when we came across this obsidian, it Jesse, world class obsidian, and big, yeah, um, beautiful stuff, working that through. You're like, wait a minute, you know, obsidian forms from felsic rocks and not mafic rocks, but the obsidian was black, and then just think about where you are, right? And and this again was early on in our backpacking trek, and it made sense because you had these really, really felsic rhyolytic lava flows all over the place, and that's where the obsidian came from. So you don't typically think, oh, I'm gonna see obsidian in Iceland. Yeah, yeah, no, because uh most of the rock is black rock, you know, and so it just kind of catches you off guard. It wasn't something that I expected to see. It did. Yep.
SPEAKER_00Yeah. To the listener, you you need to practice that to become you know pretty good at rock identif, even something simple like rock identification, you just got to do it over and over and over, and then check yourself and figure out how close you got to the right answer. And it's okay if you don't get to the right answer, it's best if you get close to the right answer and then you go wrong, but you know, you you don't want to miss the first thing, you don't want to start from oh, what is this and and go down the sedimentary route when it's really a metamorphic rock or something, you know, something big like that. So, you know, we've had episodes about how to identify rocks before, but uh in the field, these field observations, like you you definitely have to step back, work slowly towards the direction you think, and always be testing yourself and proving yourself. And if you get 80% right, great. If you get 80% there, that's great because it's hard to get to that 100%. You know, it's really hard to be totally confident interpretation.
SPEAKER_03It really is. Well, and that you know, I did think about something that you said that you got from your advisor back when you were at the University of Alberta, which is you really can't identify a rock with 100% certainty until you take it back in the lab. That thought came across my mind quite a bit actually when I was in Iceland, and I came to the conclusion actually that that that is such an accurate statement.
SPEAKER_00I mean, it's really it's it's disheartening, but I think you know, with enough experience like Chris, you you know, you you and I both have a ton of experience. We've been tricked a bunch too. With that experience of being tricked many times, you kind of get more cautious and you're like, I I think I'm at I'm seeing courts in this rock when actually there's no courts there. And you know, that can be a really big deal if you get that one wrong as far as identifying the rock. So you just have to go be tricked a bit.
SPEAKER_03With areas that are well established and and well researched, and you pick up a rock, you know, you go to Devil's Tower, you know you're looking at a phonolite porphyry because that work has already been done.
SPEAKER_00It's where traversing like when you're a couple days in the backcountry of Iceland or you're in a remote area where where we don't nobody's mapped it in super, super gruesome detail. So all right. This conversation we could we could go on and on and on about field observations and field work because it's just so fun. I mean, it is one of the more fun parts of being a geologist, I think, is working through the kind of construction. It's the best part problem solving. Yeah. Seeing the stuff out there is just amazing. So what do you think, Chris? Is that a wrap?
SPEAKER_03I think that's a wrap.
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