Field Observations
Learn With Images on the CampGeo App -
download now to get started!
[00:00:00]
Okay, we're on. Red light's
Chris Bolhuis: Hold on. I'm not done. I'm not done clicking around, Jesse.
Still.
Dr. Jesse Reimink: You're not done sucking on that orange that you just literally inhaled. Are you hungry, Chris? You just
Chris Bolhuis: no, no.
Dr. Jesse Reimink: that orange.
Chris Bolhuis: Jesse, nobody eats an orange because you're [00:00:30] hungry. You just eat them because they're delicious.
Dr. Jesse Reimink: alright,
fair enough. Fair enough. Well, let me tell you something, Chris. You just ate that orange like you were ravenous, so
Chris Bolhuis: 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.
So
Dr. Jesse Reimink: you're just ready to podcast, man.
Chris Bolhuis: I'm getting hydrated.
Dr. Jesse Reimink: You are ready to That's a podcasting setup if I ever heard one.
Chris Bolhuis: Speaking of which you took a drink of something and
[00:01:00] it's shocking. You took a drink of something called liquid death. I don't understand, you that does not fit. Jesse Reimink personality. Dr.
Jesse does not drink liquid death.
Dr. Jesse Reimink: so this is a, 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 I've always hated energy drinks, but it's always in that section. [00:01:30] And then I was listening to the podcast, how I built this, where, he interviews people who make 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 [00:02:00] try liquid death water from the grocery store from the energy drink
Chris Bolhuis: Well, there you go. Now it all makes sense. The world, the world came back together
right
Dr. Jesse Reimink: we go. That was a
long, a long story about that, but it does, I think it still fits the vibe. Carbonated water.
Chris Bolhuis: it
Dr. Jesse Reimink: that fit the
Chris Bolhuis: like an energy drink. Yeah,
that fits the vibe for sure. are you like a bubbly or LaCroix kind of guy,
Dr. Jesse Reimink: I mean, La Croix is a little fancy, but yeah, the discount brand of bubbly
water for sure.
Chris Bolhuis: they, leave me. Wanting, you know, like if you
Dr. Jesse Reimink: Cause you're used to a
beer [00:02:30]
Chris Bolhuis: no, no, because 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, ah,
Dr. Jesse Reimink: You want more?
Chris Bolhuis: I want, more? flavor.
Dr. Jesse Reimink: Yeah. Yeah. Yeah. Yeah. I get it. I
Chris Bolhuis: It's always so disappointing. every sip is a disappointment for me. So
Dr. Jesse Reimink: I wouldn't, I don't quite frame it that way, but I see what you
mean. I see your point. Yeah. Yeah.
Chris Bolhuis: it's like, Oh, this is going to be so [00:03:00] good. Uh,
Dr. Jesse Reimink: it's not. Well, hopefully this episode is not like that, Chris. I think this episode
is
like, this is good and it just keeps getting better and better and better because Um, 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 [00:03:30] colleagues who had money to go to the Acosta Nice Complex where I worked during my PhD. So it's kind of 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 going to 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 do
Chris Bolhuis: We [00:04:00] kind of, that'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?
Dr. Jesse Reimink: And I think that would be useful maybe to do these kinds 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 [00:04:30] 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
saw before
Chris Bolhuis: You have. So you were just young. You've
seen this.
Um, yeah, he were just a
baby. It was, it was a pre doctor, pre college Jesse Reimink. Craters of the Moon. We saw some of this
Dr. Jesse Reimink: Okay. All right. Yeah. Fair enough. Fair enough. We, uh, I actually saw that on our field school, [00:05:00] um, our field camp, the Penn State field camp, like two years ago that I went on, um, leading it, but we didn't, Craters of the Moon was just a side trip. Like it was a
Chris Bolhuis: Okay.
Dr. Jesse Reimink: a
vacation day for the students. 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.
Chris Bolhuis: Well, Hey, before we get into like everything, let's just a rundown of what we're going to talk about today. We're and the features that you typically, or you might see when this [00:05:30] kind of phenomenon happens, this is like a big lava flow field, and the associated features with it.
We're going to talk about fjords so we're
gonna talk about those, they're so beautiful, 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. do you want to talk about with those a little
Dr. Jesse Reimink: Yeah, I guess two things like one is sort of more philosophical just it really struck me that These rocks, the Acostanites complex, which I [00:06:00] 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.
Chris Bolhuis: you know, it's interesting because, You were with Dr. Mike Ackerson
from the Smithsonian, and it
Dr. Jesse Reimink: Friend of the
Chris Bolhuis: we talk about, that's right, [00:06:30] and we're going to get him on here again soon,
I
hope, yes, 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.
You know, like what is a magma chamber, you know, or how does granite form, You know, these things that
this is
Dr. Jesse Reimink: yeah. yeah. Yeah, yeah, Mike and I, Mike and I are nerds of the same ilk, you know, that worry about the same, you know, I don't know what seemed to [00:07:00] be basic problems that are still problems. 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, Okay. Amazingly cool and valuable, these Esker trains really are. So that kind of links to the fjords. So 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 [00:07:30] 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 audio books that 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. you see something you like, go ahead and purchase it, that helps support us.
so Chris, why don't you take it away here and talk about, I've, like we said before, rarely seen these, magma inflation features. Is that a good categorization what you [00:08:00] saw and what you want to talk about here?
Chris Bolhuis: 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, I saw these same kind of features there that we're going to 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 was towards the Tail end of our trip. Maybe the last week we were on a three week trip and the tail end of that trip, we just drove across this expansive lava [00:08:30] 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, yup, 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 [00:09:00] inflation would be
Dr. Jesse Reimink: Lava inflation or magma inflation?
Chris Bolhuis: lava inflation.
Dr. Jesse Reimink: inflation. Okay, yeah, this is interesting because, uh, you know, I know as much about volcanoes as, like, your average, undergraduate, advanced undergraduate. Uh, my guess would be that it's, lava's flowing, the top gets crystallized, and it is sort of solid, like, think, ah, lava, or Pahoehue lava, the, the bottom is still flowing and liquid, and so it kind of, uh, Andesite flows up and down and it's kind of like a river [00:09:30] system with a solid top to it.
Is that what we're talking about? Like the, the sort of
Chris Bolhuis: exactly. It's exactly right. Think about a lot like a, think about a basaltic or mayfick 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, 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. [00:10:00] And so it just inflates. up toward the crust because that's the path of least resistance. imagine a lava flow that's taking a big deep breath, you know, 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
Dr. Jesse Reimink: so two, two questions for you. One, what are the features that you saw? that were related. How does this represent itself on the surface? [00:10:30] 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?
Chris Bolhuis: So 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 [00:11:00] shaped structures,
guess typically less than like 10 meters high or, you know,
30 to 33 feet high at the most. didn't see any that were that big 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 [00:11:30] 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.
Dr. Jesse Reimink: Cool.
Yeah. Yeah.
Chris Bolhuis: It's, 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 [00:12:00] these domal structures on top of
Dr. Jesse Reimink: Okay. 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?
Chris Bolhuis: that's a good question. Oh yeah. Dozens dozens to they are all over
Jesse 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
Dr. Jesse Reimink: Okay. Gotcha. Cool. Yeah.
Oh, very cool. Okay. [00:12:30] All right. Um, that's one
Chris Bolhuis: And then another feature that we, that we Um, now when I think of like an inflation pit, I kind of, I don't know if the name is
Dr. Jesse Reimink: It's
Chris Bolhuis: 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 [00:13:00] gets thin around it. Does that make sense?
Dr. Jesse Reimink: Okay.
Chris Bolhuis: that make sense?
Dr. Jesse Reimink: Yeah. Yeah.
Chris Bolhuis: So, 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,
Dr. Jesse Reimink: I see. Okay. Yeah. Yeah. It's like a river flowing around a rock. [00:13:30] Sometimes, you know, it'll, it'll kind of dip down first and, and as the water's flowing around there, something along those lines kind of roughly.
Chris Bolhuis: imagine 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. and 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 it's not, I can see
where somebody
Dr. Jesse Reimink: [00:14:00] okay.
Chris Bolhuis: that deduction. it
does look like that.
Dr. Jesse Reimink: Yeah. Interesting. Okay. Cool.
Chris Bolhuis: And then the other thing that we saw, Tons of where 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, cause they're kind of like the long and skinny shaped, you know, they're, that's why they're called inflation [00:14:30] clefts. They resemble a lava tube. But again, they're not.
Dr. Jesse Reimink: They're not okay.
Cause they're not
hollow inside. They're not
Chris Bolhuis: they're not hollow inside. Absolutely. This 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 [00:15:00] saw tons of those
in Iceland on this trip, you know, and like I said, I've seen them too in, um, craters of the moon in Idaho, which is very, very cool place and geologically very interesting.
And then also in New Mexico.
Dr. Jesse Reimink: 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
Chris Bolhuis: Yeah. Okay. So that's a very hard question to answer. And, and the reason is [00:15:30] 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
Dr. Jesse Reimink: way?
Chris Bolhuis: to, It's It's
going well. well.
it's, it's good, but I did tell you, we just got a new
puppy. And, uh,
Dr. Jesse Reimink: yeah, yeah, yeah. Okay.
Chris Bolhuis: so
last night was the first, first full night.
yeah, so, but now she's doing great.
so [00:16:00] 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
Dr. Jesse Reimink: yeah.
Okay. Fair enough. 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, [00:16:30] 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?
Chris Bolhuis: I'm parsing through it by most of the time I know what I'm going to see before I [00:17:00] see it
because I've done my research before I got there. And so I'm so different than you be 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,
Dr. Jesse Reimink: 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. Does that
Chris Bolhuis: know if that's a fair statement. I don't know if there's, yeah, that has happened, but you know, [00:17:30] Google's a wonderful thing.
Dr. Jesse Reimink: That'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 or Jenny asks you something, it's
not obvious. What do you, I think our listeners 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.
Chris Bolhuis: so I, I know exactly what you're talking about because I can think of a couple [00:18:00] of specific situations when
we were backpacking on day one.
and, you know, we had traversed.
Dr. Jesse Reimink: us through though. This would be really interesting. Walk us through one of those. Like that'd be great. I think.
Chris Bolhuis: So Iceland has rhyolitic, lava activity in addition to Samandacidic 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 [00:18:30] readily know, like, Oh my gosh, that's what this is,
right? It wasn't just, that's Rhyolite or that's obsidian. We saw tons of obsidian too in the highlands. And I pick it up 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 or sedimentary? And to be honest with you, it looked sedimentary.
there were a couple of [00:19:00] 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, 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.
Dr. Jesse Reimink: Not common anywhere and, and
maybe unexpected in Iceland too.
Chris Bolhuis: So you come across these and, and I think you just have to kind of take a step [00:19:30] 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.
Dr. Jesse Reimink: no, what'd you end on? I mean, what was the, Yeah. do you think you're confident in your ending evaluation or decision
Chris Bolhuis: well, we definitely came across some lahar
deposits. We definitely saw some breccia,
some [00:20:00] 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, to kind of draw upon this is Rhyolitic volcanism, and what are some of the things that you can get with Rhyolitic you can, 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 [00:20:30] looking into
what we saw where, and this is obscure areas.
I mean, we're backpacking here. So this is, you know, you have to be, one or two days away from any kind of
civilization at
all. Maybe.
Dr. Jesse Reimink: mapped maybe once by a geologist or maybe twice, you know, that, you know, that 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.
Chris Bolhuis: kind of similar to you, you know, your, your area that you go to in [00:21:00] the Northwest territories is,
there aren't a lot of boots that traverse
that on a year to year
Dr. Jesse Reimink: Yeah, 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 [00:21:30] possibly, 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?
Yeah, 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. [00:22:00] 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 in certain [00:22:30] areas and certain, you know, mapping types, so,
Chris Bolhuis: That's right. there 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,
you know, I'm not that good,
you, know,
I don't know if you really want to know, then we got to stop and we got to [00:23:00] get out and we got to go
look and maybe I can tell you something
about what we're, what we're looking at.
Dr. Jesse Reimink: you can make, you can make, a more educated guess than, than the average person, but also no guarantee it's right, you know, I mean, 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 [00:23:30] Akerson, two postdocs, myself, and we're flying up to the Castanets complex. So this is get yourself to Yellowknife, which is 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. We set up camp two hours north on the Acosta River system on a beach and we set up [00:24:00] camp and the plane takes off and now we're in the Acosta Nice Complex.
It's really sort of storied thing. We we have an audio book on Ursa 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. The Kastanais 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 [00:24:30] even, camping in this location. So I've been there a bunch, 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,
Chris Bolhuis: So. Can I interrupt you, Jesse? Because 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?
Dr. Jesse Reimink: [00:25:00] Oh, I don't know where tree line would be, but 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.
Chris Bolhuis: a lot of like inland lakes and things like this. Lots of water.
The trees are not very big.
Um, you ha 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
Dr. Jesse Reimink: Yeah, bear [00:25:30] 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, 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, uh, you know, long daylight because we're at Acosta, we're right near the Arctic circle, but we're not in the Arctic [00:26:00] 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, Hey, 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, [00:26:30] you know, the other geologists with us were. We're 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? [00:27:00] And the answer is, we don't know. We don't know. Oh, do they crosscut one another?
We've talked about crosscutting relations and, you know, if something is crosscutting another unit, it must be the youngest one. And then the other one's the older one. Crosscutting relationships up here get really hard to actually tease apart because the rocks have been stretched. Think of like toothpaste, you've stretched 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 [00:27:30] are really like first order basic fundamental things that 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 you know High level research done on it and there's a lot we just don't understand
Chris Bolhuis: so 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?
Dr. Jesse Reimink: [00:28:00] So 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 [00:28:30] those samples back is going to cost us a bunch, shipping it back, doing the geochemistry, doing the geochronology. It adds up pretty quick. So you got to care. That's got to 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 [00:29:00] everybody camps and there's an outcrop right there and nobody's done it on that outcrop kind of
Chris Bolhuis: All right. So this was more of just a philosophical thing where you're like, I can't believe we don't know this, but we could,
Dr. Jesse Reimink: we
could potentially with a lot of work on one little
room sized outcrop,
Chris Bolhuis: did this lead to a discussion? You know, sitting around at night after dinner and talking about geology
and
Dr. Jesse Reimink: well definitely,
Chris Bolhuis: know that we [00:29:30] maybe should know or could know. And,
Dr. Jesse Reimink: 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 should we, pursue that path?
it also led to, so Mike Akerson, his, one of his primary goals was to collect samples for the Smithsonian Research Collection. Because they don't
have a suite of Acostini samples, and it's a really famous [00:30:00] 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 on 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 [00:30:30] 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 you. And Mike's idea, which is a really good one, was to take the boat, a little, we had a little inflatable zodiac boat, and just collect a [00:31:00] 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 rocks.
So you kind of get,
Chris Bolhuis: and younger and younger rocks
Dr. Jesse Reimink: yeah, or these are layered and tilted. So it's not entirely clear which way's up, but 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 [00:31:30] 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 cost of a nice complex. So something like that is a really good example. I think, 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
Chris Bolhuis: Okay. All right. That's a [00:32:00] really 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
Dr. Jesse Reimink: Well, yeah, I think, okay, let's maybe tease that apart. I think it's probably really easy to be 50 percent [00:32:30] 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, 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. in the case of the Acosta Nice complex up [00:33:00] here, because you have to do geochronology and all this stuff, I think it's really hard to get. Over 50 percent of the, information out of the rock. So it's easy to point to it and say, that's gotta be old.
That's pretty old 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 don't know.
That's just a
Chris Bolhuis: Yeah, that's interesting. So you, you said it's really easy to be 50 percent confident. you know, you got a [00:33:30] little long winded there
and while you were doing that, I just looked up, um, 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 Lagavegur trail backpacking.
one is a volcano called Hekla, it's like 3900
years ago, and then of course, the other one, I, I, you know, I'm gonna really butcher this, because it's Icelandic uh, [00:34:00] Eyjafjallajokull. That's horrible. But,
anyway, the volcano that erupted in 2010 disrupted travels in
Europe and so
on. So we traverse both of those. I
think that's a really good way of putting it. It's easy to be 50 percent confident,
you know?
Dr. Jesse Reimink: but yeah, before you looked that up, you would have probably put what, 90 percent confident in your assessments in the field before looking it up and sort of, and then now you're probably like 98 percent confident after
looking it up or,
you know,
Chris Bolhuis: I am. I, yeah, [00:34:30] yeah, yeah. I felt good about it because I went through this, you know, I went through the process of, all right, what am I looking at here? Because this is really weird. so 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.
is what I think we're dealing
Dr. Jesse Reimink: Yeah. Yeah. 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.
Chris Bolhuis: Yeah. [00:35:00] 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 fills up. floods, those U shaped valleys, and those are called fjords.
So you have this really long [00:35:30] finger of oceanic water that reaches up into the continent that's surrounded by a land peninsula on each side of it.
Dr. Jesse Reimink: And really, you know, 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 you're a photo of, of Norway is, is like steep sided things diving into, water.
That's so cool.
Chris Bolhuis: [00:36:00] Jesse, 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, cause we would just drive and be like, I don't want to go any further right now. This is too [00:36:30] beautiful
for me. And we would just stop right there and either pitch a tent or a car camp. And it was just amazing. And
so we did that almost always on a beautiful fjord.
Dr. Jesse Reimink: mean, so pretty. That's just so cool.
Chris Bolhuis: we 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 [00:37:00] the fjord. Uh, we saw three humpback whales,
so that was in really, really close. We walked out onto a rock outcrop and I looked down and 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.
Dr. Jesse Reimink: Yeah, 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 [00:37:30] spectacular. Um,
Chris Bolhuis: you had some glacial features too, right?
Dr. Jesse Reimink: Yeah, so we, I mean, we're up in the still on the continent, obviously, but where the, we're dealing mostly with erosional features in the glaciers. Well, it's 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 [00:38:00] in Acosta, the Acosta area, the eskers are flowing east to west because the glacier was
flowing east to west there.
Chris Bolhuis: let's set the stage on what an esker is,
Dr. Jesse Reimink: oh yeah, okay. so esker is it's a landscape feature. And when you see, it's basically a long, low hill. a ridge of sand and gravel, and it's a depositional feature. It's a stream that was coming out of glacial front.
So a continental scale glacier, [00:38:30] 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, 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 esker, and so there
Chris Bolhuis: That's right. So 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 [00:39:00] 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,
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 [00:39:30] previously.
Dr. Jesse Reimink: that's exactly right. And these eskers, they're 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 esker 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 [00:40:00] 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've got a big glacier that's like kilometers thick. And then at the, 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, we'll [00:40:30] 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, Eskers, 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, [00:41:00] 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 esker, and we're like, oh, we're going to go sample that esker.
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. [00:41:30] 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 [00:42:00] be easy to walk across this and think, oh, this is some weird breccia thing.
It's a kimberlite, we landed
on a kimberlite,
Chris Bolhuis: is it an ultramafic rock?
Dr. Jesse Reimink: They're typically ultramafic and they usually have these clasts in them, but they can be, this kimberlite was a relatively big one, several hundred meters to 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 breccia [00:42:30] of some kind, but totally different across there. So they
get
really.
Chris Bolhuis: it was breccia part is because it was ripping stuff up
Dr. Jesse Reimink: Yeah, Yeah,
exactly. It's ripping stuff up. The, the magma itself is pretty, pretty limited amount. And it just comes, brings up everything with it.
and it turns out that we had landed on a Kimberlite pipe that, or very near one, and De Beers had looked for diamonds around there. There was an old De Beers camp exploration camp, you know, a couple miles from where we landed that we flew over on the way back and like, Oh, that's a De [00:43:00] 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 esker 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 kimberlite and Mike immediately could [00:43:30] identify it. And I took a little bit because he's again, seen the kimberlite. 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 kinds of rare rock types that we've been talking about. That's
Chris Bolhuis: it speaks to what I've said before, but the best geologist is the geologist that's seen the most rocks.
Dr. Jesse Reimink: It's true. And worked [00:44:00] through
this
process. It's 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 a 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,
Chris Bolhuis: I had to think [00:44:30] this through also because when we came across this obsidian, it, Jesse, world. Class obsidian
and big, 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, [00:45:00] really felsic Rhyolitic lava flows
all over the place. And that's where the obsidian came from.
So you don't typically think, Oh, I'm going to see obsidian in
Iceland. Because 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
Dr. Jesse Reimink: Yeah. Yeah. the listener, you need to practice that to become, you know, pretty good at rock identity, 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 [00:45:30] 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 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, improving yourself. And if you [00:46:00] get 80 percent right, Great. If you get 80 percent there, that's great.
Cause it's hard to get to that 100%. You know, it's really hard to be totally
Chris Bolhuis: It is. It really is. Well, and 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 percent certainty until you take it out.
back in the lab. That thought came across my mind quite a bit actually, when I was in Iceland[00:46:30]
and I came to the conclusion actually that, that that is such an accurate statement.
Dr. Jesse Reimink: It's
really, it's
disheartening, but I think you know, with enough experience, like Chris, you know, 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
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. [00:47:00] So,
just have to go be tricked a bit.
Chris Bolhuis: with 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 faunalite
porphyry, because that work has already been done.
Dr. Jesse Reimink: But in these areas where you're,
Chris Bolhuis: like,
Dr. Jesse Reimink: 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.
Cause it's just so fun. I mean, it is, one of the more fun parts of [00:47:30] being a geologist, I think, is working through the is this kind of
continuous
problem solving. Yeah.
Chris Bolhuis: heh.
Dr. Jesse Reimink: out there is just amazing. So what do you think, Chris, is that
a wrap?
Chris Bolhuis: I think that's a wrap.
Dr. Jesse Reimink: Okay. Well, like we said at the outset, there's a couple of ways to support us.
We appreciate all the support, but there's two main ways you can, first of all, download our Camp Geo app. That's the first link in your show notes. You can click on that, download it from the app store on your mobile device. You can, uh, Listen to all of the free content we have there.
We have podcast episodes [00:48:00] organized in a order that makes a bit more sense. That's not just kind of random thoughts from Chris and Jesse. We've organized them into categories there. You can also listen to Camp Geo content, which is basically the introduction to geoscience content. Class with all sorts of images and gifts and stuff that really help you visualize and help you learn.
We think you can also purchase some of our paid audio books there as well. You can also head over to our website, planetgeocast. com. There you can support us. There's a support us link there. You can also send us an email planetgeocast at gmail. com. We love getting listener [00:48:30] questions.
So hit us up at those. You Last thing you can follow us on our social medias at planetgeocast.
Chris Bolhuis: Cheers.
Dr. Jesse Reimink: Peace.
