The Anthropocene
Dr. Jesse Reimink: [00:00:00] Welcome to Planet the podcast where we talk about our amazing planet, how it works, and why it matters to you.
Chris Bolhuis: the, the good doctor
Dr. Jesse Reimink: The good, the good
Chris Bolhuis: Joyce isn't going to call you that.
Dr. Jesse Reimink: the good doctors in the house.
in.
Chris Bolhuis: Don't ever say that
Dr. Jesse Reimink: Settle in with Chris and Jesse.
Chris Bolhuis: That's right.
Dr. Jesse Reimink: you just have a [00:00:30] drive time radio voice though. I mean. Yeah, you could be, Ah, well, traffic on I 95 is really bad. Avoid the left lane! Here's
some slow jams with Chris Bolhuis.
Chris Bolhuis: Okay. Yeah. There's a guy on our local radio that does the traffic. And every time he comes on, it's only like a, you know, 15 second segment, right? Or maybe 20 seconds, right? And then the way he signs off, I, it's like, Always repeat it when he's done [00:01:00] because it is just it's so I don't know what it is whether it's annoying or Just so distinctive and I always have to
Dr. Jesse Reimink: One of these things that just, it's like an earworm just gets in your head and you just gotta get it out.
Chris Bolhuis: and I'm all by myself and I do it every single time
Dr. Jesse Reimink: So if you're out there listening to this, and you have an earworm from Chris, let us know. Chris's, whatever Chris's catchphrase. Are you karst y? Erosion happens.
Chris Bolhuis: It
Dr. Jesse Reimink: What was the other one? Gosh, I always forget. I need to, we need to make a [00:01:30] list of Chris's t shirt slogans. What was the other one? You had another one recently.
Erosion happens. Oh, gosh, I'm not gonna remember it now.
Chris Bolhuis: I can't I don't know what you're talking about. I I
Dr. Jesse Reimink: you forgot you deleted your emails. And if you, you've forgotten the entire last three years of what we've done on the podcast.
Chris Bolhuis: When you spit out so much wisdom, Jesse, you forget it. It's, it's like, you know, I have,
yeah, I've forgotten. Yeah. More information than you know, or I don't know how that, I don't know how that goes either.
Dr. Jesse Reimink: It's, it's, it's close. [00:02:00] Okay. So you're speaking of wisdom
Chris Bolhuis: Yeah, right.
Dr. Jesse Reimink: today is, okay, the Anthropocene. Chris, what is the Anthropocene and what does it mean to you when you hear it?
Chris Bolhuis: Well, This stirs up a bit of controversy in the geologic community, the idea of whether we should have this division in the geologic time scale, what the Anthropocene is all about, is basically, should we mark a point in time when humans have had an impact on the [00:02:30] geology of our planet?
Right? That's what I think of when I think of Anthropocene.
Dr. Jesse Reimink: I think that's perfect. I mean, and I agree. And this is a, like you said, a hot topic in geoscience. And this is a listener question as well. Uh, actually a couple of people have suggested we talk about this or requested we talk about this. Cause it kind of came up this past summer. There was new batch of news on the Anthropocene.
And so Chris, the way Well, the way we're going to talk this is we're going to, we haven't actually talked about the [00:03:00] geologic timescale that much, like the actual formal geologic timescale. So I think it's probably a good time to introduce that and just talk through the boundaries in the geologic timescale, how they're divided.
sort of geologic boundaries, not the Anthropocene back in time and use that as a way to talk about the Anthropocene and the recent, proposal of a particular place to put the marker that would potentially represent the Anthropocene, but it's a proposal at the moment. And at this stage, at the [00:03:30] time of recording, we don't really know the official outcome from, the, the group of geoscientists who decides these things.
Chris Bolhuis: That's a good point. Jesse, you still have it memorized, right? You, you have the entire
Dr. Jesse Reimink: so so I, I actually take a decent amount of heat in my department because, well, we've talked a lot about this. I work on really old rocks, right? The geologic timescale is super simple. When you go back in time, there's the Hadean, there's the Archean, there's a couple divisions in the Archean. It's like always the pink [00:04:00] area of the, the geologic timescale.
I cannot for the life of me, Chris, put any of these other things in order. Can you? Like if I said list for me the order of Jurassic, Triassic, you know, Cretaceous, whatever, would you be able to do that at that level or not?
Chris Bolhuis: yes, I could do that. Only those three though. You know, so,
Dr. Jesse Reimink: Ha Okay! Ha ha ha ha ha!
Chris Bolhuis: only those three. You're right. I mean, I don't know. Do you, Make your students memorize any part of the periodic table. Like [00:04:30] what's your level of, how do you get into this? I, I have to do some of it, but I don't make a memorize much of it
Dr. Jesse Reimink: I agree. I do not either. and this is a... I don't remember when I had to memorize it in undergrad. I know I had to at some point, but I think it was in like a 200 level class. It wasn't the 100 level. It wasn't the intro class that you had to sort of memorize this. I think it was more where you're talking about a lot of sedimentary rocks.
You kind of had to at least know the big divisions. so it's a little bit more, second tier geology knowledge maybe, but I've since, that point, [00:05:00] since I was a sophomore or junior in college, I've I forgot it a long time ago, so every time somebody gives a talk, they're like, Oh, well, you know, these are Eocene volcanic rocks.
I'm like, okay, give me a number. Like, what is the number on that? Cause I don't know where the Eocene is in the time scale.
Chris Bolhuis: Yeah. So there are certain things that, that trigger for me and the Eocene happens to be one of them because the Eocene is when the Absarica volcanics were going on. And so I do have a number in my head for that, but it's, it's things like that that are just random, [00:05:30] totally like, Oh,
Dr. Jesse Reimink: Oh, yeah. Yeah. So, so you associate an event with a geologic time period, like a one, when you talk about a lot or when you really like, yeah, that's interesting.
Chris Bolhuis: What I do with my students, I think it's important is to know that the boundaries that we, that are established in the geologic timescale, they're not arbitrary. they're based upon things that happened. let's say the, the Cambrian, going from the pre Cambrian to the this explosion in life that happened.
Right. And so that's [00:06:00] why there's a marker there. And so I use things like that or, the Cretaceous tertiary boundary, you know, that was this mass global extinction that happened. And so there were things geologically or biologically that happened that caused the divisions to be placed where they are.
And I picked kind of like some important ones to emphasize from that standpoint. That's really the extent that I do it in
Dr. Jesse Reimink: So okay, well, maybe let Chris, let's back up and just give the, the geologic [00:06:30] time scale for people. So the way these are broken up, or the way that the geologic time scale is broken up with these boundaries, these boundaries have, clear meaning.
Like the, the number on the boundary is a change point in earth history of some kind. broken apart into different divisions or different, like, Geologic stages here, geologic stages. The biggest one is called an Eon. That's E O N, Eon. And that's from oldest to youngest, Hadean, Archean, Proterozoic, and Phanerozoic.
And Phanerozoic is like everything, younger than about [00:07:00] 560 million years old. the Proterozoic goes from about 560 to, you know, 2. 5 billion years. The Archean is 2. 5 to 4 billion years. So these are like huge amounts of time. Eons are big amounts of time. then eons are divided up into periods and the periods will have names like Jurassic, Triassic, Cretaceous, Quaternary.
Those are ones people have heard. And so those periods, Jurassic, Triassic, Cretaceous, those are divided up into epochs, and
Chris Bolhuis: ha.
ha. Hold on.
[00:07:30] You are a
funny guy. What
did you just say?
Dr. Jesse Reimink: epochs.
Chris Bolhuis: just say? Epoch. What? Are you, are you from across the pond now? Are you British?
Dr. Jesse Reimink: I, you know, uh, I need my bowl, my bowler's hat
from London here.
Chris Bolhuis: Jesse.
Dr. Jesse Reimink: was just in London, Chris. I don't know if you knew that or not, but.
Chris Bolhuis: Is, is, is that the doctory way to say epic then? Is epoch?
Dr. Jesse Reimink: Yeah, I think, I think, I mean, I think so, you know, if you're fancy, you say epoch,
but if you're Chris Bolhuis, you say [00:08:00] epic because you think there's an I in this word somewhere.
Chris Bolhuis: No, no, no. It's not that it's not like that. No, seriously. Like, is that the way your professors when you were like, is that your
Dr. Jesse Reimink: Oh man, Chris, this is a really hard one because I don't remember. I know in grad school, there was a lot of, uh, there's a lot of Brits in University of Alberta and Canadians. There's a lot of like British. Isms that exist in Canadian lingo
and so, you know, like color has a U in it in Canada. Kind [00:08:30] of stupid in my opinion, but it's there.
Center is spelled C E N T R E. Dumb, but that's how they do it. So there's like, so I think my grad school days, I got this sort of blended, uh,
Chris Bolhuis: You are a bit of a mixed bag, aren't you? Yeah. Yeah. Okay. That makes total sense then. Okay. You're excused. Now, I know Joyce is going to agree though. It's pronounced epic. What we're talking about, it's spelled E P O C H S. and I would, I look at that and I'm like, well, that's an epic.
Dr. Jesse Reimink: Yeah. [00:09:00]
Chris Bolhuis: So that's, I
Dr. Jesse Reimink: Okay.
Yeah, no, you're right. You're right. It's an interesting
Chris Bolhuis: I
just looked it up and both are accepted.
Dr. Jesse Reimink: Okay, good. So we don't have to take, so Joyce, we're both right. It's not just Chris who's always right. Um, so these things are going to be like Miocene, Oligocene, Eocene. You talked about Eocene before. So these are like the smaller divisions.
Epochs or epics are smaller divisions. Those can be divided into ages and the ages are at risk of offending sedimentologists. [00:09:30] Basically they're the only people who care about these things. Lutetian, Bartonian, these really, super specific, you know, there'll be several million years in length, but they're like really, really small parts of geologic time.
And the way that I talk about this, Chris, as I say, okay, look at the geologic time scale some people think of it as a clock. where time is kind of linear going around the clock from 12 o'clock AM to 12 midnight. That's linear, All of the geologic [00:10:00] divisions are in that last part, the vast majority of these epochs and ages and periods are all in this Phanerozoic, the last 500 million years, and if you look at it as a grid, if you just kind of map out all those divisions, the area of the chart is dominated by the last several hundred million years old, and the way I describe it is the scale, when you look at it that way, I think Thank you.
if people listening to this, just look up IUGS geologic time chart and you'll see the divisions, those things, the area on that chart scales with [00:10:30] information. So we have more divisions more recently because we have a lot better record recently. And they're also divided, mostly by like mass extinction events.
So when did animal life change or when did biology change on earth? That's where a lot of the divisions come from.
Chris Bolhuis: That's right. Because when you talk about the, eon that was, it was, it's formerly called Precambrian, right? We still use this all the time. That's, that's not
Dr. Jesse Reimink: Yeah, so Precambrian is, not an eon. It's a, it's like an informal,
uh, time designation.
Chris Bolhuis: Right. But that [00:11:00] encompasses over 87 percent of geologic time. it is crazy. And so, just a very small amount of the geologic timescale has happened since then. that's why you say that there's more detail that's preserved in these younger rocks. And it's almost all of it's going to fall into, know, the Cambrian and much, much
Dr. Jesse Reimink: much younger. Yeah, exactly. And that, that works, you know, forward in time. The most recent epoch is the Holocene, the Holocene, and this is part of the Quaternary period. So Quaternary, when you look at [00:11:30] a map, if you look at a geologic map, You'll have, basement gneisses, you'll have a bunch of, uh, different types of sedimentary rocks, and then you'll have a catch all term called Quaternary Cover, which is basically like river bottoms, river sediment and stuff like that.
Glacial till would be Quaternary Cover. that's the youngest period there.
Chris Bolhuis: that's right. So before we jump into talking a little bit about the Anthropocene, then we need to talk about these things that are called golden spikes. I think maybe there aren't very many people that are familiar with what [00:12:00] these golden spikes are, but these are actual physical spikes. They're little emblems, right?
Dr. Jesse Reimink: Yeah, they're like little, you know, so Chris, if you, you've hiked a lot of summits of mountains, right? You
know that the little, circular, like, brass emblazoned discs that they'll stamp in the top of a
mountain?
Chris Bolhuis: benchmarks. Absolutely.
Dr. Jesse Reimink: like this. That, that's what they
Chris Bolhuis: Okay.
Dr. Jesse Reimink: They got a little emblem on them and a little
Chris Bolhuis: Have you ever seen a golden
Dr. Jesse Reimink: I have not seen
one in, in real life. Nope.
Chris Bolhuis: Okay.
Dr. Jesse Reimink: Have you?
have you, Chris?
Chris Bolhuis: I have not. No,
so these [00:12:30] are physical spikes that are put in specific locations, but there is a bunch of rules
that
Dr. Jesse Reimink: Of course there is. I mean, if there's no rules, we
live
in a
civilization. We gotta have rules, you know?
Chris Bolhuis: now, I have a question though This is something I actually don't know Are they only put between epics?
The golden spikes or they put a golden spike between, know, between periods like the Jurassic and the Cretaceous and the, and the [00:13:00] Triassic? Do we put them there too
Dr. Jesse Reimink: Well, I think, yeah, that's a great question, Chris. And if you just look at the, the time chart, the timescale, the, the international stratigraphic chart, a lot of the ages or stages, those, the smallest subdivisions, a lot of those will have golden spikes in between them.
So then by definition. the series or epochs or the eons will also have spikes there. So, you put them between the smallest layers, then the biggest ones will have them, but not all of them. Some of them do not have golden spikes in [00:13:30] them.
Chris Bolhuis: Okay.
Dr. Jesse Reimink: Like they won't have a
place that, that fits all these rules that we're going to talk about.
Chris Bolhuis: Right, and that's the segue then. Let's let's talk about what some of these rules are. Like I said, we're just gonna kind of gloss over this. We're not hitting this. And so I apologize if we're offending some sedimentologists here. But,
Dr. Jesse Reimink: I mean, no,
we don't apply to, I take back that
apology.
Chris Bolhuis: not gonna apologize. Yeah, good point.
I don't either. I don't really care. But in order to have this, Just a couple of commonalities. First, it has to be a really thick outcrop. And I don't [00:14:00] know if there's like a definition of what thick means, but it has to be a thick outcrop and you know what else too, and I think this is cool. It has to be accessible and it has to be free
Dr. Jesse Reimink: Yeah, it's a really, that's a good, that's a good one. I like that it has to be free and publicly accessible, accessible, meaning like you can get there on a road or that's what they mean by accessible, you could drive most of the way there basically, Another thing that surprised me, another rule, was that sedimentation has to be continuous across the boundary.
So you can't have an [00:14:30] unconformity be the geologic boundary, right? You have to have a continuous record of sedimentation, which then begs the question, what is the boundary? Or how do you, put a golden spike somewhere in a continuous record of sedimentation. And basically it's the appearance of a fossil species, one of these index fossils that sort of defines the time period change, the global extinction event, or whatever happened.
It defines that time frame.
Chris Bolhuis: Right on. And so that brings a question to my mind, and I don't know if you have the answer. I don't. Would the K [00:15:00] T boundary, this extinction event with the meteor that wiped out, all the dinosaurs and, and most of the marine life, So there are certain places where you had continuous deposition of, let's say, limestone, right?
In the oceans. And so you look at Forminifera, and it's very, very diverse, and just all kinds of species that were thriving. And then all of a sudden you have this boundary clay there, and above the boundary clay, there's next to nothing. So you kind of have continuous deposition,
but... [00:15:30] would that count as an area that a golden spike would be
Dr. Jesse Reimink: So there is a golden spike, and it's in Tunisia, for that KT boundary, and that is one that, you're right, it's not a continuous, homogenous amount of limestone, like for instance, it's not just straight limestone, there is this boundary clay. But the boundary clay is in addition to the background sedimentation, I think.
So you know, the limestone is being deposited at a consistent rate or the [00:16:00] morals or whatever it is. And then you have this extra clay layer in there. That's because of the KT extinction that has the, the iridium anomaly and, you know,
Chris Bolhuis: Yeah,
Dr. Jesse Reimink: transition and all that stuff.
Chris Bolhuis: right. So I, the reason I asked the question is because I know another stipulation is that it, the outcrop can't be affected by. Plate tectonic processes or metamorphic processes or events. And so I wonder if a meteor impact would fall into a category like that, that would[00:16:30] okay,
Dr. Jesse Reimink: Oh, would alter it. Yeah, I see what you mean. I mean, yeah, it's, there is a golden spike in that, that time period. it must be the case that it is not deformed enough or it's not, you know, it's certainly not metamorphosed, but it's not disturbed enough because actually, you know, it's, this is sort of a gray area when I'd imagine, I mean, I'm not, I don't make these decisions, but I'd imagine it's kind of a gray area where It's a big event, but that represent, that
is the boundary.
The event is the boundary in a way. So globally, it's not like it's, it's some unconformity [00:17:00] somewhere on the earth and not everywhere else, but this is like the event. So, I'm guessing that's the rationale for it. So
cause you're right, Chris, you, we've talked about this boundary layer. We talked to, Ian Miller about the boundary layer for the KT extinction event that's exposed out in Colorado that you've been to, right?
I've, I've not been there before, but, the rock record is there in Colorado, but it's not the golden spike place. The golden spike is in another place that has, a slightly maybe better record of, of that event.
Chris Bolhuis: Yeah. That's true. It's a good point. And when I think about that, it, it gives me [00:17:30] chills because when you're able to put your finger on that boundary clay layer there and know what that represents, but where I saw it was in Trinidad state park, which is, in Southern Colorado and it's not free.
you
know, so
maybe
that, I don't know, I don't know, but there are
other places that are alongside the road where,
Dr. Jesse Reimink: yeah,
So maybe Chris, that's a good transition to the Anthropocene. And I think one thing to, let's take that transition and let's say, okay, if you're listening to this thing, think about a [00:18:00] setting that would fit the bill here.
how would you. Record, or where would you put your, rubber stamp or your golden spike of, Oh, humans have started to impact the planet at this point in time. Where would you like put that finger? Cause let's put it this way. There's a lot of, um, Discussion around this about whether we should or should not even have a golden spike that is the Anthropocene and whether if we do want one, where should we put it and what type of [00:18:30] setting because this is different It's not going to be in the rock record because it's too young to be making rocks mostly yet. So we're going to be not looking at, I'll Package of sediments that's like tilted in this hillside or something like that, right? We're talking about something
distinctly different than what we've been describing so far.
Chris Bolhuis: Yeah, this brings up the controversial points to the whole idea of Anthropocene to begin with, right? Where do we put the boundary? Do we put it at 1940? Do we put it in between 1940 and 1960? And [00:19:00] then, well, does that kind of Is that a sleight of hand to prior to 1940, you know, I mean, look, here's the deal.
I think this is something you and I can both agree on, Jesse, humans are having an impact. Geologically, we're a force. We're having an impact on our planet.
And I don't think that that's the controversy, at least that's not my take on it. I think it's, where do we put the line? Where do we actually draw it?
Dr. Jesse Reimink: Yeah, maybe let's talk about how the lines are drawn or
[00:19:30] let's touch on that. How are these things decided? Like how does this work functionally in the, you know, the, how did geologists decide this?
So with regard to the Anthropocene, there's a thing called the Anthropocene Working Group. And this is part of the international commission on stratigraphy. This is a bunch of, stratigraphers, sedimentologists who decide where it. These boundaries go, how do we divide geologic time?
Where do we put the golden spike? So it's a big group of people sort of studying this and thinking about this. And there's a working group, the Anthropocene and working group. It was set up in [00:20:00] 2009, To decide whether to put a boundary, and if so, where.
And they recently proposed a site for Golden Spike that's in Canada, in Ontario, Canada, a place called Crawford Lake. And Crawford Lake, Chris, I know you're thinking it in your head, you're thinking, is Crawford Lake karst y? And you would be right. Crawford Lake is karst y.
Chris Bolhuis: I knew Crawford Lake was
sty. Jesse. Don't throw me
that. I, I did know it's sty. Yeah, absolutely. Well, Crawford Lake is actually a sinkhole. It's a lake [00:20:30] Is there because water dumping into a sinkhole.
And we've covered this in past episodes recently,
Dr. Jesse Reimink: and this is a really important point to why this location is is useful for this type of record because think of a sinkhole We've described these things like caves collapsing caves can be super deep and fairly narrow and that's what this lake is It's deep and narrow. So it's a relatively small kind of I don't know in farm country We'd call is like a pothole lake, but it's deep.
Chris Bolhuis: yeah, I don't like that. I [00:21:00] don't like that. to me, that's confusing to call it a pothole lake. I think geologically, I don't like it.
Do you know what I
Dr. Jesse Reimink: no, I know completely what you mean, but like, you know, topographically it's, you know, people would say,
Oh, it's just a, it's around a circular lake. People just colloquially say, Oh, pothole lake. Right? So that's the visual, but it's deep a sinkhole lake. So it's not a pothole lake.
It's a sinkhole lake.
it. It is karst y, but this is really great because it has this like high aspect ratio. It's deep and narrow. Which means that the water, the surface waters, the ones that get seasonally warm and [00:21:30] cold and in there in Canada, so it freezes over in the winter and warms up in the summer, that does not mix with the deeper waters.
So we have kind of two different layers of water that do not mix,
which means that the bottom is super, super stable.
Chris Bolhuis: All right. Jesse, ask me a question. Ask me,
Chris,
Dr. Jesse Reimink: is your favorite color?
Chris Bolhuis: No, that's not what I want to. I want you to ask me, Where do you think, Chris, a good place to put a golden spike, [00:22:00] or to look for a golden spike, for the Anthropocene would be?
Dr. Jesse Reimink: Okay. Yeah, Chris. Um, so I got a question for you, Chris. Where do you think would be a good spot to put a golden spike for the Anthropocene?
Chris Bolhuis: So... I'm a little con I'm being honest with you here. Quit laughing at me.
Dr. Jesse Reimink: I can't help it
sometimes.
Chris Bolhuis: Crawford Lake. Okay, I get it. doesn't seem to be accessible.
Dr. Jesse Reimink: Yes. Great point. I agree completely like it, you know, this is at the,
if
Chris Bolhuis: It's [00:22:30] a bottom of a very deep lake, like this doesn't make sense, right? But, okay, so, then my other thought is, why does it have to be a lake like this? Why can't it really be any lake? Why can't it be one of the kettle lakes that we have all over the place in Michigan, Minnesota, Wisconsin? Like, you would have continuous deposition in those as well, I would think.
don't know,
Dr. Jesse Reimink: I
think there's probably a lot of lakes that fit the bill here that could potentially fit the bill. Like for instance, up in [00:23:00] Canada, where I do my research, the diamond mines are, kimberlites erupt. We've talked about this before, this kind of carrot shaped tube of an eruption. So you get these.
Circular round holes that are really deep. Some of these things have seen continuous deposition for 30 million years since the eruption of the Kimberlites. Cause it's a hole in the Canadian shield that has seen, sediment deposited. They're very deep for very narrow. you know, these fit the bill to really nice, for instance, record of barbs, which barbs are seasonal layering. So it'll go in [00:23:30] the case of, up in this part of the world, you'll have summer sediments will be organic rich and sort of black colored. And then winter sediments will be more carbonate, carbonate rich. So you kind of have these beautiful
black, white, black, white, black, white. light gray, dark gray.
light gray, dark gray.
Chris Bolhuis: yeah, it's the sedimentation version of tree rings,
right? You're able to count. and really work your way back in time because each one of those pairs represents a year. Between, organic rich and organic poor, basically.
That's the way I usually think about it, right? And I love [00:24:00] VARVs. I think VARVs are absolutely fascinating.
you know, in terms of like soft rock geology, I love it because I think of Yellowstone when I think of Varvey. Oh,
hey,
there we
Dr. Jesse Reimink: Varvey are you Var
Chris Bolhuis: Yeah
Are you feeling Varvey?
because when the ice dams blocked the rivers and the outflow from Yellowstone Lake, Yellowstone Lake expanded into these valleys like Hayden Valley and
Pelican Valley, these very
Dr. Jesse Reimink: Hey, Chris, we've got a great GIF of this in our [00:24:30] Yellowstone book that is now available on the mobile app. You can go buy it now, but our Yellowstone Geological Visual Audiobook, we have some Cool, cool gifts that we made that show, you know, the extent of Yellowstone Lake at this time when there's ice dams there.
Anyway, sorry for the
deviation and sales pitch there, but
Chris Bolhuis: No, no, that's awesome. That was shameless. Nice job. Way to go. I appreciate it. Um, and there's also a famous place called Storm Point. It's a very beautiful place takes, it's a trail from the road that walks you out along the shoreline [00:25:00] of Yellowstone Lake along the Northern edge.
Right. And it's a beautiful place where rivers Carve these bluffs into this soft sediment and if you just know what you're looking for a little bit you just go up to those bluffs and take like a spoon maybe and kind of like just Carve out a little bit of the, get the dust away is what I'm saying, basically.
And you can see these varves. It's a, it's amazing. You can see light, dark, light, dark, light, dark. And there are hundreds of them [00:25:30] or thousands of them. They're, uh, they're spectacular. So when I think of varves, that's, that's usually the, what pops into my mind. It's, it's kind of like this sentimental thing.
I
get excited.
Dr. Jesse Reimink: Yeah. I, uh, well, it's not quite as sentimental for me, but I, I did drill. Well, drill, I mean, it's take a big, steel tube and, plunk it down in these back dune lakes. So the lakes behind the dunes in Michigan. So we got the, you know, these big dunes right along the shore of Lake Michigan and these little lakes behind them, these kind of potholy lakes behind them.
And they have really nice VARV records. And in [00:26:00] undergrad, I spent a day. I think we were helping another researcher, you know, drill. So we're out sitting on a pontoon boat, you know, plunking this big steel thing down into the bottom and taking out a big core and looking at the VARVs, beautiful VARV record there, but you know, it's muddy and it would just kind of, the VARV record, if you weren't careful, would just kind of fall apart.
It would just sort of squish out. And so that this kind of segue award comes back to Crawford Lake here because Crawford Lake is really well studied, in this VARV record. And the reason that the golden spike was. proposed to be put there, [00:26:30] was that in these lake sediments, there's a very clear record of The 1940s, 1950s, and 1960s, which is atomic weapons testing atmospheric atomic weapons testing, which pushed a bunch of radioactive elements like plutonium and cesium, certain isotopes of those two elements into the atmosphere, which then rained down globally and are deposited in small amounts.
I mean, not like damaging amounts humanity, but in small amounts, detectable amounts, you can see a spike much like the [00:27:00] iridium anomaly at the meteorite impacts that we were talking about before these cesium and plutonium signals are suggested to mark the onset of the Anthropocene in this lake
bed. So basically you have the core and you can point to it.
I mean, you could dive down into the water too and figure it out, but that's more difficult and less accessible.
Chris Bolhuis: So another thought just popped into my head and you have no idea what I'm going to say, but
Dr. Jesse Reimink: Chris, I rarely have any idea what you're going to say. So this,
Chris Bolhuis: why can't we go back to this start of the Industrial Revolution [00:27:30] then? And, and
There's stuff in the atmosphere that began pumping and therefore raining down into lakes just like this. Why 1940s?
Dr. Jesse Reimink: Yeah, so this is, I think this brings us to the, the last part of this, which is I'd be very curious on your perspective on the Anthropocene. Two questions. Should we have such a thing as the Anthropocene? And B, where should we put it? Like what part of, Geologic time and where, what types of rocks or sediments should we put it in?
[00:28:00] That kind of a two part question, but let me just, say before we get to that, that this came out this summer at the time of recording. I have not seen it accepted and all the news articles in June and July suggested that by August, little bit before the recording of this, that it would have come out.
So I don't know if it's. going to be accepted as the golden spike for the Anthropocene or not, or if cause this, this Anthropocene working group proposed it to the, the larger cohort of stratigraphers and then, you know, they decide somehow vote or something like that [00:28:30] on whether to do it or not.
So it's not like official on the geologic timescale yet. And I have not seen an announcement that it has been, and we're kind of overdue. So I think this, that plays nicely into this question. What do you think, Chris?
Chris Bolhuis: well, first of all, I feel totally unqualified to answer this question, but it is our podcast, and so I'm going to answer the question.
Dr. Jesse Reimink: and I asked you,
Chris Bolhuis: Um, again, you know, you and I, we're not soft rock kind of guys. We're more hard rock people, and this is more of a soft rock question, right? [00:29:00] then again, too, think that we don't need to overthink this whole thing.
Do I think there should be a golden spike found for the Anthropocene? And do I think the Anthropocene should be acknowledged a hundred percent because I, we are a force
Dr. Jesse Reimink: so there's a counterpoint to that, and I don't really know where I stand on this particular issue, there's some aspect of me that thinks that it's sort of a pedantic argument, like, I, I don't know, I just can't, I can't get into it, I can't, care about it, And to me, that's like a representation of, uh, maybe I don't deem it [00:29:30] that important or something because there is an argument to be made by, by very good geologists that say that we don't know that humanity's impact is not pretty short lived.
not looking at geologic time, you know, most of these boundaries are big divisions between blocks of time that are 10 million years apart and there's like a big change there and all indications point to this being a mass extinction event that humans have induced and stuff, but we don't know the future.
this hasn't played out yet. [00:30:00] So it's sort of, there was one quote that somebody said that, uh, a geologist at Cornell said, you can't define your own time. And, I think it was kind of a allusion to like societal definitions. So there's part of me that that argument resonates that humans are having a big impact and we should worry about the impact we're having.
Should we care about defining it and spend some time defining it? I find that less important than like fixing the problems, I guess.
Chris Bolhuis: I guess, I find it important we need to [00:30:30] acknowledge it. if we don't, then we're kind of like saying, well, we're not really having that big of an impact. I guess that's my take on it. And again, not really educated to have an opinion on this, but I kind of do
Dr. Jesse Reimink: Yeah. Well, I mean, but
this is, I think this is, I think this is important for, for geologists of all kinds to, to sort of think through these things. Like, you know, we look at the geologic timescale and how do we think about this period of time that we're in at the moment? I think it's a really important thing.
to your point about like where to put the spike, where would you put it? Cause there were other suggestions that [00:31:00] say, let's put it when we start to see industrial revolution, like dust in the, you know, in the glacial ice cores, like, let's put it there.
And that's one argument that people who say we should not define the Anthropocene say is how would you pick which place to put it? Because we don't actually know how this plays out. should you put it in the industrial revolution side? Should you put it in the nuclear weapons testing?
Should you put it in, I don't know, pick your favorite layer. I don't know.
There's a
Chris Bolhuis: Okay, but,
Dr. Jesse Reimink: put it. So what would, what do you think [00:31:30] about that?
Chris Bolhuis: all of them fit under the same umbrella, and that's us. And so, I think that you have to put it at the beginning of our recognizable impact. And it has to go back to the Industrial Revolution, because, you know, the stuff that's raining down is not just preserved in ice cores. It has to be preserved in VARVs, and again, that's for other people to prove, but you know it is, right?
It's there. It has to be. There's no question about it. And so then, you know, you jump ahead to the 1940s and 50s with all the nuclear bomb testing, but that still falls under the umbrella [00:32:00] of us,
so that's where I would put it. I'd, I'd put it at the industrial revolution, at least.
Dr. Jesse Reimink: I would put it on, um, Chris Bolhuis's birthday, the
Chris Bolhuis: You want to put a golden spike?
Dr. Jesse Reimink: Yeah.
Chris Bolhuis: Okay, I, I think that it deserves the name Golden Spike, 1971.
Dr. Jesse Reimink: Okay. There we go.
I
mean,
Chris Bolhuis: For once, we agree, Jesse.
Dr. Jesse Reimink: For once we agree, it is an interesting question, the conversation [00:32:30] is important, at least, and maybe the result is less important of where the spike is, but the conversation about it, and like, I find this very interesting, the discussion
Chris Bolhuis: That surprises me. That surprises me because you know, when we, when you and I were talking about, you know, putting this episode together, you used that word. You said, I don't know. I just kind of, the whole Anthropocene argument is kind of pedantic and I'm not sure. I don't know. That kind of surprises me to be honest with you.
Um,
Dr. Jesse Reimink: Well, I don't know, there's [00:33:00] something about the argument that we just don't know how this plays out yet that resonates with me. Whereas when we look at geologic time, we have a before and after picture, we know what happened at that boundary. In this one, we, we don't have that after picture yet and hopefully it's not as bad as, as of the predictions would say, uh, you know, we're, we can constantly work to sort of minimize that.
So maybe there's part of me that's like clinging to hope that it's a really ephemeral thing and we can kind of get back on the right path that it isn't as big of a, uh, an event as, I mean, it's [00:33:30] certainly good. There's going to be a record of it, but hopefully we can, we can work to kind of minimize that.
Uh, maybe that ship has sailed and I'm being just completely. delusional, but
Chris Bolhuis: yeah,
I
don't I think so. Right. I think you are. I don't mean that. Like I think I actually think you are in this. do we need to know the end to be able to say that we're having an impact?
Dr. Jesse Reimink: Well, this is the thing, Chris. I, this is, this is the thing that I think, uh, for me, the argument of the industrial revolution makes a little bit more sense because there's [00:34:00] been a couple of hundred years where since that time, putting in the 1950s is like, okay, what if the
cesium spike is just, what if there's never another atmospheric nuclear you know, weapons detonation again?
Like it's just a. A one spike, uh, sort of event, whereas
I, like, I understand why that's like a, uh, a representation of, humanity's development and impact, but the industrial revolution resonates a little bit better for me, uh, I think, but there's part of me, like, I would, Well, I'm not a stratigrapher.
I [00:34:30] just, you know, looking at squiggles in the dirt is not super interesting to me out of default. And so obviously, like, the Anthropocene Working Group would not be something I would be,
like, qualified to or interested in joining.
Chris Bolhuis: That's
Dr. Jesse Reimink: Um,
Chris Bolhuis: That's true. It's a
good point. It's a good point.
Dr. Jesse Reimink: And the other, the
other aspect of this is it could get, like everything I guess in our society these days, it could get
hyper politicized. Yeah. Like, you know, this could be used for pros and cons, to both like minimize impacts before this golden [00:35:00] spike, wherever it goes, or, yeah, so it gets complicated and it gets kind
of unclear what the best path forward is. But
anyway,
Chris Bolhuis: Well, I have a feeling that in the, in the coming months, the debate is going to be settled, whether or not we are in favor of it or
Dr. Jesse Reimink: Yeah, I, it's not, it seems that way there's been a proposal on the table at least I'm sure we'll, get some more clarity, uh, what the, the group of stratigraphers think who make these
decisions.
So,
Chris Bolhuis: I wonder if this will be as big of a deal as it was when, you know, the astronomers decided to demote Pluto.
Dr. Jesse Reimink: oh [00:35:30] my goodness. Talk about your meltdown central.
Chris Bolhuis: I
know.
Dr. Jesse Reimink: Wow. That was
Chris Bolhuis: Yes. Yes. Oh, hey, you know what I got a gift from a student last year in my astronomy class, and it was a mug. And it says, I date back to the time when there were nine planets.
Dr. Jesse Reimink: That's a good one.
That's a
good
one.
And, uh, Uh, when was that? When was that like 2000? Was
that?
Chris Bolhuis: two thousands.
Yeah,
Yeah, I
Dr. Jesse Reimink: I was in, like, high school or early college, I [00:36:00] think,
when that happened. Yeah.
that was Meltdown Central, though, I remember.
Everybody was
in a big uproar.
Chris Bolhuis: People are passionate.
Dr. Jesse Reimink: Oh, I didn't know that. That's
Chris Bolhuis: Oh yeah.
Dr. Jesse Reimink: You know, we should talk to Jackie Faraday about that. We haven't had her on in the podcast in a
while. We should ask her about what her thoughts are about Pluto. That'd be fun. I'm
sure she'd have, she'd have opinions.
Well informed and very thoughtful opinions.
Chris Bolhuis: That's right. That's that's a good point. That's a good point.
Dr. Jesse Reimink: Oh, man. Hey, Chris, I think that's a wrap on the Anthropocene and Crawford Lake. and you can follow us on all the social media platforms. We're at planet geocast. Send us an email planet [00:36:30] geocast at gmail. com. We love those questions Leave us a rating in a review on your podcast platform and head over to our website, planet geocast. com. There you can subscribe, follow us, learn more and support the podcast. We love it when that happens. And also go to our mobile app, just type in camp geo into your app store and you can download. Our mobile app where you can get access to Camp Geo, all the images, all the visuals, all the basics of geoscience in a very coarse, like audio book, like platform with all the visuals you [00:37:00] need.
We also have the Yellowstone geology guide there as well.
Chris Bolhuis: Cheers.
