Badlands National Park

Chris Bolhuis: Hey, professor Reimink

Jesse Reimink: Hey Chris, you're looking particularly enthusiastic today.

Chris Bolhuis: Well, why wouldn't I be? We're talking to The Badlands today. you know, so

Jesse Reimink: that's true. you have every reason to be enthusiastic. Let's do some quick introductions here because maybe it's been a little bit Your Chris Bolhuis high school teacher, extraordinary nationally recognized regionally recognized. One, a bunch of, a bunch of bunch of teaching awards have taught earth science, college level, geology, field, geology, astronomy loads of stuff. You're my former high school teacher. And right now you're probably on the trip that really cemented me wanting to go into geology.

Chris Bolhuis: Yeah. I am. and as you said, you're Dr. Jesse Reimink and you're one of my former students. you went on to get your PhD actually in geoscience at the university of Alberta. And you now work at one of the most prestigious. geology programs in the country actually. And that's impressive, um, that you, you know, you work at Penn state university as the geoscience professor and that's awesome. love that. It's yeah, that's so cool.

Jesse Reimink: sob to be working at Penn state. Uh, they have not realized their mistake yet. So,

Chris Bolhuis: That's pretty funny.

Jesse Reimink: want to, I want to like sort of double click on this because we're releasing this the time. We're releasing it right now with meaning, because you are on this trip right now. And this trip was really fundamental to me getting into geology. And I think maybe even you getting in geology because your dad used to teach this trip back in the day when it was a little bit more biology focused. Right. And you went along as a kid and.

Chris Bolhuis: Yeah, that had nothing to do though with me getting into geology, , that had more to do with a, a gifted professor that I had in college that just, Our planet come to life, description of earthquakes and volcanoes and the PA and tectonics, and you know, what makes this planet work? That was what really did it to me. and he was just so gifted, you know, and it's the power of that.

Jesse Reimink: and you were. Professor for me at the high school level. So I was really very lucky to have someone like you, but this trip you're on it right now. Let me just paint a picture here you take, I think 26 students now from Michigan, you get in a big yellow bus and you drive out to the Western United States and you hit on. Big national parks in the sort of Eastern part of the Western United States. So that's grand Teton, national park, Yellowstone national park, glacier national park, all of which we have covered in planet geo before and talked about the geoscience of those parks. So go listen to those, but we're going to talk about the Badlands today, because this is a stop in, in South Korea. On the way to what I'm going to call here, the real mountains, but the Badlands are kind of. warmup to the mountains, or they at least were for me on this trip because you're driving from Michigan across the Prairie's, you know, Nebraska, corn fields, nothing against cornfields, but like it's pretty flat. There's a lot of them. And then you hit the bad land. Oh, typography in rocks and fossils, and like some actually interesting geology there as a sort of a warmup till you hit the real stuff in the Rockies. so we're releasing this while you were on this trip so that, you know, people who are listening can kinda kind of follow along a little bit, right.

Chris Bolhuis: That's right. Yeah. You described it very well. And in terms of also my approach to this, first of all, Geology as a field is so easy to sell because all you got to do is go out and see our planet. Go see things we live in an amazing world that's what geology is for you. And I is, it just makes it come to life. It just, it's just, ah, it's awesome. Anyway, so yeah, we go to the Badlands it's. You know, and we get there around noon, on day two and it's their first exposure. And if you've never been to the Badlands, the way I think of it is, I'm, this little tiny speck, I'm an like an aunt. Okay. And I made a gigantic sandcastle and how The Badlands feels to me,

Jesse Reimink: does very apt. Chris. That's very accurate there. Yeah. It's like, It's like beach, you know, you're at the beach and you're digging sand castles and making little sand pits and you know, all this stuff is going on And it's, kind of muddy and it's that's perfect description. So, what we're talking about specifically here is Badlands national park, which is in South Dakota, that's capital B Badlands, the national park, the location, Badlands lowercase B is a geologic feature, actually a landscape feature. And these are pretty common. Or at least let's say they're not uncommon around the world. These things occur. Like most people probably live. Driving distance. So some bad lens somewhere. And there's a few famous ones. some Pinnacle's in New Zealand, Kashani Taiwan. One of my favorites is called toadstool geologic park in Nebraska, which is a great one. And then there's big series in Alberta, in red deer near the red deer river, near where I lived in, um, in Edmonton, Alberta and Chris, I guess, what does it take? Well, could you paint a quick, really quick picture of what bad lens look like, and then lead us into a discussion about what the key components we need to form Badlands are what The key geologic features are.

Chris Bolhuis: Yeah. The only problem with your lead into that is quick. I have a hard time doing that. Okay. Cause I'm passionate about this shit. It's like, this is so good. I love the badlands. you said it Badlands national park in South Dakota, but you know, when we come back. Uh, on our way back home, uh, the trip, we don't travel through South Dakota who traveled through North Dakota and we go to theater Roosevelt national park in North Dakota. those are Badlands. And you get them in Eastern Montana. We cross bad lands. Once we leave the black Hills heading toward the big horn mountains, we crossed over these massive mountains and we are in Badlands again in between the big horns in Yellowstone. It's like, they're all over the place. And so that begs the question. Well, what does it take? Right. Well, we can boil it down. I think to four things that geologically you've got to have. And the first thing is we got to have an area that is well above sea level. We got to have, you know, erodible materials and, and in order to have that, you have to be well above sea level two, you got to have softer sedimentary rocks. That are juxtaposed to really harder and more resistant sedimentary rocks. Then, then we need to have this arid. Climate. And that's important for really two reasons, because in an arid climate, you have a lack of vegetation and vegetation holds things down and anchors things down and really like minimizes weathering an erosion. And the other thing with an arid climate is the kind of precipitation you get you know, you don't get tropical rain kind of precipitation. You get cloudburst violent events , you know, it's short, but it's extremely intense. And when you get that, then that those are the, the ingredients for like rapid, harsh erosion.

Jesse Reimink: and Chris, we sat, I remember this cloud burst type thing, just so we could paint a picture of this. We sat, I think we're at the top of Pike's peak batholith we were on a rock club trip in Colorado and we were up near Pikes peak overlooking Colorado Springs. And. We were watching this amazing Advil shaped Thunderhead move across the Prairie's to the east. And this is exactly what we're talking about. Like, if you've lived, if you've traveled across to any kind of Prairie land in north America, especially you get this all the time where you get these huge thunderheads that pile up and they move across the landscape and they write. Dump torrents of rain for about 15 minutes onto the land, and then they go away. And that's what we're talking about with this cloud burst, like really intense, really short-lived rain. And I just remember sitting there, Chris, we're looking back east, the sun is setting behind us and it's just lighting up this huge anvil shaped Thunderhead miles and miles away to the east. Just dumping torrents of rain out of the prairie's and we're sitting on his mountain overlooking. It was a beautiful, beautiful.

Chris Bolhuis: Uh, you and I have so many memories together that are just, they, they warmed the heart. Okay. I love that. I remember exactly what you're talking about. One of the things about this club, first thing in the Badlands, it is so dry that when you get these storms, It often is rocking and rolling above you. You can smell it. You can hear it, but it's not hitting you because it's evaporating before it hits the ground. And that's a common occurrence in a place like this, where this, all this stuff is going on, but it's not making its way to the ground. And obviously the longer, this goes on the closer it gets to hit in the ground, but that's a really cool experience to see a storm above you and still stay dry.

Jesse Reimink: And that brings us to the fourth point of what you really need to create Badlands lowercase B this geographic feature is that you typically need something like shale or clay at the surface. And that is a rock that is very impermeable. So many water can't flow through it very quickly at all. that is really essential for bad land formation, because what it means. When you get this really heavy downpour of rain, it doesn't seep into the ground. It flows across it. Think concrete compared to grass it'll flow across the surface. And when it flows across the surface, it starts to erode stuff, physically, meaning taking grains and moving them downstream. Like you think of a gravel road. That has those little review it's that form and a heavy rain and it's washing material downstream as opposed to percolating through it. That's really important for forming Badlands because Badlands have some of the highest erosion rates out there in the world. Meaning the most amount of sediment being removed per unit time out there. And what is it in the Badlands national park? It's like one inch per year or something like that. I mean,

Chris Bolhuis: Yeah, it's over that. It's almost in some areas it's over eight inches a year.

Jesse Reimink: Oh my goodness, eight inches per year. And that, that really highlights the fact that actually we can form these anthropogenically. There are human induced, bad lands in the world, some famous ones in Northern Spain, from Roman mining activity and also some pretty famous ones. Ontario, Canada from overgrazing. And sort of poor farming practices, which removed all the vegetation, the rocks underneath it were right. Performing Badlands in once the vegetation has gone, erosion starts to take over and boom, the system's done like it's in a bad land formation. You're going to have rapid erosion, until you kind of either replant some trees or stabilize the landscape. So. All right. That's what we need to have Badlands those four things we need to have land to C-level. We need to have soft sedimentary rocks. We need to have arid climate with this cloudburst rain, and we need to have some impermeable sediment layer at the top, like shale or clay. Chris let's work through the geologic story of Badlands national park. Now capital B Badlands national park in South Dakota. Where do we start with these rocks?

Chris Bolhuis: Well, geological. We always start at the bottom, especially when we're talking about sedimentary rocks, because the bottom is the first page of the book. The bottom is the oldest, and we got to start at the beginning in the bad lands. And it's really in the Badlands only because there are older rocks that are in other areas of that part of the country. But in the Badlands, we start with. A layer of rock that is roughly 80 million years old. And it's deposited by the Western interior Seaway. And this is a Seaway that it's a shallow sea and you know, it transgressed and regressed, it got deeper and shallower and, you know, the biology kind of went with the shifting shorelines that was going on, but it extended from the Gulf of Mexico to the Arctic. In the Western part of what is now, north America. And it also extended, like from an east west standpoint, it extended from Wyoming, from the Wyoming, Idaho boundary to the Mississippi river basin there. So like, it was really like long and skinny. that was depositing. This layer of rock that is known as the Pierre shale,

Jesse Reimink: And that's peer, but it's spelled like Pierre. I was thinking that P I E R R E shale. So you might see it, you know, spelled and think, oh, that's not what we're saying, but we're saying peer shale, but it looks like Pierre,

Chris Bolhuis: Yeah, right. It does. And they're very, they're very funny about that. it's,

Jesse Reimink: so this is the bottom. What is the rock look like? I mean, how would you identify when you're out there hiking and the bad.

Chris Bolhuis: so the pure shale is in the bad lands. The top part of it is this like bright, yellow lavender kind of color. We'll get into that in a second into why that is the case, but everywhere else, it's this dark gray, it's almost this bluish gray to black, like organic, rich. Wow. Soft wimpy, crumbly, shale, typical shale rock. But the cool part about it is that it has fossils. And I remember what we're talking about, right? We're talking about. and it has fossils in it that are amazing fossils. Like police, you have sores. These things are, you know, they were patrolling the sea. These were 80 feet, long shallow Marine saltwater organism. You know, just like incredible things. It were turtles that were sharks, just this amazing. I seen diversity of fossils that lived in this sea at this time, which is like to me, I look at that. I'm like, oh, that's amazing because it looks nothing like what it does today. We're talking about, uh, a landscape that is well above sea level and about as dry and opposite of the conditions as you can get. So there's the Pierre shale. That's the bottom most layer that you're going to find in the bad lands. So what's next? What

Jesse Reimink: so we got to touch on the top of the peer show, which you kind of talked about as this yellow layer, right? And this represents erosion chemical erosion now at the surface. So think of this black shale layer, which is being deposited in the shallow sea. Now, all of a sudden that land is uplifted and that shale is now exposed to the surface, meaning the atmosphere conditions and that causes

Chris Bolhuis: right, so Jesse, what exposed this shale? Cause you said that it's this, you know, yellow it's it's chemically altered, , but that happens when it's exposed to the elements. What did this, what what's next?

Jesse Reimink: Yeah. So this is the Laramide orogeny. And we've talked about this before. We've talked about this with the Tetons. We've talked a little bit about it with Yellowstone, but the Laramide Orogeny is this mountain building event that took place all across the Western United States. And this had a lot to do with. oceanic plate subducting underneath the north American continent, moving from west to east, underneath of north America. Most people think it probably had a flat subduction regime. So this is a, uh, oceanic plate that kind of slid underneath the continent.

Chris Bolhuis: right now. I see a, flat subduction regime. Wow.

Jesse Reimink: Yes,

Chris Bolhuis: You're getting

Jesse Reimink: all.

Chris Bolhuis: on us right now. I can, I can feel.

Jesse Reimink: Okay.

All right. All right. I'll dial

it back down the back, towed it down. Jesse. Calm down, calm down, Jesse. So this is, think of, I don't know, what's a good analogy, Chris. You probably have a great analogy of this, but it's one oceanic plate sliding underneath the continent and kind of pushing the con. A sliver. Oh, a sliver underneath your fingernail. That's a great one. Okay, perfect. That's a very painful analogy to go for, but it works,

Chris Bolhuis: I don't like thinking about it.

Jesse Reimink: but you're right. Exactly. It's taking a piece \ of oceanic crust shoving it underneath of the continental crust, which pushes up the continental cross. So this uplift a very broad region was going on. And this was, you know, started around 65 to 70 million years ago, continued for a few tens of millions of years and created this uplift, which exposed these rocks and created the potential for chemical erosion that you referenced.

Chris Bolhuis: That's right. However, A massive event happened. 65 million years ago, our planet was met with a massive catastrophe, and that was the meteor, the asteroid impact that caused the extinction of the dinosaurs. So at this time, 65 million years ago, we had a lot going on right there. This is a lot that's happening. We have this mountain building event that really shaped the Western part of the United States. As we know it today, we have the sea that is being drained by this uplift cause you uplift the land, the sea goes away and then a meteor hits that is just game-changing, it's a bad day to be alive on the planet during this time. And at this time that all, dinosaurs. All flying reptiles, just essentially vanished in a very short period of time in the sea life was dramatically changed. Ammonite. Muscle source, which are these large swimming reptiles that were like kind of important in terms of Wegners, you know, continental drift theory. We talked about that earlier, foraminifera for the diversity of this hugely diverse, , Marine organisms. Too much, much, much smaller, and just a few species remained after this impact. So this was a massive deal. so the Seaway as this was going on eventually entirely disappeared from the region and an entirely new ecosystem gained traction,

Jesse Reimink: Yeah. And so this is. Catastrophe for the dinosaurs and the mammals would consider it a great opportunity because the mammals have ended up taking over the knee, all the biological niches, right? And this was the expansion of the mammals. So back to the rock record here, how we see this massive catastrophic event represented in the rock record is first of all, it was a bunch of fossils in this entire region that represent this episode.

Chris Bolhuis: Hold on. I'm going to interject your Jessie. You're right. The Badlands are one of the most prolific fossil troves anywhere in the country. I mean, the Badlands proper, the fossils you're going to find are mostly mammals, not dinosaurs. You have to go elsewhere to find the dinosaur fossils, but it is so incredibly rich and fossils. So sorry. I had to interject

Jesse Reimink: no, that's absolutely true. We're going to come back to that in a, just a minute or two. So the sediment, this Pierre Shale was exposed above sea level, exposed to the atmosphere which induced chemical weathering, which turned this BlackRock into the yellow rock. And this is a really, really beautiful rock that you can see. At the base of the mid-level of most of the cliffs that you can see, it's still a Pierre Shale, but it's weathered it's chemically weathered. And what happens is it makes these beautiful yellow lavender colors, and it's an iron hydroxide mineral. So it's taking iron, which was in a reduced state in the black shales. And it's turning into an oxidized version, which creates these yellow minerals like goethite. Rusting, except it's not red. It's yellow of the rock layers

Chris Bolhuis: I could to drop in weird mineral names, like go tight, you know, like nobody knows what go tight is. Hey, nobody knows what go tight is. Well, hold on of, of our many thousands of listeners, some of them probably know what go tight is, but

Jesse Reimink: Yeah. Yeah. Don't

disrespect. People, people know what go tight is Chris. You know, you're going to get some hate mail for that one.

Chris Bolhuis: please. Don't please. Don't I respect all of you. you know, the pure shale also had pyrite in it and the pirate is when it chemically weathers. It turns it into this beautiful lavender and bright yellow colors, the best place to see this. Cause like, hopefully people are going to go there, is Kanada pass. Can I a pass, you can see it all. You can see the peer shale and it's beautifully weathered, colors. And then you can see the, the white river group above that, which we're going to talk about here in a couple of minutes. can see all of the formation of the Badlands really at Kanada pass. It's an, it's an amazing place. I love that. That's my favorite place.

Jesse Reimink: At the top of the pierre shale. Now we transition into a different type of deposit, a different tub of sedimentary rock, and it represents a different type of environment, right? And th the uplift of the black Hills, which is just to the west of this region at this time and still is to stay. But the black Hills uplifting, allowed rivers to deposit sediments. So we have this peer shale that's exposed to the atmosphere. It's chemically weathered. Now we have sediment being deposited in this region because the black Hills were uplifted. And so then we pushed rivers that flowed from the black Hills east and deposited all the sediment. And I don't know, Chris landscape, I kind of always envisioned with this is. Uh, you know, those scenes in Jurassic park where the helicopters like flying over the river valley and there's like all sorts of animals. They just Chuck all the dinosaurs all into one, image one shot in the movie, all the dinosaurs that you've got, like all these herds, the dinosaurs, my dinner, I was birds flying everywhere. That's kind of what I envisioned, except instead of dinosaurs, remember dinosaurs got knocked out by this meteorite impact. Now it's mammals. And so we have things like deer, giant pigs, small horses, like it, but this really kind of fertile floodplain region. Right. Is that kind of an apt description of.

Chris Bolhuis: It's a very apt, but I think you're shortchanged the F biodiversity. I mean, you said we had these giant pigs and small horses with Sabretooth cats. I mean, are you kidding me? Like what,

Jesse Reimink: Totally cool.

Chris Bolhuis: we had rhinoceros hippopotamus. We had alligators, squirrels, burrowing organisms. The bio-diversity tells us a ton about the climate, right? Like this was a warm tropical climate that existed during this time. And the biology let alone, I mean, we're, we haven't talked about fauna. You know, in terms of like, the plant diversity that we had to that's preserved as pollen and spores the sedimentary rocks. Also, like this was a much, much, much warmer climate than what we have today and, and wetter too.

Jesse Reimink: So, Chris, what are the names of the sedimentary units that represent this environment? We're discussing.

Chris Bolhuis: Yeah. I think that's important to talk about. So, you know, you said that we have the uplift of the black Hills now that has begun due to the Laramide Orogeny and go back to our black Hills episode, a few weeks prior, which talks really in detail about how the black Hills formed, but the black Hills are integral to the formation of Badlands. So, but like 60 miles away. Of the Badlands. And when you're sitting at Kanata pass, looking down on the pier shale and all these other layers of rock that you can see on a clear day, on a dry day, you can see the outline of the black Hills and it is so cool. they're uplifting. I mean the, the extent of the uplift was in excess of 15,000 feet. So as they were uplifting, the granite that was exposed there with these rocks was getting shed off by these mountain streams and they were flowing towards what is now the Badlands. And so what did this look like at the time? Right. We talked about the shadow. That existed here. That's easy to envision. Well, now envision mountains rise into the west streams coming off and slowing in water and all the Badlands. So that makes this a floodplain deposit. And so you have these rivers that are slowing down depositing clay silt, and sometimes even sand, which is higher energy. And they formed these layers that are called the Chadron. And the Brule, the Chadron is red on top of the, pier shale, and the Brule is on top of the Chadron. They have slightly different characteristics, This is where rivers were slowing down and depositing sediment in a typical floodplain, which is also why Jesse. Why we have so many fossils here. So Jesse, I want, I'm going to defer to you on this. Why do fossils equate to a flood plain?

Jesse Reimink: Well, floodplains are very actually sort of fairly dynamic environments for biological diversity. There's just loads of animal life there, but they're also kind of traumatic environments, too. You have floods in a flood, plain and floods can very easily come through and. A bunch of animals and deposit them all in one spot. So you could have, you know, floods. Treacherous things that happened. Right? And so it's easy to kill a herd of stuff and dump all the bodies in one location, bury them under a bunch of sediments. So it's an anoxic and those bodies don't decompose quickly. Eventually that gets turned to rock. And that's one way to form a lot of fossils in a flood plain region. But Chris, you talked about this and this is a rock feature that we often see is what's called paleo souls and that's just paleo soul ancient soil. And you, you touched on this, that in this floodplain region, you have a bunch of stuff deposited, but in a flood plain, you also have soil exposed at the surface and rock exposed to again, atmospheric chemical weathering, which creates an ancient soil environment. And there are loads of these preserved along with lots of other classic geological features, which maybe we can go through those really quickly, Chris, like what are some other classic features that we see?

Chris Bolhuis: Well, first of all, just want to talk about the paleo salts. I envision, a rhinoceros walking up to the river. Dip in his head down to, to get a little sip of water and then just getting demolished by this flood comes ripping down the, you know, the valley and, you know, just kills the runoff, serous and berries there an asterisk, because that's usually how fossils are preserved as they

Jesse Reimink: Yeah. Yeah.

Chris Bolhuis: in quick

Jesse Reimink: me, let me say something about that. I remember the fossils are everywhere. We didn't really harp on this point, but we need to harp on this spot because fossils are everywhere in the Badlands. I remember walking along on a hike with you, uh, you know, as part of the class and you just see pig fossils laying. right next to you, you're walking along this beautiful high yeah. Everywhere. And they're just all over the place. It's really just an unbelievable place. If you just go for anything more, well, just go for a mile hike anywhere. And you're basically always going to see a fossil and they always kind of eroded. Positively out. So they kind of are on the top of little mounds, but they're still in place. And it's just that they're a little bit more resistant to weathering than the clay rock around them. And so they weather out a little bit positively, but they're just all over the place. It's spectacular. And there's a really famous one called the pig dig. I remember that. Cause it's like a whole herd of pigs that were like varied. Fossilizes they call it the pig. Dig is great. I love that name.

Chris Bolhuis: out a whole herd of pigs. Yeah that's right. I do want to say though that you know, get out and explore the Badlands. you're going to see fossils galore. Right. Don't collect them. Like you never, you don't do that. it's, it's so tempting, but. one it's wrong, like really wrong. And don't do that. And two is you can pay a massive, fine. I mean, they really, really monitor for this. Okay. So the Sharon on top of the pier, the shed is like this Shaylee Sandy mixture. the sand that's in the shale allows water to percolate more. And so the weathering is different. They're on top of the Shadowrun is the Brule in the brutal. Very little sand at it, actually, and more clay, which makes it shed water like a roof. And so this is the stuff that tends to form the peaks and the Shadowrun below it forms like these hummocky like swell and swale kind of thing. But here's what happens when the Brule falls on top of the Chadron. It forms a toad stool or a mushroom rock. Okay. Where you get this, the Brule, which is much tougher and more resistant doesn't allow water to percolate through. It sits out, lands like a thud on top of the Chadron, and then it forms this like really narrow pedestal and forms. Really cool formations. You alluded to it cause it's one of your favorite in Nebraska, I think. Right?

Jesse Reimink: Yeah. Yeah, that's right. That's right. And there's several other futures. The most interesting, I think is classic dykes. So we've talked about fossils. We've talked about paleo souls. We talked about mushroom rocks, classic dykes are this really interesting phenomenon? We often think in geology of dykes as being igneous rocks. So think of a igneous rock intrudes across the sedimentary layers. So it pumps a bunch of magma through a sediment. It forms a vein basically of magma, which we call it Dyke if it's big enough, that crystallizes and sits there. And then we have this igneous rock crosscutting, a sedimentary rock. Now clastic dykes are sedentary rocks, cross-cutting other sedimentary rocks. And there's two different ways that they can form. Both of them are realistic. One is if you have a water packed sediment sitting down underneath

Chris Bolhuis: That's a funny way of putting it, by the way, just going to say. Both of these are realistic

Jesse Reimink: Yeah. Well, here I go, now

Chris Bolhuis: I appreciate that.

Jesse Reimink: I'm going to lecture to you and I don't want to hear any interruptions out of you either.

Chris Bolhuis: You, I love interrupting you and you hate it when I. interrupt you. Like i.

Jesse Reimink: here's the thing. I have relatively simple mind.

Chris Bolhuis: No, you do not. That is a bold face lie right there.

Jesse Reimink: Okay. Well, if I get distracted, it's very hard for me to recover. to what I was thinking about beforehand. So

Chris Bolhuis: You have a one track mind that is not a simple mind.

Jesse Reimink: Okay.

Chris Bolhuis: Is those are two different

Jesse Reimink: I have a very one track mind. So where was I? Anyways? I was onto something really important. I had something important to say, if you distracted me

Chris Bolhuis: sorry. I fell

asleep, so I can't help you.

Jesse Reimink: we're talking about what are we talking about? The bad lens?

Chris Bolhuis: general.

Jesse Reimink: Well, I don't actually, I honestly don't remember. What was I talking about?

Chris Bolhuis: I don't know, Jesse. Cause I was thinking about how rambling you were getting

Jesse Reimink: yeah, I am pretty rambly, PA paleo sows or something. Oh, classic dikes. That's

Chris Bolhuis: Oh, Classic dykes. Oh yeah. How there they're volts reasonable. That's

Jesse Reimink: They're both reasonable. They're both reasonable things to see. Yeah. So classic dykes, these are sediment tracks across getting other said, renter rocks. Two ways to form them one way. Uh, water rich sediment, that's buried under other sediments. So think of something that's packed full of water, really kind of a squishy think of a water bed. Really. If you pack enough stuff, layer up enough stuff on top of a water bed, eventually that water layer. Going to rupture and it's going to squirt water up, right? The pressure releases upward. And basically if you have a sediment filled with water down deep and you layer on top stuff, that pressure is going to build up. You layer more on pressure is going to build up. Eventually that'll break the seal in the sediment and water will flow up into a crack and you can kind of get that. It's just the sort of diking type of thing. This number two. If you have a sediment layer sitting there, a bunch of sedentary rock. Pull them apart with some extensional force, they create cracks and joints in the rock. And then if wind or sand blows into those cracks, it'll fill up the cracks with sand or wind or other sediment. And those will form. Sedimentary rock that is cross-cutting other ones. So there's this sort of bottom-up or top-down formation for clastic dikes. And there's some great examples in the Badlands because the classic dykes weather out positively with Chris. And so I remember these hikes where you can kind of see there's this little cliff or Ridge running along, and then you get to the end of the Ridge and you look at it and it's a clastic dike. The Ridge is there because there's a different rock type. That's more resistant you that you were walking along the whole way and you only see it when you see the end of it.

Chris Bolhuis: Do you remember what color they are?

Jesse Reimink: I think, I think like a bluish or, or sorta grayish. Is that what the CR I don't know, something along those lines. That

Chris Bolhuis: They're more.

Jesse Reimink: Okay. All right. Okay.

Chris Bolhuis: Yeah, like a greenish gray. Um, yeah, I think so. I remember your group actually. Um, we go on this little hike. It's like our first introductory. It's not, I can't even call it a hike. It's like a walk. Um, it's maybe a mile and it is really tame, but it's kind of cool. Cause you know, we're walking through the Brule formation, which sits on top of the shed run so it's got more resistant nature anyway. And then this is where the classic dykes are, which you said are more resistant. So they formed the peaks and pinnacles. So it's a pretty spectacular like geologically, differentially, weathered feature.

Jesse Reimink: totally cool.

Chris Bolhuis: And we get there to the end of it. And I'm like, all right, what have you guys seen? And you guys are like, uh, oh, Well, what do we see Mr was that I was pissed. I'm like son of a bitch guys. We just walked through an area that is like, you're walking through gigantic sandcastles and you didn't notice a thing. So I called you guys accidental tourist. And I think I berated you a little bit. Did I, is

Jesse Reimink: I think so. I think so you, you, you gave us a pretty good speech if I remember correctly and I'm sure you've given that speech to many groups before and after ours seemed well-practiced, but

Chris Bolhuis: you guys were the worst,

Jesse Reimink: the worst anyway. Okay. There are so many things to see in the bad lens. In the thing about the bad lenses, you can see almost all of them. With like a couple hikes. You don't need to go on massive, huge day long tracks to see this stuff it's everywhere because this floodplain area that deposit all his stuff, it's so vast, but it kind of forms these little areas where, you know, the river bend will deposit one type and then the other, the inside and the outside of river bend will deposit different types of sediments. So basically as you're walking down here, you see all different types of stuff on all the hikes. And so. It's kind of a place you don't need to spend a week in the Badlands to see all the geology. You can see all the different types of geology in a day or two, probably. And there's very cool stuff. So you got to spend some

Chris Bolhuis: Easily easily a day and would recommend. especially if you can drop a car spot, a car is to do the castle trail, it walks you right through the heart of the bad lands. It's a five mile one way. So that's why I said spot a car because then it's just a five mile hike is relatively flat. It's pretty well marked. But if you can't, it's worth the 10 mile because you're going to see things in reverse. Because it's just an out and back then. It's awesome. Um, so look it up. One of the things I want to say, the popcorn weathering is a pretty cool feature that you can see, especially in the Chadron formation, which is where the water percolates down through the shale, Sandy Shayla a little bit, and then it dries. So the shale expands and then dries and cracks. And so you can literally. Bend down and scoop it up with your hands. And it literally you'll have a wad full of this Shaley clay, sand stone in your hands that looks like popcorn and just sheds like crazy. And so this is one of the reasons why the Badlands erode so fast is because of the popcorn weathering kind of nature to it. So that's, that's another pretty cool feature that you can see there. So.

Jesse Reimink: So Chris we've covered a lot of the rocks. We've covered a lot of the features. We have one last event to get us to where we are today.

Chris Bolhuis: So Jessie wanted the thing though. That's on top of the Brule and these clastic dykes is related to volcanic activity. And actually what is now Nevada? So you had these volcanoes erupt in that were depositing thick layers of Ash, and then also the streams from, you know, because remember this is still a flood, plain streams are depositing, this ashy layer, which formed this like brilliantly white ashy cat. On top of the Brule. So that's the most recent sedimentary rock layer that you're going to find in the bad lands. So we have, again, the pier shale, the Chadron, the Brule, and you have this volcanic Ash layer on top. That is, uh, like it's bright white. You can't miss it. And those are the rocks that we typically see in the Badlands national park.

Jesse Reimink: And there's one final geologic step to get us to where we are today. We have these rocks being deposited, the sanction floodplain environment with some Ash being deposited on top of that. You know, that's not what we see today. So what we need is uplift. We need more uplift to get these rocks exposed above. I mean, we need to get these rocks lifted up so that they can be eroded. And this is what's called stream rejuvenation, and this is basically reactivating. The streams downcutting force. So a stream, if it has lots of elevation loss, if it's a steep gradient, he wants to cut down and you sort of reactivate that to make the stream cut down more. And that's what really drives this really rapid erosion. What did you say Chris? Eight. Eight. Was it eight inches per

Chris Bolhuis: Up to

Jesse Reimink: number up to 80.

Chris Bolhuis: where you are. Yeah.

Jesse Reimink: that's, that is such a fast erosion rate you know, that's not going out in a flood plain environment that you have to have uplift to do that. And so the climate has shifted gradually in the last 500,000 years, the last half, a million years and regional uplifts. Rejuvenated these streams such that you can have such a rapid erosion rate going on to form Badlands, because remember that erosion rate is part of what defines Badlands lowercase B Badlands.

Chris Bolhuis: That's right. The streams had to shift from a depositional personality to an erosional personality and they did that through. That changed the slope or the grading of the rivers. It changed the velocity of it and turned it into downcutting, which turned into erosion.

Jesse Reimink: So that's the story of the bad lands. And if you're, you know, envisioning this and thinking, wow, I really got to go there. Chris is your guy and you can just envision Chris's out there right now. All right, Chris, you're out there hanging out with 26 high schoolers, teaching them all this stuff over the next couple of days. You're probably even.

Chris Bolhuis: accidental tourists.

Jesse Reimink: even giving them a really good lecture about that, right. At the moment as we're releasing this episode. So go to the Badlands. It's great. It's a great warmup for, you know, the real hard rock geology stuff we get out of the sediments. As soon as you hit the rocky mountains and you see some.

Chris Bolhuis: hard rock guys,

Jesse Reimink: Yeah, we really liked that stuff. So, but the Badlands are amazing, amazing place. You can see so much interesting geology in a one mile hike. It's, it's probably, you know, one of the more geologically, dense, uh, places to see stuff. So go to the Badlands. It's beautiful, excellent place. Follow us on all the social medias we're @planetgeocast. Send us an email smash that like subscribe button on your podcasts and leave us a review and a five star rating fat. Really really helps the algorithm. If you didn't know that already, I'm sure you do, but that really helps us. We appreciate that greatly.

Chris Bolhuis: And share our podcast with other people that may or may not like our plans.

Jesse Reimink: That's right. And people who like to just travel around our

Chris Bolhuis: Cause if the, yeah, cause if they don't like it, then they need to like it and they'll like it by listening to us. So,

Jesse Reimink: right. That's right. And next week we are going to have an episode on devil's tower. We're going to keep in this theme of following Chris along the summer science Institute, field geology course. And we're going to talk about devil's tower next week. So tune in for that take care.

Chris Bolhuis: Cheers.