Red River Gorge, Kentucky

Jesse Reimink: Welcome to planet geo the podcast where we talk about our amazing planet, how it works and why it matters to you.

Christopher bohi.

Chris Bolhuis: Hey, how you doing Jesse?

Jesse Reimink: Hey, happy Jesse. Happy. Jesse's here today.

Chris Bolhuis: yes, everybody. We get happy, Jesse. It's a good Jesse. He's the fun.

Jesse Reimink: I've got my fun pants on today. It's

Chris Bolhuis: Good. Good for you. I'm happy about that. That

Jesse Reimink: So let's, let's just dive right in here but before we do quick introductions, you're Chris Bolhuis I'm Jesse Reimink. You are mentor I'm mentee in this relationship. You're my former high school teacher, uh, high school teacher in Huntsville public schools in Michigan. You have won many teaching awards at the national and regional level. You teach you a field geology course. You taught me the basics of geology and all the things that we're gonna kind of cover today.= Most of them, I first saw under your tutelage.

Chris Bolhuis: That's right. And you are Dr. Jesse Reimink. You're one of the best students I ever had. And I'll say

that I've gone on record. I know I've gone on record saying that too many times. It makes me feel bad, but

anyway, you are.

Jesse Reimink: If you keep saying that too much.

Chris Bolhuis: and you went on, got your PhD in geoscience. You got it at the university of Alberta in Canada. And now you work at one of the most prestigious geoscience schools, in the country at Penn state. And that's awesome.

Jesse Reimink: We are Penn state.

Chris Bolhuis: and we are planet geo

Jesse Reimink: this is planet geo let's. Uh, I don't know. We talk about a lot of cool stuff. We like to talk about locations as well. This is one of 'em and Chris, this is gonna be, I've never been there. I've never been to the red river Gorge. I live in the Appalachians now. And so the regional geology's kind of similar, but you're the expert here. You've been there. I think you guys have gone on climbing trips, right? To the red river Gorge you and your family.

Chris Bolhuis: Um, no, we haven't. No, we haven't actually. Um, we talked about it. My son is really into climbing a lot. he's quite good. and the last time we were there, which was in December, we had this like, discussion about whether he was gonna bring all of his gear. He's got a big trunk of gear and it didn't make the cut. Yeah. So anyway, this. This episode, Jesse, this is a public service podcast right here today. Cause I am in love with red river Gorge. This is it's red river Gorge in Kentucky. That's what we're talking about today. We're gonna go into the geology of this amazing place. We're gonna talk about some of the features that make this place so cool. And then round off with some hiking recommendations based on my experience, you know, it's just like, this place is so cool that I wanna put it out there. know, I live in Michigan and, uh, It's a seven hour drive, which for us, that's a doable thing for like, even a long weekend.

Jesse Reimink: Yeah, and it doesn't really have the international cache of a place like Yellowstone or Yosemite national park, but on the east coast, you know, it is well known for east coasters as like one of the climbing destinations that's within driving distance from many of the, Southern east coast cities in the United States. So great

Chris Bolhuis: Yeah, that's right. It is, it is a climbing Mecca so I've never been there in the summertime. And everybody that I've spoken to about this says it is so incredibly busy during the summer.

Jesse Reimink: Right.

Chris Bolhuis: So that's why I avoid it. Then we go in the wintertime and like, this is something that we have just kind of, as we've gotten older with my kids, my son's in the military and my daughter's in college. And so. We've kind of gone away from Christmas presents and things like that because they have everything they need. And our Christmas present to our family, to our kids is destinations now. And this is one of the things that we love to do. So we'll pay for everybody to get there. We rent a house, in the mountains and we just spend our time hiking and, and playing board games and cooking and that kind of thing. And red river. Man. It's just, when I think of it, I get all warm and fuzzy inside because it's family. it's it's I love it, man. It's so cool.

Jesse Reimink: That's a great spot. So let's give a little rundown of where we're going here. First of all, we have to talk about the Appalachian mountains. We have to at least give a, a sort of a broad summary. What happened in this area from a geologic standpoint, and that goes back several hundred million years. We're gonna talk about how the rocks themselves that are exposed in red river Gorge, how they were deposited, how those rocks were formed. And then we have to talk about how did those things get above sea level? How did they get uplifted? How did they get eroded? And finally. There's a couple of really amazing features, the arches and the natural bridges and the banding, this really colorful banding. So we're gonna talk a little bit about that near the end or interject that throughout. So Chris lead us off, man. Ancestral, Appalachian mountains.

Chris Bolhuis: Yes. Some say Appalachia, some say Appalachia. I say Appalachia the Appalachians. We have to talk about this. If you want a more detailed. Explanation for the geology of the Appalachians and how that all happened. Go back to our great smokey mountain national park episode. we have to talk though about the Appalachians and their formation here, because they do relate in a more remote kind of way, but they do relate to red river Gorge for sure. So the bottom line is the Appalachians. They began forming as Pangea came together. The last. Time, there was a super continent. There were a lot of things going on and it was, this occurred over a, to me, what I think is an impressive amount of geologic time. So we're just glossing through this. But when, north America began to collide with north Africa, as this super continent was form. So this was a continent to continent, convergent boundary. That's when the Appalachians began to really rise to this prominent mountain chain that is now like this north south range in the Eastern part of the United States. when I say it's complicated, I think the one thing I want to point out is that the entire north south range, which now goes, you know, from Alabama up through Maine and through, Newfoundland and is a part of the Caledonian mountains in Northern Europe, Northwestern, Europe. This linear chain didn't all happen at the same time. To me, it's more like, the analogy of a swinging door, as the door closes gradually. In other words, the collision took place first in the Northern part of the Appalachians. And then as the door began to close, as the continents began to collide. this central and Southern part of the Appalachians began to uplift. and so a continent to continent, convergent, boundary forms, mountains, like the Himalayas. And it is, widely said that. In their prime in these young, muscular mountains, the Appalachians may have been every bit as impressive as the modern day Himalayas. And we could determine that based on things like the amount of sediment that has been shed off from the Appalachians.

Jesse Reimink: And it is a massive amount of sediment. I mean, all of the rocks that are exposed. The physiographic features that we'll talk about the Allegheny mountains, the Allegheny plateau, the Cumberland mountains, the Cumberland plateau, all of those rocks are formed by the shedding of the sediment. So ancient mountain belts now deposited into sandstones and quartzites and conglomerates, and shales all that stuff is deposited there. So lost a massive amount of the crust was lopped off due to erosion at this time. and eventually deposited to form the rocks. We see.

Chris Bolhuis: So Jesse, what happens when, Pangea comes together, the mountains have formed and then, Pangea began to break apart. what are the patterns that we can often see in geology? When a mountain building event ceases the uplift process ends, what happens then? What takes over?

Jesse Reimink: Yeah. So then it's erosion. If you don't have stuff pushing up while erosion's kind of always going on in the background, but as soon as you stop this uplift, then. Erosion is the main thing that's happening. And

Chris Bolhuis: Yeah, it becomes that dominant process.

Jesse Reimink: Exactly. And you end up knocking off lopping off the top of the mountain belt by erosion and weathering and depositing that material, that mass, all those elements and minerals somewhere else. And that happens to be in this case to the west in an inland sea or actually river Delta Plains as well. So you can think of this as like a shallow sea with lots of rivers flowing into it. Lots of deltas and all that stuff is being deposited to the west. So interior of the current day continent think of the Appalachian mountain belt. That used to be much higher. There used to be an inland sea to the west of that, and all the sediments in Pennsylvania, West Virginia, Kentucky, all the way down , were deposited in this inland sea region.

Chris Bolhuis: Yeah. And again, you hit it. You said it, we're talking about massive amounts of sediment. When we talked about the formation of the great smokey mountain national park, some of the sediment accumulations exceeded nine vertical miles. that's a truly, hard to wrap your mind around what the hell is going on here. Really. I mean, that's, that's amazing. And, and that's one of the things I love love about geology is scale. I like numbers, right? I like to put things in order. So the first thing in terms of the formation of red river Gorge is the Appalachians. This uplift massive important event. Two is the end of that event, which then, erosion begins to dominate which is carry and then sediment, like you said to the west depositing it in what is now the root of her Gorge. The third thing. Leads us into really the heart of red river Gorge, which is this famous sandstone layer. Jesse what's this sandstone layer called

Jesse Reimink: This is the Corbin sandstone, and these things are generally massive. And what we mean by that is, relatively homogenous grain size across them. So it looks like a massive piece of rock, right? Marbles would be massive. It's not finely layered. It's not broken apart into a whole bunch of different little sections. It's basically what we call a quartz arenite sandstone, which means it's very pure quartz sandstone. There's not a lot of stuff apart from quartz in this thing. And this layer is 323 million to about 315 million years old. That's kind of the age of deposition of the sandstone. When those sand grains were being deposited by an ancient river system, flowing to the west from the Appalachians to the west depositing sand in really pure quartz, arenite, sandstone.

Chris Bolhuis: And for our geology nerds out there that are into the geologic time scale, which that's not a derogatory comment. I, I just made there that's early Pennsylvanian time that we're talking that's right. But we categorize ourself in that. Right. Like we are the biggest nerds we know that's right. This sandstone is the whole story, right? I mean, it's the Corban sandstone and what happens in it that makes this a climbing Mecca. It's the Corban sandstone that has been carved into these Gorge, which is, you know, hence the name red river Gorge. So the beauty of this place is because of the Corbin and what happened to it. So let's get into some of that. I think if. For the first time you go hiking in red river Gorge, you're gonna, I don't care who you are. You're gonna recognize certain things. And we're gonna talk about those things, in a little bit here, we'll get into more detail at the end of the episode, in terms of what exactly happened to these. But one of the things that anyone can see is what's called cross bedding. It is a dominant sedimentary feature that we see in red river Gorge. it's beautiful. And so let's, should we get into cross beds here?

Jesse Reimink: Yeah, let's do it. And cross biddings everywhere in any, well, not any, but in most sandstones of this type, like the Corbin sandstone, you're going to have massive amounts of cross bidding. We have it here in Pennsylvania and the ridges are usually made of quartzites. There is cross bedding in there. You have it in places like the grand canyon in the United States where you have a super thick package of sandstones, right. At the top that caps the grand canyon. That stuff has huge cross beds in it too. And so cross bedding is it's a

Chris Bolhuis: can I add to that list a second? Because you know, up in the, up in pictured rocks, national lake shore, beautiful crossed

Jesse Reimink: the up is the upper peninsula of Michigan for those who aren't from, from, Michigan yet.

Chris Bolhuis: Is that not widely known. I'm serious. I'm asking. Are you really? Ah, okay. Yep. Um, so we call 'em uper up. Upper peninsula is what it refers to it's or the upper hand of Michigan, right?

Jesse Reimink: right,

Chris Bolhuis: yeah. Anyway, pictured rocks, national lake. Gorgeous area. I've taken you there. I took you there when you were a high school student and then you've actually joined me when I was teaching another class. You were, you, you joined us,

Jesse Reimink: That's right. Yeah. I went up there. I think I was, I had graduated college by that point, but I was a chaperone along on your geology trip, which was very fun.

Chris Bolhuis: I really need to do better with my chaperones. If,

Jesse Reimink: yeah. Yeah, no, you, you need to be more selective for sure.

Chris Bolhuis: Yeah. I, I

Jesse Reimink: betting.

Chris Bolhuis: is. that you getting us back

on track, Jesse? Is that like

Jesse Reimink: here.

Chris Bolhuis: okay. Let's

Jesse Reimink: bedding is so cool. So cross bedding is it's kind of self described here in the name it's beds that cross each other, crosscut each other, and you can imagine it looks like, you'll have a layer, a horizontal layer of a bedding plane. So this is a deposition plane, uh, in the rock and a big scoop will be taken out of one side of it. And that scoop will have other layers that cross. The older layers and then these things are stacked up on top of each other over time. And the way that this works is imagine a dune that's sand is blowing up one side and down the other side,

Chris Bolhuis: all right, Jesse, I'm gonna interrupt you here. The STO side is what that's called in geology, which is the, the side where the wind is coming from, cuz you used a Dune analogy. And so what happens is these imagine grains of sand getting blown by the wind and they they're lifted a little bit and then they land and they get lifted again. That's called saltation. So they, saltate their way up to the top of the Dune, where then you get at that Ridge of the dune you get this accumulated sand until, it gets too steep and it can't support that little buildup Ridge anymore or, or just the current of the wind pushes it over and it it now pushes the sand down the Lee side. Of the dune, which is the side opposite from the wind where the wind is coming from. So we have STOs and Lee side of a dune. And so you get this deposition that follows the Lee side, the angle of the slope. You get these deposition layers on that side and that's called cross bedding. Okay. And then what'll happen then is the wind will shift direction and you'll get then new layers that are deposited on the Lee side at a slightly different angle to the beds below. so that's, why we get the, what we call cross bedding.

Jesse Reimink: And these dunes are, constantly moving in one direction from the other. So as you're blowing sand up one side and down the other that dune is actually migrating forward with the wind. And over time, these things pile up on top of each other and generate cross bedding. So anything where you have flowing wind or water that is moving things like dunes you'll get cross bedding. And so this can happen in a river system where. Doing exactly the same process, except now it's water moving the sediment instead of wind moving the sediment. And so cross bedding is this beautiful representation in rock. We can see an ancient surface process being preserved in there and crossed is just a great example of this.

Chris Bolhuis: That's right. And cross bedding is so important to geologists to determine. Deposition environment. Was this a tidal setting? Was this a dune setting? What was the paleo current coming from or the, the direction that the ancient wind came from or the ancient river came from. So they're really, really important to help us reconstruct the geologic history of that location.

Jesse Reimink: So Chris, we're focusing on the Corbin sandstone here, but you know, this isn't formed in isolation, there's rocks above and below in this process. So we'll get to why we're focusing on the Corbin sandstone in a minute, but what's above and below it.

Chris Bolhuis: Massive accumulations of sediment to be blunt. the the layer right below it is called the Nancy member. And it's a, weekly ified, siltstone and, and shale or clay rich member. Um, it's. Pretty cool looking, actually, I, I have a big slab of it. It's really dark green color. but I don't keep it outside because it's so soft and crumbly that it won't last long. So I've learned that stuff like that. I gotta keep, more protected. Um, and so seeing as this is below the Corbin member, that means geologically. Older. So this, layer was deposited between 359 to 331 million years ago. It's kind of cool too. Uh, not only is its color beautiful, but it also has very interesting fossils. They're called zoo FICO. they indicate the, the fossils And the type of sediment is that this was a much lower energy and deeper Marine setting than what the Corbin sandstone is. So, and then above the Corbin sandstone, again, we have just massive. Accumulations of sediment in this area though, they've been eroded away. They've been removed further away to another basin and deposited yet again. So again, massive amounts of sediment above and below it.

Jesse Reimink: And you touched on the, really the key point in why we are focusing on the Corbin sandstone here is that the sediment below it is really weak. This Nancy member is really weak. You can't even leave it outside your house in Michigan. Cause it'll break apart. That sandstone, you could leave outside for a long, long time in Michigan and it wouldn't break apart. So. Resistant Corbin sandstone means that when this area is uplifted above sea level, now that Corbin sandstone is resistant and will be able to form a Gorge through it, which is now the red river Gorge and the stuff under, it could not preserve a Gorge of this magnitude. Whereas this resistant sandstone can actually have river cut right through it and not be eroded along the sides and make a big wide valley. So that brings us Chris to the regional uplift, which is kind of part four in the geologic story. what got from this sandstone depositing shallow sea environment to what we see today.

Chris Bolhuis: just speaking in really general terms, we had this broad kind of regional uplift, and we're not talking about here, mashing together, this the kind of, massive, violent tectonic collision going on here. This is more of this. It's kind of Jesse. Like if I said, Hey, take a deep breath. And your chest kind of heaves. That's like a regional broad uplift that we're talking about here. it formed, what's now known as the Cumberland plateau and it goes really from, Alabama to Western New York, it was gentle enough that it kept everything relatively flat yet, but it lifted this area up to, 600 or so meters above sea level. So, you know, on the order of maybe 2000 feet ish above sea level,

Jesse Reimink: And so now these rocks are exposed to both sea level. The ones above the cor sandstone have been eroded away. which there weren't that many. It drained the sea. Exactly. And then started this erosion process that we kind of see the representation of today. And so the modern then bring us forward to the modern red river in all its tributaries. where does this come from? What's going on currently to form the Gorge.

Chris Bolhuis: that's the perfect question. This is like the last stage in the formation of how do we get from where we started with the formation of Appalachians to the red river Gorge, looking like it does today, this last and final stage. Now it's all about erosion. It's erosion by the red river. And by the way, the red river in that whole region gets its name because the rocks, the Corbin sandstone, they're iron rich. And so they've oxidized into shades of orange and red. They're beautiful. so hence the name red river Gorge because of the rocks that they're cutting through, but the Corbin sandstone has. A lot of these vertical fractures in it. and so fractures, they form a path of least resistance for water. And so water then running water, moving water streams, exploits these, and, that's the beginning. Then these cracks and fractures, the beginning of a. river canyon developing or a Gorge developing. And, and that's really where we're at is just the exploitation of the fractured Corbin sandstone.

Jesse Reimink: Yeah, this fracture process, you can kind of think of it in really simplistic terms of, I don't know what the, the, a piston beneath some sort. A cake or something like that. You know, if you put a cake down on a, on a, a rounded table, it's gonna kind of crack at the top because it's kind of bending and folding around it. That's more or less what's going on here is you're creating these vertical cracks, cuz the rock is being split by this uplift part. And then the river is exploiting that, system and that process, and this really leads to. The natural beauty of this area, right? Chris and we have two main features that we're gonna talk about here, arches and bridges. Those are kind of in the same category here and then the coloration, the Liesegang banding.

Chris Bolhuis: That's right. So we talked about this I'm gonna go ahead and cover as best I can, the arches and bridges and, how they form and, distinguish between them. I want you to, to cover this, Liesegang banding or it's I don't know, Jesse, is it it's Liesegang or Liesegang.

Jesse Reimink: Uh, yeah, I, I think it's Lee's gang, but, um,

Chris Bolhuis: Liesegang. Okay. So I'm gonna have, I'm gonna have you talk about the Liesegang because it's very doctory , and you're the doctor in the house. So

Jesse Reimink: Right.

Chris Bolhuis: like, I, I figure it's appropriate for the professor in the house to, to, to do the

Jesse Reimink: there's a, there's a lot of doctory stuff too, in regard to these arches and bridges, I

Chris Bolhuis: Oh, I know this is crazy. So jump in if you want, go

Jesse Reimink: There's doctory stuff everywhere here, but

Chris Bolhuis: All right,

Jesse Reimink: so there's two names here when you're looking and I've again, never been here. So when I was looking online, I'm like, okay, there's things called bridges. There's things called arches. What the heck is the difference here? Could you guide us, give us a guide through the differences and how they're

Chris Bolhuis: Okay, I'll do my best. It's very, very confusing. And so here's the bottom line. A natural bridge is formed by running water. Erosion and arch is formed by weathering minus the running water. That's the technical distinction between them, but the confusion happens because these names are old, right? So they named all these bridges and arches that they have in the red river Gorge area. they were named by people that had no real understanding of geology necessarily. They're just named. Right. And so They'll name them bridges when they're arches and they have arches that they named bridges and they just kind of interchange the term bridges and arches all the time. So it is splitting of hairs actually. And it's a little annoying for me that we, do this. I don't know. This is where you said it gets doctory,

Jesse Reimink: we've, talked before about how you're a lumper and actually you had a job as a watermelon lumper and you, so you like lumping things in general.

Chris Bolhuis: I like simplification. I like geology. Here's my thing. Jesse is geology needs to be explained in ways that can be understood by the many, not the few and lumping. Okay. Helps that along. I think, you know, like we, we don't always need to, to go down the rabbit hole of like,

Jesse Reimink: Well, I okay. It, yes. I begged to differ. I like to go down the rabbit hole, but yes, you're right. Nobody. We don't need to go down this rabbit hole too far, but , either way, whether it's an arch or bridge, what's the take home summary lumper version of how they're formed.

Chris Bolhuis: Yeah. I think I got this. I wanna use an analogy. so we talked earlier about the fractures in the Corbin sandstone. Well, these fractures lead to the formation of ridges. So let's talk about this. I want everybody to envision a book. So if we take a book and we put the binding edge down on the tabletop, so the pages are sticking up. Okay. In other words, , the front cover of the book is facing to the side and the back cover of the book is facing to the other side. so the pages themselves represent the fractures in the Corbin sand.

Jesse Reimink: Okay. I'm with

you.

Chris Bolhuis: does that make sense? So they, they extend down through the Corbin, right. But the fractures are roughly parallel to each other. Now, if you throw in weathering and erosion and rivers, all of it, let's throw it all in there. some of those pages are gonna fall down to the tabletop. Okay. But the middle of the book will be the last to go because it's protected by these other fractures that are on the sides of it. Okay. Does that make sense?

Jesse Reimink: Yeah, it does. This

Chris Bolhuis: I'm saying.

Okay.

Jesse Reimink: this one. Yeah, absolutely. So you're kind of peeling off the layers of this book and what you're left with.

Chris Bolhuis: That's right. I'm peeling the first pages of the book off and I'm peeling the last pages of the book off, but I'm leaving the middle standing straight up. Okay. So in the end, what you have then is a narrow Ridge. And what happens then is, well, you either get a bridge or an arch. okay if we're gonna distinguish between them. And so if you have, water that flows off each side of the Ridge, this narrow Ridge that's left this kind of spine, or it's think of it like a fin. Okay. Then, it will create, the beginning it'll scour out. The middle of that Ridge. what happens then is that , once it's breached through, you have the beginning of, you know, a little pinhole, a little arch right now, this is kind of cool too. Once this happens, it's becomes a self-fulfilling prophecy kind of cuz recent research suggests how now I have. , the edges of the pillars of the arch and it gets compressed, which makes the sandstone actually more durable. It's more resistant to weathering in any erosion because of the compression that's taken place.

Jesse Reimink: And the way to think about this, this is really cool research article. I think you found by Brons at all, uh, where they did some experiments about this to try and model how this happened, both in the lab and numerically simulated, but you're right. This is a feedback loop of, if you can think of it, like standing on one leg versus standing on two legs, if you're standing on two legs, you're distributing your weight. More. And if you stand on one leg, you're distributing your weight less and it's more focused on one leg. And so the pressure, the vertical pressure on that one leg is higher, which means in a sandstone you're putting vertical pressure on these sand grains. And you're kind of. annealing them together, making that stronger. And so this is the process that's going on to make these arches is there's this positive feedback loop where if you erode more around the edges, you're putting more of that weight. That high weight is being focused down vertically, which strengthens the rock, which makes it harder to erode and as really cool, really cool process.

Chris Bolhuis: It is. And, and then what happens eventually, right, is the arch itself will be the next thing to collapse, leaving the pillars that used to be connected by the arch, uh, standing alone. So we get to see all of this in the red river Gorge. I mean, the arches, there are over a hundred natural bridges and arches in, this area. And it. It makes it a destination. They're beautiful. they're curious. They're awesome. And that's how they form, I don't know. Did, did we nail that

Jesse Reimink: I think so. Yeah. That's, uh, really interesting and a really great place to, to see arches, you know, arches national park in Utah is another place where there's a lot of arches around and it's sort of a different erosional process, but.

Chris Bolhuis: It is a little, because arches national park it created these ridges or fins in a totally different way. In arches, it did this by a salt dome by Burial of rock salt. And when it gets buried to a certain depth, it becomes actually fluidized. And so this fluid gets, squeezed laterally until it can, uh, find a zone of weakness leading closer to the surface and it forms what we call in geology, a diaper. Or these like upside down teardrops that domed up the sandstone. Well, sandstone's brittle and that doming caused it to crack into these ridges. So the fin forming process of arches national park is different from what was going on in the Corbin sandstone.

Jesse Reimink: So is it time to move on to Liesegang

Chris Bolhuis: Yeah, can we get doctory here? Let's do this. Let's let's get, let's get professory, so, alright.

Jesse Reimink: too much.

Chris Bolhuis: Alright. Jesse. this Lee gang banding is. So cool. And the first time I was there, you know, first times you remember, it's, these what it is, these swirling bands of dark red, dark brown, bright orange swirls in the rock. And to me, they looked like a soft sediment, Def. The kind of thing that happens with a tsunami, you know, like those really prominent swirls, but it has nothing to do with that at all. It's not soft ed deformation. It's something entirely different. Take it away. Dr. Reimink

Jesse Reimink: So the word we're saying here is Liesegang, which is L I E S E G a N G Liesegang. And it's not a sediment depositional feature because these bands, these coloration bands cross cut the deposition layers. So we know it happened after the sediment formed. Now there's a whole field of research on what these bands actually represent, and there's a. Discussion about the processes behind these bands and how they're actually formed. They were discovered this type of concentric banding was actually discovered in gel experiments. So take a gel in a cylindrical test tube, drop some other substance in it, some die in it. And you would expect if you think of it in water, you, if you drop a bit of food, coloring into water, it'll just kind of diffuse through it and it'll change the car of the water. With a gel, this didn't happen. You dropped some dye in there and it formed these concentric rings that were spaced equally apart. And depending on what kind of stuff you dropped into the gel, it would form different spacings of the bands. And you can actually get some really interesting co screw patterns in this. So lease gang banding is a chemical phenomenon that is observed in various ways. That is not restricted to just rocks. This is. Part of the Liesegang phenomenon is in rocks as we see in red river Gorge, but it basically works. there's many nuanced in the weeds debates about how this process forms, but it's basically fluids moving through the rock. And diffusion happening. So you can think of this as the chemical experiment you might have done in chemistry class, where you super saturate some liquid. So you kind of like, you know, heat up some liquid dump, a ton of salt in it, or a ton of sugar and cool that thing down and then drop a little piece of sugar in it. And it nucleates all the sugar kind of saturates out. What you're doing there is forming a super saturated liquid. There is too much sugar in it than there should be. Like it's oversaturated in sugar in the solution and it wants to precipitate out, but all it needs is that seed. You have to have that little seed to get it to precipitate out. You can kind of think of it this way, that these bands are representing zones that got super saturated, and then they Nucleated that seed was there and boom, they precipitated out. And what it does is it soaks up all the chemicals from the areas around it, into that band very rapidly.

Chris Bolhuis: And that super saturated material that we're referring to is rust it's iron oxide. Right. And. Super tough, very, very resistant material. And so these Liesegang bands often stick out they'll protrude from the Corbin sandstone.

Jesse Reimink: That's important to note Chris, that we can put these in order of events then, right? The Lees gang banding formed before the erosion happened. Right? So the erosion is preferentially weathering and eroding different bands and the Liesegang banding because of the chemical reactivity of those things, the darker bands and the lighter bands have different preferences, different strengths to them.

Chris Bolhuis: And also to point out too, is the Liesegang banding is one of the reasons why the Corbin sandstone and the red river gorg area is a climbing Mecca. It makes for awesome handholds, you know, it's

Jesse Reimink: I never thought of that. Yeah, totally. That's great. So that's, uh, a brief intro Liesegang banding is kind of everywhere in nature and in chemistry. It's very interesting. Very, probably important, not well understood. Let's get to some hiking recommendations,

Chris Bolhuis: Hold on a second though. Can you just do a 15 second? I mean, literally like 15, second summary of Liesegang . What's the takeaway with it. Okay. Cause you, you got Ramly there and , uh, I

Jesse Reimink: so,

Chris Bolhuis: in the most affectionate way,

Jesse Reimink: right, right, Of course. the, okay. So 15 second takeaway Liesegang banding is something that happened after the sediment was formed by fluids flowing through the rock, depositing different minerals in different locations to create these beautiful concentric. Zoned rings that then weathering overprints or weathering attacks differently to form the physical structures, the relief that you see sometimes. So, Chris, let's finish up here really quick with some hiking recommendations. Where are some good places to go to see some of the stuff that we're talking about?

Chris Bolhuis: Okay. Um, well, Honestly, like anywhere it's, it's such a cool place. Um, I do wanna throw a shout out and this is not, we're not advertising at all here, but Miguel's pizza is amazing. Okay. so cool. Um, alright, I'm gonna do this in no particular order. But I have three main recommendations here that vary in length and, and you have all kinds of options, too, Jesse, with all of these, actually there's so many different offshoots that you can take. So you can, you can take what I'm giving you here and make it much longer. You can actually take what I'm given and make it much shorter. I'm gonna begin natural bridge. it's an icon in the park, it obviously takes you to this, beautiful, natural bridge. I don't know much else to say about it. It's awesome. You get great. Liesegang banding examples in here. Great cross betting. you can actually see. in some of the Corbin sandstone, you can see some fossilized petrified wood, these were from trees that got, that were being carried by the rivers that resulted in the deposition of the Corbin. So it's very cool. And it's, it's very example, rich of things that, typify the beauty of this place, the next one is, ay Ridge. and this is again, you see cross betting, like crazy on this trail. again, it indicates this kind of ti DIC sediment, deposition environment that was going on. it also in this area too, it indicates that this was deposited in an estuary environment. so an estuary is this kind of submergent coastline or, or drowned river mouth. and you, you live near estuaries,

Jesse Reimink: Yeah, that's right. We're We're

Chris Bolhuis: you like

Jesse Reimink: we're, close enough to the Chesapeake bay to

Chris Bolhuis: Chesapeake. Yeah, That's right. That's right. Um, and there are different examples of what you can do here. we took the long one, you know, it was like a, I don't know, it ended up maybe being a 12 mile day for us. it's flat and then it's down and then it's up and it's, but it's awesome. All the way it takes you out to like double arch, which is super cool. Because you they're stacked up on top of each other. there's a place it's a famous landmark called courthouse rock, which is this huge monolith that has flat square sides on each part of this thing. It's it just sticks up like a sore thumb. It's pretty amazing. so that's Augie Ridge trail.

it's a cool hike. My favorite though, is. Going to cloud splitter via Indian staircase. now this it's, it's not really a, a big deal, but there is some exposure, on this and, and people

every, every

month.

Jesse Reimink: a little bit nervous because

Chris Bolhuis: Mm-hmm

Jesse Reimink: high up and there's a cliff

Chris Bolhuis: Yeah, you can get hurt for sure. Yeah. and every month there's always a search and rescue that involves either going to the top of cloud splitter or up Indian staircase. Uh, just because people, uh, you know, take it for granted. I think so there is exposure there, but it's my favorite when you end up on, on top of cloud splitter and there is by the way, a, a rope that is fixed. To use to get you up to the top of it. And it's highly advisable to use that rope, going up and down, when you get out onto that point and you can see the confluence of two tributaries merging into the red river. it's a destination on a great day. Yeah. It's bring a beer. Sit there. Relax. Contemplate life. It's awesome.

Jesse Reimink: Awesome. Well, that sounds like some, uh, great recommendations there, Chris. And, uh, I'll, I'll have to go check it out. I have never been, uh, gets me excited to go check these things out. It'll be awesome. This is within driving distance with us, so

Chris Bolhuis: that's and

Jesse Reimink: it there eventually.

Chris Bolhuis: a great time.

Jesse Reimink: okay.

Chris Bolhuis: time.

Yeah.

Jesse Reimink: Sweet. Well, Hey man, I think that's a wrap here.

Chris Bolhuis: You bet. so.

Jesse Reimink: All right, well, Follow us on all the social medias. We're @planetgeocast, send us an email. We love that stuff. We love hearing from everybody about what they liked, what they didn't like, what their questions are based on episodes and give us a like subscribe review rating. Those really help the algorithm and really help us, teach geoscience to every.

Chris Bolhuis: That's right. And please just share it with somebody that you think that, you know, loves our planet, loves the beauty of it and how it all works. Share it with them. We love that. Yeah. Cheers.