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Arches National Park · PlanetGeo: The Geology Podcast

0:03
SPEAKER_02: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
0:13
SPEAKER_02: How's your technology over there today, Chris?
0:16
SPEAKER_01: I am I'm good actually.
0:18
SPEAKER_01: My bonus son uh has me set up now.
0:21
SPEAKER_01: I got a new desk, uh two huge monitors in front of me.
0:25
SPEAKER_02: Look at you, IT consultant.
0:27
SPEAKER_02: You know, it's a useful skill set.
0:28
SPEAKER_02: Nice.
0:29
SPEAKER_01: Got it going on.
0:30
SPEAKER_02: I can see why you're bringing him into the Bullheis family fold.
0:33
SPEAKER_02: That's a good uh good on you, man.
0:34
SPEAKER_01: Good strategy.
0:35
SPEAKER_01: Hold on a second.
0:36
SPEAKER_01: Let's be real clear.
0:37
SPEAKER_01: I have no choice in this matter.
0:40
SPEAKER_02: That's true.
0:41
SPEAKER_02: Yeah, it's true.
0:41
SPEAKER_02: That's true.
0:42
SPEAKER_02: Hey, did he ask?
0:43
SPEAKER_02: Just out of curiosity, did he ask you before he proposed to Bella?
0:46
SPEAKER_02: Or was it He did?
0:47
SPEAKER_02: Oh, he did, okay.
0:48
SPEAKER_01: He asked, yeah.
0:49
SPEAKER_01: And then he he knew I I don't know if I told you this, he knew that, or I knew that he was gonna propose at the base of the middle Teton.
0:56
SPEAKER_01: So when he did it, then he started to walk away to this rock that was awesome.
1:02
SPEAKER_01: Just this awesome toothpaste metamorphic rock, and uh that's where he wanted to do it, and so he started walking that way.
1:08
SPEAKER_01: So Idiot Dad gets his phone out and starts walking around.
1:13
SPEAKER_01: So Annabelle is looking at me thinking, what the hell is he doing?
1:18
SPEAKER_01: Oh, I I know what's going on, you know, because I'm an idiot and I gave it away.
1:22
SPEAKER_01: So you gave it away.
1:23
SPEAKER_02: I mean, uh it wouldn't be unreasonable for her to think, oh, dad's just being weird looking at rocks, taking videos of rocks again, you know.
1:29
SPEAKER_02: Like, dad, stop being weird out there.
1:31
SPEAKER_02: You're embarrassing me.
1:34
SPEAKER_01: She's used to that, she doesn't get embarrassed by that stuff anymore.
1:37
SPEAKER_02: So she's immune.
1:38
SPEAKER_02: Okay, that's good.
1:39
SPEAKER_01: Well, she is good.
1:40
SPEAKER_01: Yeah.
1:42
SPEAKER_02: Well, how are you doing, man?
1:43
SPEAKER_02: I'm doing great.
1:44
SPEAKER_02: How are you?
1:45
SPEAKER_02: Yeah, I'm doing good, man.
1:46
SPEAKER_02: Before we get started, we should just make a little announcement that we will be at the Geological Society of America meeting, you and I together again in person.
1:56
SPEAKER_02: Very excited for that.
1:57
SPEAKER_02: But that's in Denver.
1:58
SPEAKER_02: I think it's early October.
1:59
SPEAKER_02: So if any of you listening are going to GSA uh and Denver, presenting there, grad students, faculty, undergrads, whatever, let us know.
2:08
SPEAKER_02: I don't know.
2:09
SPEAKER_02: Look us up, send us an email beforehand.
2:11
SPEAKER_02: Uh we can meet up.
2:12
SPEAKER_02: I think, Chris, you've got a talk.
2:13
SPEAKER_02: Is that right?
2:13
SPEAKER_02: You're gonna be talking about Planet Geo.
2:15
SPEAKER_02: I believe so.
2:16
SPEAKER_01: I I do have a talk.
2:18
SPEAKER_01: I'm not sure exactly what that talk is gonna look like at this point, but yeah, I have a talk.
2:23
SPEAKER_02: It'll be fun.
2:24
SPEAKER_02: It'll be great.
2:24
SPEAKER_02: So anyway, look us up there.
2:26
SPEAKER_01: Anyway, welcome to Planet Geo.
2:28
SPEAKER_01: We are your host.
2:28
SPEAKER_01: I'm Chris Bullheis, and I'm looking across at my little young sage over there, Dr.
2:33
SPEAKER_01: Jesse Rymink.
2:34
SPEAKER_00: Hello, hello.
2:35
SPEAKER_01: And we're gonna be talking all about Arches National Park, which I think is really appropriate at this point because we did Red River Gorge just a few weeks ago.
2:44
SPEAKER_01: We talked about natural arches and bridges, and we alluded a little bit in that episode to Arches National Park and how the arches are formed a little bit differently.
2:54
SPEAKER_01: So we're gonna get into all of that today, and I can't wait.
2:57
SPEAKER_01: Jesse, have you been there?
2:59
SPEAKER_02: I have, yes.
3:00
SPEAKER_02: We so let me think through this.
3:02
SPEAKER_02: I don't believe that the summer science trip that you led went to Arches when I was a student.
3:08
SPEAKER_02: Is that correct?
3:09
SPEAKER_01: Correct.
3:09
SPEAKER_01: And we don't I I've never taken students there.
3:12
SPEAKER_02: Okay, I have been there because actually my dad led the summer science trip for five or six years when I was a kid.
3:18
SPEAKER_02: My dad was a high school biology teacher in the school that you now teach at, in the high school I went to, and he led that trip when I was growing up.
3:25
SPEAKER_02: So I have been there maybe two or three times as a kid, and it's so cool.
3:30
SPEAKER_01: Wait a minute.
3:30
SPEAKER_01: He took students there?
3:32
SPEAKER_02: Yeah.
3:33
SPEAKER_02: I have this distinct memory of I can't remember the river in there, but we were there's a cliff jump off the river that was like so scary.
3:40
SPEAKER_02: I was a little kid, and it was like terribly terrifying.
3:42
SPEAKER_02: I'm sure it was like five feet high.
3:43
SPEAKER_01: You are afraid of a lot of things.
3:45
SPEAKER_02: Yeah, yeah.
3:45
SPEAKER_02: I I am a little bit of a wuss sometimes.
3:47
SPEAKER_02: But I remember this in arches, and it's just so beautiful there.
3:50
SPEAKER_02: Yeah, it has.
3:51
SPEAKER_02: I I've been there.
3:52
SPEAKER_02: So have you been there, Chris?
3:53
SPEAKER_02: I'm assuming you have.
3:54
SPEAKER_01: I have been there.
3:55
SPEAKER_01: Uh, I went there with my family a while back, and I cannot look like how busy that was, I cannot imagine taking students there.
4:03
SPEAKER_01: It seems like a logistical nightmare.
4:05
SPEAKER_02: Yeah, well, I think this was a while back, you know, this would have been like the early 20 aughts, and so this was it was maybe a little bit calmer there.
4:12
SPEAKER_02: It's a very good thing, and in some ways it's a little bit of a bad thing, but the national parks have blown up recently, especially during COVID.
4:18
SPEAKER_02: You know, that's that's good and bad, but mostly good, I would say.
4:21
SPEAKER_02: So Arches National Park.
4:22
SPEAKER_02: I think, Chris, we should start out by reiterating what an arch is.
4:27
SPEAKER_02: Because we talked about this a little bit in the Red River Gorge episode, so you can go back to that and listen to it.
4:32
SPEAKER_02: But I don't know, Chris, uh, what's the lead in here?
4:34
SPEAKER_02: What's the pitch?
4:35
SPEAKER_02: What is an arch?
4:36
SPEAKER_02: I think people kind of know it, but let's define it.
4:38
SPEAKER_01: Okay, there are 2,000 cataloged arches in Arches National Park.
4:43
SPEAKER_01: And the the definition.
4:46
SPEAKER_01: It's a lot.
4:47
SPEAKER_01: It's a lot.
4:48
SPEAKER_01: The definition that they have put out there is a little weird.
4:52
SPEAKER_01: Um, it has to be three feet long in order to be classified as an arch, which seems like what a what an arbitrary number to put at it.
5:00
SPEAKER_01: And it can be three feet in any dimension, but as long as it there's a three foot wide or high three feet diameter arch, whatever, it's classified as an arch.
5:12
SPEAKER_02: It is such a weird definition.
5:14
SPEAKER_02: I mean, totally arbitrary, right, Chris?
5:16
SPEAKER_02: I mean, this is the way it works, I guess.
5:17
SPEAKER_02: You know, in order to be an arch, it has to be three feet in some dimension, like a continuous span, right?
5:23
SPEAKER_02: Across the you can't have, you know, two and a half feet or you can't have it broken in the middle, but it could be one inch high and three feet wide, and it's an arch.
5:31
SPEAKER_02: That's kind of what we're looking at here.
5:32
SPEAKER_01: The longest arch in Arches National Park is 306 feet long, which is a huge arch, but the longest one in the world, known anyway, is in China, and that's about 400 feet wide.
5:45
SPEAKER_02: And to give some perspective, it's hard to picture the scale of this.
5:49
SPEAKER_02: You just kind of have to Google an image and Google an image and find one that has people in it or something to scale, because that is a massive amount of rock held really high.
5:59
SPEAKER_02: And the arches here are just beautiful.
6:01
SPEAKER_02: And what we're talking about is Arches National Park, which is a relatively small national park by land area in eastern Utah, and it's just really, really beautiful.
6:13
SPEAKER_02: And we're going to talk about the regional geology of this area a little bit more as we go through.
6:17
SPEAKER_01: It is, but we never really defined arches and bridges.
6:20
SPEAKER_01: It's like it's a bit squishy, the definition here.
6:25
SPEAKER_02: Yeah.
6:25
SPEAKER_02: Squishy is a good word for it.
6:27
SPEAKER_01: They get mingled all the time.
6:30
SPEAKER_01: I guess the best way to define this is that arches do not involve running water.
6:36
SPEAKER_01: Whereas bridges can and do in terms of the way that they formed.
6:42
SPEAKER_01: So they look the same, but in terms of the formation, I guess I don't know.
6:47
SPEAKER_01: Do you have a better way to define the difference between an arch and a bridge?
6:51
SPEAKER_02: No, I mean we've talked about this before.
6:52
SPEAKER_02: You're a lumper, you used to lump watermelons, right?
6:56
SPEAKER_02: That's true.
6:57
SPEAKER_02: I I fall into the lumper category too.
6:59
SPEAKER_02: I uh I just don't really care what we call it an arch or a bridge.
7:03
SPEAKER_02: I just can't get up for either discussion.
7:04
SPEAKER_02: But there are various definitions.
7:06
SPEAKER_02: Some people will get um a little bit more nuanced and particular about whether things are an arch or a bridge.
7:12
SPEAKER_02: But I think it's fairly safe to say in Arches National Park, they're mostly arches because there's not a lot of running water around out there.
7:18
SPEAKER_02: So they're mostly strictly defined arches.
7:22
SPEAKER_02: So, Chris, should we move into the regional geology?
7:25
SPEAKER_02: We're gonna kind of cover the regional geology, then we're gonna talk about how these particular arches form, and they're different than the Red River Gorge, which we talked about uh a few weeks ago or even a couple months ago.
7:34
SPEAKER_02: And then we're gonna talk just a little bit about the particulars of Arches National Park and some features that you find in deserts more generally.
7:42
SPEAKER_02: So that if you're walking around Arches National Park, like go there, it's amazing.
7:45
SPEAKER_02: If you got an RV, if you got a camper, if you got a tent, it's awesome.
7:48
SPEAKER_02: Or there's lodges, you can stay in Airbnbs.
7:51
SPEAKER_02: I mean, it's an awesome place.
7:52
SPEAKER_02: Go there and you can see all of these features everywhere.
7:55
SPEAKER_02: It's one of those parks that I'm gonna use a crisp bullized ism here.
7:58
SPEAKER_02: It smacks you in the face, man.
8:00
SPEAKER_02: It smacks you in the face, right?
8:01
SPEAKER_01: It does.
8:02
SPEAKER_01: It does.
8:03
SPEAKER_01: It's spectacular.
8:04
SPEAKER_01: I love Arches National Park.
8:06
SPEAKER_01: Plain and simple.
8:07
SPEAKER_02: Chris, the regional geology, this is kind of the high-level general overview.
8:13
SPEAKER_02: There's so many details in these rocks that we're not gonna cover.
8:16
SPEAKER_02: We just don't have time to.
8:17
SPEAKER_02: But the regional geology, it really starts in the Colorado Plateau.
8:21
SPEAKER_01: That's right.
8:22
SPEAKER_01: The Colorado Plateau is this huge, uplifted area that's kind of centered on what's called the Four Corners.
8:28
SPEAKER_01: And the Four Corners is where New Mexico, Northeast Arizona, Utah, and southwest Colorado all kind of meet.
8:35
SPEAKER_01: You know, you can go there and get a picture taken with your feet right at that four corners area.
8:40
SPEAKER_01: That's where the Colorado Plateau is kind of centered.
8:43
SPEAKER_01: So huge, uplifted area.
8:46
SPEAKER_02: And we've talked a lot about things around the Colorado Plateau before.
8:51
SPEAKER_02: For instance, the Grand Canyon is kind of on the southwest side of the Colorado Plateau, and there's a lot of features in there that are really important.
8:59
SPEAKER_02: It's a really important geological province for the western United States, really.
9:04
SPEAKER_02: But the discussion today is centered kind of at near the center of the Colorado Plateau, what's called the Paradox Basin.
9:12
SPEAKER_02: And this is a basin in the geological sense, meaning that there are sedimentary rocks that were formed in an ancient basin.
9:20
SPEAKER_02: So the rocks themselves were formed a long time ago in a basin where sediment was being deposited.
9:25
SPEAKER_01: Question for you.
9:29
SPEAKER_01: What's the paradox?
9:30
SPEAKER_01: Do you know?
9:30
SPEAKER_01: I I don't know this.
9:32
SPEAKER_01: I don't know where the derivative of this basin is.
9:35
SPEAKER_01: That's a great question.
9:36
SPEAKER_02: I I read this late at night, several nights ago while we were preparing for this episode.
9:39
SPEAKER_02: I can't remember exactly what it is, but it's something to do with the rivers kind of wander aimlessly.
9:44
SPEAKER_02: And I don't know if it's the modern rivers or like the paleo rivers, the rivers that are recorded in the rocks, but there's something to do with the random drainage network in the basin that made it a paradox.
9:54
SPEAKER_02: So I can't remember though.
9:55
SPEAKER_02: It's a good question.
9:56
SPEAKER_01: Interesting.
9:57
SPEAKER_01: Anyway, the paradox basin is the reason why arches is where it is.
10:02
SPEAKER_01: So this is really an important thing.
10:05
SPEAKER_01: The basin itself was caused by the collision of two supercontinents.
10:09
SPEAKER_01: And those supercontinents are called Gondwana and Laurasia.
10:13
SPEAKER_01: We talked a little bit about this earlier in our episodes.
10:16
SPEAKER_01: Where was that, Jesse?
10:17
SPEAKER_01: Where did we talk about those supercontinents?
10:19
SPEAKER_01: A little bit with Red River, I think, and I think with um also the smoky mountains.
10:25
SPEAKER_01: We alluded to these supercontinents then.
10:27
SPEAKER_02: Absolutely.
10:27
SPEAKER_02: Yep.
10:28
SPEAKER_01: So anyway, when these supercontinents, Gondwana and Laurasia, collided, they created this basin, this kind of trough, and this trough was surrounded by mountains all around.
10:39
SPEAKER_01: But mainly the one that we're concerned with are the mountains that were to the east of this basin.
10:46
SPEAKER_01: When these two continents collided, they formed this trough.
10:49
SPEAKER_01: So this trough, imagine this kind of rumpled carpeting.
10:53
SPEAKER_01: Go to one end of a room where the carpeting is all torn up and just kind of push it and it forms these kind of like folds in the carpeting.
11:01
SPEAKER_01: That's what the Paradox Basin looked like.
11:03
SPEAKER_01: It was in this trough, surrounded by mountains all around it.
11:08
SPEAKER_02: That's a great analogy, Chris.
11:09
SPEAKER_02: I might steal that one from you because I here, I want your insight, being the sage educator.
11:14
SPEAKER_02: Because the analogy I always use for this kind of thing in class is I like, okay, super continents.
11:20
SPEAKER_02: That's kind of cool.
11:21
SPEAKER_02: I also really like, I mean, I used to read these Jane's battleship books growing up when I was a kid.
11:26
SPEAKER_02: Like I love like battleships, old battleships and stuff.
11:28
SPEAKER_02: So the like did not know that about you.
11:30
SPEAKER_02: Yeah, I know, weird, right?
11:32
SPEAKER_02: Um major deviation here, but I I love World War II naval history.
11:36
SPEAKER_02: So, like Pearl Harbor, I was there this summer.
11:37
SPEAKER_02: I was in heaven, it was amazing.
11:39
SPEAKER_02: Anyway, I think of like two super battleships or super carriers.
11:44
SPEAKER_02: And if you collide like two big ships, if you imagine like the flight decks of an aircraft carrier and you run two of them into each other, the front end's going to be completely smashed, but the back end will kind of get rumpled, right?
11:56
SPEAKER_02: This sort of rumpling pattern.
11:58
SPEAKER_02: That's kind of what you're referring to here.
12:00
SPEAKER_02: The same kind of process.
12:01
SPEAKER_02: We're not in the collision zone, but we're near enough to it that the crust is rumpling because of the collision.
12:07
SPEAKER_02: Is that an accurate assessment?
12:10
SPEAKER_01: Absolutely.
12:10
SPEAKER_01: So I always use this in class, the rumpled carpeting, or I don't know if my kids know what I'm talking about, actually, when I think about now saying this, but an accordion.
12:20
SPEAKER_02: Oh, okay.
12:21
SPEAKER_02: Yep.
12:21
SPEAKER_01: You know, it's it's kind of kind of ripples where you have the up and the down and the up and the down and the up and the down, and that's what this looked like.
12:30
SPEAKER_01: But in the Paradox Basin, a shallow sea invaded the area.
12:36
SPEAKER_01: Okay, and Jesse, I mean, we know this.
12:39
SPEAKER_01: What like what do you tell your students?
12:41
SPEAKER_01: What happens in any basin for that matter?
12:44
SPEAKER_01: What happens in any basin?
12:45
SPEAKER_02: Well, all the water's gonna run into the center of the basin, which means you're bringing sediment, you're bringing dissolved ions, you're bringing material to the center of that basin, and then that water is going to either evaporate or it's gonna be connected to the ocean, but rocks are going to be deposited basically almost as soon as you're below sea level.
13:03
SPEAKER_02: In general, you're going to be kind of depositing rocks.
13:05
SPEAKER_02: So we start to get sediments deposited.
13:08
SPEAKER_01: And this is hold on, I just want to go back and reiterate that that any basin has deposition in it, especially when it's surrounded by mountains, and that's what we have going on here.
13:18
SPEAKER_01: Collision of two supercontinents creates this trough surrounded by mountains, deposition.
13:24
SPEAKER_01: Now, in this trough, a shallow sea invades.
13:29
SPEAKER_01: But this was a little different from the standpoint of it was kind of a restricted basin, and so it was super warm, it got very, very salty.
13:41
SPEAKER_01: And what happens when the water gets super, super, super salty?
13:46
SPEAKER_02: Oh man, I mean, we talked about this several times, including lithium, talking about lithium just recently.
13:51
SPEAKER_02: But when you have water that's eroding and is very salty, it flows into a basin and it just evaporates, it's got nowhere to go.
13:58
SPEAKER_02: It's a called a restricted basin, like you just said, and it just deposits salt.
14:02
SPEAKER_02: And this is really the key here.
14:04
SPEAKER_02: This is one of the main keys to why arches are in where Arches National Park now is, is that salt.
14:10
SPEAKER_02: So the salt's deposited.
14:12
SPEAKER_02: We also have some other really important sedimentary layers on top of this.
14:16
SPEAKER_01: We do, but it's important to emphasize how thick these salt deposits were.
14:21
SPEAKER_01: I mean, this is great point.
14:22
SPEAKER_01: This is impressive.
14:23
SPEAKER_01: We're talking about over a thousand feet of salt.
14:26
SPEAKER_01: So I think we need to do a better job of what does a salt mean?
14:30
SPEAKER_01: We're not just talking about rock salt, particularly, like the mineral halite.
14:35
SPEAKER_01: I mean, that certainly was involved in this, but we're talking about potassium salts too, like potassium chloride.
14:41
SPEAKER_01: So we have sodium chloride, potassium chloride, we have gypsum that's being deposited, which is also a salt.
14:49
SPEAKER_01: And then on top of that, what happens?
14:52
SPEAKER_02: Oh, on top of that, we get these really amazing rocks that you can kind of find all over the western United States.
14:58
SPEAKER_02: We talked about this in the Grand Canyon too.
15:00
SPEAKER_02: We get big, huge packages of sandstone.
15:04
SPEAKER_02: And there's a few important ones here: the Navajo, the Caramel or Caramel, depending on how you pronounce that, and the entrata sandstones.
15:12
SPEAKER_02: And these are the important ones that we're going to talk about here.
15:14
SPEAKER_02: And there's slight differences, which we'll come to uh briefly here, but big, thick sandstone layers.
15:20
SPEAKER_02: The Navajo sandstone is basically you could envision a massive desert with windblown sand.
15:26
SPEAKER_02: It's called an erg, E-R-G, like the rowing machines are sometimes called ergs.
15:31
SPEAKER_02: This is called an erg, but wind blown sand is depositing this big sandstone layer, so a desert-like environment.
15:39
SPEAKER_01: I find that term to be hilarious because then an erg, this sea of sand.
15:46
SPEAKER_01: Erg is also a unit of energy measurement.
15:50
SPEAKER_01: Right.
15:50
SPEAKER_02: Yeah.
15:51
SPEAKER_01: Okay.
15:51
SPEAKER_01: And I use this in astronomy.
15:53
SPEAKER_01: An erg is about the same amount of energy as a fly doing a push-up.
16:01
SPEAKER_01: That's an erg.
16:02
SPEAKER_01: So when I when I read that reading this, I'm like, erg, a fly push-up.
16:07
SPEAKER_01: That's that's I don't know.
16:08
SPEAKER_02: It's that's an awesome one.
16:10
SPEAKER_02: I like that.
16:10
SPEAKER_02: Okay, a fly doing a push-up, or a rowing machine, or a massive desert of windblown sand.
16:15
SPEAKER_02: There you go.
16:16
SPEAKER_02: It's so weird.
16:17
SPEAKER_02: I mean, you know, you're gonna be so popular at dinner parties if you just have those three definitions for erg.
16:22
SPEAKER_02: Like, I mean, bust this out at the next party, and everybody's gonna be following you around for the rest of the night, seeking you for information.
16:28
SPEAKER_01: Jesse, everybody follows me around anyway.
16:30
SPEAKER_01: What do you think?
16:30
SPEAKER_01: Come on, you know that.
16:31
SPEAKER_02: That's true.
16:32
SPEAKER_02: Just look at you.
16:33
SPEAKER_02: Okay.
16:33
SPEAKER_02: All right, back at the rocks.
16:34
SPEAKER_01: Okay, salt.
16:35
SPEAKER_01: Okay, salt.
16:36
SPEAKER_01: That's what we have in this shallow, restricted sea in the Paradox Basin is this salty water.
16:44
SPEAKER_01: As water evaporates, the water gets saltier and saltier and saltier.
16:50
SPEAKER_01: When it gets saturated with those salts, it can't like hold it in solution anymore.
16:55
SPEAKER_01: As evaporation continues now, it begins to deposit or lay down these salts, just like a beaker that you fill with salty water, and then you just set it on your counter and you let it sit.
17:06
SPEAKER_01: When all the water is evaporated, you're gonna have a crust on the bottom of that beaker of just salt.
17:12
SPEAKER_01: And that's what we have going on here in the Paradox Basin.
17:15
SPEAKER_01: There isn't much room for fresh water to come in and kind of dilute it, where you would get then deposition of other rocks like shales and sandstones.
17:25
SPEAKER_01: Not yet.
17:26
SPEAKER_01: All we primarily have being deposited here are just these various salts from this super salty, shallow, restricted basin.
17:35
SPEAKER_02: And these sandstones, now the Navajo, the Caramel, and the Entrada sandstones are sitting on top of the salt, which is going to be very important in our next phase when we're talking about how arches form.
17:45
SPEAKER_02: But we have to finish up the differences here.
17:47
SPEAKER_02: The Navajo is this erg environment, ERG, desert windblown sand.
17:51
SPEAKER_02: The caramel and entrata sandstones are also windblown sand, but we also have stream deposits in there too.
17:58
SPEAKER_02: So they're kind of more like a braided stream environment with lots of sand deposited, and we get these beautiful cross beds in here where we have these stacking of kind of dune or stream environments.
18:08
SPEAKER_02: You can see these in the Grand Canyon, you can see these in arches, these beautiful big cross beds that are stacked into the rocks.
18:15
SPEAKER_01: And I just want to point out, too, that in terms, just so you can see it, you have these salt beds, and then you have deposition on top of that, like many thousands of feet of deposition on top of it.
18:27
SPEAKER_01: Higher up, closer to the surface, you have the Navajo sandstone, the caramel sandstone, and then the entrata on top of that.
18:36
SPEAKER_01: So just in terms of ages that we're referring to here, the salts in the Paradox Basin are the oldest, and then you have a bunch of other rocks on top of that, but then we're kind of skipping ahead.
18:47
SPEAKER_01: And you alluded to this at the beginning of the episode.
18:49
SPEAKER_01: We're keeping it general here, so we're not bogging you down with all kinds of different formations.
18:56
SPEAKER_01: There are other formations in between, but then you have the Navajo, and then younger yet is the Carmel, and then younger yet is the entrata.
19:05
SPEAKER_01: And the entrata is the one where the vast majority of all the arches in Arches National Park are preserved, so that's why we're honing in on those layers.
19:15
SPEAKER_02: That's exactly right, Chris.
19:16
SPEAKER_02: And we're going to talk about why that's the really important one.
19:18
SPEAKER_02: It's a really cool story there, but I just want to make a comment here about this.
19:21
SPEAKER_02: And this is common amongst all of our national park episodes and the ones we've talked about, a geological story.
19:28
SPEAKER_02: We always kind of paint this picture, right, Chris?
19:30
SPEAKER_02: We tell the story, and then we say, and this happened, therefore the rocks are there.
19:35
SPEAKER_02: Which, especially in like regions where the Colorado Plateau, where there's a lot of uplift and sea level change, and those two things are going on, and the rocks change in composition, like we're talking about.
19:45
SPEAKER_02: We move from salt to sandstones and different types of sandstones.
19:48
SPEAKER_02: I always kind of get a little bit confused in these sequences.
19:52
SPEAKER_02: And we paint this really nice, clear story, and we say, then the rocks formed.
19:56
SPEAKER_02: But actually, that's not the way this story is figured out.
19:59
SPEAKER_02: We're not just like given this story as scientists.
20:02
SPEAKER_02: The story is actually made from geologists looking at those rocks.
20:05
SPEAKER_02: So geologists work through the Navajo sandstone, the Entrada sandstone, the salt that's in there, and they say, Oh, this is what happened.
20:13
SPEAKER_02: The salt is there, so therefore, this was a restricted basin back in time.
20:17
SPEAKER_02: And there's this big package of sediments here in the center.
20:20
SPEAKER_02: It's a thinner sequence of sediments over there, and on the opposite side, if I turn to the left, it's thinner over there as well.
20:26
SPEAKER_02: So I'm standing in the center of an ancient basin.
20:29
SPEAKER_02: This is how geologists use the rocks to paint a picture of the ancient Earth or a planet that does not exist anymore, really.
20:36
SPEAKER_02: And Marty Gilmore used that phrase.
20:38
SPEAKER_02: That's a great phrase.
20:39
SPEAKER_02: I'm stealing it from her though, but go ahead.
20:40
SPEAKER_01: That is a really good point, my young sage.
20:43
SPEAKER_01: Well done.
20:44
SPEAKER_01: But I want you to do one thing real quick.
20:47
SPEAKER_01: Just say what you want to say here about this in a sentence.
20:51
SPEAKER_01: Boil it down.
20:52
SPEAKER_01: What are you trying to say?
20:53
SPEAKER_02: Okay, I'm trying to say that the rocks tell the story, even though we're telling the story and then pointing to the rocks.
21:00
SPEAKER_02: The rocks tell us the story.
21:01
SPEAKER_02: And also, it's complicated.
21:03
SPEAKER_02: The rocks are complicated.
21:04
SPEAKER_02: It's not always crystal clear exactly what the interpretations are.
21:08
SPEAKER_02: So if the story's a little bit squishy and unclear, it's because the rocks are a little bit squishy and unclear sometimes too, right?
21:14
SPEAKER_02: Like we don't know everything.
21:15
SPEAKER_02: We're missing pieces of information.
21:16
SPEAKER_02: And geology is just totally cool.
21:18
SPEAKER_02: So I went longer than you gave me the allotted time, but in summary, geology is awesome.
21:22
SPEAKER_01: No, that's all right.
21:23
SPEAKER_01: No, it's a really good point.
21:24
SPEAKER_01: I mean, in geology, we only get the la we get to see the last page of a book.
21:30
SPEAKER_01: We get to see the end.
21:31
SPEAKER_01: All right, here's what it looks like now.
21:33
SPEAKER_01: We have to then use that last page to put in all the other chapters from the beginning of the book to that last page.
21:40
SPEAKER_01: We have to interpret what happened.
21:43
SPEAKER_01: And I think like that's what you're saying.
21:45
SPEAKER_02: That's really well put.
21:46
SPEAKER_02: That's exactly what I'm saying.
21:47
SPEAKER_02: So, you know, Chris, give me my ten seconds back and I will say, Oh, you know what it's like?
21:51
SPEAKER_02: It's like the end of a book.
21:52
SPEAKER_02: We're leading the last page of a book and we have to infer everything before it.
21:57
SPEAKER_01: I don't know if you're being serious or or I absolutely am.
22:00
SPEAKER_01: I'm stealing that.
22:01
SPEAKER_02: I just I just gave this lecture.
22:04
SPEAKER_02: No, I just gave this lecture uh on Thursday to my big intro level class of 200 students, and I gave my version of it, which was clearly not as intriguing as yours because they looked at me blankly.
22:14
SPEAKER_02: So maybe on Tuesday I'll try your style.
22:18
SPEAKER_02: See if it works.
22:19
SPEAKER_01: This is the hard part of geology, though, is doing this.
22:22
SPEAKER_01: This is why it's so difficult for beginning geology students to look at this and then try to make sense of how did we get to this point?
22:31
SPEAKER_01: That is it's a different way of looking at the world.
22:36
SPEAKER_01: Most people don't do this.
22:37
SPEAKER_01: Geologists are a little odd.
22:39
SPEAKER_01: We look at the world, we only ever get the last, you know, well, we're more than a little odd, but we only get the last page, and we have to then think about things differently.
22:49
SPEAKER_01: I love the way geologists think.
22:51
SPEAKER_02: Oh, me too.
22:52
SPEAKER_01: Because it's uh it's difficult.
22:54
SPEAKER_01: It's not an easy way of looking at the world.
22:55
SPEAKER_02: No, it's it's super great though.
22:57
SPEAKER_02: Okay, Chris, let's get into how the arches formed and why they are where they are.
23:01
SPEAKER_01: Okay, before we get into the arches, I want to talk a little bit about the transition from when we go from salt to the other rocks on top.
23:09
SPEAKER_01: Something happened geologically.
23:11
SPEAKER_01: The salt was this restricted basin, it got super salty, saturated, and began to lay down these various kinds of salt.
23:19
SPEAKER_01: Then conditions changed.
23:21
SPEAKER_01: This restricted basin got connected to a larger sea, which allowed then this influx of fresher water.
23:30
SPEAKER_01: It was still salt water, but it wasn't salty enough to lay down salt.
23:34
SPEAKER_01: So it started to deposit other kinds of rocks from the highlands around it, things like shales and sandstones and limestones and things of this order.
23:43
SPEAKER_01: So it changed from the bottom of the Paradox Basin to the top of it, in that it went from salty to fresher water.
23:54
SPEAKER_01: So the rocks changed and reflected that.
23:56
SPEAKER_01: Exactly.
23:57
SPEAKER_02: Does that make sense?
23:58
SPEAKER_02: Yeah, absolutely.
23:59
SPEAKER_02: And and thank you for pointing that out because we've belabored the salt point because it's so important.
24:04
SPEAKER_02: Like salt is key.
24:05
SPEAKER_02: And the reason that salt is key to this story is that salt is not very dense compared to the rocks above it.
24:12
SPEAKER_02: It's light.
24:12
SPEAKER_02: You can think of it as light, and the rocks are heavier.
24:14
SPEAKER_02: So if you take a salt layer, a really thick salt layer up to a thousand feet, and you bury it with really heavy rock on top, that salt is under a lot of pressure and it begins to migrate upward due to the massive pressure of the rocks on top of it.
24:28
SPEAKER_02: And this is really important for the hydrocarbon industry.
24:31
SPEAKER_02: They're always looking for salt domes, what we call salt domes, where salt is moving up through the rocks that overlie it that are heavier than it because it's less dense.
24:41
SPEAKER_01: That's right.
24:42
SPEAKER_01: I want to interrupt and say one thing though, that the reason why it migrates is salt behaves differently when it has a lot of pressure on it.
24:50
SPEAKER_01: Salt becomes kind of toothpaste-like with that kind of pressure.
24:55
SPEAKER_01: Or think about a lump of silly putty, let's say.
24:59
SPEAKER_01: If you have like silly putty laying on the floor, a ball of it, and you step on it, it's going to behave in this kind of toothpaste way and it's going to begin to flow.
25:08
SPEAKER_01: And that's what salt does.
25:10
SPEAKER_01: When it gets a lot of this overburden on top of it, it becomes somewhat liquefied and flows.
25:17
SPEAKER_01: And then when it finds these avenues leading to the surface because it's less dense than the rocks on top of it, it's going to begin to migrate up to the surface, forming these domes that you were talking about.
25:28
SPEAKER_02: Exactly.
25:28
SPEAKER_02: And these domes, like I said, are really important for trapping hydrocarbons, oil, natural gas, reservoirs.
25:34
SPEAKER_02: Actually, Chris Jackson, who we interviewed in season one, who's an amazing, amazing geoscientist, he focuses a lot on the salt domes and is an expert in sort of analyzing this.
25:45
SPEAKER_02: There's a lot of focus on understanding how salt moves through rocks because it creates these little traps and seals for hydrocarbons to move around, for fluids to move throughout the sedimentary package layer.
25:57
SPEAKER_02: And this really brings us as well into the arches.
26:00
SPEAKER_02: So why is salt important for arches, Chris?
26:03
SPEAKER_01: Well, when salt moves up through the denser rocks above it, and encountered these more brittle sandstones that we talked about before, the Navajo, the Caramel, and the Entrada, it began to bulge them up.
26:16
SPEAKER_01: But sandstone that's close to the surface is quite brittle.
26:20
SPEAKER_01: And so as it bulged them up, it cracked those sandstones.
26:24
SPEAKER_01: And it's kind of like sometimes during the winter time, I get dry skin on my hands, particularly.
26:30
SPEAKER_01: I kind of look like a reptile unit.
26:32
SPEAKER_01: I don't even absolutely and your knuckles get drier than everything else, right?
26:37
SPEAKER_01: And so when you have this dry skin and you make a tight fist, you stretch the skin and your skin splits over the knuckles.
26:46
SPEAKER_01: So you get these like ridges and valleys where your skin splits.
26:49
SPEAKER_01: It's a gross analogy, I know, but it I think it works.
26:51
SPEAKER_02: No, it's great.
26:52
SPEAKER_02: It's a great one.
26:52
SPEAKER_02: I mean, you are the analogy master today.
26:54
SPEAKER_02: I mean, it's unbelievable.
26:55
SPEAKER_02: That is a great one.
26:56
SPEAKER_02: It's perfect.
26:57
SPEAKER_02: It's these little like cracky fins you get in your knuckles.
27:00
SPEAKER_02: I mean, I totally know what you're talking about.
27:01
SPEAKER_02: Easy to visualize.
27:02
SPEAKER_02: Nicely done, Chris.
27:03
SPEAKER_02: Nicely done.
27:04
SPEAKER_01: Can I do one more?
27:04
SPEAKER_02: Yeah, yeah.
27:05
SPEAKER_02: I mean, you're on a roll.
27:06
SPEAKER_02: I'm not going to stop the flow here.
27:07
SPEAKER_02: I mean, my God, yeah.
27:08
SPEAKER_01: Well, well, so this the sandstone cracks into these parallel fin-like, I'm saying fin, F-I-N.
27:17
SPEAKER_01: You know what it's like?
27:18
SPEAKER_01: It's like taking a book and putting it with the binding edge down on a table, and so you have the pages standing vertical, and you just kind of quit holding it together and let the pages spread out a little bit.
27:32
SPEAKER_01: That's what these fins and valleys look like.
27:35
SPEAKER_02: Oh, good one.
27:36
SPEAKER_02: Yeah.
27:36
SPEAKER_02: Does that make sense?
27:37
SPEAKER_02: Yeah, absolutely.
27:38
SPEAKER_02: Yeah, you kind of get some space in there, and this brings us really nicely into exactly why the arches are where they are.
27:46
SPEAKER_02: And so I'm going to try and keep this as clear as possible, Chris.
27:50
SPEAKER_02: But uh so keep me on track here a little bit, okay?
27:52
SPEAKER_02: But I'll do my best.
27:53
SPEAKER_02: I'll try.
27:54
SPEAKER_02: Okay.
27:54
SPEAKER_02: I want to just give the sequence of rocks again.
27:56
SPEAKER_02: Remember, there's salt.
27:57
SPEAKER_02: That salt is doming, it's kind of moving up through these sandstones, it's cracking the sandstones.
28:02
SPEAKER_02: But let's remember the order here.
28:04
SPEAKER_02: We have Navajo at the bottom, we have caramel right on top of that, and then we have entrata on top of that.
28:10
SPEAKER_02: And we said before that the entrata sandstone is the one where all the arches are in.
28:15
SPEAKER_02: That's the sedimentary layer where the arches exist in.
28:17
SPEAKER_02: And the reason for that is because the caramel is slightly different than the entrata.
28:24
SPEAKER_02: The entrata is basically all sand.
28:27
SPEAKER_02: Water can work its way really easily through the entrata.
28:30
SPEAKER_02: And these cracks give the water avenues to get deeper down as well.
28:34
SPEAKER_02: But water can't go as easily through the caramel or the caramel.
28:39
SPEAKER_02: So water percolates through the entrata and then it hits the caramel, and the caramel has a bit more clay in that unit.
28:47
SPEAKER_02: It was a slightly different depositional environment.
28:48
SPEAKER_02: Chris, you talked about the sea, this ancient sea in the Paradox Basin.
28:52
SPEAKER_02: Sea level was rising and falling, and we were changing the environment of deposition.
28:56
SPEAKER_02: So a slight change will put more clay into this sandy environment.
29:00
SPEAKER_02: And so the entrata is clean sand, water goes through it very easily.
29:04
SPEAKER_02: The caramo, the caramel, has clay in it, so water doesn't go through there as easily.
29:09
SPEAKER_02: So what happens?
29:10
SPEAKER_02: Well, this water percolates through the entrata and then hits the caramel and can't move, so it just sits there.
29:16
SPEAKER_02: And we've talked about how water is the universal solvent.
29:21
SPEAKER_02: It likes to dissolve stuff.
29:22
SPEAKER_02: And so what does it dissolve?
29:23
SPEAKER_02: It dissolves the cement that holds the sand grains together.
29:28
SPEAKER_02: The cement that makes a sand pile a sandstone.
29:32
SPEAKER_02: If you have a loose pile of sand and you want to turn that into a sandstone, you need to cement those grains together.
29:37
SPEAKER_02: So the Navajo sandstone, the Entrada sandstone, those are cemented together, sand grains.
29:42
SPEAKER_02: And this water dissolves the cement that holds them together.
29:48
SPEAKER_00: I have another analogy.
29:50
SPEAKER_00: Go for it for yeah.
29:53
SPEAKER_02: Back in my uh basketball playing days here, when somebody was on fire, the phrase was feed the dog, man.
29:58
SPEAKER_02: You gotta feed the dog.
29:59
SPEAKER_02: You're on fire right now, Chris.
30:00
SPEAKER_02: I'm gonna feed you.
30:01
SPEAKER_02: Go for it.
30:02
SPEAKER_01: Well, you're talking about the process of lithification.
30:06
SPEAKER_01: You're talking about the process of converting sediment into rock, loose sediment into rock.
30:11
SPEAKER_01: You need compaction and you need cementation.
30:14
SPEAKER_01: What's the cement?
30:15
SPEAKER_01: What's the glue?
30:16
SPEAKER_01: All right.
30:17
SPEAKER_01: Take a Dixie cup, a little plastic cup, fill it with sand, and squish it.
30:22
SPEAKER_01: Okay.
30:23
SPEAKER_01: If you take a pin and put little holes in the bottom of the cup, the sand stays in the cup, but not the holes aren't big enough to let the sand drain out.
30:31
SPEAKER_01: And then you take bottled water and you pour it through the sand-filled Dixie cup.
30:37
SPEAKER_01: And the water begins to drip out.
30:38
SPEAKER_01: Okay, and you take that cup and you let it sit on a windowsill.
30:42
SPEAKER_01: Just let it sit.
30:43
SPEAKER_01: Take another cup, do the same thing.
30:44
SPEAKER_01: Fill it up.
30:45
SPEAKER_01: Poke little holes in the bottom of it.
30:47
SPEAKER_01: And now pour salty water through the Dixie cup.
30:51
SPEAKER_01: The water will drip out.
30:53
SPEAKER_01: You just let it sit on the windowsill.
30:55
SPEAKER_01: Come back in a week, everything is dried up.
30:58
SPEAKER_01: You take cup number one, where I poured bottled water through it.
31:00
SPEAKER_01: You tear the cup away, and what do you have in your hand?
31:03
SPEAKER_01: You have a lump full of sand.
31:05
SPEAKER_01: Okay, nothing.
31:06
SPEAKER_01: Right?
31:07
SPEAKER_01: You take cup number two that you poured the salt water through, and you tear the cup away, and the sand doesn't fall apart.
31:13
SPEAKER_01: It's bound together by the salt.
31:16
SPEAKER_01: That's what's holding, it's sticking all the grains of sand together in the pore space.
31:22
SPEAKER_01: The little air pockets where the water was circulating through.
31:25
SPEAKER_01: That's what happens to sandstones.
31:28
SPEAKER_02: So let me jump in there, Chris.
31:30
SPEAKER_02: That's a great analogy.
31:31
SPEAKER_02: And what's going on here is a reverse of that process.
31:34
SPEAKER_02: You had your little Dixie cup, you put some salt water through it, you cemented those sand grains together, you turn it upside down, you dump it on the kitchen table, and you pull the cup away, and you have this cup-shaped sand brick that's shaped like the Dixie cup, right?
31:48
SPEAKER_02: But it's cemented together.
31:49
SPEAKER_02: What we're doing here at the base of the entrata on top of the caramel, because water can't go through the caramel, so water percolates down through the entrata, it sits there, it ponds at the base of the caramel, and what happens is that water dissolves that salt.
32:02
SPEAKER_02: So we take that cemented cup-shaped block of sand, we put it on a plate, and we put more water in there, and we just let it sit and it dissolves, it redissolves the salt.
32:11
SPEAKER_02: We put this really clean water, it's very reactive, it dissolves that salt, and then the sand just kind of is loose.
32:17
SPEAKER_02: It's not in a cement.
32:18
SPEAKER_02: It's sand now, it's not a sandstone.
32:20
SPEAKER_02: And that is key because now when the arch, you remember these big fins that you talked about, the salt domed up, created these big fins.
32:30
SPEAKER_02: Now wind and water can get in there and can hit the base of the entrata, which is much, much weaker because all of the cement has been dissolved.
32:38
SPEAKER_02: That's where the arches are forming.
32:41
SPEAKER_02: And so there's a great picture, there's a great drive in Arches National Park where you could look and you see this singular unit on the horizon.
32:48
SPEAKER_02: It's one big sandstone block, and there's a whole bunch of arches right at the base of that.
32:53
SPEAKER_02: That is the base of the entrata sandstone, and the caramel is just beneath it.
32:57
SPEAKER_02: And all the arches form at the base of the entrata because that's where the water sat, that's where it dissolved the cement, which made it weaker, which made it easier for wind and water to create the arches.
33:08
SPEAKER_01: That was a great explanation, actually, Jesse.
33:12
SPEAKER_01: Well done.
33:13
SPEAKER_01: Thank you.
33:14
SPEAKER_01: Well, that was a team effort.
33:15
SPEAKER_02: I mean, yeah, that I would say that was a team effort.
33:17
SPEAKER_02: You're still on fire.
33:18
SPEAKER_02: I'm gonna keep feeding you the ball, man.
33:19
SPEAKER_02: I'm gonna keep feeding it to you the whole rest of this episode.
33:22
SPEAKER_00: So no, I think I'm done.
33:24
SPEAKER_02: I think we just wanna I just want to wrap this part up, and then we're gonna finish up with some desert features that you can see in Arches National Park as well as other deserts.
33:31
SPEAKER_02: But I just want to point out that the arches are actually formed by wind and water action beating down these sandstones, and they're just beating down the weak areas at the base of the entrata faster.
33:44
SPEAKER_02: And so that's why arches are there.
33:46
SPEAKER_02: But arches are not a permanent feature, and there's a really famous one, the Wall Rock Arch, that collapsed in 2008.
33:52
SPEAKER_02: And so if you go to Arches National Park, I think actually nowhere, there might be one you can walk on, but basically you can't walk on any of these because they're really, really fragile things actually, and they're not permanent features, they're ephemeral, like weathering and erosion is still going on in arches, and it's still breaking down these things, and arches will collapse, and then you'll just have a column of rock.
34:14
SPEAKER_02: And then new arches are also being created as well.
34:16
SPEAKER_02: So this is a very active environment on the human timescale.
34:20
SPEAKER_01: This arch that collapsed, wall rock in 2008, happened during the summertime, so it's during the busy season, and it was heard by people that were camping in Devil's Garden campground in the middle of the night.
34:32
SPEAKER_01: Just this massive, they didn't know what it was.
34:35
SPEAKER_01: It's it startled a bunch of people, and then of course the next morning people went and looked at the what happened, and the center of the arch was gone.
34:44
SPEAKER_02: Oh man, yeah, it just collapsed.
34:46
SPEAKER_01: That'd be so cool to hear.
34:47
SPEAKER_01: Yeah, it would rock fall is amazing.
34:49
SPEAKER_02: It really is.
34:50
SPEAKER_02: Really powerful stuff.
34:51
SPEAKER_02: Um, all right, Chris, let's just wrap up here, real quickly, with some other desert features.
34:56
SPEAKER_01: Okay, Jesse, we're gonna talk about desert varnish and another feature, less commonly known feature called Tephoni.
35:02
SPEAKER_01: So let's start with desert varnish, Jesse.
35:05
SPEAKER_01: What's going on?
35:06
SPEAKER_02: Yeah, it's a really cool process.
35:08
SPEAKER_02: It creates beautiful features that you can see on the surfaces of rocks.
35:12
SPEAKER_02: It's a surface feature.
35:13
SPEAKER_02: And what it is, is these black, red, and white streaks and all shades in between there that occur on the rocks.
35:21
SPEAKER_02: And you can see this as coatings on rocks on the ground as well.
35:24
SPEAKER_02: So if you you see some rocks that are kind of blackish on the ground, turn them over and you'll see that's a very different color on the underside.
35:30
SPEAKER_02: That's desert varnish.
35:31
SPEAKER_02: And what's going on here is it's basically clay minerals, oxides, hydroxides, they're weathering minerals that are formed from dust and rock covering the surface of these rocks over a long time period.
35:44
SPEAKER_02: So in the desert, the little water that you do get, it sits there, it creates these clay minerals, then it evaporates pretty quickly.
35:51
SPEAKER_01: This is a kind of weathering called chemical weathering.
35:54
SPEAKER_01: So now this is not a mechanical weathering process, and it is so common in the western United States.
36:00
SPEAKER_01: I saw tons of this in the Tetons, in the Rocky Mountains.
36:04
SPEAKER_01: It doesn't have to be just this really, really dry, arid climate.
36:09
SPEAKER_01: This is a common feature in the western United States, period.
36:12
SPEAKER_02: Yeah, and it's really nice because there's none of that GD biology all over the place.
36:17
SPEAKER_02: I mean, I was just up in the Arctic and there's lichen everywhere.
36:20
SPEAKER_02: Lichen is always covering the rocks.
36:22
SPEAKER_02: If it's not some you know, shrub, it's lichen.
36:25
SPEAKER_02: And going down to the southwestern US is beautiful because there's no biology on top of it.
36:30
SPEAKER_02: You can just see the rocks, but basically, this stuff is forming there because there's no biology.
36:35
SPEAKER_02: So most of these minerals are rich in iron and manganese, and manganese-rich regions are typically black, where the iron-rich ones are, as we've talked about before, reddish, right?
36:44
SPEAKER_02: They mostly make red.
36:45
SPEAKER_02: If you have iron, you're getting a red color most of the time.
36:48
SPEAKER_01: And you can also see this quite easily because you can see the direction the water's streaking down the rock.
36:55
SPEAKER_01: It looks kind of like um somebody that wears a lot of makeup, goes out for a run, sweat, and the makeup kind of streaks down the face.
37:04
SPEAKER_01: That's what desert varnish looks like to me.
37:07
SPEAKER_02: Chris, you went with makeup.
37:08
SPEAKER_02: That's the funny one.
37:09
SPEAKER_02: I would have gone with like sunscreen or something like that, but makeup's a good analogy.
37:13
SPEAKER_02: Okay, I like that one.
37:14
SPEAKER_01: Sunscreen isn't really colorful, like so you know, eyeliner and stuff just running down and you know.
37:20
SPEAKER_02: I I might I might take uh I might take the ball from you a little bit from now on.
37:23
SPEAKER_02: I don't know if your hot streaks still continue.
37:25
SPEAKER_02: You don't like that?
37:26
SPEAKER_02: I thought that was really good.
37:27
SPEAKER_02: It's a pretty good one.
37:28
SPEAKER_02: It's a pretty good one.
37:28
SPEAKER_02: All right, you can keep it.
37:29
SPEAKER_02: All right, all right, you convince me.
37:30
SPEAKER_02: So let's wrap up Devert Varnish by just saying that some of these things, especially the manganese varnish, can take a thousand years to actually make.
37:38
SPEAKER_02: So that means that this stuff has been going on for a thousand years, but also don't damage it.
37:43
SPEAKER_02: Like, don't scrape it, don't carve over it.
37:45
SPEAKER_02: This is a beautiful feature that takes a long time to form.
37:48
SPEAKER_02: So, you know, if you go to arches, don't scrape the rock, don't try and carve your name into it.
37:52
SPEAKER_02: That stuff drives me crazy.
37:53
SPEAKER_02: Um I appreciate that comment.
37:55
SPEAKER_02: I like that as natural.
37:57
SPEAKER_02: So, Chris, the next one, Tefony.
37:59
SPEAKER_02: What do we got?
38:00
SPEAKER_02: What's going on here?
38:01
SPEAKER_01: This is a lot lesser known and not nearly as common, but it is kind of common in arches.
38:08
SPEAKER_01: I I think of tephony as these mini arches, these kind of mini caves, or a honeycomb kind of weathering, or Swiss cheese rock.
38:19
SPEAKER_01: That's what Tefony kind of looks like to me.
38:23
SPEAKER_01: So this is found in our rocks, the rocks that are super important in terms of the arches themselves.
38:30
SPEAKER_01: So it's found in the Navajo sandstone, it's found in the entrata.
38:34
SPEAKER_01: Why would that be?
38:36
SPEAKER_01: What's going on?
38:37
SPEAKER_01: Why are they in those rocks?
38:39
SPEAKER_02: Yeah, it's the exact same reason why the arches are there.
38:42
SPEAKER_02: It's the exact same process just on a smaller scale.
38:44
SPEAKER_02: And you can see this on the walls near the arches.
38:48
SPEAKER_02: You can kind of see these mini honeycomb things, mini arches, mini caves, honeycomb weathering.
38:52
SPEAKER_02: You can see it on the rocks themselves.
38:53
SPEAKER_02: You can also see it on rocks that lay it on the ground, too.
38:55
SPEAKER_02: It's all over the place if you just keep your eye open and look carefully for it.
38:59
SPEAKER_02: And it's the exact same process.
39:00
SPEAKER_02: Cement in one area is getting a little bit more weathered because, for whatever reason, water is ponding there.
39:06
SPEAKER_02: And this is a positive feedback loop phenomenon.
39:08
SPEAKER_02: So if you have one region where a little bit more water ponds, it's gonna dissolve the cement there more because there's more water there.
39:16
SPEAKER_02: Then the next time water comes in, the next batch of rainfall that brings water in, more water is gonna pond there and it's gonna dissolve quicker because there's less cement there.
39:25
SPEAKER_02: So it's more porous, more water is gonna go in there.
39:27
SPEAKER_02: It's going to dissolve the cement faster.
39:29
SPEAKER_02: And so you can see how a little bit of dissolution makes more dissolution the next time and more and more and more until there's none left.
39:36
SPEAKER_02: And so those little honeycomb weathering, there's sort of an immature arch, right?
39:41
SPEAKER_02: It's going to be an arch someday because it's making the rock weaker.
39:44
SPEAKER_02: It just hasn't yet.
39:45
SPEAKER_02: So you can kind of think of those as future arches in a way.
39:48
SPEAKER_01: The cementing agent for a lot of these sandstones, the Navajo and the Entrada, is a calcium carbonate, which is a calcite cement, which is very soluble, so it dissolves much easier than other kinds of cement, and that kind of aids in the process of making tifhony.
40:04
SPEAKER_02: That's kind of a wrap on this episode.
40:06
SPEAKER_02: You know, we talked about the regional geology, the paradox basin in the center of that, the value and the importance of salt for forming these fins and as it migrates up, and then how the Navajo carmel and entrata sandstones are the ones there, and why we have all the arches are in the entrata sandstone because of water precipitating and percolating through that unit.
40:27
SPEAKER_02: So uh man, this is a great place, Chris.
40:31
SPEAKER_02: Go there, go check it out.
40:32
SPEAKER_02: We're I don't know, maybe we're end of the travel season.
40:34
SPEAKER_02: No, probably not southwest US.
40:36
SPEAKER_02: You can probably still make it in the fall or the winter.
40:38
SPEAKER_02: And if you can't do it this year, make a plan for 2023 to go there.
40:41
SPEAKER_02: It's an amazing place.
40:43
SPEAKER_01: And Canyon Lands is right next to Arches.
40:47
SPEAKER_01: It's very big, more remote, just as awesome.
40:51
SPEAKER_01: I love Canyon Lands.
40:53
SPEAKER_01: That is gonna be coming up next week in our Geo Short.
40:56
SPEAKER_01: And yeah, do both at the same time.
41:00
SPEAKER_02: Yeah, and you could do so much down there.
41:02
SPEAKER_02: I mean, Utah is just like the playground state.
41:04
SPEAKER_02: There's so much good stuff there.
41:05
SPEAKER_02: It's awesome.
41:06
SPEAKER_02: It really is.
41:06
SPEAKER_02: All right.
41:07
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41:09
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41:10
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41:12
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41:15
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41:25
SPEAKER_02: But most importantly, Chris, what do people do?
41:28
SPEAKER_01: Most importantly, you need to share Planet Geo with somebody that cares about our planet.
41:32
SPEAKER_02: Or somebody that doesn't and should, you know, that I think we're trying to convey that, you know.
41:37
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41:39
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41:43
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41:45
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41:48
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41:51
SPEAKER_02: Yeah, cheers.
41:52
SPEAKER_02: Take care.