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The Epic Earthlings Grand Canyon Questions - Answered! · PlanetGeo: The Geology Podcast

• 0:02
  SPEAKER_00: Welcome to Planet Geo, the podcast where we talk about our amazing planet, how it works, and why it matters to you.
• 0:11
  SPEAKER_01: I'm fired up for multiple reasons.
• 0:15
  SPEAKER_01: Give me one or two of the reasons.
• 0:17
  SPEAKER_01: Both good and bad.
• 0:19
  SPEAKER_01: So, Dr.
• 0:19
  SPEAKER_01: Rymank, why are you fired up this morning?
• 0:22
  SPEAKER_01: What's going on?
• 0:23
  SPEAKER_01: I got a couple things for your life.
• 0:24
  SPEAKER_00: Oh, wait, hold on.
• 0:25
  SPEAKER_00: I was gonna show you something.
• 0:26
  SPEAKER_00: I'll be right back.
• 0:27
  SPEAKER_00: Hold on.
• 0:30
  SPEAKER_00: This.
• 0:30
  SPEAKER_00: So I'm fired up.
• 0:32
  SPEAKER_01: I love it.
• 0:33
  SPEAKER_01: I love it.
• 0:33
  SPEAKER_01: This is my fault.
• 0:35
  SPEAKER_01: I couldn't take the pressure.
• 0:37
  SPEAKER_01: I love it.
• 0:38
  SPEAKER_00: And notice notice how couldn't is spelled.
• 0:44
  SPEAKER_01: There's no L in it.
• 0:46
  SPEAKER_01: It's spelled wrong.
• 0:46
  SPEAKER_01: I didn't even spell it.
• 0:48
  SPEAKER_01: It's just C O U D N T.
• 0:51
  SPEAKER_01: Couldn't.
• 0:52
  SPEAKER_01: No L.
• 0:53
  SPEAKER_01: So uh Alright.
• 0:54
  SPEAKER_01: Was that like a discounted shirt then?
• 0:56
  SPEAKER_01: Because it they spelled it wrong.
• 0:58
  SPEAKER_01: So what happened?
• 0:59
  SPEAKER_00: So you know, my dear wife knows that I hate geology puns.
• 1:03
  SPEAKER_00: And this is a very geology pun shirt.
• 1:05
  SPEAKER_00: And every year for my birthday, she gets me a geology pun shirt.
• 1:09
  SPEAKER_00: And that was yesterday.
• 1:10
  SPEAKER_00: So this shirt is a birthday shirt from her that I had to wear all day yesterday.
• 1:15
  SPEAKER_00: It's actually kind of a good one though, because it actually has educational value a little bit.
• 1:20
  SPEAKER_00: Like usually geology puns are like, oh, nice shist or whatever, you know, something stupid like that.
• 1:26
  SPEAKER_00: This one's like a fault and I told you one of mine.
• 1:30
  SPEAKER_01: That is a good one.
• 1:31
  SPEAKER_01: But I like that nice one.
• 1:33
  SPEAKER_01: I like the the one that says nice chert.
• 1:35
  SPEAKER_00: But still there's no connection to it.
• 1:37
  SPEAKER_00: It's just kind of stupid.
• 1:38
  SPEAKER_00: There's no linking of the geological ideas.
• 1:41
  SPEAKER_00: This is this one says a fault, it ruptures because of the pressure.
• 1:45
  SPEAKER_00: That to me is it's one of the better ones I've seen.
• 1:48
  SPEAKER_00: I like it.
• 1:49
  SPEAKER_01: Yeah.
• 1:49
  SPEAKER_01: It's very colorful too.
• 1:50
  SPEAKER_01: Holy crazy.
• 1:51
  SPEAKER_00: It's very colorful.
• 1:52
  SPEAKER_01: Like it's busting with color.
• 1:53
  SPEAKER_01: Very bright.
• 1:54
  SPEAKER_00: Yeah.
• 1:55
  SPEAKER_01: Stands out in a crowd.
• 1:57
  SPEAKER_01: Well, you already stand out in a crowd, you big giant.
• 2:02
  SPEAKER_01: It's true.
• 2:03
  SPEAKER_01: You don't you don't need all that.
• 2:05
  SPEAKER_00: No, wearing extra large shirt that's very brightly colored that says it's it's my fault.
• 2:10
  SPEAKER_00: What else am I fired up about?
• 2:11
  SPEAKER_00: Oh, uh well, you said publication stuff.
• 2:14
  SPEAKER_00: I we had a publication re uh rejected again uh this just this morning.
• 2:19
  SPEAKER_00: So it's just a fresh thing to wake up to.
• 2:22
  SPEAKER_01: Send me the names.
• 2:23
  SPEAKER_00: I'll be your hitman.
• 2:24
  SPEAKER_00: Okay.
• 2:25
  SPEAKER_00: We're gonna go out and bust some heads for this.
• 2:28
  SPEAKER_00: You'd write.
• 2:29
  SPEAKER_00: You don't pick on my guy.
• 2:30
  SPEAKER_00: Uh-uh, uh-uh.
• 2:31
  SPEAKER_00: You know what's funny?
• 2:32
  SPEAKER_00: That was my wife's response too.
• 2:33
  SPEAKER_00: I woke up this morning and I was just cranky.
• 2:35
  SPEAKER_00: Because you know, these emails inevitably come in at like 3 a.m.
• 2:38
  SPEAKER_00: or something, right?
• 2:38
  SPEAKER_00: So the my grad student, who's the lead author, forwarded it to me.
• 2:42
  SPEAKER_00: And uh I was just in a cranky mood because of this this morning.
• 2:45
  SPEAKER_00: And anyway, and she she did the same thing.
• 2:48
  SPEAKER_00: She got into real attack mode.
• 2:50
  SPEAKER_00: Like, screw these people.
• 2:51
  SPEAKER_00: Who should we who should we go talk to about this?
• 2:54
  SPEAKER_01: You know, yeah.
• 2:55
  SPEAKER_01: I'm well, I'm not gonna do any talking, Jesse.
• 2:57
  SPEAKER_01: I'm gonna bust some heads like you said here.
• 2:59
  SPEAKER_01: I'm gonna take care of business.
• 3:00
  SPEAKER_01: You just don't mess with my people.
• 3:02
  SPEAKER_00: Don't mess with my team, man.
• 3:04
  SPEAKER_00: I love it.
• 3:04
  SPEAKER_00: I love it.
• 3:05
  SPEAKER_01: Yeah.
• 3:05
  SPEAKER_01: Um, let's see, there was something else that I wanted to ask you about.
• 3:09
  SPEAKER_01: So tell me about the misspelling, though.
• 3:11
  SPEAKER_01: How did that happen?
• 3:12
  SPEAKER_00: Oh, I have no idea.
• 3:12
  SPEAKER_00: I think this shirt, the the couldn't with a no L.
• 3:16
  SPEAKER_00: I think I don't know if it's meant to be that way, or if, you know, this is just a shirt she found in some random corner of the internet uh made by people who don't know how to spell couldn't for some reason.
• 3:28
  SPEAKER_00: I don't know.
• 3:29
  SPEAKER_00: I don't know if it's intentional or not.
• 3:31
  SPEAKER_00: I don't really know where she finds these ridiculous, complicated punny shirts, but she's managed for like eight years to get one, a new one every year.
• 3:39
  SPEAKER_01: I have one that says never help a geologist move.
• 3:45
  SPEAKER_01: That's a good one.
• 3:46
  SPEAKER_01: I like that one.
• 3:47
  SPEAKER_01: I saw something it's got a bunch of like piles of box piles, you know, and they're all just full of rocks.
• 3:52
  SPEAKER_00: So that's a really good one.
• 3:55
  SPEAKER_00: I um I had one recently.
• 3:56
  SPEAKER_00: Well, I've seen this before, but there's this uh I think it's like a you know newspaper cartoon.
• 4:02
  SPEAKER_00: One person says, Oh, I'm a geologist, and the other person says, Oh, that's not a real thing.
• 4:06
  SPEAKER_00: That's just alcohol and guessing.
• 4:12
  SPEAKER_01: That's pretty good.
• 4:13
  SPEAKER_00: It's the famous among geology circles.
• 4:14
  SPEAKER_00: I saw that again the other day.
• 4:15
  SPEAKER_00: I was like, that's quite a good inaccurate but funny.
• 4:19
  SPEAKER_01: It's loosely inaccurate.
• 4:21
  SPEAKER_01: It's um anyway.
• 4:24
  SPEAKER_01: So hold on a minute though.
• 4:26
  SPEAKER_01: I feel I feel really bad a minute.
• 4:27
  SPEAKER_01: Yesterday was your birthday.
• 4:29
  SPEAKER_00: That that's the last reason I'm worked up, Chris.
• 4:32
  SPEAKER_00: I am a bad friend.
• 4:34
  SPEAKER_01: Oh my gosh, are you serious?
• 4:36
  SPEAKER_00: But it's okay.
• 4:37
  SPEAKER_00: It's to the point we don't celebrate the number anymore.
• 4:39
  SPEAKER_00: So, you know.
• 4:40
  SPEAKER_01: Well, I know I know all about that.
• 4:41
  SPEAKER_01: I I totally get that, but still, I mean, I I could have at least texted you and said some snide remark about whatever and recognized your birthday anyway.
• 4:50
  SPEAKER_01: But you you are a funny guy, though.
• 4:52
  SPEAKER_01: You have no social media presence at all.
• 4:56
  SPEAKER_01: That's right.
• 4:57
  SPEAKER_01: You just I know you do, and so I don't get any reminders about hey, it's it's Jesse's birthday or anything like that, right?
• 5:04
  SPEAKER_01: So I guess as soon as we're done here, I have to just put it in my phone as a recurring.
• 5:08
  SPEAKER_00: You know, that's what I've taken to be doing because so did Handy Andy call you.
• 5:13
  SPEAKER_00: We played phone tag yesterday and uh we talked this morning.
• 5:16
  SPEAKER_00: Okay.
• 5:16
  SPEAKER_00: So you know, the family is really all that matters for this purpose.
• 5:22
  SPEAKER_00: But um, so Chris, how are you doing?
• 5:25
  SPEAKER_00: I mean, it's not about you, it's about me really.
• 5:27
  SPEAKER_00: So yeah.
• 5:28
  SPEAKER_01: Um so I'm just gonna wrap it up by saying I'm doing great.
• 5:31
  SPEAKER_01: Okay, good.
• 5:32
  SPEAKER_01: We're we're we're kind of hunkering down for a blizzard today.
• 5:35
  SPEAKER_01: So it's uh yeah.
• 5:37
  SPEAKER_01: A big one here.
• 5:38
  SPEAKER_00: Seems like a big one hitting Michigan.
• 5:40
  SPEAKER_00: Bullseye on Huntsville, Michigan, the map that I saw.
• 5:44
  SPEAKER_00: That'll be good.
• 5:45
  SPEAKER_00: That's I mean, it's kind of fun to have those once every every little bit.
• 5:48
  SPEAKER_00: So it is.
• 5:49
  SPEAKER_01: It'll be nice.
• 5:50
  SPEAKER_01: I just gotta get my house all like I there's some things I have to do yet because I don't know how long we're gonna be socked in.
• 5:56
  SPEAKER_00: Oh, yeah, for sure.
• 5:57
  SPEAKER_00: Well, Chris, the the last reason I'm fired up is because this is a fun episode.
• 6:00
  SPEAKER_00: This is a really I really like this kind of stuff.
• 6:03
  SPEAKER_00: Um, and I know I'm sure I know you do too, because you know, the yeah, the educator in you is just very excited for this episode, right?
• 6:11
  SPEAKER_00: Absolutely.
• 6:12
  SPEAKER_01: Why don't you tell everybody what what happened and how this all came about?
• 6:16
  SPEAKER_00: Yeah, so uh a listener of ours, Kat, who is a teacher at the Bronx Little School in the in Bronx, New York, has a fourth grade class, and they were working on a unit on sort of the natural wonders of the world, and the Grand Canyon came up.
• 6:30
  SPEAKER_00: And so Kat reached out to us and said, Hey, can I can I send you some class questions?
• 6:34
  SPEAKER_00: If I have my class put together some questions, can I send them to you?
• 6:37
  SPEAKER_00: So we got a list of questions from Kat's fourth grade class from the Bronx Little School about the Grand Canyon.
• 6:43
  SPEAKER_00: And so we're gonna go through these, and this is a really well, Chris, you and I, we just got done.
• 6:48
  SPEAKER_00: Well, we just published the Grand Canyon audiobook on the Camp Geo app.
• 6:52
  SPEAKER_00: So it's a great time for these questions to come up because we've thought a lot about the Grand Canyon recently and put together a lot of cool stuff and have these answers, you know, readily at the forefront of our brains.
• 7:04
  SPEAKER_00: So that's the structure here.
• 7:05
  SPEAKER_00: We're gonna answer those questions.
• 7:06
  SPEAKER_00: We're gonna go through those, and these aren't really good questions.
• 7:09
  SPEAKER_00: So really well done.
• 7:10
  SPEAKER_00: Kat's fourth grade class, really well done on the questions.
• 7:13
  SPEAKER_00: These are great, great questions, and some of them are quite deep.
• 7:16
  SPEAKER_01: And uh just to be clear too, when I wrote this out in terms of what we want to talk about, I kept the questions as they asked them.
• 7:24
  SPEAKER_01: I kind of maybe tweaked the order of a couple of them, but the questions are the same, and we're gonna tackle all of them that they're that's right, that's right.
• 7:32
  SPEAKER_00: And so I think we should just dive in, Chris.
• 7:35
  SPEAKER_00: I mean, let's work through them.
• 7:37
  SPEAKER_00: There's kind of four or five different themes to these.
• 7:42
  SPEAKER_00: And and also I must say, class, well done on writing the questions down.
• 7:46
  SPEAKER_00: I mean, that was really nicely structured.
• 7:49
  SPEAKER_00: You had really nice introductions.
• 7:50
  SPEAKER_00: I mean, this was a a well-formated letter.
• 7:53
  SPEAKER_00: I love it.
• 7:54
  SPEAKER_01: I would say it was awesome, it was cute.
• 7:56
  SPEAKER_01: Um, and so Jesse, now listen, hey, our audience right now is we're answering questions that came from fourth grade.
• 8:03
  SPEAKER_01: So you can take your doctor title and put it on that shelf right behind you, Kate.
• 8:07
  SPEAKER_01: Now we're talking that's right.
• 8:08
  SPEAKER_01: We're we're gonna stay sure we do a good job here, okay?
• 8:11
  SPEAKER_01: We're gonna we're gonna stay out of the weeds.
• 8:12
  SPEAKER_00: If you want some of the weeds, not the class necessarily, but you listening, if you want some of the weeds, you can go to our audiobook on our Camp Geo app.
• 8:19
  SPEAKER_00: We've just published in the last month.
• 8:21
  SPEAKER_00: We published a Grand Canyon audiobook.
• 8:23
  SPEAKER_00: So this is the geological story of the Grand Canyon with great images that we've produced that really drive home the geological story of the Grand Canyon in what I think, Chris, is a really beautiful way.
• 8:33
  SPEAKER_00: So you can head there.
• 8:34
  SPEAKER_00: That's the first link in your show notes.
• 8:35
  SPEAKER_00: You can head there if you're interested in in more of the weed.
• 8:38
  SPEAKER_00: So, Chris, hold on, Jesse.
• 8:39
  SPEAKER_01: I want to throw one thing out too.
• 8:41
  SPEAKER_01: And we didn't really talk about this, but I I have an idea too that I would really like to, if you and I can maybe find the time to zoom in with their class a little bit, maybe for like 20, 30 minutes and and just talk to these kids maybe about education and and kind of a QA kind of thing.
• 8:57
  SPEAKER_01: I I don't know.
• 8:58
  SPEAKER_01: I we didn't really discuss this.
• 9:00
  SPEAKER_01: So I I know this is like just kind of filling it in your lap here, but what do you think about that?
• 9:04
  SPEAKER_00: Oh, yeah, totally.
• 9:05
  SPEAKER_00: You know, Chris, I zoo I at least I haven't done the last year or two, but I used to zoom into your class a lot.
• 9:10
  SPEAKER_00: And I think it's a I don't know what it's like to be on the receiving end of Zooms.
• 9:14
  SPEAKER_00: Actually, I you know, I had this in my entrepreneurship class.
• 9:17
  SPEAKER_00: We had people come in via Zoom, um, geoscience entrepreneurs to my class and you know just discuss.
• 9:22
  SPEAKER_00: And it's actually it's not that bad.
• 9:25
  SPEAKER_00: You know, you would kind of think it's it's not fun to zoom in or not fun to not be there in person or to not interact in person, but it does a pretty decent job, you know.
• 9:32
  SPEAKER_01: Um yeah, I mean, we're all in the same time zone.
• 9:35
  SPEAKER_01: So, Kat, if you're listening, reach out to us if you're at all interested in this.
• 9:38
  SPEAKER_01: I think we'll do our best to try to coordinate something if you're down for that.
• 9:42
  SPEAKER_00: Yeah.
• 9:42
  SPEAKER_00: So yeah, and so how about we start, Chris, with kind of a basic one?
• 9:47
  SPEAKER_00: I mean, really, like you're looking at the Grand Canyon, it's spectacular.
• 9:50
  SPEAKER_00: It's one of the natural geological wonders of the world.
• 9:53
  SPEAKER_00: How deep is it?
• 9:54
  SPEAKER_00: It's a great question with uh several different points to it, I think.
• 9:58
  SPEAKER_01: Right.
• 9:58
  SPEAKER_01: So in and we're not just gonna answer these questions point blank.
• 10:02
  SPEAKER_01: We want to kind of set this up a little bit, right, Jesse?
• 10:05
  SPEAKER_00: Set the stage.
• 10:06
  SPEAKER_01: When you talk about the depth of the Grand Canyon, I think it's which is impressive, it's really important to note that the Grand Canyon, the rim of the canyon is 7,000 to 9,000 feet above sea level.
• 10:18
  SPEAKER_01: Because it's so high, that's what allowed the river to cut so deeply through this.
• 10:23
  SPEAKER_01: So that's something that I don't think a lot of people realize.
• 10:26
  SPEAKER_01: I mean, even though we're in Arizona, the rim of the Grand Canyon, either the north side or the south side, is significantly high above sea level, and it's it actually gets cold.
• 10:38
  SPEAKER_01: I mean, they get snow up there, and that's something that I think a lot of people don't realize, too.
• 10:43
  SPEAKER_01: So you think of snow in Arizona, but it it it's a common occurrence.
• 10:46
  SPEAKER_00: Yeah, exactly.
• 10:47
  SPEAKER_00: So, Chris, that's a really great point, and I think this is why it's a little bit misleading, or at least the elevation is not obvious because we think of high elevation places, we think of jagged mountains and stuff.
• 10:57
  SPEAKER_00: But when you're standing at the rim, you're on the plateau, which is the rocks are flat all around you.
• 11:02
  SPEAKER_00: And usually when we see flat land, we're close to sea level.
• 11:04
  SPEAKER_00: That's not the case here in in Arizona in the Grand Canyon.
• 11:07
  SPEAKER_00: So that's why it's why you said it's kind of surprising, and and I think that's why, is because you look around and everything's kind of flat.
• 11:14
  SPEAKER_00: Um, so it's a plateau, is what we call that.
• 11:17
  SPEAKER_01: Anyway, so this high elevation makes the river what you kind of term hungry, Jesse.
• 11:22
  SPEAKER_01: You say the the Colorado River is a hungry river.
• 11:25
  SPEAKER_01: So describe what that means.
• 11:27
  SPEAKER_01: Why is the Colorado so hungry?
• 11:28
  SPEAKER_00: This is not a term that uh you and I came up with.
• 11:31
  SPEAKER_00: It's obviously one we've adapted, but I love the term hungry water.
• 11:34
  SPEAKER_00: And you think of it as rivers like to, well, they're usually cutting something.
• 11:41
  SPEAKER_00: They're cutting, they're either cutting down or they're cutting out.
• 11:44
  SPEAKER_00: So we're talking to the Bronx Little School students, so you're sitting there.
• 11:47
  SPEAKER_00: Think of you know one of the rivers around New York City.
• 11:50
  SPEAKER_00: You're very close to sea level in New York City, and right around there, all the rivers are very close to sea level.
• 11:56
  SPEAKER_00: So they actually can't cut down anymore.
• 11:58
  SPEAKER_00: They can't cut below sea level.
• 12:00
  SPEAKER_00: Sea level is a term we call base level, but they can't cut down.
• 12:04
  SPEAKER_01: Jesse, real quick.
• 12:05
  SPEAKER_01: So those those rivers are slow, they're lazy, they're sluggish, you know, so they're not actively eroding.
• 12:13
  SPEAKER_01: Exactly, they're doing the opposite.
• 12:14
  SPEAKER_01: They're not hungry anymore.
• 12:16
  SPEAKER_01: Right, they're not hungry.
• 12:17
  SPEAKER_01: They're not hungry.
• 12:18
  SPEAKER_00: They're totally satisfied.
• 12:19
  SPEAKER_00: They're they're right near their home, so they're not hungry.
• 12:22
  SPEAKER_00: Now, the Colorado River in the Grand Canyon is seven to nine thousand feet above sea level, or at least it used to be before it cut down.
• 12:30
  SPEAKER_00: That's hungry.
• 12:31
  SPEAKER_00: There's a long way over a mile between that river's where it's flowing and the ocean.
• 12:36
  SPEAKER_00: So it can cut down a lot because it's at high elevation.
• 12:40
  SPEAKER_00: And so we think of rivers that are hungry are ones that can cut down.
• 12:44
  SPEAKER_00: They don't have much sediment, they're not very close to what we call base level or the ocean.
• 12:49
  SPEAKER_00: There's a long way that they can cut down, and that's really why the canyon is so deep here, is because the river, the Colorado River, is hungry in this situation.
• 12:59
  SPEAKER_00: So that kind of brings us full circle to answer the question, Chris.
• 13:02
  SPEAKER_00: How deep is the Grand Canyon?
• 13:05
  SPEAKER_00: Okay, I'll I'll take it.
• 13:06
  SPEAKER_01: Okay.
• 13:07
  SPEAKER_01: So the canyon is anywhere from 4,000 to 6,000 feet deep.
• 13:12
  SPEAKER_01: Amazing.
• 13:13
  SPEAKER_01: So, in other words, and you just alluded to it, it means it's about a vertical mile.
• 13:18
  SPEAKER_01: And I I want to just say, like, I'm looking outside right now, outside my window at my house, and it's kind of cloudy, and this is, you know, in New York, it's it's cloudy season as well.
• 13:27
  SPEAKER_01: Basically, on any given day, if you look out and up at the clouds, they're about a mile high.
• 13:33
  SPEAKER_01: And so that's what we're talking about from the rim of the canyon down to where the river is, is about the same difference as how high the clouds are.
• 13:43
  SPEAKER_01: Does that make sense?
• 13:45
  SPEAKER_00: It works, Chris.
• 13:46
  SPEAKER_00: It's about four Empire State Buildings stacked bottom to top.
• 13:50
  SPEAKER_01: Yeah, all right.
• 13:51
  SPEAKER_00: If we want to put it in New York terms, um, you know, it it's a lot.
• 13:55
  SPEAKER_00: This is tall, this is deep, and it's stunning to sort of look at.
• 13:59
  SPEAKER_00: And I don't think it's at all obvious that it's a mile deep when you're looking there, just because the scale of the canyon is huge.
• 14:05
  SPEAKER_01: And you know, you and I have both been here.
• 14:07
  SPEAKER_01: I've been down to the very, very bottom of the canyon, and where we started at the rim and walked our way all the way down, me and my my wife and my two kids, and it was awesome.
• 14:16
  SPEAKER_01: We spent four days down in the bottom of the canyon.
• 14:19
  SPEAKER_01: It's so different when you talk about that.
• 14:21
  SPEAKER_01: You know, what is it like to be a mile apart, right?
• 14:25
  SPEAKER_01: Of the bottom of the canyon versus the top.
• 14:27
  SPEAKER_01: You have two totally different climates going on there.
• 14:31
  SPEAKER_01: And the bottom of the canyon in the summertime is scorching hot.
• 14:35
  SPEAKER_01: I mean, it's brutal.
• 14:36
  SPEAKER_01: It can be 120 degrees, but on the rim, it can be a very pleasant 80 degrees on that same day.
• 14:44
  SPEAKER_01: It's like it's it's almost two different worlds.
• 14:47
  SPEAKER_00: And we touched on this in the in our book on the Camp Gio app is that native peoples would use this difference in climate seasonally, right?
• 14:54
  SPEAKER_00: So in the winter, you'd want to go down into the canyon, you'd stay warmer down there.
• 14:58
  SPEAKER_00: In the summertime, you'd move up to the rim where it's cooler.
• 15:00
  SPEAKER_00: And I think also, Chris, it's important to point out when you're down in the bottom of the canyon, a mile is a long way to walk back up.
• 15:08
  SPEAKER_00: You know, like that's a serious hiking endeavor to go up a vertical mile.
• 15:12
  SPEAKER_01: It absolutely is.
• 15:14
  SPEAKER_00: So just to reiterate, you know, the rim of the canyon, seven to nine thousand feet above sea level, the canyon is over a mile deep from there.
• 15:21
  SPEAKER_00: So the Grand Canyon, the river at the bottom of the Grand Canyon is not yet at sea level, so it's still hungry and it's still cutting.
• 15:28
  SPEAKER_00: All right.
• 15:29
  SPEAKER_00: So, Jesse, let's move on to the next question.
• 15:32
  SPEAKER_01: And this one is interesting, and this is, I think, what everybody sees when you go to the Grand Canyon.
• 15:37
  SPEAKER_01: The question is why are the rocks orange, red, and black?
• 15:40
  SPEAKER_01: And then how were the rocks made?
• 15:42
  SPEAKER_01: I think I combined the two into there.
• 15:44
  SPEAKER_01: How were the rocks made?
• 15:45
  SPEAKER_00: Two different questions.
• 15:46
  SPEAKER_00: They're they're intimately related.
• 15:47
  SPEAKER_01: They are though, they're intimately related.
• 15:49
  SPEAKER_01: So let's go ahead.
• 15:50
  SPEAKER_01: Let's start off, Jesse, with talking about the rocks that we see.
• 15:54
  SPEAKER_01: I think we have to start with that, right?
• 15:55
  SPEAKER_01: What are the rocks there?
• 15:56
  SPEAKER_01: How are they made?
• 15:57
  SPEAKER_01: Then we'll talk about the colors because I think that's the only order that makes sense in tackling this kind of question.
• 16:02
  SPEAKER_00: No, I agree with you, Chris.
• 16:03
  SPEAKER_00: And the color is to sort of level set here.
• 16:06
  SPEAKER_00: Color is a there's a bunch of different rocks that have very different formations that have the same color.
• 16:12
  SPEAKER_00: So there are a lot of ways to form a black rock.
• 16:15
  SPEAKER_00: And so black rocks don't mean that it's you know formed one way.
• 16:18
  SPEAKER_00: There are three types of rocks really generally in geology.
• 16:23
  SPEAKER_00: We have igneous, metamorphic, and sedimentary.
• 16:26
  SPEAKER_00: And in the Grand Canyon, we have all three of them.
• 16:29
  SPEAKER_00: The igneous and metamorphic ones, and this is really common on Earth, are deeper.
• 16:34
  SPEAKER_00: The ones right down at the bottom of the canyon, right down at the river level, are igneous and metamorphic.
• 16:39
  SPEAKER_00: So igneous is a category that means they came from lava or magma.
• 16:44
  SPEAKER_00: They crystallized from liquid rocks.
• 16:47
  SPEAKER_00: We had a magma that was molten rock and it cooled and crystallized into form an igneous rock.
• 16:53
  SPEAKER_01: If you look at the word igneous, it's very similar to the word ignite.
• 16:58
  SPEAKER_01: And you you associate ignite with fire, right?
• 17:00
  SPEAKER_01: And igneous rocks then are thought of as born of fire.
• 17:04
  SPEAKER_01: And so we're talking, like you said, red lava, red magma.
• 17:08
  SPEAKER_00: Important to point out though, we think of lava as like red.
• 17:11
  SPEAKER_00: When it cools, it usually forms either black or tan or gray, sometimes a little bit reddish, but it forms rocks that are not red.
• 17:20
  SPEAKER_00: And in the Grand Canyon, the igneous rocks that we have are either some of them are reddish and some of them are blackish, but they're all down at the bottom of the canyon.
• 17:29
  SPEAKER_00: So the igneous rocks are magma that intruded in, it kind of shoved its way, you describe it, Chris, as shouldering its way through the rocks in the earth, and then it kind of gets frozen in place.
• 17:41
  SPEAKER_00: And that's what we look at from the igneous side.
• 17:44
  SPEAKER_01: Alright, Jesse, the metamorphic rocks that we see, they only occur again down in the deepest parts of the canyon.
• 17:51
  SPEAKER_01: So in order to get up close and personal with these, you have to actually go from the rim down to the bottom at river level to see these metamorphic rocks.
• 18:00
  SPEAKER_01: But metamorphic rocks, the word meta means change, and morph means shape or form.
• 18:08
  SPEAKER_01: And so these are changed rocks.
• 18:11
  SPEAKER_01: In other words, they were a rock that existed, and then stuff happened to it.
• 18:16
  SPEAKER_01: It got subjected to geologic stuff, right?
• 18:19
  SPEAKER_01: And heat and pressure, which changed the rock, it altered the rock.
• 18:25
  SPEAKER_01: And so you and I often refer to them as metamorphic rocks are tortured because they kind of to us, they look like it, right?
• 18:33
  SPEAKER_01: Can you describe that?
• 18:34
  SPEAKER_01: What is that when we talk about a tortured rock?
• 18:36
  SPEAKER_01: What do we mean?
• 18:37
  SPEAKER_00: Yeah, it's taking a rock and heating it up and squeezing it and putting it under pressure.
• 18:43
  SPEAKER_00: So when you heat rock up, it can become a little bit like Chris, you described as hot plastic.
• 18:50
  SPEAKER_00: It can kind of flow.
• 18:51
  SPEAKER_00: It's like putty.
• 18:52
  SPEAKER_00: If you squeeze it, it'll flow out through your fingers.
• 18:56
  SPEAKER_00: And that's kind of what happens.
• 18:57
  SPEAKER_00: And you can imagine, like toothpaste, when you push it out of the tube, if you have that sort of classic striped toothpaste with like blue and white and green stripes in it, if you squeeze that, it'll change that banding.
• 19:08
  SPEAKER_00: That pattern, that sort of banding pattern will kind of flow in whichever way you want it to, or whichever way you squeeze it.
• 19:14
  SPEAKER_00: And so these rocks have what's called an internal fabric.
• 19:17
  SPEAKER_00: We can tell that they have been squished.
• 19:20
  SPEAKER_00: And in order to form that fabric, it has to be squished at high pressure, high temperature.
• 19:24
  SPEAKER_00: They also, this is super in the weeds, but they have minerals in them.
• 19:27
  SPEAKER_00: They have little garnets that we can use to calculate.
• 19:30
  SPEAKER_01: Here we go.
• 19:31
  SPEAKER_01: He can't help himself.
• 19:33
  SPEAKER_00: I can't help because it's cool, Chris.
• 19:34
  SPEAKER_00: This this stuff, these rocks were metamorphosed miles deep in the crust, very deep down in the earth.
• 19:40
  SPEAKER_00: So very deep down in the earth, and they got kind of buoyed up.
• 19:43
  SPEAKER_01: And the most common metamorphic rock that we see down there, that black colored rock with these kind of whiter and different colored toothpaste veins running through it, it's called a schist down there.
• 19:55
  SPEAKER_01: That's S-C-H-I-S-T, schist.
• 19:58
  SPEAKER_00: That's right.
• 19:59
  SPEAKER_00: And Chris, let me just the the colors.
• 20:00
  SPEAKER_00: So we talked about the igneous rocks can be red or black, depending on if it's a basalt, the black one, or if it's a granite, the red, reddish kind of one.
• 20:09
  SPEAKER_00: The schist is usually pretty dark colored.
• 20:11
  SPEAKER_00: It can be dark colored with little white streaks in it.
• 20:13
  SPEAKER_00: It'll be kind of banded, a little bit banded.
• 20:15
  SPEAKER_00: That's what you think of, but generally dark colored.
• 20:18
  SPEAKER_00: Now we're gonna move into the sediment layers because above that we have this huge package of sedimentary rocks, very flat lying.
• 20:26
  SPEAKER_00: The ones when you look at the Grand Canyon, it looks like horizontal stripes.
• 20:29
  SPEAKER_00: These are all sedimentary rocks, which is the third category of rocks, and sediments are formed by water.
• 20:37
  SPEAKER_00: Water depositing stuff out of it.
• 20:39
  SPEAKER_00: And there's kind of a couple different categories, but generally these things are being deposited by water in an ocean.
• 20:45
  SPEAKER_00: So an ocean is dumping sediment out, and that stuff's being compacted and then forming rock from it.
• 20:51
  SPEAKER_00: And these have massive color variation.
• 20:53
  SPEAKER_00: The sediments are just I don't particularly love sediments to study, but they make the Grand Canyon spectacular, the sedimentary rocks.
• 21:00
  SPEAKER_01: Yeah, Jesse, you can't say that anymore.
• 21:02
  SPEAKER_01: Come on, with all the stuff that we've done with the Grand Canyon, you're not allowed to say that you don't love sedimentary rocks, right?
• 21:09
  SPEAKER_01: Okay, fair enough.
• 21:10
  SPEAKER_01: Fair enough.
• 21:11
  SPEAKER_01: Nope.
• 21:11
  SPEAKER_01: I'm calling you out on it.
• 21:13
  SPEAKER_01: Look, they look different.
• 21:15
  SPEAKER_01: Sedimentary rocks look different from the other two that we've already described.
• 21:18
  SPEAKER_01: I mean, I always say that it's kind of simple and kind of dumb, but you know what?
• 21:22
  SPEAKER_01: If it looks like dirt, tastes like dirt, it's because it's dirt.
• 21:25
  SPEAKER_01: That's right.
• 21:26
  SPEAKER_01: Sedimentary rocks are made of this loose sediment that got compacted together.
• 21:31
  SPEAKER_00: That's a great way to put it, Chris, because these rocks, they're not as well put together as the ignison metamorphic ones.
• 21:35
  SPEAKER_00: They're easier to break apart.
• 21:36
  SPEAKER_00: And there are some that are harder to break apart, some that are really easy to break apart.
• 21:40
  SPEAKER_00: So that's why we get the cliffs and then we get slopes, and they kind of occur in patterns across the canyon.
• 21:46
  SPEAKER_00: But these have a ton of color variation, and in general, the color variation comes from the amount of iron in the rock.
• 21:54
  SPEAKER_00: And the way to think about this is rusting.
• 21:57
  SPEAKER_00: When something rusts, we think of rust turning red, which you Have a steel plate and it gets rusty, or a steel utensil gets rusty, it turns kind of a dark reddish, right?
• 22:06
  SPEAKER_00: The same thing will happen in rock.
• 22:08
  SPEAKER_00: And it doesn't take a lot of iron in the rock to form this rusty color, to kind of have this iron staining to it.
• 22:15
  SPEAKER_01: That's right.
• 22:15
  SPEAKER_01: It's shocking.
• 22:16
  SPEAKER_01: I mean, not very much iron at all is just as little as 3% iron in the rock can make the whole rock be stained a different color.
• 22:26
  SPEAKER_00: That's right.
• 22:27
  SPEAKER_00: And so the white rocks typically have no iron in them.
• 22:31
  SPEAKER_00: Some of the ones at the top of the canyon typically have no iron in them.
• 22:34
  SPEAKER_00: The sort of the greenish to grayish rocks will have iron in it, but it will not be rusted.
• 22:39
  SPEAKER_00: It's kind of unrusted iron if you think of it that way.
• 22:42
  SPEAKER_00: That's kind of the green rocks there.
• 22:45
  SPEAKER_00: And then orange is a little bit rusted, and red is very rusted.
• 22:49
  SPEAKER_00: You can kind of think of it, or different types of rusting, different types of rusting reactions, I guess.
• 22:54
  SPEAKER_01: I am so proud of you right now.
• 22:55
  SPEAKER_01: I am proud of you, Jesse.
• 22:57
  SPEAKER_01: Again, you you really took your geochemistry, funny little brain over there, and you you kept it.
• 23:04
  SPEAKER_01: I love it.
• 23:05
  SPEAKER_01: That was awesome.
• 23:06
  SPEAKER_01: Well put.
• 23:07
  SPEAKER_01: Real quick, Jesse, something that an analogy or something that they might be able to tie into in terms of iron staining a rock, right?
• 23:15
  SPEAKER_01: Walking down the sidewalk, we often see these brown stains in a sidewalk.
• 23:21
  SPEAKER_01: They resemble the kind of the way a comet looks, if you will.
• 23:24
  SPEAKER_01: You know, you got the the head of the comet and this like tail that streaks away.
• 23:28
  SPEAKER_01: We see these all over the place in roads and sidewalks.
• 23:32
  SPEAKER_01: And that's a perfect example of iron staining a rock because those brown streaks that we see on a sidewalk, that's from an iron-bearing mineral that is a part of the material that makes up the concrete or the asphalt, right?
• 23:49
  SPEAKER_01: So that little tiny bit can bleed into a much larger part of the sidewalk.
• 23:56
  SPEAKER_01: And that's really what happens with this kind of iron staining that we see all over the place, and that makes the Grand Canyon so absolutely beautiful.
• 24:06
  SPEAKER_01: A big part of it is the colors.
• 24:07
  SPEAKER_01: So beautiful.
• 24:08
  SPEAKER_00: I mean, these sort of pastel reds and oranges and whites and grays and greens.
• 24:12
  SPEAKER_00: I so beautiful.
• 24:13
  SPEAKER_00: So that's a great analogy, Chris.
• 24:15
  SPEAKER_00: I I like that one, and it's kind of really drives it home that it's mostly about iron that's going on in the that's giving the color to these rocks.
• 24:22
  SPEAKER_00: So, Chris, the next question here is why is the Grand Canyon so steep?
• 24:28
  SPEAKER_00: And uh there's kind of two parts to this.
• 24:30
  SPEAKER_00: Let me take the first one, Chris, and then you maybe you could take the second one.
• 24:33
  SPEAKER_00: The first one is fairly simple.
• 24:35
  SPEAKER_00: We've talked about it before.
• 24:36
  SPEAKER_00: The river's hungry, and as we said before, a hungry river is one that's like way above sea level, so it wants to cut down, it's really wanting to cut down.
• 24:44
  SPEAKER_00: And so if a river's hungry, it cuts down first before it starts cutting like out side to side.
• 24:51
  SPEAKER_00: So it cuts down first, which kind of makes steep sides.
• 24:54
  SPEAKER_00: If you kind of envision, I guess the way to think about this is you if you cut down, the only way the sides are going to move is if they kind of collapse in on themselves, and all those sediments in the Grand Canyon, they form cliffs.
• 25:06
  SPEAKER_00: So we end up having a really steep-sided canyon when we have a hungry river, because the river's cutting straight down.
• 25:12
  SPEAKER_00: Think of a mountain valley stream, it cuts straight down, which means you have really steep sides to it.
• 25:17
  SPEAKER_01: There's a common saying with the Grand Canyon.
• 25:20
  SPEAKER_01: The saying goes like this Old rocks, young canyon.
• 25:24
  SPEAKER_01: And when you have a hungry river that hasn't been downcutting for very long, now geologically, it hasn't been very long.
• 25:33
  SPEAKER_01: From a human standpoint, it's been going on for a long time, but we'll touch on that as we wrap this episode up.
• 25:39
  SPEAKER_01: But the canyon is young, and if you were to come back to the Grand Canyon in a million years, it would look really different than it does today.
• 25:50
  SPEAKER_01: It would be much, much wider.
• 25:52
  SPEAKER_01: And I think actually, Jesse, probably less impressive.
• 25:55
  SPEAKER_01: I think one of the things that makes the canyon so beautiful is the fact that it is very steep from this aggressive, actively down cutting, hungry river, right?
• 26:06
  SPEAKER_01: But now that the river is getting closer to sea level, it's beginning to change its dynamics a bit.
• 26:13
  SPEAKER_01: And what that means is now it's also going side to side more than it has in geologic past.
• 26:19
  SPEAKER_01: And so as the river goes side to side, it's undercutting other rocks.
• 26:24
  SPEAKER_01: So what you have then, what this creates, is what's called rock fall, which is a very common occurrence.
• 26:31
  SPEAKER_00: Let me just describe it in an analogy here.
• 26:33
  SPEAKER_00: Like you go to the beach and you know you're making a sandcastle, let's say, and the water is kind of coming up.
• 26:39
  SPEAKER_00: You build it right on the edge, and as the tide moves in and out, the water starts coming up and kind of hitting your sandcastle a little bit.
• 26:44
  SPEAKER_00: But it's calm day, so the waves aren't crashing into it.
• 26:48
  SPEAKER_00: They're just kind of lapping the edge of your sandcastle.
• 26:50
  SPEAKER_00: The water is gonna hit the base of your sand castle and it's gonna start to move some of the sand from the bottom, the sort of bottom edge of the wall of your sandcastle, which means it's gonna erode right there.
• 27:02
  SPEAKER_00: And then you get to a point where the wall of your sandcastle, the top, you have like some turret, let's say you've got like a nice turret up top, it's gonna be unsupported because the bottom has been eroded out from underneath of it and it's gonna collapse down, and then the water can start to erode that collapsed material and start to eat away at that collapsed material.
• 27:21
  SPEAKER_00: Is that a good analogy for the process that we're kind of?
• 27:23
  SPEAKER_01: That's a really good analogy.
• 27:24
  SPEAKER_01: That was worthy of an interruption, Jesse.
• 27:26
  SPEAKER_01: Nice done, nicely, nicely done.
• 27:29
  SPEAKER_00: No, absolutely right.
• 27:30
  SPEAKER_00: And that was a good way to phrase it, Chris.
• 27:32
  SPEAKER_00: Worthy of an interruption.
• 27:34
  SPEAKER_00: You have to have something very important to say to interrupt Chris Police.
• 27:37
  SPEAKER_01: You better, you better.
• 27:39
  SPEAKER_01: Um, so when that collapse happens in the Grand Canyon, it's called a rock fall.
• 27:45
  SPEAKER_01: And these are spectacular things to witness and to hear because it's just this loud, thunderous, crashing, horrifying yet awesome event if you're fortunate enough to you know to witness one of these things.
• 28:00
  SPEAKER_01: But and when that happens, then it results in the canyon becoming just a little bit wider, right?
• 28:05
  SPEAKER_01: So over geologic time, it's gonna get wider and wider and wider and a little bit deeper.
• 28:11
  SPEAKER_01: So it's widening now more than it's deepening, if that makes sense.
• 28:15
  SPEAKER_00: You know, the river's getting less and less hungry, less and less hungry, and so it's cutting out instead of cutting down.
• 28:21
  SPEAKER_00: So it starts as it gets less and less hungry, it starts to cut out a little bit more.
• 28:24
  SPEAKER_01: So right now, Jesse, you can stand on the south rim of the Grand Canyon and you can pretty easily see across the canyon to the north rim, to the other side of the plateau.
• 28:35
  SPEAKER_01: Come back in a million years, and you probably will not be able to see across from one rim to another.
• 28:40
  SPEAKER_01: It'll widen that much.
• 28:42
  SPEAKER_00: It is gonna widen a lot.
• 28:44
  SPEAKER_00: Which brings us very nicely, I think, Chris.
• 28:47
  SPEAKER_00: We're starting to talk about time, to really the last question here, which is how old is each layer of the Grand Canyon?
• 28:54
  SPEAKER_00: And I think I wanna, as a way in, as a way to describe this, Chris, you have a really nice analogy or nice visual for this.
• 29:01
  SPEAKER_00: But before we get to that, I want to come back to our question about the rock colors and talk about the different packages of rocks that we have, because we talked about how the igneous and metamorphic rocks, the really hard rocks, are down at the bottom of the canyon, really far down there, near the river level.
• 29:16
  SPEAKER_00: So that's kind of one package.
• 29:17
  SPEAKER_00: We're gonna talk about the igneous and metamorphic rocks, what we call the quote unquote basement, way down at the river level.
• 29:23
  SPEAKER_00: There's another package of rocks of sediments, and these are tilted sediments.
• 29:27
  SPEAKER_00: They're sitting right on top of the igneous and metamorphic rocks, but they're below the main sequence of rocks.
• 29:33
  SPEAKER_00: So they're kind of in the middle there.
• 29:35
  SPEAKER_00: They're sort of sandwiched in the middle.
• 29:37
  SPEAKER_00: And then the third package of flat-lying sedimentary rocks is what you see from the rim, the sort of rim of the canyon.
• 29:45
  SPEAKER_00: You can kind of see all the way down to what's called the Tonto platform, this sort of big platform that you can easily see that kind of hides the river when you're looking down at so most of what you see in the Grand Canyon is this last package of rocks, but there's three in there, and you can see all three of them just depending on where you're standing.
• 30:03
  SPEAKER_01: We can't talk about the ages, or at least we we could, but it wouldn't be really appropriate here to talk about the age of each rock layer because there are over a hundred different named, well-known rock layers that come that make up the Grand Canyon.
• 30:19
  SPEAKER_01: So you're dividing it into three categories instead.
• 30:23
  SPEAKER_00: And let me interrupt real quick, Chris, there, because this uh this is an important point.
• 30:27
  SPEAKER_00: This is really complicated.
• 30:28
  SPEAKER_00: We are oversimplifying this, and there's a lot of really interesting unanswered questions about the Grand Canyon and about these rocks.
• 30:34
  SPEAKER_00: It's you could spend a long time studying the Grand Canyon.
• 30:37
  SPEAKER_00: There's a lot of detail in the Grand Canyon geological story that we're not talking about.
• 30:42
  SPEAKER_00: So I I think that's inspiring.
• 30:44
  SPEAKER_00: Like I think that's inspiring, especially for students, to be like, whoa, there's more to learn here.
• 30:48
  SPEAKER_00: And I just wanted to double-click on that and say there's a lot more to learn here.
• 30:51
  SPEAKER_01: So, in order to do this though, Jesse, I think we need to talk about age a little bit.
• 30:56
  SPEAKER_01: It's always fun.
• 30:57
  SPEAKER_01: I don't care where you are, if you're listening to this, where you are in your geologic background, whether you have a really deep background or whether you have almost no background, trying to wrap your mind around geologic time is a fun exercise, I think, for everybody.
• 31:14
  SPEAKER_01: Because it's fun and hard.
• 31:16
  SPEAKER_01: Yeah, it is.
• 31:17
  SPEAKER_01: It's nearly impossible to comprehend.
• 31:19
  SPEAKER_01: So here are some analogies.
• 31:21
  SPEAKER_01: Let's should we do that?
• 31:22
  SPEAKER_01: Should we go through some of these?
• 31:23
  SPEAKER_00: Chris, I love I love this analogy you've got.
• 31:26
  SPEAKER_00: So yes, take it away.
• 31:27
  SPEAKER_01: Okay.
• 31:28
  SPEAKER_01: Geologically, the earth is 4.54 billion years old, which is a number that is very difficult to comprehend.
• 31:35
  SPEAKER_01: So let's first talk about a million, because to me, I have a hard time with a million, and we throw a million around it all the time in geology, right?
• 31:43
  SPEAKER_01: I just did it.
• 31:44
  SPEAKER_01: I said, hey, come back to the Grand Canyon in a million years, and it's gonna look really different than it does right now.
• 31:50
  SPEAKER_01: Yeah, casual.
• 31:51
  SPEAKER_01: Yeah, that's a million.
• 31:52
  SPEAKER_01: I'm chucking that around like no big deal, right?
• 31:55
  SPEAKER_01: Well, so let's let's try to like do this a little bit.
• 31:58
  SPEAKER_01: I have just one analogy.
• 32:00
  SPEAKER_01: I've a million.
• 32:01
  SPEAKER_01: If you were to count to a million, counting once per second with no breaks at all, no naps, you don't go to sleep or anything like that, it would take you 11 days and 14 hours to count to a million.
• 32:16
  SPEAKER_01: That's that's incredible, right?
• 32:17
  SPEAKER_01: It's a long time.
• 32:19
  SPEAKER_01: Counting to a billion would take you the same way, no breaks, one every single second, no naps.
• 32:28
  SPEAKER_01: It would take you 32 years to count to a billion.
• 32:32
  SPEAKER_01: Amazing.
• 32:33
  SPEAKER_01: Just amazing.
• 32:34
  SPEAKER_01: No human, Jesse, not even you, and you like to think of yourself as superhuman sometimes, not even you could count to four point five four billion years.
• 32:47
  SPEAKER_01: You couldn't do this because you're not gonna live to be 147 years old, which is how long it would take you.
• 32:53
  SPEAKER_01: 147 years to count to 4.54.
• 32:58
  SPEAKER_00: Amazing.
• 32:58
  SPEAKER_00: Chris, I just want to I just want to reiterate that, restate that because it it really nicely shows the difference between a million and what are you restating that you think you're superhuman?
• 33:06
  SPEAKER_01: Is that what you're restating?
• 33:08
  SPEAKER_00: Yeah, yes, that part, exactly.
• 33:09
  SPEAKER_00: Uh so just so everybody knows, uh no, counting to a million would take 11 days and 14 hours.
• 33:16
  SPEAKER_00: That's okay, we can conceive of that, a couple weeks.
• 33:18
  SPEAKER_00: Counting to a billion would take you 32 years.
• 33:20
  SPEAKER_00: I think that really highlights the difference between a million and a billion very, very nicely.
• 33:25
  SPEAKER_00: I like that one a lot.
• 33:26
  SPEAKER_00: And Chris, I just want to say this is a really hard thing for everybody to comprehend.
• 33:31
  SPEAKER_00: Like even practiced, seasoned geologists like ourselves, we throw these words around a lot, but actually comprehending it is still very hard, at least for me personally.
• 33:41
  SPEAKER_01: Yeah.
• 33:41
  SPEAKER_01: And there are so many cool things that you can do with this.
• 33:45
  SPEAKER_01: You know, like all right, you can string how many paper clips around the you know, 4.54 billion paper clips, how many times would they wrap around the earth?
• 33:53
  SPEAKER_01: And you know, you can do all these calculations.
• 33:56
  SPEAKER_01: There are so many very cool exercises that you can do in education to to mimic what geologic time looks like and how vast it is.
• 34:06
  SPEAKER_01: Like you said, it I don't care where you are in your geologic background, doing this is always fun and I think a valuable exercise.
• 34:14
  SPEAKER_00: Absolutely, absolutely.
• 34:15
  SPEAKER_00: Okay, so how old then, Chris?
• 34:18
  SPEAKER_00: We've kind of thought about deep time, what the these big numbers mean.
• 34:21
  SPEAKER_00: Let's frame it in how old each layer is.
• 34:24
  SPEAKER_00: Let's go back to the three rock layers again.
• 34:26
  SPEAKER_00: The the old stuff at the bottom, young stuff on top.
• 34:28
  SPEAKER_00: Frame this for us.
• 34:29
  SPEAKER_00: How do we think about this?
• 34:31
  SPEAKER_01: So the oldest suite of rocks, what you termed the basement rocks, and I just I it's a term that we use in geology all the time, and I love it because I think it just makes sense.
• 34:39
  SPEAKER_01: These are the bottom bedrock, hard rock stuff, right?
• 34:44
  SPEAKER_01: These basement rocks in the Grand Canyon are 1.84 to 1.66 billion years old.
• 34:52
  SPEAKER_01: Now, again, so Jesse, should we like do the our our year thing?
• 34:58
  SPEAKER_00: Yeah, I like this, Chris.
• 34:59
  SPEAKER_00: Let me just let so you said 1.84 to 1.66, and the earth is 4.54 billion years old, 4.56 billion years old.
• 35:09
  SPEAKER_00: If we think of Earth time as a year, so January 1, Earth started, and December 31 is yeah.
• 35:18
  SPEAKER_01: At 1159 and 59 seconds.
• 35:20
  SPEAKER_01: Exactly.
• 35:21
  SPEAKER_00: Is today if we think of the Earth time as one single year, where does 1.84 and 1.66 billion fall in a calendar year of Earth history?
• 35:31
  SPEAKER_01: Yeah, that would be from August 6 to August 21, if you think about it that way.
• 35:39
  SPEAKER_01: So that means that there isn't a record of January, February, March, all the way into August.
• 35:47
  SPEAKER_01: There's no record of rocks in the Grand Canyon for that whole part of the year.
• 35:53
  SPEAKER_00: They're not there.
• 35:54
  SPEAKER_00: And this is a good little lesson to pay attention to here.
• 35:57
  SPEAKER_00: There's a lot of missing time.
• 35:58
  SPEAKER_00: There's a lot of missing time in the Grand Canyon.
• 35:59
  SPEAKER_00: There's a lot of rocks, there's a lot of beautiful record preserved, but there's a lot missing as well.
• 36:04
  SPEAKER_00: So that's the oldest suite, right?
• 36:06
  SPEAKER_00: August 6, August 21, that's 1.8 to 1.6 billion years ago.
• 36:11
  SPEAKER_00: This layer of tilted rocks, the second series, these are sedimentary rocks, what's called the Grand Canyon Supergroup.
• 36:17
  SPEAKER_00: These are 1.1 billion years, 1.2 billion years, and then it also, there's some that are 800 million years old.
• 36:24
  SPEAKER_00: So right around, we're kind of closer to a billion years.
• 36:27
  SPEAKER_00: And this on our calendar year is end of September to early October, and then end of October to early November.
• 36:35
  SPEAKER_00: So we're kind of we're in the fall season here, you know, September 22 to October 4, and then again October 28 to November 2.
• 36:42
  SPEAKER_00: Okay, so Chris, that's layer one and two.
• 36:46
  SPEAKER_00: What about the big stuff?
• 36:47
  SPEAKER_00: I mean, the stuff that dominates the really spectacular rocks of the Grand Canyon.
• 36:51
  SPEAKER_00: Where are those on our geologic clock?
• 36:53
  SPEAKER_01: Yeah, they're it's called the Paleozoic strata.
• 36:56
  SPEAKER_01: It's what everybody sees when you go to the Grand Canyon, and you know, geologically, the numbers on them are a little over 500 million years old to 270 million years old.
• 37:07
  SPEAKER_01: And a calendar year, that's November 19 to like December 9.
• 37:13
  SPEAKER_00: So this is relatively recently compared to you know the start of Earth.
• 37:16
  SPEAKER_00: It's crazy.
• 37:17
  SPEAKER_01: It's not even a month, Jesse.
• 37:19
  SPEAKER_01: The this vast volume of rocks and a year timeline doesn't really seem like a lot.
• 37:25
  SPEAKER_01: You know, it's it's shocking.
• 37:26
  SPEAKER_00: Crazy, crazy.
• 37:27
  SPEAKER_00: So those are a few hundred million years old, and there are some rocks, they're relatively minor, and you're not going to see them unless you head to the western part of the Grand Canyon.
• 37:36
  SPEAKER_00: But you see them on the drive to the Grand Canyon, or if you're kind of in that region, there are young volcanic rocks that are a few hundred thousand years old.
• 37:45
  SPEAKER_00: And so these would be, I don't know the calculation, these are like end of December type rocks, like you know, the last day of December.
• 37:52
  SPEAKER_01: These would be New Year's Eve, yes, exactly.
• 37:55
  SPEAKER_00: Right.
• 37:55
  SPEAKER_00: Um, so these are pretty young in geologic terms, a couple hundred thousand years old, but you're not going to see a lot of those.
• 38:02
  SPEAKER_00: The bulk of the Grand Canyon is that August 6 to August 21, then end of September, basically to early November, and then another series from November 19 to December 9.
• 38:12
  SPEAKER_00: That's kind of the big bulk of the rocks that you see if you're standing on the rim.
• 38:17
  SPEAKER_01: So, Jesse, before we wrap this up, and we're getting a little bit long in the tooth here, but there was one question that they didn't ask that we can just touch on real quick, which is how exactly did the Grand Canyon get cut?
• 38:28
  SPEAKER_01: Because this is a we devoted almost an entire chapter to this in the in our audio visual book of the Grand Canyon.
• 38:35
  SPEAKER_01: And the reason why this is a big deal is what, Jesse?
• 38:39
  SPEAKER_00: And this this bothers me, and I get on you about it sometimes, but you know, like what's it bothers you and it it uh excites me, and I think it it should excite students, I think, is that we don't know the answer to that.
• 38:50
  SPEAKER_00: Like, really, okay, the river's hungry, but how did it get so hungry?
• 38:54
  SPEAKER_00: How did it do the cutting?
• 38:55
  SPEAKER_00: Like, we don't actually understand that as a scientific community, so there's more yet to discover, which I think should be inspiring to people who are in classes are asking really good questions.
• 39:08
  SPEAKER_00: So, this this class, the fourth grade class at Bronx Little School, signed their letter, The Epic Earthlings.
• 39:13
  SPEAKER_00: And so the Epic Earthlings, great questions, really well-written letter to us, and there's more to learn.
• 39:19
  SPEAKER_00: So keep asking questions.
• 39:21
  SPEAKER_01: Hey, you know what?
• 39:21
  SPEAKER_01: Maybe one of them will figure out how the Grand Canyon got cut.
• 39:26
  SPEAKER_01: That's the moral of your story right there.
• 39:28
  SPEAKER_00: Exactly.
• 39:29
  SPEAKER_00: It it's I I think it should be thought of as inspiring that there's more to learn about the Grand Canyon, which we know a lot about already.
• 39:37
  SPEAKER_00: So I don't know, Chris.
• 39:39
  SPEAKER_00: Uh that was fun.
• 39:40
  SPEAKER_00: That was good.
• 39:40
  SPEAKER_00: And if you know, we stayed out of the weeds.
• 39:42
  SPEAKER_00: I think we did a pretty good job.
• 39:43
  SPEAKER_00: If you want more of the weeds, you can go to our Camp Geo app and you can get access to our Grand Canyon audiobook, which is the full geologic story of the Grand Canyon and in like 10 chapters with all the images you need.
• 39:54
  SPEAKER_00: If you want to send us an email, if you have more questions on this, please send us an email planetegeocast at gmail.com.
• 40:00
  SPEAKER_00: You can hit us up on all the social medias.
• 40:02
  SPEAKER_00: We're at Planet Geocast, and you can head to our website, planetgeocast.com.
• 40:06
  SPEAKER_00: Cheers.
• 40:07
  SPEAKER_00: Thanks for the questions.
• 40:08
  SPEAKER_00: Peace.