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Home Away From Home - The Grand Tetons · PlanetGeo: The Geology Podcast

• 0:02
  SPEAKER_01: Welcome to Planet Geo, the podcast where we talk about our managing planet, how it works, and why it matters to you.
• 0:13
  SPEAKER_01: Do I have your approval to get hit record here?
• 0:16
  SPEAKER_03: Oh, so now you're back to asking me what I think.
• 0:19
  SPEAKER_03: I don't know.
• 0:19
  SPEAKER_03: What is happening right now?
• 0:21
  SPEAKER_01: Every once in a while.
• 0:22
  SPEAKER_03: Usually you just tell me what to do, and then I just I reluctantly do it.
• 0:26
  SPEAKER_01: There's a phrase, Chris, that comes to mind which is throw the dog a bone.
• 0:29
  SPEAKER_01: And I'm throwing you a bone right now.
• 0:33
  SPEAKER_03: Keep him happy.
• 0:33
  SPEAKER_03: You're a benevolent dictator.
• 0:35
  SPEAKER_01: That I am.
• 0:36
  SPEAKER_01: I am benevolent and a dictator.
• 0:39
  SPEAKER_01: That's exactly right.
• 0:40
  SPEAKER_01: Very, very good description.
• 0:44
  SPEAKER_03: Oh if you get cranky, Chris, then you know you're not being benevolent.
• 0:49
  SPEAKER_03: That's right.
• 0:49
  SPEAKER_03: I need to throw them a bone.
• 0:51
  SPEAKER_01: And uh, you know, give them give them the feeling of control, and then it's all good.
• 0:57
  unknown: Yeah.
• 0:58
  SPEAKER_03: Hey, do we have video going on this too?
• 1:00
  SPEAKER_01: We got video going on.
• 1:01
  SPEAKER_01: Yep.
• 1:01
  SPEAKER_03: Good, because I got my nice shirt on.
• 1:02
  SPEAKER_03: You see, you didn't even give me nothing.
• 1:04
  SPEAKER_03: I got nothing.
• 1:05
  SPEAKER_01: It that looks like it's got the uh the little opal buttons on it or uh the little uh fancy.
• 1:11
  SPEAKER_01: It does that's your fancy going out shirt.
• 1:13
  SPEAKER_03: It is, it's my did up shirt.
• 1:15
  SPEAKER_03: Got it.
• 1:16
  SPEAKER_01: Chris is taking Jenny out to the bar.
• 1:19
  SPEAKER_03: Painting the town green.
• 1:21
  SPEAKER_01: Yeah.
• 1:22
  SPEAKER_01: Here we go.
• 1:23
  SPEAKER_01: That's right.
• 1:23
  SPEAKER_01: And then so Chris, I called you the other day.
• 1:25
  SPEAKER_01: Maybe even this was yesterday, I'm not sure which.
• 1:27
  SPEAKER_01: Called you at nine o'clock or something.
• 1:30
  SPEAKER_01: We were talking business, and uh then Jenny chimes in.
• 1:34
  SPEAKER_01: And then, you know, I'm putting two and two together here and realizing you're sitting on the couch next to your wife.
• 1:39
  SPEAKER_01: Uh, you're watching TV, so I just go, uh Chris, how's that bag of Doritos treating you?
• 1:44
  SPEAKER_01: And Jenny goes, Oh my goodness, how did you know?
• 1:49
  SPEAKER_01: I was laughing about that today when I woke up.
• 1:51
  SPEAKER_01: That was funny.
• 1:52
  SPEAKER_03: She was actually doing work, she was working on banging around on her keyboard, and you thought it was the crinkling of a Dorito bag.
• 1:58
  SPEAKER_01: But I wasn't wrong either.
• 2:00
  SPEAKER_01: You had just had some Doritos, right?
• 2:02
  SPEAKER_01: I did, yeah.
• 2:05
  SPEAKER_01: Chris and his Doritos.
• 2:06
  SPEAKER_01: So, okay, Segway Award nominee coming up here, Chris.
• 2:09
  SPEAKER_01: You ready for this one?
• 2:10
  SPEAKER_01: Yes.
• 2:11
  SPEAKER_01: Okay.
• 2:11
  SPEAKER_01: So the Bullheis household in Hudsonville, Michigan.
• 2:14
  SPEAKER_01: That's house number one of the Bull Heises.
• 2:16
  SPEAKER_01: Home number two for Chris Bullheis is hot tub.
• 2:20
  SPEAKER_01: Is his hot tub on his back deck.
• 2:22
  SPEAKER_01: House number three might be arguably Grand Teton National Park.
• 2:27
  SPEAKER_03: Yes.
• 2:28
  SPEAKER_03: I yes.
• 2:29
  SPEAKER_01: As far as places Chris Bullheis spends time, it's house, hot tub, Grand Teton National Park, probably in that order.
• 2:35
  SPEAKER_01: Ballpark, maybe.
• 2:37
  SPEAKER_01: I'm not too far off, right?
• 2:38
  SPEAKER_03: Yes.
• 2:39
  SPEAKER_03: I would really love it to be Grand Teton National Park number one, and then everything else follows after that.
• 2:44
  SPEAKER_03: But I just can't because I have to actually earn a living.
• 2:47
  SPEAKER_03: Yeah, you gotta work.
• 2:48
  SPEAKER_03: Yeah, I I've spent Jesse a ridiculous amount of time in Grand Teton's.
• 2:54
  SPEAKER_01: So you and um you and Jenny and well, your whole family actually, you guys have spent a lot of time there.
• 2:58
  SPEAKER_01: You'd go there during the summer science trip, obviously.
• 3:00
  SPEAKER_01: We talked about that before, but for a while, I mean you guys had like a series of what six straight years or something where your your like three or four-week family trip would be out to the Tetons, or at least in part the Tetons, and sometimes the most of it, yep, absolutely.
• 3:14
  SPEAKER_03: Yeah.
• 3:14
  SPEAKER_01: So tons of time in the Tetons, which made the lead up to this episode really fun, which we just finished recording and producing, and it's now published, a geology of the Grand Tetons audiobook with images on our Camp Geo apps.
• 3:28
  SPEAKER_01: You can go to the first link in your show notes, download the app.
• 3:32
  SPEAKER_01: The audiobook for the Grand Tetons, the geology of the Grand Tetons in 12 chapters is there now live.
• 3:38
  SPEAKER_01: And this was very fun to put together, Chris.
• 3:42
  SPEAKER_01: Um yeah, very fun.
• 3:44
  SPEAKER_01: And it's actually, I don't know, it's been a while.
• 3:45
  SPEAKER_01: We did a Planet Geo episode like a long time ago.
• 3:49
  SPEAKER_03: Ooh, this was a long time ago.
• 3:51
  SPEAKER_03: Absolutely.
• 3:52
  SPEAKER_03: Yeah.
• 3:52
  SPEAKER_03: This is season one, like early.
• 3:54
  SPEAKER_01: Yeah, back in the days where it's like painful to go back and listen to, to be honest with you.
• 3:58
  SPEAKER_01: Uh it's it's it's been a minute since we talked about the Tetons, really, which is kind of a shame, actually, I think, um, just because they're so near and dear to your heart and they're such spectacular geology, really.
• 4:09
  SPEAKER_03: You you said it.
• 4:10
  SPEAKER_03: I feel like we're stuck in a rut with the Tetons, but it's not I don't mean that in a bad way, and it kind of has a bad connotation.
• 4:17
  SPEAKER_03: I like the rut I'm stuck in.
• 4:19
  SPEAKER_03: I I never get tired of going back there.
• 4:23
  SPEAKER_03: And I don't know, I'm a little torn because you know how I love like diversity.
• 4:27
  SPEAKER_03: I I love new things and new experiences, but there's something also that's really comforting about familiarity.
• 4:35
  SPEAKER_03: Oh, totally.
• 4:36
  SPEAKER_03: I just I feel that way in the Tetons.
• 4:38
  SPEAKER_03: I feel like I'm at home, I really do.
• 4:41
  SPEAKER_03: Home away from home.
• 4:42
  SPEAKER_01: It's the bullheads home away from home.
• 4:44
  SPEAKER_01: Back in the day, you guys used to have that little uh trailer RV.
• 4:47
  SPEAKER_01: You'd go camping around places, but the Tetons are that now.
• 4:49
  SPEAKER_01: The Tetons are the home away from home for you guys.
• 4:52
  SPEAKER_01: The geology, Chris.
• 4:53
  SPEAKER_01: Maybe what we should do.
• 4:54
  SPEAKER_01: Let's do a quick overview of the geo.
• 4:57
  SPEAKER_01: So we have 12 chapters in the audiobook.
• 4:59
  SPEAKER_01: And so obviously, this is like a there's a lot of content, a lot of stuff, a lot of weedy, really cool, weedy geology to get into with this, I think, right?
• 5:09
  SPEAKER_03: So I was thinking about this today, actually, that I think we put this together for everybody in mind.
• 5:15
  SPEAKER_03: I I think unless you're one of just a few people walking, where you are a scientific expert on the formation and the geology, the geologic story, the Tetons, unless you're one of those few people out there, you're gonna get something out of what we've put together here.
• 5:32
  SPEAKER_03: But I think there's something for everybody here.
• 5:35
  SPEAKER_03: I think there's actually a lot for everybody here, whether you are just the casual, curious person that's gonna go on a family vacation there, or whether you have a degree in geology and you want to bone up on your Teton knowledge before you head that way, you're gonna get a lot out of this.
• 5:53
  SPEAKER_03: So it's not weedy, it's not out of the weeds.
• 5:56
  SPEAKER_03: It's I think we do a good blend of both.
• 6:00
  SPEAKER_03: There's just there's a lot here, but I think that the Tetons are worthy of that.
• 6:05
  SPEAKER_01: That's true.
• 6:06
  SPEAKER_01: That's very true.
• 6:07
  SPEAKER_01: It is, however, too much to get into in a single planet geopodcast episode.
• 6:12
  SPEAKER_01: So how how should we?
• 6:14
  SPEAKER_01: I don't know, how do we go through this?
• 6:16
  SPEAKER_01: What do we cover?
• 6:17
  SPEAKER_01: This is a hard thing.
• 6:18
  SPEAKER_01: Like how there's so many cool events, so much depth and detail and richness to this story, but we should do a quick five-minute overview of the geology of the Tetons, because then when we talk about our interests here and what we've learned, it'll add some context to that, right?
• 6:31
  SPEAKER_03: Yeah, that's a good place to start.
• 6:33
  SPEAKER_03: Let's go ahead and do that.
• 6:34
  SPEAKER_01: Let's do like a high-level quick question before we get started.
• 6:38
  SPEAKER_01: What on your summer science trip, how many days or time or exercises do you do with students in the Tetons and about the Tetons?
• 6:48
  SPEAKER_03: That's a really good question.
• 6:50
  SPEAKER_03: It's um I don't really know how to answer it.
• 6:53
  SPEAKER_03: It it's uh you know how I am.
• 6:55
  SPEAKER_03: I'm not a a scripted, I'm more of the fly by the seat of my pants.
• 7:01
  SPEAKER_03: If we see something, we're gonna talk about it.
• 7:03
  SPEAKER_03: Uh you know, when when we're hiking in the Tetons, a lot of the hikes that we do, we can see uh these uh glacial features.
• 7:12
  SPEAKER_03: We can see lateral moraines and end moraines and moraine-dammed lakes and U-shaped valleys and arets and cirques and horns and just all of this really beautiful stuff that they've only ever seen before in a textbook.
• 7:28
  SPEAKER_03: Yeah, yeah, yeah.
• 7:28
  SPEAKER_03: And so we'll stop and sit and talk and eat a snack and maybe sit a little bit longer and just soak it up, and then we'll head on.
• 7:39
  SPEAKER_03: We'll head on to the whatever our destination is.
• 7:41
  SPEAKER_03: So I also Jesse, like I've got so many personal stories about the Tetons that I like to share with my students.
• 7:51
  SPEAKER_03: And some of them are emotional stories.
• 7:52
  SPEAKER_01: Uh I do remember though, you have like you do have the the classic pull-off spot where you know you kind of always stop at the one pull-off where you're looking at the Tetons, you know, pull out the pull out the diagrams, look and and give, you know, a spiel there.
• 8:05
  SPEAKER_01: I guess you need to hit some content, right?
• 8:07
  SPEAKER_01: You like you need to hit key points at some point in what three days?
• 8:12
  SPEAKER_01: Do you spend two days in the Tetons?
• 8:14
  SPEAKER_01: Three days, three days.
• 8:15
  SPEAKER_01: Okay, so you got three days in the Tetons, and you're saying you kind of intersperse the content throughout those three days.
• 8:21
  SPEAKER_01: So it's not like you have one whole exam or something like that on the Tetons.
• 8:24
  SPEAKER_01: It's three days of hiking around a little breadcrumbs along the way, let's say, or something like that.
• 8:30
  SPEAKER_03: You know, I'll uh get them up to a place, let's say Amphitheater Lake or Delta Lake or something like that, and and go try to find a nice quiet place where I'm not gonna bother everybody else with my loud, excited, you know, voice about because you know as well as anybody, I love to talk about stuff I love.
• 8:46
  SPEAKER_01: So you know that attracts a crowd.
• 8:49
  SPEAKER_01: A crowd attracts a crowd, right?
• 8:51
  SPEAKER_01: So you have a bunch of hangers on that are just kind of listening and being like, what is going on right now?
• 8:55
  SPEAKER_03: Yeah, so I absolutely do that.
• 8:57
  SPEAKER_03: I like to, well, hey, let's eat lunch, and then when you're done eating, let's sit around and talk about this.
• 9:01
  SPEAKER_01: You know, what if you're gonna be able to do in this circle like what's going on here?
• 9:04
  SPEAKER_01: Look around you, let's talk about it.
• 9:06
  SPEAKER_01: That's cool.
• 9:06
  SPEAKER_03: Right on.
• 9:07
  SPEAKER_03: But Jesse, you know, kind of how my style is.
• 9:10
  SPEAKER_03: I I I like to teach by asking a lot of questions too.
• 9:12
  SPEAKER_03: What have we seen?
• 9:13
  SPEAKER_03: You know, what does that mean?
• 9:15
  SPEAKER_03: You and I spent a couple three hours walking down from Amphitheater Lake up in the Tetons.
• 9:20
  SPEAKER_03: And by the time we got down to the bottom, you'd worked out the pretty much the geologic history of the Tetons.
• 9:26
  SPEAKER_01: Which is an amazing story, which we should maybe let's finally get to that five-minute the brief little high-level summary.
• 9:32
  SPEAKER_01: Okay, yeah, let's do it.
• 9:33
  SPEAKER_01: Let's do it.
• 9:33
  SPEAKER_01: And then we can get to that.
• 9:34
  SPEAKER_01: So, okay, let's start kind of in my home turf, let's say, the early earth.
• 9:38
  SPEAKER_01: There are old rocks in the Tetons, let's put it that way.
• 9:41
  SPEAKER_01: And some of these we've talked about before on this podcast, really old rocks, these what we call Archean gray nice terrains, which there's just a bunch of gray rocks, it's toothpaste rock.
• 9:51
  SPEAKER_01: They're formed in the roots of ancient mountain belts.
• 9:54
  SPEAKER_01: We've talked about this even recently on this podcast.
• 9:57
  SPEAKER_01: We talked about old rocks, right?
• 9:58
  SPEAKER_01: There's what we would call like TTG, quote unquote, rocks, 2.7 billion years ago-ish.
• 10:04
  SPEAKER_01: That's like the oldest rocks in the Tetons that we have, right?
• 10:07
  SPEAKER_03: That's right.
• 10:07
  SPEAKER_03: But if you think about it, too, this is our oldest rocks exposed in the Tetons, this is in the middle of the life of the Earth.
• 10:15
  SPEAKER_03: You know, teenagers.
• 10:17
  SPEAKER_03: It's way older than a teenager.
• 10:19
  SPEAKER_03: This is half of Earth's life has already gone by by the time these rocks formed.
• 10:24
  SPEAKER_01: That's true.
• 10:25
  SPEAKER_03: You know, that's an amazing thing.
• 10:26
  SPEAKER_03: I mean, one, these are really, really old, very spectacular rocks, by the way.
• 10:31
  SPEAKER_03: These are awesome looking rocks, but as old as they are, they only represent the you know the second half of Earth's life.
• 10:37
  SPEAKER_03: That's I don't know.
• 10:38
  SPEAKER_03: It's really cool to think about.
• 10:40
  SPEAKER_01: It's crazy looking at how old those rocks are.
• 10:42
  SPEAKER_01: The next interval, which again, we've actually just talked about 2.5 billion years ago, there's granite.
• 10:47
  SPEAKER_01: There's a bunch of granite, and it kind of caps many of the peaks.
• 10:50
  SPEAKER_01: It's it intruded the gneisses, and this represents, this is you know, I get excited about this, it represents the distillation of the continental crust.
• 10:58
  SPEAKER_01: This first distillation, which we had a podcast about the sort of nature paper we just published on this topic.
• 11:03
  SPEAKER_01: But you can look at those rocks and you can say, Whoa, the crust was getting distilled halfway through Earth's history, and that rock represents it.
• 11:12
  SPEAKER_01: That's just a cool phenomenon.
• 11:14
  SPEAKER_01: And this kind of sets the stage for the old history of the Tetons.
• 11:18
  SPEAKER_03: That's right.
• 11:18
  SPEAKER_03: And then, Jesse, after this, you said 2.5 billion years old.
• 11:22
  SPEAKER_03: So, really, geologically, only slightly younger than the gneisses that we talked about first.
• 11:28
  SPEAKER_03: You had a lot of uplift.
• 11:30
  SPEAKER_03: That this was really deep stuff.
• 11:32
  SPEAKER_03: This was deeply rooted stuff that then got brought closer to the surface.
• 11:36
  SPEAKER_03: And really, the next thing that we're able to see are these mafic, what are called diabase dikes that intruded all of this stuff.
• 11:46
  SPEAKER_03: It is beautiful.
• 11:47
  SPEAKER_03: It intruded the stuff about 775 million years ago.
• 11:51
  SPEAKER_03: So a long time went by.
• 11:53
  SPEAKER_03: But how do we know that this happened closer?
• 11:58
  SPEAKER_03: These igneous intrusions happened closer to the surface than when these older two bodies formed.
• 12:04
  SPEAKER_03: How do we know that?
• 12:05
  SPEAKER_01: Well, we can look at things like how fast the rocks cooled and a dike will intrude and it'll cool.
• 12:11
  SPEAKER_01: Sort of traditional thinking was that that cools fast because it's near the surface, it's fine-grained, whereas the granite right next to it cooled down slowly and therefore was probably a bit deeper.
• 12:21
  SPEAKER_03: Which, by the way, I have another question for you.
• 12:24
  SPEAKER_03: Why do we call these a diabase dike and not a basaltic dike?
• 12:28
  SPEAKER_03: What's the distinction with that?
• 12:30
  SPEAKER_01: Yeah, it's uh basically because it's an intrusive rock.
• 12:33
  SPEAKER_01: It's looks a lot like basalt, but you can tell from the structure that it's intruded in the crust.
• 12:39
  SPEAKER_01: It's it didn't flow out on the surface, but it's pretty dang close to the surface.
• 12:43
  SPEAKER_01: This is a feeder, this is a feeder conduit to a basaltic flow, most likely.
• 12:47
  SPEAKER_03: And Jesse, like you can see these almost anywhere, but the most famous place is Mount Moran, you know, on the northern side of the Grand Tetons and Mount Owen and Mount Tiwanot.
• 12:59
  SPEAKER_00: Totally.
• 12:59
  SPEAKER_03: Um, like they're all over.
• 13:01
  SPEAKER_03: If you get into the mountains, you can see smaller versions of that Moran dike all over the place.
• 13:08
  SPEAKER_03: And you know what?
• 13:09
  SPEAKER_03: To the that I think is really interesting is they're almost all oriented the same way.
• 13:14
  SPEAKER_03: These things run and they cut across east-west in this north-south trending range.
• 13:20
  SPEAKER_01: That's a reason for that.
• 13:22
  SPEAKER_01: I mean, it's beautiful, and Mount Moran has just uh such an exceptional geological story all tied up into it.
• 13:28
  SPEAKER_01: And it you can look up a geological sketch of Mount Moran, and it's really impressive.
• 13:33
  SPEAKER_01: Like it's cool how much history is sort of shown in that one mountain range, or you can go to our audiobook and and buy the audiobook because we have cool images for that too.
• 13:43
  SPEAKER_01: Nice plug.
• 13:44
  SPEAKER_01: But there's a yeah, thank you.
• 13:45
  SPEAKER_01: But there's a ton of information right there, right?
• 13:48
  SPEAKER_01: I mean, right in that one rock unit, Chris.
• 13:51
  SPEAKER_01: Like, and I'm sure you tell your students about this, right?
• 13:54
  SPEAKER_01: Look at that.
• 13:54
  SPEAKER_01: Here's the history, work out cross-cutting relationships with that one mountain.
• 13:58
  SPEAKER_01: I mean, it's really, really cool.
• 14:00
  SPEAKER_03: Absolutely.
• 14:01
  SPEAKER_03: I use my own pictures actually in my classroom all the time of Mount Moran.
• 14:06
  SPEAKER_03: And the that leads us to the next rock that we see after the intrusion of these diabase black mafic dykes.
• 14:14
  SPEAKER_03: We have just a long, long time of shallow marine sedimentary rocks that were deposited right on top of this Precambrian core, which means all these deep-rooted, deep-seated formed rocks got brought to the surface, eroded relatively flat, sunk down, it's you know, subsidence happened, and then you had deposition of these shallow marine sedimentary rocks.
• 14:40
  SPEAKER_03: And one of those is the flathead sandstone, that brown, light tan rock sitting right on top of Mount Moran.
• 14:49
  SPEAKER_03: And it's a knife-like contact between those granites and dye-based dykes and the sedimentary rocks line right on top.
• 14:56
  SPEAKER_03: So that's a long period of time that's just missing.
• 14:59
  SPEAKER_01: Long period of time, as these interior seaways often do.
• 15:03
  SPEAKER_01: They sort of come and go back and forth over a long period of time, hundreds of millions of years, depositing rocks and sort of eroding rocks, erasing the record, making the record, erasing the record, making the record.
• 15:13
  SPEAKER_01: We'll get to about 160, 150 million years ago, and the severe, what's called the severe erogeny, started to drain that sea, uplifted the land surface and drained that sea.
• 15:23
  SPEAKER_01: And that's one tectonic event that is really interesting and it is a compliment, starts the really complicated story of the Western United States.
• 15:31
  SPEAKER_01: Like that's the kind of kickoff point of complicated geology from there to present day.
• 15:36
  SPEAKER_01: So let's take it from there.
• 15:38
  SPEAKER_01: 160, 150 million years ago, severe erogeny.
• 15:41
  SPEAKER_01: What's next in our story?
• 15:42
  SPEAKER_03: Well, yeah, you hit it, Jesse.
• 15:44
  SPEAKER_03: It's mass confusion between the severe erogeny and the Laramite erogeny.
• 15:50
  SPEAKER_03: And even Jesse is trained geologists, you and I sometimes in the literature have a hard time wading through it and keeping them straight.
• 16:00
  SPEAKER_01: Is that a fair statement?
• 16:01
  SPEAKER_01: Yeah, and the reason is because we don't know.
• 16:02
  SPEAKER_01: The jury is still out on, you know, where the severe starts, not really where it starts, but what events or what features are severe features versus which ones are later events, which we'll come to here in a minute.
• 16:14
  SPEAKER_01: But the Lair Miterogenies, the next, so the sort of the other one that's quite confusing here is the Laramiterogeny, which started much later, 60, 70 million years ago.
• 16:25
  SPEAKER_03: And there's overlap between them, like when did the severe end and when did the Laramide begin?
• 16:30
  SPEAKER_03: But between the Severe and the Laramide, there was another shallow sea that invaded the area, a very, very important sea called the Western Interior Seaway.
• 16:40
  SPEAKER_03: And this went from the northern territories of Canada that you're very familiar with all the way down to Mexico.
• 16:46
  SPEAKER_03: I mean, this was uh it dissected North America into two parts almost all the way through, or literally all the way through.
• 16:54
  SPEAKER_03: So that happened, and then the Laramide happened that began, you know, around 80 million years ago, and it finally drained.
• 17:03
  SPEAKER_03: The Laramiderogeny is this famous western iconic mountain building event that really resulted in muscular shoving mountains vertically as opposed to the severe, which was a lot more low profile.
• 17:18
  SPEAKER_03: It was more what we call thin-skinned kind of a mountain building event.
• 17:21
  SPEAKER_03: So, yeah, you had this the Laramiderogeny that happened, and that was a big deal.
• 17:27
  SPEAKER_03: We get into it as much as we can in our new audio book, but yeah, that's that's the next event that finally drained the seas away for good.
• 17:36
  SPEAKER_01: That's right.
• 17:36
  SPEAKER_01: And this is, as you said, muscular.
• 17:38
  SPEAKER_01: I think that's a great word for the Laramide, muscular orogenic system, big mountains, these really high, high mountain belts that were formed around this time period.
• 17:48
  SPEAKER_01: The Teton fault, however, which is what is so dramatic and striking, or why it's it's the reason why the Tetons are so dramatic and striking, is you're looking at a normal fault when you're looking at the Tetons.
• 18:00
  SPEAKER_01: And that activation, well, there's some debate about this, but we're talking like 10 million years ago.
• 18:06
  SPEAKER_01: So this particular feature is not a compressional Laramide feature.
• 18:11
  SPEAKER_01: It might be reactivating an old Laramide feature, but it is a normal fault.
• 18:15
  SPEAKER_01: It's a completely different structural style, struct structural pattern from compression.
• 18:20
  SPEAKER_01: This is a more of an extensional feature.
• 18:22
  SPEAKER_01: But 10 million years ago, that Teton fault started to move in the direction that it's currently moving or has been moving in the recent history.
• 18:29
  SPEAKER_03: That's right.
• 18:30
  SPEAKER_03: And that's amazing because what that means is that Grand Tetons are the youngest mountains in North America.
• 18:36
  SPEAKER_00: Yeah.
• 18:36
  SPEAKER_03: You know, they they didn't begin forming until 10 million years ago.
• 18:40
  SPEAKER_03: But you know what?
• 18:41
  SPEAKER_03: Most of the movement has occurred in the last five million years.
• 18:45
  SPEAKER_03: From a geologic perspective, that's really not a long amount of time.
• 18:51
  SPEAKER_03: So these are the youngest mountains.
• 18:53
  SPEAKER_03: So, Jesse, why is it possibly that the Grand Tetons have really accelerated their uplift in the last five million years, in particular the last two million years?
• 19:04
  SPEAKER_01: Yeah, so there's a there's a debate, I think, in the in the community about the impact of the Yellowstone hotspot track.
• 19:10
  SPEAKER_01: And the Yellowstone Hotspot track, we've talked about this, we have an audiobook on the geology of Yellowstone, but there's this big swath of no mountains just to the northwest of this, which is where that Yellowstone hotspot track passed.
• 19:23
  SPEAKER_01: And now the Yellowstone Hotspot is where it is in Yellowstone at the moment.
• 19:27
  SPEAKER_01: But this was a dramatic event that affected the tectonics of the area, most likely.
• 19:32
  SPEAKER_01: It's up for debate about how dramatic that effect was, uh, but it certainly had at least some impact on the Teton Fault in particular.
• 19:41
  SPEAKER_01: And so that was around five million years ago.
• 19:43
  SPEAKER_01: And we've gone through this before, but the last couple million years is when the big eruptions occurred in Yellowstone Park proper, like the eruptions that occurred where the caldera is today in Yellowstone National Park.
• 19:56
  SPEAKER_01: That's five million years ago.
• 19:57
  SPEAKER_01: The hotspot track starts to get close to the Tetons, and then the big eruptions start two million years ago.
• 20:02
  SPEAKER_03: I think the takeaway with this whole thing and this discussion about the Teton Fault, the takeaway for me is that these mountains are born from seismic disaster.
• 20:13
  SPEAKER_03: It's locked up, it's dormant, it's seemingly quiet, and nothing's going on, and hundreds or thousands of years go by and a massive earthquake rips, and there's offset by as much as ten feet in an instant, really.
• 20:28
  SPEAKER_03: And so it's punctuated violence that's separated by quite a long time from a human perspective in terms of quiescence.
• 20:38
  SPEAKER_03: Not a lot going on.
• 20:39
  SPEAKER_01: Yeah, super cool.
• 20:40
  SPEAKER_01: And then the last event, Chris, really, that I think had something to say about sculpting the beautiful terrains we've alluded to at the outset here.
• 20:48
  SPEAKER_01: Something to say, yes.
• 20:49
  SPEAKER_01: Something to say about it is glaciation.
• 20:51
  SPEAKER_01: So the glaciers came in and did all this amazing glacial carving of the Tetons that just makes such spectacular and classic textbook geological glacial features that you have varets and horns and cirques and all the really cool stuff that uh that you have there.
• 21:06
  SPEAKER_01: Chris, what's your favorite glacial feature in the Tetons?
• 21:09
  SPEAKER_03: Well, you know, I get excited about this because glaciated mountains, glaciers are they are what make mountains beautiful to me.
• 21:16
  SPEAKER_03: They make them angular, they make them chiseled and and sharp and jagged and just uh rugged, I guess is the what I would say.
• 21:24
  SPEAKER_03: My favorite glacial feature, I I mean this is impossible to answer, but when I'm sitting in Jackson Hole and I'm looking at the Tetons, what strikes me the most, I guess, are these all the horn peaks.
• 21:38
  SPEAKER_03: I can't get past them.
• 21:39
  SPEAKER_03: They're spectacular.
• 21:40
  SPEAKER_03: I don't know how else to describe it.
• 21:42
  SPEAKER_03: I mean, they make you feel small, they make you feel humble.
• 21:44
  SPEAKER_01: Yeah, totally.
• 21:46
  SPEAKER_01: Just really that's what I love.
• 21:47
  SPEAKER_01: They look so cool.
• 21:48
  SPEAKER_01: So cool.
• 21:49
  SPEAKER_01: What about you, Jesse?
• 21:50
  SPEAKER_01: I really like I like the glacial lakes.
• 21:54
  SPEAKER_01: I mean, I it's hard to beat walking up and seeing a little lake in this big beautiful tarn and just like l having the wall.
• 22:00
  SPEAKER_01: Walls all around you.
• 22:00
  SPEAKER_01: I mean, it's just totally cool.
• 22:02
  SPEAKER_01: Uh yeah.
• 22:03
  SPEAKER_01: There's something about it.
• 22:04
  SPEAKER_03: When you when you come across a glacial lake like that, it it's a rule.
• 22:08
  SPEAKER_03: You have to swim.
• 22:09
  SPEAKER_03: It doesn't matter how cold it is, it's gonna be cold.
• 22:11
  SPEAKER_03: It's gonna be very cold.
• 22:12
  SPEAKER_03: It's a glacial lake.
• 22:14
  SPEAKER_01: By definition, cold.
• 22:16
  SPEAKER_03: Yes.
• 22:16
  SPEAKER_03: But you have to take advantage of that and expert the full experience, you have to swim.
• 22:20
  SPEAKER_01: I agree completely.
• 22:22
  SPEAKER_01: So, Chris, that's our quick and short sort of summary, quick and dirty summary of the geology of the Tetons.
• 22:28
  SPEAKER_01: I'm curious.
• 22:29
  SPEAKER_01: Well, what I want to I what I want to know from you is during this process, especially, I mean, even putting together a Planet Jew episode, let alone a big audiobook on the Tetons, there's always rabbit holes that we kind of end up going down, right?
• 22:42
  SPEAKER_01: What was your favorite rabbit hole or favorite realization, maybe, or something like that?
• 22:48
  SPEAKER_01: What was your favorite sort of thing that pushed you further than you had thought about the Tetons previously?
• 22:55
  SPEAKER_03: That is a really good question.
• 22:56
  SPEAKER_03: I can't wait to flip this right back to you, so be ready.
• 22:59
  SPEAKER_03: Okay.
• 23:00
  SPEAKER_03: Oh crap, I gotta think about that.
• 23:02
  SPEAKER_03: You know, Jesse, you and I, over the last four years in this podcast, have had a lot of discussions about the Laramida Rajny and about the severe Rajni and what we know and what we don't know.
• 23:14
  SPEAKER_03: And there's a lot of debate.
• 23:16
  SPEAKER_03: There's a I mean, that's a that's putting it mildly.
• 23:19
  SPEAKER_03: But I think for me, the biggest rabbit hole was going down that path of parsing them out.
• 23:27
  SPEAKER_03: And I have more clarity than I've ever had before in it.
• 23:32
  SPEAKER_03: I mean, it's not a huge section of our audiobook.
• 23:37
  SPEAKER_03: It's a part of it, but it's not a massive part of it.
• 23:40
  SPEAKER_03: And the reason is because it played a role in the formation of the Tetons, but it really has not a ton to do with why the Tetons look the way they do today.
• 23:51
  SPEAKER_03: It was a part of the story, but it's not it wasn't a major part of the story.
• 23:55
  SPEAKER_01: Well, that's a good it's a good uh rabbit hole, then that's like a perfect answer to the rabbit hole question, then, because it's not an essential piece to the puzzle necessarily, right?
• 24:04
  SPEAKER_01: Because as we said, the Teton fault is much younger than both of those events.
• 24:07
  SPEAKER_03: Yeah.
• 24:08
  SPEAKER_03: Before I flip it back to you, I want to just say one other thing is that another rabbit hole for me that I've really come to appreciate, but man, it just takes so much time.
• 24:19
  SPEAKER_03: Um, working with you and learning about these early rocks and how they pertain to the formation of continents, that's a really cool thing for me.
• 24:29
  SPEAKER_03: It's your wheelhouse, but for me, I'm I'm playing keep up on that.
• 24:33
  SPEAKER_03: And it's something that I really enjoy, though.
• 24:35
  SPEAKER_03: I love to learn, and uh that's that's another thing that really has been satisfying for me.
• 24:40
  SPEAKER_01: Yeah, yeah, totally.
• 24:41
  SPEAKER_01: Well, that's a good one.
• 24:42
  SPEAKER_01: I mean, that's a it's a deep one, the severe versus larmide.
• 24:45
  SPEAKER_01: I mean, it part of the complexity is that it's so different across different parts of the Western U.S.
• 24:49
  SPEAKER_01: So if somebody asks, like, what's the difference between the severe and the Laramide?
• 24:52
  SPEAKER_01: It's a hard question to answer.
• 24:53
  SPEAKER_01: But if you're like, what's the difference or what is the impact of those two in this one area called Grand Teton National Park?
• 24:59
  SPEAKER_01: That's a bit of an easier bite to take out of the topic, right?
• 25:03
  SPEAKER_01: Because it you can map the severe faults versus the Laramide fault.
• 25:07
  SPEAKER_01: People have mapped these things in different areas.
• 25:09
  SPEAKER_01: So it gets easier if you really focus it in on one setting, maybe.
• 25:13
  SPEAKER_03: When I think about that, I I think a lot about well, what's the difference between, say, Glacier or the Canadian Rockies versus Rocky Mountain National Park in Colorado?
• 25:24
  SPEAKER_03: There are huge, huge differences between them.
• 25:26
  SPEAKER_03: And and therein really lies the difference between the Severe and the Larabide.
• 25:30
  SPEAKER_01: Totally, for sure.
• 25:30
  SPEAKER_01: That's a really good one.
• 25:31
  SPEAKER_03: Okay, Jesse, I'm gonna flip it back to you.
• 25:34
  SPEAKER_03: What was what was your favorite rabbit hole or what was your favorite thing maybe that you learned as we put this together?
• 25:41
  SPEAKER_01: Yeah, um, I think I think the Teton Fault was probably it for me.
• 25:48
  SPEAKER_01: This is a a struggle for me as well, and it kind of it's stuff we've talked about before with the Grand Canyon.
• 25:56
  SPEAKER_01: How did the Grand Canyon form?
• 25:57
  SPEAKER_01: When did the Grand Canyon form?
• 25:58
  SPEAKER_01: The debate around that is very similar to the debate around the Teton Fault activation, I think, because these young events that we can like still see happening, there's all sorts of different data sets that could be brought into the the discussion or the the debate.
• 26:14
  SPEAKER_01: And so you have people that are like mapping terraces, and you have people that are looking at ancient fossils and some young sediments somewhere, and they're putting rates of fault movement onto the Teton Fault.
• 26:26
  SPEAKER_01: And then you have the geochronologists, not quite like me, but the people who date the rocks and when they're uplifting in the same way that they date the Grand Canyon and get these kind of exposure ages.
• 26:36
  SPEAKER_01: Like there's all sorts of different tools that people can use, and sometimes that information's conflicting.
• 26:42
  SPEAKER_01: And so that one was really a deep dive on the question of when did the Teton, when did the Grand Teton start to lift up and what was the rate through time?
• 26:51
  SPEAKER_01: Like we said 10 million years, 15 million years, it started.
• 26:54
  SPEAKER_01: How fast has that been and has it been constant through time?
• 26:57
  SPEAKER_01: Like that's a a big question that there's a lot of debate about, and it's a super interesting one, I think, but confusing because there's so many different data sets that people bring in with very different, sometimes conflicting results.
• 27:10
  SPEAKER_03: But this rabbit hole that you went down led you down a path where you flipped something to me not too long ago, just a few weeks ago, about the math behind how the length of the fault and the uplift of the fault, how they play into each other, which I think you flipped me this, and actually you you kind of like you just uh added a comment to something that I'd done in a script.
• 27:33
  SPEAKER_03: Wait a minute.
• 27:34
  SPEAKER_03: I got I got instantly mad.
• 27:36
  SPEAKER_03: I'm like, where are you getting this from?
• 27:37
  SPEAKER_01: This number coming from that you added a sub-sub comment in the in the script.
• 27:43
  SPEAKER_01: Yeah, that was a really interesting one.
• 27:45
  SPEAKER_01: So you can calculate, well, you can actually kind of see it.
• 27:47
  SPEAKER_01: It's kind of beautiful.
• 27:48
  SPEAKER_01: You look at the Tetons and you look at the peaks, and you said the flathead sandstones on Mount Moran, just the top of it, the Grand, the middle Teton, those don't have any sediment at the tops anymore.
• 27:58
  SPEAKER_01: Whereas if you go to the edges, if you're looking at the Tetons, you go right and left, you the sediment, the sort of sediment that used to be on top, is present in place if you go further along.
• 28:07
  SPEAKER_01: And what that means is that the Tetons, what you're looking at, the most movement along the fault is right there.
• 28:15
  SPEAKER_01: And so if you can calculate the amount of vertical movement along the fault right there, which people have come up with something like six kilometers or more of vertical uplift in that one location, then there's basic physics about normal fault movement that if you say that's the maximum movement, the fault must be at least some length.
• 28:35
  SPEAKER_01: And if you plug this into that equation, you get like a hundred to a hundred and twenty kilometer long fault, which extends into and perhaps north of Yellowstone National Park.
• 28:45
  SPEAKER_01: So this research group's idea was that actually the Yellowstone hotspot track didn't really initiate the fault.
• 28:51
  SPEAKER_01: Yellowstone obliterated the fault.
• 28:53
  SPEAKER_01: The hotspot, just like Chris, you were teaching me the geology when we were driving through the Snake River Plain, and I was a high school student, I was sitting in the front seat of the bus, actually the front little stoop, you know, the little stairs there, and just ask you questions about the Snake River Plain.
• 29:06
  SPEAKER_01: And you're like, look to your right, there's mountains, look to your left, there's mountains, look ahead of us, there's no mountains, look behind us, there's no mountains.
• 29:12
  SPEAKER_01: What are we driving along?
• 29:13
  SPEAKER_01: I was like, river system, blah, blah, blah.
• 29:15
  SPEAKER_01: No rivers can't cut through those kind of mountains at this scale.
• 29:18
  SPEAKER_01: And we're driving through a hotspot track where the hotspot had just blown its way through the mountains, it just carved its way through the mountains.
• 29:25
  SPEAKER_01: This sort of style of research had proposed that the hotspot blew through the Teton Fault, too, and that the Teton Fault used to be super long, but it's been blown apart by the hotspot track, which uh it's very cool.
• 29:37
  SPEAKER_01: I mean, what a cool that is what a cool idea.
• 29:40
  SPEAKER_01: And it could be right or could be wrong, it requires testing, but what a cool idea.
• 29:44
  SPEAKER_01: I I don't know, I loved that.
• 29:46
  SPEAKER_01: That was interesting.
• 29:46
  SPEAKER_03: So the things we learn as we do this kind of work is uh it's it's just great.
• 29:53
  SPEAKER_01: And you know what's fun about it, Chris, is that it certainly obviously applies to these spectacular places Tetons, Mammoth Cave.
• 30:01
  SPEAKER_01: This deep rich geological story obviously applies to those locations, but it actually can be applied anywhere.
• 30:07
  SPEAKER_01: That there's interesting stuff all around you, sort of no matter where you are.
• 30:12
  SPEAKER_01: There's a deep, rich, interesting geological storyline behind it, I think.
• 30:17
  SPEAKER_01: And we get emails from listeners that are kind of along those lines, like, oh, I live in Florida, never really thought about this before.
• 30:23
  SPEAKER_01: But I was reading about this aspect of beaches and how cool is that, or whatever, you know.
• 30:27
  SPEAKER_01: I mean, it's super interesting, and it's kind of everywhere.
• 30:30
  SPEAKER_01: So it's easy to go down these rabbit holes and get super excited about things I would have never guessed going into this, Chris, that I would read, you know, five papers on the Teton fault formation necessarily and get super into the weeds about it.
• 30:42
  SPEAKER_03: Yeah, I agree.
• 30:43
  SPEAKER_03: And this brings me so much clarity in my own head.
• 30:48
  SPEAKER_03: The the way that the what I know about the Tetons now is organized in a different way than ever before.
• 30:54
  SPEAKER_01: So, Chris, one final question, then we should wrap up here.
• 30:57
  SPEAKER_01: What will you, if anything, tell your students this summer?
• 31:01
  SPEAKER_01: At the time of recording, we haven't gone on summer science yet.
• 31:04
  SPEAKER_01: I mean, will you tell it a a different story when you're standing somewhere?
• 31:07
  SPEAKER_01: Not maybe different, but an additional story and what is that?
• 31:10
  SPEAKER_01: What do you think?
• 31:11
  SPEAKER_03: All right, I don't know, Jesse.
• 31:13
  SPEAKER_03: Um I don't know.
• 31:15
  SPEAKER_03: It is a tough one.
• 31:16
  SPEAKER_03: You know, I'm at the stage of my career that I know so much about the Tetons and I have so much familiarity with them.
• 31:24
  SPEAKER_03: I have to curate what I'm gonna tell my kids, what I'm gonna tell the students in front of me.
• 31:28
  SPEAKER_03: What stories I can't tell them everything, it was just too much.
• 31:32
  SPEAKER_03: But I think this year I'm gonna bring in the math of the fault.
• 31:36
  SPEAKER_03: Okay, you know, the the way that there's a rhyme and a reason to this.
• 31:41
  SPEAKER_03: I at least want to talk about that because I have a perfect place to do this.
• 31:45
  SPEAKER_03: It's a place where we can see the displacement at the base of Twinot.
• 31:51
  SPEAKER_03: It's the cathedral group turnout, and we can see 60 feet of displacement along the Teton Fault that's happened since the Ice Age because that displacement cuts right across a glacial moraine.
• 32:04
  SPEAKER_03: And the moraine can't be any older than you know 13, 14,000 years ago.
• 32:08
  SPEAKER_01: And so you can look you can stand there and be like, look to your north, what's north of you?
• 32:13
  SPEAKER_01: It's Yellowstone.
• 32:14
  SPEAKER_01: We just came from there, we're just going there, whichever way you do it.
• 32:16
  SPEAKER_01: And yeah, that's cool.
• 32:17
  SPEAKER_01: That'll be a cool visual for them.
• 32:19
  SPEAKER_01: Well, I hope they get excited by that because they they dang well should.
• 32:22
  SPEAKER_03: Well, if they if they're not, then they better act it.
• 32:26
  SPEAKER_03: They better protect it.
• 32:28
  SPEAKER_01: That's right.
• 32:29
  SPEAKER_01: Yeah, that's exactly right.
• 32:30
  SPEAKER_01: Exactly right.
• 32:31
  SPEAKER_01: Well, I don't know, Chris.
• 32:32
  SPEAKER_01: What do you think?
• 32:33
  SPEAKER_01: That's kind of a wrap on uh it's so interesting how much we've learned throughout this process and all these it's so fun.
• 32:40
  SPEAKER_01: It's fun.
• 32:40
  SPEAKER_01: I mean, like you've said this many, many times.
• 32:42
  SPEAKER_01: This is the best professional development you can do is you know, go start a podcast.
• 32:45
  SPEAKER_01: So you're forced to talk about it and forced to learn about it before you talk about it.
• 32:49
  SPEAKER_01: It's so good.
• 32:49
  SPEAKER_01: What do you think?
• 32:50
  SPEAKER_01: Is that a wrap?
• 32:51
  SPEAKER_01: It's a wrap.
• 32:52
  SPEAKER_01: Okay, sounds good.
• 32:52
  SPEAKER_01: Hey, you can support us.
• 32:54
  SPEAKER_01: We always appreciate that two ways to support us.
• 32:56
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• 33:00
  SPEAKER_01: We have a bunch of free content there.
• 33:01
  SPEAKER_01: Basically, the introduction to geology class that Chris and I teach at the college level.
• 33:06
  SPEAKER_01: You can also purchase access to a bunch of audiobooks that we have there, including the Geology of the Grand Tetons, Geology of Elstone, Geology of the Grand Canyon, and a whole bunch of other stuff.
• 33:14
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• 33:18
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• 33:19
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• 33:22
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• 33:24
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