Latest / PlanetGeo: The Geology Podcast / The Hit and Run Rockies - With Professor Basil Tikoff

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The Hit and Run Rockies - With Professor Basil Tikoff · PlanetGeo: The Geology Podcast

• 0:02
  SPEAKER_02: Welcome to Planet Geo, the podcast where we talk about our making planet, how it works, and why it matters to you.
• 0:14
  SPEAKER_02: Mr.
• 0:14
  SPEAKER_02: Bull Heist.
• 0:16
  SPEAKER_02: What's going on, Jesse?
• 0:18
  SPEAKER_04: How are you?
• 0:19
  SPEAKER_04: Well, you told me just kick something over, Jesse.
• 0:22
  SPEAKER_02: We're gonna we gotta You kick something over over there?
• 0:25
  SPEAKER_02: Yeah.
• 0:25
  SPEAKER_04: Yeah.
• 0:26
  SPEAKER_02: What did I do?
• 0:27
  SPEAKER_02: You know, I'm a little scared of you now because uh you told me a story that the students are putting together a virtual fight club and that they all voted that you would win amongst the teachers.
• 0:36
  SPEAKER_04: Well, I don't know if they all voted, but the teacher said the consensus is that I would win in the fight club.
• 0:44
  SPEAKER_02: I don't know.
• 0:45
  SPEAKER_02: I don't know.
• 0:46
  SPEAKER_02: I I I've wrestled you before and uh I don't think you'd win.
• 0:49
  SPEAKER_02: I don't I think they're wrong.
• 0:50
  SPEAKER_04: I think they don't want they did bring up a rather large contender um who's also one of my fellow earth science, geoscience teachers.
• 0:59
  SPEAKER_04: Um he's a rather he's a big dude, and but I said um, I could take him.
• 1:03
  SPEAKER_04: I'm a lot meaner.
• 1:04
  SPEAKER_02: Yeah, yeah, yeah.
• 1:05
  SPEAKER_02: That's right.
• 1:05
  SPEAKER_02: Yeah, yeah, you're a lot meaner, a lot more cranky.
• 1:08
  SPEAKER_02: Um, all right.
• 1:08
  SPEAKER_02: Hey, this is a very exciting interview.
• 1:11
  SPEAKER_02: We've been thinking about doing or we've been, I don't know, organizing, thinking about doing this, tackling the Rocky Mountains for a very long time, and we finally got an expert, a true expert, Basil Tegoff, Dr.
• 1:22
  SPEAKER_02: Basil Tegoff, professor at University of Wisconsin.
• 1:25
  SPEAKER_02: So, although he's at Wisconsin, we don't need to hate him because he studies Rocky Mountains and has produced a really cool model for how the Rocky Mountains formed, which listeners have been asking about this for a while.
• 1:36
  SPEAKER_02: You and I have been talking about how do we tackle the Rocky Mountains for a long time.
• 1:41
  SPEAKER_04: You know, Jesse, I think that what sums this up, right, is why we've I don't we haven't actively avoided it, but it's just uh it's monumental.
• 1:49
  SPEAKER_04: We could interview so many people and do a huge series actually on the Rocky Mountains.
• 1:55
  SPEAKER_04: And so we've kind of shied away from it, maybe because it's there's still so much that's not known.
• 2:02
  SPEAKER_04: I flat out asked Basil, uh, could you teach an hour-long lecture on the formation of Rockies?
• 2:07
  SPEAKER_04: And he's like, I wouldn't want to do that.
• 2:09
  SPEAKER_04: You know, there's so much that we don't know, and and I couldn't do it in that you know, limited time frame.
• 2:14
  SPEAKER_02: And I I it's just it's too big.
• 2:16
  SPEAKER_02: I mean, it's it's just a as you said, monumental problem or monumental thing, how the Rockies formed.
• 2:23
  SPEAKER_02: There's this old school view, well, trad not even that consensus view.
• 2:27
  SPEAKER_02: Basil has produced this hit and run model.
• 2:30
  SPEAKER_02: Very interestingly, a paper, initial paper from like 1996, I think the date was.
• 2:34
  SPEAKER_02: And then you know, it's it's kind of been rekindled the discussion about whether the traditional model adequately explains everything, or whether we need to kind of modify that, or chuck the whole thing in the trash and have a different model, which Basil has has produced in part.
• 2:51
  SPEAKER_02: So, Dr.
• 2:52
  SPEAKER_02: Tikoff, he's uh professor at the University of Wisconsin, like we said, uh a really very interesting blend of of field geologists, but very quantitative, structural geologists, stress strain, how rocks deform.
• 3:02
  SPEAKER_02: Worked on a ton of very cool stuff.
• 3:04
  SPEAKER_02: I mean, the magma strain that he talked about was just so cool to me.
• 3:09
  SPEAKER_02: And it just has comes that thing about magma chambers in a very different way than any geochemist or geochronologist does.
• 3:15
  SPEAKER_02: And it's just that kind of blew my mind, that discussion has worked on a ton of different stuff, highly cited, highly published, um, and has done some of this potentially controversial and also very, very cool and original work on the formation of the Rocky Mountains, which we talk a lot about today.
• 3:32
  SPEAKER_02: Let's get to it.
• 3:32
  SPEAKER_02: All right, let's do it.
• 3:33
  SPEAKER_02: Basil teek off.
• 3:39
  SPEAKER_02: All right, basil, welcome to Planet Geo.
• 3:42
  SPEAKER_02: We're I can speak for Chris and I we're very excited to have you here.
• 3:44
  SPEAKER_02: Thanks for joining us and giving us some of your time.
• 3:46
  SPEAKER_01: It's my pleasure.
• 3:47
  SPEAKER_01: Happy to be here.
• 3:48
  SPEAKER_02: This is gonna be great.
• 3:49
  SPEAKER_02: Uh, we're gonna get into the weeds about the Rocky Mountains, amongst other things, right, Chris?
• 3:53
  SPEAKER_02: That's right.
• 3:54
  SPEAKER_04: Right on.
• 3:54
  SPEAKER_04: Hey, well, so should we just jump right in then, Jesse?
• 3:56
  SPEAKER_04: Yeah, let's do it.
• 3:57
  SPEAKER_04: Good deal.
• 3:58
  SPEAKER_04: So, Basil, we always start off uh when we do interviews with this question: what got you into geoscience?
• 4:04
  SPEAKER_04: You know, was there something that happened, a life event that maybe occurred, or uh somebody inspired you?
• 4:10
  SPEAKER_04: Like what kind of steered you in this direction?
• 4:13
  SPEAKER_01: I was kind of a crappy physics major, as it turned out.
• 4:18
  SPEAKER_01: I didn't really like the subject matter, and I wasn't particularly good at it.
• 4:24
  SPEAKER_01: And so I kind of wandered over junior year, spring semester, to Steve Wital's office, and I said, you know, I had taken intro geology at another university.
• 4:35
  SPEAKER_01: I started at Columbia, University in New York City, and then I wound up at Oberlin College, and I walked into Steve's office because it was that kind of place, and I was like, Do you have anything that's coming up that might be of interest?
• 4:46
  SPEAKER_01: And he was like, Well, you might try structural geology.
• 4:49
  SPEAKER_01: So I went from intro to structure.
• 4:51
  SPEAKER_02: Wow, that's a heavy start to jump into geology, yeah.
• 4:54
  SPEAKER_01: Exactly.
• 4:55
  SPEAKER_01: So in the curriculum, but Steve was like, just do that, and we hit um stress and strain at about the midway port portion, and I was like, this is what I really like.
• 5:08
  SPEAKER_01: So I'm one of those really weird people.
• 5:11
  SPEAKER_01: I came to geoscience a strain nerd.
• 5:15
  SPEAKER_01: I really love thinking about strain and how things deform, and rocks are great.
• 5:24
  SPEAKER_01: Very tactile.
• 5:25
  SPEAKER_02: That is the most unique answer to this question I think we've ever had, Chris.
• 5:28
  SPEAKER_02: Do you agree with that?
• 5:29
  SPEAKER_04: Uh yeah, but I I get it though.
• 5:31
  SPEAKER_04: I mean, there are there's so many people that go into geology that thought they were gonna go into the physics realm and world and figured that I don't really like that, or I totally understand.
• 5:41
  SPEAKER_04: I get that.
• 5:42
  SPEAKER_02: Yeah, I'm gonna use this.
• 5:44
  SPEAKER_02: I teach an intro to physical geology class where I get a lot of engineers.
• 5:47
  SPEAKER_02: I get all the civil engineers or mining engineers because they need it for accreditation.
• 5:50
  SPEAKER_02: So, you know, it's 190 students and 170 of them are engineers.
• 5:54
  SPEAKER_02: And I'm gonna use this one as a recruiting tactic.
• 5:56
  SPEAKER_02: Like if you don't like engineering, you know, come you can study stats, stress, and strain.
• 6:02
  SPEAKER_01: I'm the I'm happy to boost your enrollment numbers.
• 6:06
  SPEAKER_02: I appreciate it.
• 6:07
  SPEAKER_02: That's great.
• 6:08
  SPEAKER_02: Was that linear after that?
• 6:10
  SPEAKER_02: Like after that, you know, oh, this is cool.
• 6:12
  SPEAKER_02: Structural geology, you said you were junior.
• 6:13
  SPEAKER_01: Is that is that when you were that's right.
• 6:16
  SPEAKER_01: It wasn't quite.
• 6:17
  SPEAKER_01: I had a little bit of um uh foray back into physics.
• 6:20
  SPEAKER_01: I actually I somehow managed them as an undergraduate to teach a seminar in fluid mechanics, and I realized I liked that too.
• 6:30
  SPEAKER_01: And the the fascinating thing was I was as good as the other physics majors when we were talking about that, and there was just the aha moment of my undergraduate career is you have to care about what you do to be good at what you do.
• 6:45
  SPEAKER_01: Oh wow, okay.
• 6:46
  SPEAKER_01: Right?
• 6:47
  SPEAKER_01: There are some people who are just smart enough, but it wasn't me.
• 6:50
  SPEAKER_02: But I but once I got into something that was just like inherently interesting, that's that is such I I want to kind of we need to reiterate that a little bit because that's that that sort of same type of advice has been given.
• 7:02
  SPEAKER_02: I forget who it was, Chris, what who you know talks about choose something you love because what you'll work hard at what you love and therefore you'll be good at it, and you get more of that then.
• 7:10
  SPEAKER_02: So it's like a really good feedback loop there.
• 7:13
  SPEAKER_02: And I feel the same way about geochemistry.
• 7:15
  SPEAKER_02: I hated chemistry all the way through.
• 7:17
  SPEAKER_02: I hated it as a tool, like studying chemistry just for the tool aspect.
• 7:20
  SPEAKER_02: But once it came to geochemistry, I was like, oh, my mind is blown.
• 7:24
  SPEAKER_02: This is amazing.
• 7:25
  SPEAKER_02: This tool is unbelievably cool, and you know, still can't get enough of that aspect.
• 7:30
  SPEAKER_02: So yeah, that's that's really that's cool.
• 7:32
  SPEAKER_02: I like how you phrase that.
• 7:33
  SPEAKER_02: That's awesome.
• 7:34
  SPEAKER_02: So then from there to graduate school, what was the leap from Oberlin College, you said, to graduate where you're like structural geology graduate school, that's what I want to do.
• 7:42
  SPEAKER_01: So I took a year off and I watered plants in a greenhouse.
• 7:47
  SPEAKER_01: Because that seemed like the right thing to do.
• 7:49
  SPEAKER_01: Um and actually, the only sad thing about that job was it was at an experimental greenhouse, and they knew then they found out I was a physics major and understood Fourier transform, so they made me work halftime computer programming.
• 8:07
  SPEAKER_03: So but it was fun.
• 8:10
  SPEAKER_01: I mean, I enjoyed both of those things, and it wasn't you know, it wasn't a heavy lift.
• 8:13
  SPEAKER_01: Um, and then I just applied to graduate schools again, mostly on recommendations from Steve at Oberlin, and just found a place that I thought fit.
• 8:24
  SPEAKER_02: And the project, how did you choose a project or what I mean?
• 8:27
  SPEAKER_02: How did you how I guess how did you get into you know your disciplinary situation now, I suppose?
• 8:34
  SPEAKER_02: How how did you get into what you're into?
• 8:36
  SPEAKER_01: Um I had the best graduate advisor, I had the best undergraduate advisor, but I had the best graduate advisor too, because he was his attitude.
• 8:44
  SPEAKER_01: So this is Christian Tessier at the University of Minnesota, and his attitude was just like you'll figure out something interesting to do.
• 8:51
  SPEAKER_01: And his advice was go find a Pluton in California.
• 8:54
  SPEAKER_01: And I was like, I can find Pluton in California, right?
• 8:57
  SPEAKER_01: That's the big target.
• 9:00
  SPEAKER_01: Plutons, and um so my first year, I got uh another student to go with me who was also somebody weirdly coming from physics, but was had a lot of backpacking experience, and I thought I would study Pluton in placement at this time, late 80s, was sort of a hot topic.
• 9:18
  SPEAKER_01: People were trying to figure it out.
• 9:20
  SPEAKER_01: So I had this idea that I wanted to study how these magmas come up in the earth, and then in the Sierra Nevada, they're huge, they're like 30 miles by 10 miles.
• 9:33
  SPEAKER_01: You're like, how in the world do you get that much magma up?
• 9:37
  SPEAKER_01: And I thought this is great, you know.
• 9:40
  SPEAKER_01: I could study this, and their strain, they you know, they flow around, so you can, you know, sort of the fluid dynamics aspect was kind of interesting to me.
• 9:49
  SPEAKER_01: And there was a path you had to go in.
• 9:52
  SPEAKER_01: And every time I looked down, I was like, this rock is really weird.
• 9:57
  SPEAKER_01: This this rock I'm on, because it's not like a granite, it's like it's like a gneiss rather than a granite.
• 10:04
  SPEAKER_01: And the whole field season, this guy I'm with, Brad Murray, says to me, You shouldn't be studying that.
• 10:12
  SPEAKER_01: What do you want to study?
• 10:13
  SPEAKER_01: You should be studying this, the stuff you keep walking over.
• 10:17
  SPEAKER_01: And so it totally changed.
• 10:20
  SPEAKER_01: And I forget about the Pluton and the Pluton in placement.
• 10:24
  SPEAKER_01: I'm gonna worry about this, and what that was a shear zone.
• 10:29
  SPEAKER_01: At the Earth's surface, we had things like the San Andreas fault that moved past each other.
• 10:34
  SPEAKER_01: But this was one that was far enough down in the earth that it didn't break, but it pulled like Taffy, and it pulled exactly parallel to the San Andreas fault in exactly the same way.
• 10:45
  SPEAKER_01: We call it right lateral, but it doesn't matter, it's the same way.
• 10:48
  SPEAKER_01: It's basically the west side is going north, but it happened at 80 million years ago.
• 10:53
  SPEAKER_02: Oh, interesting.
• 10:55
  SPEAKER_04: In the magnet chamber, was that the was that the um asthenosphere, lithosphere boundary then, where it was kind of taffy-like?
• 11:02
  SPEAKER_01: Is that what you're thinking about that?
• 11:04
  SPEAKER_01: So this was way up in the crust.
• 11:06
  SPEAKER_01: So lithosphere is the as a tectonic plate, right?
• 11:10
  SPEAKER_01: And the thing about the tectonic plate is there's a little bit of mantle stuck on to the bottom of the plates, right?
• 11:15
  SPEAKER_01: The a plate is not the crust, a plate is the crust plus a good chunk of mantle.
• 11:21
  SPEAKER_01: And so and the crust is uh let's say 40 kilometers, maybe 30 miles, round numbers thick.
• 11:29
  SPEAKER_01: It turns out if you get below about eight to ten miles thick or 12-15 kilometers, then everything is taffy after that, the whole way down.
• 11:40
  SPEAKER_01: It might be that the uppermost mantle has faults again, but that's a that's a detail we don't need to worry about.
• 11:46
  SPEAKER_01: And so these rocks were actually way shallower than that, but they were in huge magma chambers, and so they stayed really hot.
• 11:53
  SPEAKER_01: The heat came up with the granite, right?
• 11:57
  SPEAKER_01: If you had let them cool at those depths, they would have been really hard.
• 12:01
  SPEAKER_01: But it's because they were the shearing was happening while the magmas were coming in.
• 12:06
  SPEAKER_01: That's what was fascinating.
• 12:08
  SPEAKER_01: It was it was all kind of in one fell swoop.
• 12:12
  SPEAKER_02: Wow, okay.
• 12:13
  SPEAKER_02: So that this leaves me to I don't know, I don't think this is a loaded question, but I I I'm kind of paying attention a little bit to the magma chamber.
• 12:21
  SPEAKER_02: I don't know, may are do you think that the magma chamber debate is been rejuvenated a little bit?
• 12:27
  SPEAKER_02: Like the question of what is a magma chamber, like what state does it exist in?
• 12:31
  SPEAKER_02: How do you think about that?
• 12:32
  SPEAKER_02: Because I I think the geochemists probably think about this in a very different way than a structural geologist does or a quantitative field geologist like yourself does.
• 12:41
  SPEAKER_01: The record of fabrics and granites is really hard because granites have a bad case of amnesia.
• 12:49
  SPEAKER_02: If they decide I love that description.
• 12:51
  SPEAKER_01: That's if they basically flow as a magma, you can't tell, right?
• 12:56
  SPEAKER_01: Because you can only tell once they are all crystallized, locked in, and then they start to deform the minerals.
• 13:03
  SPEAKER_01: That we can figure out.
• 13:04
  SPEAKER_01: But if they flow before that, you don't know.
• 13:07
  SPEAKER_01: There's a great video by Win Means who did these analog experiments, and you can see all this crazy stuff going on, and then it crystallizes, and you see like the last bit.
• 13:19
  SPEAKER_01: That whole history, it's totally gone.
• 13:22
  SPEAKER_02: So it's just obliterated by the fact that it it recrystallized that effect effectively a granite becomes a high-grade metamorphic rock right after it solidifies, like it almost has to become a 500 degrees C, right?
• 13:35
  SPEAKER_02: I mean, this is a metamorphic rock.
• 13:36
  SPEAKER_01: It doesn't it doesn't even have to become a metamorphic rock, it can just stop because the rology, right, is so different, right?
• 13:43
  SPEAKER_01: It's like half EV4, and it's like harder than a hard rock.
• 13:48
  SPEAKER_01: I mean, yeah, like granites are harder than most things once they've crystallized.
• 13:54
  SPEAKER_02: I mean, I kind of have this vision in my head now with going back to, oh geez, what is it, 2004 or whatever, the the the advent of of high precision geochronology in plutonic complexes where we started to see that Tuoline truser suite was a 10 million-year-old thing and not like a not the simple zoned magma chamber that crystallized outside in and differentiated, but more like a mush system or something like that?
• 14:16
  SPEAKER_02: That's kind of the way I think about that.
• 14:18
  SPEAKER_02: Crystals are interlocking and there's little bits of magma in between there, but it's fundamentally supported by the crystals.
• 14:26
  SPEAKER_02: Is that similar to the way you would think about these systems, or is that completely different?
• 14:31
  SPEAKER_01: Or it's how I think about it once they're cool, but while they're forming, again, you it you could happen.
• 14:38
  SPEAKER_01: That's exactly where I was.
• 14:40
  SPEAKER_01: I was in Yosemite National Park and just south of that.
• 14:45
  SPEAKER_01: And so the geochemists were like, at the time, they were like, There's no way these things, you know, they're fast.
• 14:51
  SPEAKER_01: You can't open enough tectonic space.
• 14:54
  SPEAKER_01: And I was like, the reality on this ground is that you're opening this tectonic space.
• 14:59
  SPEAKER_01: I mean, that the the fabrics we're seeing are consistently dextral that looks like, in fact, this fault system is allowing these granites in.
• 15:08
  SPEAKER_01: And they were like, No, these granites, you know, they're cooling too fast, there's not enough time.
• 15:12
  SPEAKER_01: So it was one of these cases where there was this mismap of things, and when the this long extended period of like, yeah, okay, well, that works then.
• 15:21
  SPEAKER_02: Good.
• 15:21
  SPEAKER_02: My my analyses in the 90s, like, okay, you agree with what I said a decade ago.
• 15:25
  SPEAKER_02: Exactly.
• 15:26
  SPEAKER_02: Finally, yeah, that must have been I yeah, that's so interesting.
• 15:30
  SPEAKER_02: I never knew this history.
• 15:31
  SPEAKER_02: That's so cool.
• 15:32
  SPEAKER_02: Chris has spent a bunch of time in US 70 too.
• 15:34
  SPEAKER_04: Sorry, I have, yeah, yeah, yeah.
• 15:36
  SPEAKER_04: No, so Basil, is this you said the deck this dextral motion, which is this right lateral motion.
• 15:41
  SPEAKER_04: Is that is that what got you thinking about, and we're not there yet to this part of the interview, but with with your the new way of thinking about how the Rockies came to be this hit and run model, is that is this where it all started for you then?
• 15:54
  SPEAKER_01: Yes, that's exactly right.
• 15:56
  SPEAKER_01: Because as a student, you write proposals, right?
• 16:00
  SPEAKER_01: And you try and get yourself funded.
• 16:01
  SPEAKER_01: So I never was funded like externally for my PhD.
• 16:05
  SPEAKER_01: And I was fine with that.
• 16:06
  SPEAKER_01: My advisor was fine with that.
• 16:08
  SPEAKER_01: And I when I would write proposals, I would say, okay, we have a dextral fault in the middle of the Sierra Nevada Bath.
• 16:15
  SPEAKER_01: And the reviewers would write back, there is no dextral shearing in the Sierra Nevada Bathlet.
• 16:20
  SPEAKER_02: Really?
• 16:20
  SPEAKER_01: Well, I'm really, really good with Photoshop then because that's a picture, right?
• 16:25
  SPEAKER_01: And that's the only way you could do it.
• 16:28
  SPEAKER_02: Can you paint for me a picture of what that looks like in the field?
• 16:30
  SPEAKER_02: Like I think everybody can visualize Yosemite National Park.
• 16:33
  SPEAKER_02: You're walking across all these things, and and dextral is the other side of the fault, the land on the other side is moving to the right.
• 16:39
  SPEAKER_02: And it doesn't matter which side of the fault, you're looking at we're going right.
• 16:42
  SPEAKER_02: So if you're standing looking at the Pacific, looking towards the Pacific, the other side of the fault's going right.
• 16:46
  SPEAKER_02: How many of these things are there?
• 16:48
  SPEAKER_02: What's the scale of them?
• 16:50
  SPEAKER_02: How big are they?
• 16:50
  SPEAKER_02: If you're looking, if people who've been there are walking across and they can see one of these fault zones and say, Oh yeah, it moved to the right, how do you how do you see that and how frequently do you see that?
• 17:00
  SPEAKER_01: That's a great question.
• 17:01
  SPEAKER_01: So again, in the late granites, because they've got the amnesia problem, you can't see it except you walk across it and it stops being a nice granite with equal, you know, sizes of feldspar, and you know, things that you would look at and say, Oh, that's a granite.
• 17:21
  SPEAKER_01: And you start going into a gradient where it's like, oh no, this is no longer a granite.
• 17:26
  SPEAKER_01: It's starting to look more like a schist, and now it's looking more like a gneiss.
• 17:29
  SPEAKER_01: So it's you're looking at fabrics, you're looking at changes in fabrics.
• 17:33
  SPEAKER_01: There's no place where there's obviously something that has been pushed off and moved, right?
• 17:41
  SPEAKER_01: That would make it easy.
• 17:42
  SPEAKER_01: So the reason they were missing it is it was these hugely wide zones that were just sheer zones where you're looking, you have to look at the fabrics and realize, oh, they're all right lateral.
• 17:53
  SPEAKER_01: They're all moving.
• 17:54
  SPEAKER_01: So, how do you tell that then?
• 17:55
  SPEAKER_02: Do you do that in the field?
• 17:56
  SPEAKER_02: How do you tell it's right lateral?
• 17:57
  SPEAKER_01: So you look for a symmetry of fabrics, and you'll get little places where it'll just be there's these big feldspars.
• 18:06
  SPEAKER_01: And so on the edges of the big feldspars, because they block the flow, you get little zones that have more displacement, and you can see that they're moving to the right.
• 18:17
  SPEAKER_01: This is how you know that the shear zones happening as it's going from a magma into a solid, is it deformed over wide areas without gradients.
• 18:28
  SPEAKER_01: If the thing had solidified and then sheared, it would have broken into these zones into pods that you could easily see offsets.
• 18:37
  SPEAKER_01: Yeah.
• 18:37
  SPEAKER_01: So it's the fact that it that's deforming while it's coming in.
• 18:41
  SPEAKER_01: It's syntectonic magmatism or syn magmatic tectonism.
• 18:46
  SPEAKER_01: You can go either way at the relationship, but you can't get around the fact that these are deforming as they come in.
• 18:55
  SPEAKER_04: So this is in Yosemite, and you said just south of Yosemite, right?
• 18:58
  SPEAKER_04: When this all started.
• 18:59
  SPEAKER_04: Well, how much motion happened on this strike slip fault?
• 19:03
  SPEAKER_01: That's a great question that we spent a lot of time trying to figure out.
• 19:08
  SPEAKER_01: There's a okay, there's a lot to go on, but basically, if you take the most conservative, so only the solid state, and only from the granites, you wind up in the eight to ten kilometer range.
• 19:25
  SPEAKER_01: So I mean that they're big, but they're not like spectacular.
• 19:30
  SPEAKER_01: We now know it's hundreds, and we know that from a geochemical argument, Jesse will be happy to know.
• 19:37
  SPEAKER_01: Um excellent, love it.
• 19:38
  SPEAKER_01: Yes.
• 19:38
  SPEAKER_01: That you that you can actually use geochemical indicators as markers and see that the marker's been offset 400 kilometers.
• 19:47
  SPEAKER_02: So these are the strontium isotopes or oxygen isotopes or one of those?
• 19:51
  SPEAKER_02: Okay.
• 19:52
  SPEAKER_01: Exactly.
• 19:52
  SPEAKER_01: So it's the old boundary of North America, which has this very different signal of strontium.
• 19:59
  SPEAKER_01: So Jesse was already on that.
• 20:00
  SPEAKER_01: It's this 87-86 ratio of strontium.
• 20:04
  SPEAKER_01: And it just says, did these granites come up through a crust that was pre-Cambrian, or did it come through a crust that was much younger than that?
• 20:12
  SPEAKER_04: So we're trying to get a picture of what this looks like in the field, trying to paint that picture.
• 20:16
  SPEAKER_02: Um Chris, before before you paint that picture, can I just put a timestamp on this again?
• 20:20
  SPEAKER_02: Like this is this is what bait this is 90 to 80 MA, 90 to 82 MA, and there's right lateral shearing happening throughout that time period.
• 20:29
  SPEAKER_02: From the that's what you observe in the rocks?
• 20:30
  SPEAKER_01: That's correct.
• 20:32
  SPEAKER_01: That the evidence we had was from the 87 to 85 million-year-old Plutons that they were shearing at the end.
• 20:39
  SPEAKER_01: That's really all I had during my PhD.
• 20:42
  SPEAKER_01: Sorry, Chris, I wanted to do that right before you got to this, Chris.
• 20:46
  SPEAKER_01: Sorry, yeah.
• 20:46
  SPEAKER_04: But how sharp is the contact?
• 20:49
  SPEAKER_01: Very, very not sharp.
• 20:51
  SPEAKER_01: It's a completely gradient.
• 20:53
  SPEAKER_01: Okay.
• 20:54
  SPEAKER_01: You just go in and then it starts pulling, and you're like, is this it?
• 20:57
  SPEAKER_01: You go a little bit more, is this it?
• 20:59
  SPEAKER_01: And at some point you're like, all right, I'm gonna come up with a criteria that the quartz has to be stretched 1.5 on a long direction to one, and it doesn't matter the size because it's just a ratio, and you use that, but it's truly a gradient.
• 21:12
  SPEAKER_04: Okay.
• 21:12
  SPEAKER_04: So can you like can you approximate the width of the of the sheer zone then?
• 21:17
  SPEAKER_01: Yes.
• 21:18
  SPEAKER_01: And so, okay, so this is where things get fascinating.
• 21:22
  SPEAKER_02: Oh, this is where oh oh yeah, because before it was really boring.
• 21:25
  SPEAKER_02: I mean, my goodness.
• 21:26
  SPEAKER_01: This is cool.
• 21:28
  SPEAKER_01: It's a great story, actually.
• 21:30
  SPEAKER_01: So I was working in the granite.
• 21:32
  SPEAKER_01: So in the one to the south called Domono Creek Granite, and then there's one to the north, which is called the Cathedral Peak.
• 21:38
  SPEAKER_01: So that's after Cathedral Peak in Yosemite National Park, and there's a the shearing is up by Saddlebag Lake there.
• 21:44
  SPEAKER_01: If you ever get a chance, it's super exposed there.
• 21:47
  SPEAKER_01: And at the same time, a fellow graduate student was working in the Wal Rocks, and his name was David Green.
• 21:53
  SPEAKER_01: And this is the great thing about geology.
• 21:56
  SPEAKER_01: David's been uh become a really good friend of mine.
• 21:58
  SPEAKER_01: So we're there, we're both.
• 22:00
  SPEAKER_01: Doing PhDs, I'm showing him what I'm studying, and we like walk literally along strike into what he's doing, and it's the same shear zone, except that where I'm working, all the little lines that tell you the indications are horizontal and the zones really wide, and we go into where he is, all the lines are vertical and the zones really thin.
• 22:24
  SPEAKER_01: And it's just like, oh, wait a minute.
• 22:26
  SPEAKER_01: So this is where being a strain nerd helps.
• 22:29
  SPEAKER_01: I was like, this is an exact prediction of a model.
• 22:33
  SPEAKER_01: It's it's like a dead-on prediction.
• 22:36
  SPEAKER_02: Square that circle for me.
• 22:37
  SPEAKER_04: Hold on, can I take a stab at it a second, though?
• 22:40
  SPEAKER_04: Basil, is this because of seriously?
• 22:42
  SPEAKER_04: Is this because in some spots the rock was brittle?
• 22:46
  SPEAKER_04: In some spots it was hotter and softer, maybe?
• 22:49
  SPEAKER_04: Is that what determined that?
• 22:51
  SPEAKER_01: No, that would be a great guess, but no, this is a very 3D effect, as it turns out.
• 22:57
  SPEAKER_01: So these zones, like Jesse said, they're basically like the San Andreas, right?
• 23:02
  SPEAKER_01: They're moving side to side, right?
• 23:04
  SPEAKER_01: But on these zones, a little something else is going on too.
• 23:08
  SPEAKER_01: They're actually smashing together.
• 23:10
  SPEAKER_01: So the east side is coming closer to the west side.
• 23:14
  SPEAKER_01: And if the zone is really thin, you've basically pushed all that upward motion into a single place, and it has to basically form these vertical lineations, but as or or these vertical stretching, but as you go away in the granite, you have a wide zone over which to do that.
• 23:32
  SPEAKER_01: So you don't see that and it stays very horizontal.
• 23:35
  SPEAKER_01: It was one of these cases where like strain it was just like strain.
• 23:38
  SPEAKER_02: Well in the vertical, in the uh in the wall rocks, where it's the strain thing, the strain ellipses are is that the right word?
• 23:45
  SPEAKER_02: Strain ellipses are vertical.
• 23:46
  SPEAKER_01: The long axis, yeah, it's vertical.
• 23:48
  SPEAKER_02: It's vertical.
• 23:49
  SPEAKER_02: Where is the lateral strain?
• 23:51
  SPEAKER_02: Where is the right lateral strain going?
• 23:53
  SPEAKER_02: Or like it does it disappear in that part?
• 23:55
  SPEAKER_02: That's what I'm having trouble visualizing here.
• 23:57
  SPEAKER_01: No.
• 23:58
  SPEAKER_01: So when David was working, he said, I'm just ignoring them because I can't, I don't understand why everything's vertical.
• 24:05
  SPEAKER_01: But when I look at a horizontal surface, I see all of these swirly asymmetric things that you see over there in your granite.
• 24:13
  SPEAKER_01: I see them here, but I also have this vertical lineation.
• 24:16
  SPEAKER_02: Oh, so it's still it's still going right.
• 24:18
  SPEAKER_02: There's just a large vertical component to the okay.
• 24:22
  SPEAKER_02: I see.
• 24:22
  SPEAKER_02: Okay, gotcha.
• 24:23
  SPEAKER_02: And that's because of the width.
• 24:25
  SPEAKER_02: It's just kind of shrunk down the width of deformation.
• 24:27
  SPEAKER_02: Uh that's right.
• 24:28
  SPEAKER_02: Actually, can we back up and can you describe the difference between stress and strain really quickly?
• 24:32
  SPEAKER_02: Just very briefly.
• 24:33
  SPEAKER_01: Sure.
• 24:34
  SPEAKER_01: So stress is forces that act on surfaces.
• 24:38
  SPEAKER_01: So it's not a force, though, because it's normalized to an area.
• 24:41
  SPEAKER_01: And that's all geologists can work with, right?
• 24:44
  SPEAKER_01: Because we don't have like hydraulic lifts or whatever.
• 24:47
  SPEAKER_01: So we have to work with stresses.
• 24:49
  SPEAKER_01: But stress is fundamentally an idea.
• 24:53
  SPEAKER_01: There is no manifestation of stress in a rock.
• 24:56
  SPEAKER_01: This manifestation of in the rock is strain.
• 25:00
  SPEAKER_01: And you can see it through a fabric, like how the crystals are aligning.
• 25:04
  SPEAKER_01: You can see it through if you have things that look like class.
• 25:09
  SPEAKER_01: So imagine like a sandstone, right?
• 25:11
  SPEAKER_01: It's made of these individual grains, but you can see how the grains have moved and which is the direction that they've been squished the most has become longer.
• 25:20
  SPEAKER_01: And so everything you see is basically a manifestation of either a large strain or a small strain.
• 25:25
  SPEAKER_01: And so that's the physical reality on the ground.
• 25:29
  SPEAKER_02: And you and you can like look at that the deformation, the strain, the the rock implications of stress, and see where it was squishing, where it was not squishing, like what the directions of stress were basically by looking at these features.
• 25:42
  SPEAKER_01: You can infer the directions of stress if you make a model and go backwards.
• 25:49
  SPEAKER_01: But you have to document what the strain does.
• 25:52
  SPEAKER_01: And I know, I mean, this is again just because I'm a nerd, right?
• 25:55
  SPEAKER_01: This it's a big difference, but it turns out everybody gets confused about this.
• 25:59
  SPEAKER_02: Well, I was I was sitting in a it was I think I'm having a little trouble remembering it because I was in graduate school, but I'm pretty sure it was a job talk.
• 26:06
  SPEAKER_02: Somebody was giving an interview talk, and I think they were just nervous, but they mixed up stress and strain in their talk repeatedly.
• 26:13
  SPEAKER_02: And our structural geologists on stuff at that point raised their hand and said, you know, I don't mean to pick, but I believe you're mixing these up.
• 26:21
  SPEAKER_02: Am I accurate in thinking that you're what you're referring to here is actually, I forget which way, stress or strain or something like that.
• 26:26
  SPEAKER_02: So that always sticks in my mind as the explanation of like don't screw those up.
• 26:30
  SPEAKER_02: Yeah, it was I think it was but I think it was like a postdoc interview or something.
• 26:34
  SPEAKER_02: It wasn't like uh I don't think I don't remember as a faculty job, but it was a job that was more it was a talk that was there was more pressure to it than just that.
• 26:41
  SPEAKER_02: But anyways, stress and strain.
• 26:42
  SPEAKER_02: I was like, ooh, don't mess, don't forget those the difference between them.
• 26:46
  SPEAKER_01: So yeah, no, and it you know, it's good.
• 26:48
  SPEAKER_01: It's like we're trying to sort of feed we want to know everything.
• 26:51
  SPEAKER_01: We want to know both.
• 26:52
  SPEAKER_01: Yeah, yeah.
• 26:53
  SPEAKER_01: You always have to work yourself backwards.
• 26:55
  SPEAKER_02: Yeah, this is such an interesting start.
• 26:57
  SPEAKER_02: So, okay, the the strain, you're seeing the strain, right lateral.
• 27:01
  SPEAKER_02: Chris, what do you think?
• 27:02
  SPEAKER_02: Is this a good time?
• 27:02
  SPEAKER_02: Should we dive into the Rockies?
• 27:03
  SPEAKER_02: Because we're kind of there.
• 27:04
  SPEAKER_02: Like, yeah, can we just get that?
• 27:06
  SPEAKER_02: I can tell you're kind of itching, itching to I am.
• 27:08
  SPEAKER_04: I I want to get to this because I I want to sp I want to make sure that we have as much time as we want to talk about the Rockies.
• 27:15
  SPEAKER_04: So, Basil, can you explain the traditional model for the formation of the Rockies first?
• 27:23
  SPEAKER_04: Can we start with that?
• 27:24
  SPEAKER_01: Sure.
• 27:25
  SPEAKER_01: So we'll just take the standard approach, which is in California, there's this idea that there must have been a subduction zone.
• 27:32
  SPEAKER_01: So that means the oceanic plate goes underneath North America and it produces when it m gets down and it releases its water, it produces an arc, and that's the Sierra Nevada arc.
• 27:46
  SPEAKER_01: That's just normal subduction.
• 27:47
  SPEAKER_01: And then associated with that is right at the plate interface, things are a mess.
• 27:53
  SPEAKER_01: So that's called an accretionary prism, just because the two plates are together, and you can imagine there's a lot of off-scraping and so forth.
• 28:00
  SPEAKER_01: So in California, that's the Franciscan.
• 28:03
  SPEAKER_01: And then between those two is a basin, and so that basin is called the Great Valley.
• 28:08
  SPEAKER_01: So if you've ever been to California, you've been to Sacramento, that's called the Valley, and it's flattered pancake, and we get our vegetables from there in the Midwest during the winter, and it's a good thing.
• 28:19
  SPEAKER_01: So all of that is what people thought.
• 28:22
  SPEAKER_01: And then something really weird happens about 80 million years ago that that plate, rather than going down at a normal angle, just basically shoots off just underneath North America, just like skimming the bottom of the mantle away, and just basically pushing in and sort of like pushing against the bottom of a carpet.
• 28:47
  SPEAKER_01: It kind of pushes the carpet above it together and into lumps.
• 28:52
  SPEAKER_04: So this kind of flat slab subduction, right?
• 28:54
  SPEAKER_04: So you had a flat slab subduction.
• 28:56
  SPEAKER_04: You had a traditional subduction zone, relatively steep angle, and then you say that it just flattened out for whatever reason later on.
• 29:05
  SPEAKER_04: Now you're talking so the traditional subduction zone formed the severe rojini, right?
• 29:10
  SPEAKER_04: Is that that's what you're talking about?
• 29:11
  SPEAKER_01: Where it's a little bit more complicated than that, but the idea is that the severe, again, this is the old idea, is that the severe belt was already formed.
• 29:23
  SPEAKER_01: People had recognized that it started at it starts at 125, it's kind of kind of doesn't do very much, but it's definitely happening.
• 29:32
  SPEAKER_01: But then it really kicks on, you know, 195, something like that.
• 29:38
  SPEAKER_01: So in the traditional model, that this was what was going on in the retro arc.
• 29:42
  SPEAKER_01: So behind the arc with respect to the plate boundary.
• 29:46
  SPEAKER_01: So like and so the idea people had was well, this is no different from the Alt Plano in the modern day Andes.
• 29:53
  SPEAKER_01: So that there's a series of volcanoes in Chile that you can go see, but behind them, there's this high plateau that's about 18,000 feet high, and then coming off that 18,000 foot high, there's a series of faults that are basically thrust faults that are causing a shortening, so a horizontal compaction in Argentina.
• 30:18
  SPEAKER_01: And so people said, okay, so during the well, the uh Sierra Nevada is active, we get this altiplano, and then you do shallow subduction, and then you stop that, and then you push the deformation much further into the continent than that.
• 30:36
  SPEAKER_01: And so that's when you get things like the Wint River Mountains or the Black Hills in South Dakota or the Front Range in Colorado, any of those.
• 30:43
  SPEAKER_02: Can you play that forward a little bit?
• 30:45
  SPEAKER_02: Like what gets us from there to you know what happens after the slab goes down there, and then right.
• 30:50
  SPEAKER_01: So then the flat then the slab has to leave, right?
• 30:53
  SPEAKER_01: And so you peel it off, and then the idea is that allows the mantle's got to come back in, then, right?
• 31:01
  SPEAKER_01: Because you can't take something away.
• 31:03
  SPEAKER_01: And the so the idea is a mantle which can flow at certain levels anyway, comes back in and it warms up, and so it creates some magmatic centers.
• 31:16
  SPEAKER_01: See, these are the things that are not particularly well known, sort of commonly the Henry Mountains in Utah might be something that people would know.
• 31:25
  SPEAKER_01: But these are things along the Utah and Nevada border for the most part, and so this is Cenozoic magmatism.
• 31:33
  SPEAKER_02: And then is that that that sort of coincides with well, okay, correct me where I'm wrong here.
• 31:39
  SPEAKER_02: I'm gonna say something.
• 31:40
  SPEAKER_02: I'm very open to this being wrong.
• 31:41
  SPEAKER_02: But isn't the idea that you have this big high mountain belt and and you know you dilute remove the flat slab, and then you kind of have this orogenic collapse thing that leads to basin and range extension, and it kind of sloughs out on itself a little bit.
• 31:52
  SPEAKER_02: It that's a very simplistic understanding of basin range, but how do we get from that to basin and range?
• 31:57
  SPEAKER_02: Is kind of okay.
• 31:58
  SPEAKER_01: So the originic plateau comes down a little bit, but it still doesn't look like Nevada that we know today.
• 32:04
  SPEAKER_01: What happens with that, and this is pretty well accepted.
• 32:08
  SPEAKER_01: This was Tanya Atwater was really the person who nailed this one.
• 32:13
  SPEAKER_01: So the subduction ends, let's say 50 million years ago, or 55 really million years ago.
• 32:20
  SPEAKER_01: That's when we don't have any more evidence for shortening in Wyoming.
• 32:25
  SPEAKER_01: It swings back, you go back to a normal subduction zone in California.
• 32:31
  SPEAKER_01: But what happens then is that the Pacific plate, you subduct all the Ferrallon plate and you locally push North America right against the Pacific plate.
• 32:42
  SPEAKER_01: And the process takes a long time because of these weird monterey microplates off California.
• 32:48
  SPEAKER_01: You don't need to know anything about that, except that at 19 million years, the Pacific plate grabs Western California.
• 32:55
  SPEAKER_01: It grabs everything from Mendocino all the way down through LA, and that joins the Pacific Plate.
• 33:02
  SPEAKER_01: But the Pacific Plate is moving away from North America in addition to moving right laterally.
• 33:08
  SPEAKER_01: So it's moving north toward Alaska, but it's also moving just straight out away.
• 33:13
  SPEAKER_01: And 19 is when the entire basin range starts.
• 33:16
  SPEAKER_02: Okay.
• 33:16
  SPEAKER_01: So gotcha.
• 33:17
  SPEAKER_01: When Western California is grabbed, everything starts.
• 33:21
  SPEAKER_01: And so there's a whole separate history of that versus this earlier history, which seems to really be done around 30 million years ago.
• 33:31
  SPEAKER_02: Okay.
• 33:31
  SPEAKER_02: So the debate we're kind of going to focus on is between 55 and 30 million years?
• 33:36
  SPEAKER_02: Is the the debate?
• 33:38
  SPEAKER_01: No, the debate is really in the let's say the 125 to 55.
• 33:43
  SPEAKER_02: Oh, okay, gotcha.
• 33:44
  SPEAKER_04: The flat slab subduction zone.
• 33:47
  SPEAKER_04: The flat slab subduction.
• 33:48
  SPEAKER_04: Okay, so Basil, can you explain why that like that very prevalent model?
• 33:56
  SPEAKER_04: What's problematic with it?
• 33:59
  SPEAKER_01: Great question.
• 34:00
  SPEAKER_01: So the PhD student walking around the Sierra Nevada said, wait a minute, there's a right lateral shear zone.
• 34:06
  SPEAKER_01: This doesn't make any sense, right?
• 34:08
  SPEAKER_01: If all if this is the time that you're trying to make flat slab subduction, nobody had called on it being oblique subduction.
• 34:15
  SPEAKER_01: It was just straight in.
• 34:16
  SPEAKER_01: That's completely incompatible with this right lateral slip.
• 34:21
  SPEAKER_01: And then I went to school with a friend, Julie Maxon, and she was working in Canada.
• 34:29
  SPEAKER_01: She's a sedimentologist.
• 34:30
  SPEAKER_01: She was working on um the detailed sedimentology, and she hooked up with uh another scientist, Jane Wynne, and they looked at the paleomagnetic signature of this basin Julie was working on, which was the Tyoton.
• 34:45
  SPEAKER_01: Julie is a sedimentologist, so she knows really well when things are horizontal, right?
• 34:50
  SPEAKER_01: Because she has this bedding and she knows what are the fine-grained beddings to do.
• 34:54
  SPEAKER_01: When they did all that study, and the study's perfect for Paleo Mag for a variety of different reasons, they found that the that basin, which is now in sort of central British Columbia, couldn't have been there.
• 35:08
  SPEAKER_01: That the paleomagnetic data said it was offshore Mexico when it formed at about 80 million years.
• 35:15
  SPEAKER_01: Well, let's say it's 85, 3,000 plus.
• 35:19
  SPEAKER_04: Holy cow.
• 35:20
  SPEAKER_04: Okay.
• 35:20
  SPEAKER_04: All right.
• 35:21
  SPEAKER_04: That's okay.
• 35:22
  SPEAKER_01: Okay.
• 35:22
  SPEAKER_04: That's a lot of that's a lot of movement.
• 35:24
  SPEAKER_01: That's a lot of movement.
• 35:26
  SPEAKER_01: But if that's there, it's attached to this whole other thing called the insular super terrain.
• 35:34
  SPEAKER_01: We know the insular super terrain has a huge set of faults on its eastern side, and they're all a hundred million years old.
• 35:44
  SPEAKER_01: So it hit something at a hundred.
• 35:46
  SPEAKER_01: I mean, there's no ambiguity about that.
• 35:48
  SPEAKER_02: The insular terrain hit something.
• 35:52
  SPEAKER_01: Okay.
• 35:52
  SPEAKER_01: But the problem is the paleomagnetic data said it had to hit northern Mexico, the western United States, and maybe even up into Canada.
• 36:00
  SPEAKER_01: Because it's so big that you can't get around it.
• 36:05
  SPEAKER_01: And if that's true, you can't have a shallow slab.
• 36:10
  SPEAKER_01: Right?
• 36:11
  SPEAKER_04: Okay, how come?
• 36:12
  SPEAKER_04: How come?
• 36:13
  SPEAKER_01: Because the this terrain as it comes in has a magmatic arc.
• 36:18
  SPEAKER_01: It has a subduction zone under it the whole time.
• 36:22
  SPEAKER_01: You can't put yet another subduction zone in there to go shallowly.
• 36:27
  SPEAKER_01: You have to have one subduction zone out in the Pacific Basin underneath the insular terrain, so it has its own magmatic arc that keeps going this entire time.
• 36:38
  SPEAKER_01: And then you have to put a strike slip fault between the insular super terrain and North America.
• 36:44
  SPEAKER_01: The problem is you run this thing in.
• 36:47
  SPEAKER_01: The California and all of basically western part of the US had the insular terrain against it rather than anything else.
• 36:58
  SPEAKER_01: There's two interesting predictions.
• 36:59
  SPEAKER_01: It says at 100, everything's going to be dextral because you have to move the stuff from way south to way north.
• 37:07
  SPEAKER_01: And that was exactly what we were seeing in the arc.
• 37:09
  SPEAKER_01: And it was just like Okay.
• 37:11
  SPEAKER_04: All right.
• 37:11
  SPEAKER_04: So Basil, you saw this dextral motion.
• 37:14
  SPEAKER_04: How did you come across the Paleomag then?
• 37:17
  SPEAKER_04: Did you go looking for that data?
• 37:19
  SPEAKER_01: No, Julie and I drank way too much coffee.
• 37:21
  SPEAKER_01: So, like, okay, every day Cafe Royale, right?
• 37:26
  SPEAKER_01: And we're just jabbering about something.
• 37:30
  SPEAKER_04: So was she coming to the same conclusion you were, just uh like coming at this from two different directions?
• 37:36
  SPEAKER_01: Yeah, that's exactly right.
• 37:38
  SPEAKER_01: Because I want to say this the people who have been doing the Paleomag have not been focused on the Western part of the US because they've been focused on what moved, which is all now in Canada.
• 37:49
  SPEAKER_01: And so it left the people in the Western U.S.
• 37:51
  SPEAKER_01: to say, okay, well, is there a terrain there?
• 37:53
  SPEAKER_01: But nobody was willing to go there.
• 37:55
  SPEAKER_01: It was fascinating.
• 37:57
  SPEAKER_04: Can you say, can you talk about why?
• 37:59
  SPEAKER_04: Why was nobody willing to go there?
• 38:01
  SPEAKER_01: Oh, sure.
• 38:02
  SPEAKER_01: So Julie and I wrote this paper.
• 38:04
  SPEAKER_02: Uh, which is this the hit and run paper?
• 38:06
  SPEAKER_02: Is this the hit and run paper 96?
• 38:09
  SPEAKER_02: Oh, one of one of the cooler titles.
• 38:12
  SPEAKER_02: I mean, just a very, very cool title.
• 38:14
  SPEAKER_02: Well done on coming up with that.
• 38:16
  SPEAKER_02: I think that's great.
• 38:17
  SPEAKER_01: Well, we'll we'll see.
• 38:19
  SPEAKER_01: Some people like it, some people don't.
• 38:20
  SPEAKER_01: But anyway, so it was just because we were talking about it all the time.
• 38:25
  SPEAKER_01: And people would get up and scream at us.
• 38:28
  SPEAKER_01: Literally, like people who are reasonable people, you know, these are geologists, they're cool, they're the people I like to hang out with, would just get really worked up over this, and we're like, this is the data.
• 38:40
  SPEAKER_02: I mean, like when you're this is when you're giving talks at conferences or posters or that kind of thing.
• 38:45
  SPEAKER_02: Okay.
• 38:45
  SPEAKER_01: Yeah, exactly.
• 38:46
  SPEAKER_01: Wow.
• 38:46
  SPEAKER_01: That you can't do that.
• 38:47
  SPEAKER_01: And I had a good friend who said, You should not do this.
• 38:51
  SPEAKER_01: If you keep doing this, everybody's gonna think you're a crackpot.
• 38:54
  SPEAKER_01: Oh, really?
• 38:55
  SPEAKER_01: And you know, let's just say a lot of people are more politically astute than I am.
• 39:00
  SPEAKER_01: And so I I was like, okay, this guy clearly is looking out for my best interest, and so that's what I'm gonna do.
• 39:09
  SPEAKER_01: And so I went to the Idaho wilderness at that point, right?
• 39:13
  SPEAKER_01: I went to work in Idaho, I left the Sierra because of this.
• 39:16
  SPEAKER_04: You needed you felt like you needed to avoid the controversy.
• 39:19
  SPEAKER_01: Oh my gosh, there's so much controversy in the Sierra Nevada.
• 39:21
  SPEAKER_01: I don't know what it is, it's the water.
• 39:23
  SPEAKER_01: Oh man, I don't know.
• 39:24
  SPEAKER_02: I had a PhD stud a PhD student who's working on, I mean, he's really working on zircon geochemistry, but you know, in the twelve media intrusive suite and just published his first paper.
• 39:31
  SPEAKER_02: And you know, it was a it is a controversial place to work, whether you're a geochronologist, a geochemist, or apparently a structural general, like it's just it's something that people studied for so long, there's such cemented opinions about, I think.
• 39:46
  SPEAKER_01: And yet we can come back to this.
• 39:48
  SPEAKER_01: There's things that we just don't know.
• 39:50
  SPEAKER_01: Like it's crazy.
• 39:52
  SPEAKER_01: Like there's so much to do.
• 39:54
  SPEAKER_01: So, anyway, okay, I made a very strategic move because Idaho, first of all, nobody cares about Idaho.
• 40:01
  SPEAKER_01: Like nobody, like it's just not part of anybody's model.
• 40:04
  SPEAKER_01: It doesn't fit the California subduction model, and it doesn't fit the Canadian model.
• 40:09
  SPEAKER_01: But if you just restore the faults, you take the faults in the in Canada and in the North Cascades, and you just restore them.
• 40:18
  SPEAKER_01: The insular terrain has to be outboard of Idaho.
• 40:21
  SPEAKER_01: Sandra Wyatt.
• 40:22
  SPEAKER_02: Outboard, meaning, meaning out in the ocean, away from the ocean, because the Idaho Bath this is the Idaho Batholith.
• 40:28
  SPEAKER_02: Is that what you're talking about?
• 40:29
  SPEAKER_02: This is the Idaho Bath, exactly.
• 40:30
  SPEAKER_02: That's an arc that's the same as the Sierra Nevada's, right?
• 40:34
  SPEAKER_02: Kind of brought at the same time and it extends all the way up into British Columbia.
• 40:38
  SPEAKER_02: That is what we thought.
• 40:40
  SPEAKER_02: Oh, okay.
• 40:40
  SPEAKER_02: That yeah, yeah, sure.
• 40:41
  SPEAKER_02: Traditional model.
• 40:42
  SPEAKER_02: Okay, traditional model would say.
• 40:43
  SPEAKER_02: Okay.
• 40:44
  SPEAKER_01: But if you buy the Paleo mag, it's there, right?
• 40:47
  SPEAKER_01: Because the whole thing's so big.
• 40:48
  SPEAKER_01: You can move it down to Mexico and it's still against Idaho.
• 40:50
  SPEAKER_01: So it had to be there.
• 40:52
  SPEAKER_01: But even if you didn't buy that, even if you thought that the Paleo Mag somehow was a mass hallucination by a community, you can still restore all the faults, and the faults are all offshore Idaho, which is to say the terrain must be as far south as Idaho.
• 41:09
  SPEAKER_01: All right.
• 41:10
  SPEAKER_02: Which terrain are you referring to there?
• 41:11
  SPEAKER_01: So this is the insular super terrain or the Baja BC.
• 41:15
  SPEAKER_01: Okay.
• 41:15
  SPEAKER_04: So hold on a second.
• 41:17
  SPEAKER_04: You you say you're going to Idaho to avoid the controversy, but what you're saying is you're going to Idaho to maybe keep stirring it a little bit, right?
• 41:26
  SPEAKER_04: You you found stuff.
• 41:28
  SPEAKER_01: Oh, it was I went there to figure out the problem, right?
• 41:32
  SPEAKER_01: But I didn't have to say I was figuring out the problem.
• 41:35
  SPEAKER_01: I could just say, I'm, you know, here's an interesting place to go.
• 41:38
  SPEAKER_01: And and the thing about Idaho, it's interesting because I've really enjoyed working there.
• 41:44
  SPEAKER_01: The people there, the workers there are just happy to have anybody else working there because like there's so much to do, and like nobody cares.
• 41:50
  SPEAKER_01: And it's always nice to have somebody who cares, right?
• 41:52
  SPEAKER_01: So yeah.
• 41:53
  SPEAKER_01: So I was happy to work there, and I thought, okay, I'll study Pluton in placement.
• 41:58
  SPEAKER_01: I'll get back to what this thing I was gonna do for my PhD, study Pluton in placement.
• 42:03
  SPEAKER_01: And I get to Idaho and it's a right lateral shear zone.
• 42:07
  unknown: Yeah.
• 42:09
  SPEAKER_01: And it's just like, what did I do wrong?
• 42:11
  SPEAKER_01: Right?
• 42:12
  SPEAKER_01: So I keep trying to study an arc, and I keep failing because there's this thing that's called the Western Idaho shear zone.
• 42:19
  SPEAKER_01: And here's the thing about it it looked exactly like some of the rocks in the Sierra, except way more so.
• 42:23
  SPEAKER_01: It's way more deformed.
• 42:25
  SPEAKER_01: And what's interesting about it, you can tell exactly when it started because again, it took like 15 years to sort of work all that out.
• 42:34
  SPEAKER_01: No, 20.
• 42:35
  SPEAKER_01: But whatever.
• 42:36
  SPEAKER_01: It started 100.
• 42:37
  SPEAKER_01: It started at 100.
• 42:39
  SPEAKER_01: I mean, it's very clear when it started.
• 42:42
  SPEAKER_02: The deformation or the the magnetism?
• 42:44
  SPEAKER_01: The deformation, the magmatism actually is before and it's after.
• 42:48
  SPEAKER_02: Oh, okay.
• 42:49
  SPEAKER_02: So both.
• 42:50
  SPEAKER_01: And but this this timing of this shear zone is 100 to 85.
• 42:55
  SPEAKER_01: And I should give credit.
• 42:56
  SPEAKER_01: I mean, that we've done some fancy things.
• 42:58
  SPEAKER_01: Claire Harrigan working with Mark Schmitz at Boise State, and then Sarah Trevino, who did a PhD in a postdoc here, really nailed this and done it in a really cool way.
• 43:10
  SPEAKER_01: So we can actually tell when that shear zone started, which is a hard thing to do.
• 43:14
  SPEAKER_01: But it's like, no, wait a minute.
• 43:16
  SPEAKER_01: So this arc is also going on.
• 43:18
  SPEAKER_01: So the idea with studying this here in Idaho, there's no ambiguity about what happened.
• 43:23
  SPEAKER_01: The arcs go into this dectural transpression, so this right lateral smash and move at the same time, and they're all doing it at 100.
• 43:33
  SPEAKER_01: They start at 100 and they keep going.
• 43:36
  SPEAKER_01: So the Idaho Western Idaho Shear Zone was active when the shear zone I was looking at in the Sierra was active.
• 43:42
  SPEAKER_04: So, Basil, can you just uh I feel like we need to back up a little bit and describe in as visual a way as we can what you're saying the insular peninsula did?
• 43:53
  SPEAKER_04: It hit and then it ran.
• 43:55
  SPEAKER_04: Can you describe that a second?
• 43:57
  SPEAKER_04: And then let's I just want to make sure that everybody can.
• 44:00
  SPEAKER_04: has like a kind of this visualization of what's what we're talking about and then we'll talk about some of the other things.
• 44:05
  SPEAKER_02: Could could we maybe do that for the traditional model as well?
• 44:09
  SPEAKER_02: And especially I mean I I came of age scientifically in Canada where I think it was the five terrains or something in British Columbia.
• 44:15
  SPEAKER_02: I didn't study British Columbia geology, but these five terrains they're kind of just shoved on board.
• 44:19
  SPEAKER_02: Can you do that?
• 44:20
  SPEAKER_02: I don't know, Chris, maybe we've already done this.
• 44:22
  SPEAKER_02: Do you feel like we've done this well enough?
• 44:23
  SPEAKER_02: Like how does stuff get accreted to a conversation and Jesse you and I have talked about the flat slab and yeah yeah I'm just thinking about this kind of accretion no movement right or left but just kind of throwing stuff on a con and maybe we've done that pretty well already actually so well that right that's the Canadian model.
• 44:37
  SPEAKER_01: So the Canadian model is also a 2D model.
• 44:40
  SPEAKER_01: It's just that there's and I'm going to simplify it down to two one comes in called the Intermontane Super Terrain which consists of a lot of terrains and it just basically smashes on board then you wait 50 million years and then the next one comes in.
• 44:55
  SPEAKER_01: Maybe it's a hundred million years.
• 44:57
  SPEAKER_01: So it's one boom and then the next boom comes in in Canada.
• 45:02
  SPEAKER_01: So the story I was telling you was kind of how I got there rather than the story of how I think the mountain belt got there.
• 45:09
  SPEAKER_01: So Chris I think wants me to tell the mountain belt story which I'm happy to do just to sort of set the stage.
• 45:14
  SPEAKER_02: Of the hit and run model is that right Chris of the hit and run model.
• 45:17
  SPEAKER_01: Yeah absolutely yeah yeah so there's something like Japan.
• 45:22
  SPEAKER_01: In fact maybe make it two Japan's that's sitting out in the Pacific basin and it's on a separate plate.
• 45:30
  SPEAKER_01: And that plate is subducting underneath North America.
• 45:34
  SPEAKER_01: It's not the Farallon plate it doesn't matter what its name is but it's a separate plate.
• 45:39
  SPEAKER_01: And because it's subducting under North America it's pulling this Japan with it.
• 45:44
  SPEAKER_01: And then at a hundred million years round numbers Japan's got nowhere to go because it can't go down and it just basically smashes on to the western edge of North America.
• 45:56
  SPEAKER_01: But it smashes in northern Mexico it does not smash in southern Mexico there's actually no evidence for that but there is reasonable evidence in northern Mexico that this is true.
• 46:06
  SPEAKER_01: And it hits the Sierra California system it hits the Idaho system and there's some evidence in Canada that it also hit up there.
• 46:16
  SPEAKER_01: So the idea is that it just it hits at 100 but it wants to move north too so it takes the weakest part of the system which is the magmatic arcs and it puts all the strikes left faults into that arc.
• 46:30
  SPEAKER_01: So the hit is between 100 and 85 and it hits and it's smashing the arcs the arcs are getting basically shortened at least the Idaho one is and North America unbelievably feels this hit.
• 46:45
  SPEAKER_01: There's an uplift in Texas called the San Marcos Arch that is up at 100 so it this thing is not just I mean it hits and it hits hard there's all these uplifts the Rockies go further east than you think because there's these uplifts and arches but they're covered by the detritus the miles of detritus that are basically coming off the Colorado Rockies.
• 47:10
  SPEAKER_01: So there is nothing coming up before 100 and then there's a lot coming up starting at 100.
• 47:15
  SPEAKER_01: And so if it's like wait a minute it's a hundred we know it's a hundred from the insular terrain we know it's a hundred because that's when the arcs are going and you look inboard and the block uplifts are starting to go up not all of them but some of them are starting to go up at 100.
• 47:30
  SPEAKER_01: And so it's like wait a minute that's just too coincidental.
• 47:34
  SPEAKER_01: The severe thrust belt which people thought was this ongoing thing it turns out you keep dating it it keeps coming up at 100.
• 47:41
  SPEAKER_01: So the severe belt turns on at 100 there is a severe belt before then it turns out that's a complicated 3D effect.
• 47:48
  SPEAKER_01: But in terms of a major feature it really starts at 100 and then just keeps going.
• 47:54
  SPEAKER_01: Okay.
• 47:54
  SPEAKER_04: Um what about the run part then so that's a good question.
• 47:59
  SPEAKER_01: So and I and I think the answer is again in the arcs.
• 48:02
  SPEAKER_01: The arcs only have magmas because there's a subduction zone.
• 48:06
  SPEAKER_01: But that subduction has stopped right because that insular is now against North America the plate keeps going down so you get about 10 million years more of magmatism as this thing eventually burbles its way down into the mantle than it stops.
• 48:22
  SPEAKER_01: And you don't have anything else to produce magmas.
• 48:24
  SPEAKER_01: So the arcs freeze and the thing that was taking up the faulting that took up the shearing can't do it.
• 48:32
  SPEAKER_01: And you have to break into a new system and it breaks over on the plate boundary and now you don't see the effects on North America except for the irregularities of the boundaries but basically it's like a hit and a lean when I say that run the run is more like a run lean right as this thing basically leans against the continent as it goes north.
• 48:54
  SPEAKER_02: So it's smashing when it when it hits it hits kind of at an oblique angle and there's there's this big magma mush zone because of the subduction zone.
• 49:02
  SPEAKER_02: So it kind of squishes that and and moves that magma mush zone to the north starts to move everything on the continent as well because there's like what 100 150 kilometers of continent before you get to the volcanic arc so all that's kind of going north then the magma shuts off freezes the continent and now this new addition this sort of Japan like thing just scrapes along the edge of the continent as it goes north.
• 49:24
  SPEAKER_02: Yes.
• 49:25
  SPEAKER_02: So square this for me that how do you get deformation so far inboard while having a big squishy why isn't all that I don't know what the right word is stress or stress stress accommodated by the why don't you just squish the arc out of existence as opposed to like all this deformation what 5000 kilometers inboard?
• 49:45
  SPEAKER_02: Like how far is that?
• 49:46
  SPEAKER_02: That's a long ways inboard like how do you get it that far on a squishy margin I guess.
• 49:51
  SPEAKER_04: Basil is that jumping ahead in in your story because I feel like there's stuff in between that needs to be teased out first.
• 49:58
  SPEAKER_04: Is that what do you think?
• 49:59
  SPEAKER_01: Well I I I I can answer Chris's question easily I I think and then we can go back to it.
• 50:04
  SPEAKER_01: It's a good question.
• 50:06
  SPEAKER_01: And the answer is that the crust is not where the strength in the mantle is the strength is in the mantle and the mantle can transmit that.
• 50:15
  SPEAKER_01: There's no way stress can be transmitted through a crust in that way the crust feels it because of this weak rheology but the push must be in the mantle whenever you run two things together that you won't subduct India into Asia you form these far foreland uplifts right Lake Vikal is going up and down in Russia because of India which is a long way away and you go to India and it's flat in a pancake I mean it's amazing so oh that's interesting.
• 50:46
  SPEAKER_02: Just because there's like quartz in the crust or there's these quartz and feldspar's deformable lithologies in the crust they can't transmit that that strain but the lithosphere is rigid enough the mantle the upper part is rigid enough to kind of transmit that force all the way in exactly yeah okay oh interesting that's very cool.
• 51:02
  SPEAKER_04: Sorry Chris that that's just totally no no that's okay basil I I like analogies and I want to try to I'm gonna give a go at this a second so the insular hit and run it's kind of like a Chris is going to bring up his tractor probably right now and use an analogy with his tractor.
• 51:17
  SPEAKER_04: Okay you're not a tailback gets the ball and just a violent collision at the line of scrimmage and there's nowhere to go and so the tailback then stays up and just bounces it laterally to the side to the outside hit and run.
• 51:32
  SPEAKER_01: That's what happened to the Insular peninsula yes um yeah I I maybe football it's not my sorry I can't really admit that in Wisconsin with the power this thing and then slide badger country yeah yeah right yeah so yes but I think it's the oblique motion of the surrounding plate that's that's moving it.
• 51:54
  SPEAKER_01: So in other words even these big arcs are embedded into a plate tectonic system right and they if the subduction is pulling it to the north it will go to the north so that it's it's that long tail that really pulls it so the fact that the insular terrain goes north might be because there's a subduction zone to the north side of it that keeps going and keeps dragging it towards Alaska.
• 52:22
  SPEAKER_01: Alaska also known as the Great Terrain wreck because all sorts of things wind up in Alaska it's just like it just it's where everything loose and it goes up there.
• 52:33
  SPEAKER_02: Oh that's really interesting.
• 52:34
  SPEAKER_02: Okay so Chris do you think we've covered the this part like I have so many questions about like you know reception of this model and what's needed to go forward and all that kind of stuff.
• 52:44
  SPEAKER_01: But I don't I want to make sure we Jesse we have to get to that yeah but I want to cover the topic first you know that okay so basil the the flat slab subduction model explains how this went so far inboard right how did that happen with the hit and run model it turns out it's a weakness of the shallow slab it's not a strength of the shallow slab that it went as far the uplifts are further east and they start earlier than the shallow slab is intended can predict they think that the seduction is still going on until 80 that the uplifts are starting at 100 that's a problem so there's a timing so am I reading that wrong I I guess I always thought that that was the flat slab model I think came into being to explain how far how how the Rockies got so far inland.
• 53:35
  SPEAKER_01: That's correct and it and it did that by analogy with the Sierra Pompeonis because they could look at that but the Sierra Pompeyanis first of all they're up in the early Cretaceous do the really shallow uranium therm helium dating they're up in the early Cretaceous where are the Sierra Pump Pump they're in Argentina oh this is Argentinian okay and the Andes analog and they are much closer to the continental market than the uplift that we have and the other problem is I mean you can't get around there's everything's right lateral.
• 54:10
  SPEAKER_01: So basically I go back to the Sierra and there was a student Aeneas stories Andre who looked at that and we found that the shear zones actually they started 100 in the Sierra as well and so the Sierra is see is seeing the 100 million year effect.
• 54:25
  SPEAKER_01: And then David Green remember David Green from back there also kept working and he documented that there's a huge event and it's right at 100.
• 54:34
  SPEAKER_01: So it's like wait a minute there's a predictive model here that says something is happening at 100.
• 54:41
  SPEAKER_01: So what's fascinating to me is there's actually yet another model by Bob Hildebrand and it's interesting to me that there's now three different models to explain the same set of data.
• 54:51
  SPEAKER_01: And it's like as soon as there's like a problem scientists are very creative.
• 54:55
  SPEAKER_01: They will come up with ways of solving things I don't think Bob's model works and it's way more mobilist than the hit and run.
• 55:02
  SPEAKER_01: The hidden run's like a conservative way of trying to explain these things and I think if I'm wrong about the hit and run it's because I'm not being mobilist enough.
• 55:12
  SPEAKER_01: It's not that I'm being too crazy.
• 55:14
  SPEAKER_01: I mean I'm not being crazy enough.
• 55:16
  SPEAKER_01: Interesting can you transmit strain all at 100 MA rough numbers I mean if if something hits can you impose deformation inboard of a continent and is there a good analogy for that like way like really quickly so again most of the Rockies that we think of sort of uh wind river range front range in Colorado they have a small uplift event at a hundred to eighty five in the hit range but they really kick on after 85 sort of in the 80s so you can see why people came up with the shallow slab at 80 because there is more uplift particularly in Wyoming at that time but that doesn't say that there wasn't this earlier uplift as well okay that that makes complete sense okay so I think of it as like you're pushing on the edge of a really stiff carpet and the carpet will fold or there'll be a pre-existing weakness that you'll just reactivate.
• 56:12
  SPEAKER_02: Alright that makes a lot of sense so how do you get the Cenozoic volcanism in this hit and run model?
• 56:18
  SPEAKER_02: Ah because that always seemed a great strength of the Laramite is of the flat slab model as the flat slab dumps off and we can see you meet you melt hydrated like that's what the geochemistry looks like.
• 56:30
  SPEAKER_01: So is that compatible that's presumably with the hit and run model as well yeah I actually think it again I think this is a it's interesting that the best evidence for the shallow slab is actually what happened after the shallow slab right in some sense right what I think that Cenozoic magmatism is is the collapse of the orogenic plateau that formed as a result of the collision so the collision you still get this this sort of uh there's no question collapse of this thing and stretching yeah okay gotcha and it makes way more sense because if you go to Idaho again going on the analogy you have faults that reactivate the magnetism is older in Idaho and it's moving its way south that makes no sense with a shallow slab because the shallow slab is an east-west thing why would there be a north-south tendency but what's happening and this is just dumb luck on my part Idaho was the highest point in the origin and there's reasons for that that are hard to explain it's a 3D effect basically there's a corner in Idaho and things keep getting shoved on to that corner very much like the corner in Alaska and you see that from the the bending of the old North American continent and so there's basically the southward tearing down as you go as the thing collapses.
• 57:52
  SPEAKER_01: Oh so interesting yeah yeah I love that the thing that changed all of this the reason this has come back up is because they now have tomography you know images of the slab there's no shallow slab the shallow slab was supposed to be done 50 million years ago and the best technique you have for finding a slab is tomography and it's not there.
• 58:14
  SPEAKER_01: That's a problem.
• 58:15
  SPEAKER_02: You mean it's not sinking through the mantle right now.
• 58:17
  SPEAKER_02: It's not like you know beneath there sinking down.
• 58:20
  SPEAKER_01: The problem is the current plate that's down there has been going since 100 million years.
• 58:25
  SPEAKER_01: Like literally there's a plate that's going for 100 million years we see the whole thing there's no shallow part of it.
• 58:31
  SPEAKER_01: Oh I see I see you mean right because it's not broken there's no tear it's not broken yeah but it breaks at 100 and what's fascinating is that that's exactly what the hit and run model would predict that you run out of one plate and that plate's now way offshore in New Jersey.
• 58:47
  SPEAKER_01: We know where that is it's there and this plate is still existing.
• 58:52
  SPEAKER_01: You can wiggle your way around it but the fact is the reason the debate has come back up is that the mantle tomography is not consistent with the shallow slab it could be consistent with different models right it's not that it's really hard to find a single shallow slab down there.
• 59:10
  SPEAKER_01: Wait a minute you said something really interesting that I don't want to get lost you you said you you brought in New Jersey can you double click on that a second again sure so that's a long ways away from where we're talking so absolutely so and Karin Siglock is the person who really should be credited for doing this she she worked on the tomography and she initially interpreted as well as other people that there's this slab segment so a major thing it's actually pulling down New Jersey a little bit because of this effect of if you have something really heavy below you it sinks and it kind of sucks down the surface a little bit it's a matter of tens of feet but it's still an effect so it's kind of cool to think about so we don't have slabs and shallow slabs under continents what we have are slab walls and they go for thousands of kilometers and one of those walls is underneath basically the eastern seaboard New Jersey and the reason is that North America is moving west over time as the Atlantic opens.
• 1:00:18
  SPEAKER_01: So we are overriding the slabs that have been subducted it's like the perfect situation to figure out slabs.
• 1:00:28
  SPEAKER_01: And what's clear what they thought before was that the Farallon now undergoing underneath Oregon and Washington was connected to the New Jersey monster this big thing going down.
• 1:00:40
  SPEAKER_01: But they've now got resolution says no those are completely different things.
• 1:00:44
  SPEAKER_01: There's no connection between them so you can't a vertical wall literally it's literally a vertical wall.
• 1:00:50
  SPEAKER_01: Yeah it's really cool current data is amazing.
• 1:00:53
  SPEAKER_01: And then the question is how to interpret it and then there's yet another like wall that's down that's underneath like Kansas.
• 1:01:00
  SPEAKER_01: And so there's like these multiple different walls coming in and so you have to the slabs as Eldritch words once said don't have names on them right we don't know which belongs to what the only thing we're pretty sure of is the one that's attached to the Farallon plate is probably the Farallon plate.
• 1:01:16
  SPEAKER_02: Yeah yeah okay okay I want to I because we're we're kind of closing in on the end of our time here but from your view I mean what are the flaws in the hit and run model or or what are you uncertain about or what are you kind of making you know grasping at straws to explain or I I don't know how to explain ask this question but what are what do you think are the flaws or things that need to be tested about this model?
• 1:01:36
  SPEAKER_01: Yeah that's a that's a good question.
• 1:01:39
  SPEAKER_02: I know it's a tough one but or like what I I don't know what do you what piece of data would do you wish you had you know going forward?
• 1:01:47
  SPEAKER_01: Well okay I'll tell you what I'm thinking about is I'm pretty sure it hit in Idaho I'm pretty sure in California it'd be really nice to go to northern Mexico and see if we have exactly the same structures in exactly the same place where the Paleomegs say they are so that's one thing.
• 1:02:03
  SPEAKER_01: The second thing predicted this five years ago I still think it's gonna be true the battle's going to be in the Mojave.
• 1:02:09
  SPEAKER_02: Because the Mojave is completely trashed by this big event and so the question is is there going to be an arc there or is it a terrain collision there as you work that out because the Mojave has at least in its eastern part North America right it's all that stuff you see in the grand in the Grand Canyon comes all the way over and into the eastern you mean North American basement like this is not one of these terrains this isn't this old this like Japanese like thing or Japan like thing that hit this is all North American there's unambiguous 350 million years old North American continent.
• 1:02:43
  SPEAKER_02: Okay so that's where the where the I like the way you phrase that where the battles can be fought.
• 1:02:47
  SPEAKER_01: Right.
• 1:02:48
  SPEAKER_01: I I I think the Great Valley and Franciscan is is almost going to be a matter of faith.
• 1:02:55
  SPEAKER_01: There are people who just will never accept it it's sort of like the beginning of play tectonics right there are some people who just could never accept it and that's going to be true in California.
• 1:03:06
  SPEAKER_01: There's gonna be people who would just like nope didn't happen.
• 1:03:09
  SPEAKER_02: Sorry I I want to know that how do you interpret the Franciscan complex or how does the hit and run model explain the Franciscan complex?
• 1:03:17
  SPEAKER_01: Oh that's a that's a super good question.
• 1:03:19
  SPEAKER_01: So the Great Valley is rigid because it's sitting on basically oceanic lithosphere which is stronger than continental lithosphere and I think the Franciscan is way more of a jumble than other people think.
• 1:03:33
  SPEAKER_01: I think particularly the central belt of the Franciscan because the Franciscan's got some paleo mag problems of its own.
• 1:03:39
  SPEAKER_01: There's the Lawtonville stuff where there's a block that has moved 4000 kilometers from the south in that from paleomagnetic and the the timing is a little bit different but it's moved way from the south.
• 1:03:50
  SPEAKER_01: And so the question is like wait a minute that something else is going on.
• 1:03:54
  SPEAKER_01: Again the other thing about California is if you look up and down the coast there is not another California.
• 1:03:59
  SPEAKER_01: There's no place else where you have arc for arc accretionary prism.
• 1:04:03
  SPEAKER_01: It doesn't exist.
• 1:04:05
  SPEAKER_01: The only places that come close are actually the insular train when you're looking at the opposite side of the insular train not what hit North America but the opposite side and there it's like okay I can buy that.
• 1:04:16
  SPEAKER_04: Basil you said something um I want to ask a question.
• 1:04:20
  SPEAKER_04: I don't know if you want to answer it though so if you don't then we'll just you know cut this out but you mentioned the you know in the 1960s when plate tectonics came on and the you know this was kind of the same thing right people were screaming at each other over this is this the same thing do you see this on uh at that level you know the whole hit and run model versus the traditional model like is is that is that fair to ask it is so it's not the same insofar as it's not gonna sort of change how we think about plates generally the debate you can characterize a shallow slab versus hit and run the debate is actually you're gonna treat an origin as a two-dimensional thing or a three-dimensional thing that's really the gist of it and to me it's a three-dimensional thing where there's promontories and salience and the continent is you're hitting two things and neither one of them has a straight edge and you're just gonna get all kinds of weird effects.
• 1:05:20
  SPEAKER_01: So what we're I think we're doing is we're just looking at are we going to move into this next phase of being a little bit more subtle in like how we do that.
• 1:05:30
  SPEAKER_01: I mean it's kind of amazing here we are and we don't know why the Rocky Mountains formed like just astonishing it is just astonishing.
• 1:05:38
  SPEAKER_01: I so how and I think part of the problem is we never challenged it.
• 1:05:43
  SPEAKER_01: This idea that Dickinson and Snyder had that people just it went right from idea to like fact like people don't write this is the shallow slap hypothesis they're like there was a shallow slap under Colorado and I'm like whoa yeah that's a model for how things are but maybe that's That's not true.
• 1:06:00
  SPEAKER_02: It's not.
• 1:06:01
  SPEAKER_02: I have so many questions about how consensus builds.
• 1:06:03
  SPEAKER_02: Because we're see I at least I've been doing this long enough to see models that were consensus when I was in graduate school completely go away now.
• 1:06:10
  SPEAKER_02: Like the late heavy bombardment is almost completely dead as a model, and it happened since you know 2009 or whatever.
• 1:06:16
  SPEAKER_02: And so the question is like, how do these things get entrenched when the underlying data might be not that convincing upon close inspection?
• 1:06:25
  SPEAKER_02: And there's this really negative phrase of ideas, they don't die, it's people die, and the ideas and consensus go with them.
• 1:06:33
  SPEAKER_02: Do you think that's the case here?
• 1:06:35
  SPEAKER_02: And I know it's a really offensive way to phrase this, but like, is there people who have the initial ideas move on and another generation comes through with new ideas?
• 1:06:44
  SPEAKER_02: And maybe that's a healthy turnover way to turn over these things, or is it actually there's a brand new set of data like the tomography you referred to?
• 1:06:50
  SPEAKER_02: That's like, holy crap, we got to reconsider the entire game.
• 1:06:54
  SPEAKER_01: Um yeah, that's it's a tricky question to ask.
• 1:06:58
  SPEAKER_01: I've actually raised that exact issue before.
• 1:07:02
  SPEAKER_01: This was not a movable subject in 1996.
• 1:07:05
  SPEAKER_01: That became extremely clear to me that this was just there were people who were too entrenched, who were too sure that this was absolutely right and wouldn't accept that and any alternative.
• 1:07:17
  SPEAKER_01: Right.
• 1:07:18
  SPEAKER_01: It's just like it's talking to someone and saying, okay, here's a picture of a right lateral shears on the Sierra Nevada, and they're like, There's no right lateral on the Sierra Nevada.
• 1:07:24
  SPEAKER_01: It's just like, what do you do with that?
• 1:07:26
  SPEAKER_02: Yeah, you're like, okay.
• 1:07:27
  SPEAKER_02: So where do we go from here?
• 1:07:28
  SPEAKER_02: Yeah.
• 1:07:29
  SPEAKER_01: Right.
• 1:07:29
  SPEAKER_01: And so, like Elizabeth Miller, I really like Elizabeth Miller.
• 1:07:32
  SPEAKER_01: I think she does great science, but she also told me there's no way you can possibly convince me.
• 1:07:37
  SPEAKER_01: There's a church of the Laramide, and I'm part of that church.
• 1:07:40
  SPEAKER_01: That's that's her term, and I just can't we'll never be able to see it in that other way.
• 1:07:44
  SPEAKER_01: And I and you know, it's like this is great.
• 1:07:47
  SPEAKER_01: Thank you for telling me.
• 1:07:48
  SPEAKER_01: But things move on.
• 1:07:49
  SPEAKER_01: We're dealing with models, they're all models.
• 1:07:52
  SPEAKER_01: And the reality is the first Paleo Mag results are from 1972.
• 1:07:58
  SPEAKER_01: The win it all study that nailed it is 1995.
• 1:08:02
  SPEAKER_01: That's 30 years ago, and people are still just it's like la la la, I can't hear you about this paleomagnetic data.
• 1:08:10
  SPEAKER_01: It's just it makes no sense.
• 1:08:11
  SPEAKER_01: And the thing about the paleomagnetic data is it's so consistent and it tracks the progress of the terrain north.
• 1:08:19
  SPEAKER_01: You look at younger rocks, they're less far traveled.
• 1:08:22
  SPEAKER_01: Everything about it like holds together.
• 1:08:25
  SPEAKER_01: It is incumbent on us to try and figure out like how that happened.
• 1:08:29
  SPEAKER_01: And so people are like, oh, you put it offshore.
• 1:08:31
  SPEAKER_01: It's like you didn't put it offshore.
• 1:08:34
  SPEAKER_01: You know, it hits something, right?
• 1:08:35
  SPEAKER_01: There are pre-Cambrian grains in the Nanaimo group, which is undoubtedly on this stuff.
• 1:08:41
  SPEAKER_01: They're pre-Cambrian grains that started around 83.
• 1:08:44
  SPEAKER_01: It was against North America.
• 1:08:46
  SPEAKER_01: There's no way around this.
• 1:08:48
  SPEAKER_01: So I really don't know how this will play out.
• 1:08:51
  SPEAKER_01: In a way, the 1996 paper was just the foot in the door to say maybe we can be thinking about this, but it really wasn't cited very much.
• 1:08:59
  SPEAKER_01: It was cited less than like 50 times in its 20 years, and it's now getting cited more, right?
• 1:09:04
  SPEAKER_01: So something the 2023 paper is um is doing, you know, in terms of people looking at and thinking, oh, this is reasonable.
• 1:09:14
  SPEAKER_01: But the thing about that is I also, you know, you look at the history of science, and people will not reject an idea unless there's an alternative.
• 1:09:23
  SPEAKER_01: The 2023 is a very long paper, it is a slog to get through.
• 1:09:27
  SPEAKER_01: And I wrote it.
• 1:09:29
  SPEAKER_02: Yeah, uh, yeah.
• 1:09:31
  SPEAKER_02: It's uh it reads as a monumental piece of work, is what it reads like.
• 1:09:35
  SPEAKER_02: I'll be honest.
• 1:09:36
  SPEAKER_01: Well, it reads as a full articulation of what could have happened without like trying to piss anybody off, but just like maybe this is it, maybe this is it.
• 1:09:45
  SPEAKER_01: And now it's like, okay, there's at least there's now really three ideas out there about what happened, and you know, the paleo mag doesn't work with shallow slab at all, and the hundred million year event does not work with a shallow slab at all.
• 1:10:01
  SPEAKER_01: It's a sort of accumulation.
• 1:10:04
  SPEAKER_04: Basil, if you had an hour to teach the geology of the Rockies, first of all, could you do it?
• 1:10:13
  SPEAKER_04: Could you do it in that time frame?
• 1:10:15
  SPEAKER_04: And second of all, um, how different would it be the way you would approach this to the traditional models?
• 1:10:24
  SPEAKER_01: Um, I haven't figured it all out, right?
• 1:10:27
  SPEAKER_01: The data is still the data.
• 1:10:29
  SPEAKER_01: The people who are doing the geology in Colorado, Wyoming, it doesn't matter, are doing great geology, right?
• 1:10:36
  SPEAKER_01: And they're documenting it.
• 1:10:37
  SPEAKER_01: And although they interpret it in terms of a shallow slab, the data actually could be compatible with either.
• 1:10:46
  SPEAKER_01: So what we have the hard task of doing is going back and reading the literature and not reading the discussion so much and reading like what does your data actually say?
• 1:10:56
  SPEAKER_01: Because you can read papers and people have rejected papers outright because it doesn't fit the model, and that's crazy, right?
• 1:11:03
  SPEAKER_01: There's a lot of non-conforming data in the US West that just makes no sense in the shallow slab.
• 1:11:10
  SPEAKER_01: And those papers have been rejected.
• 1:11:12
  SPEAKER_02: And how much innumerable have not been published because of a discussion.
• 1:11:18
  SPEAKER_02: You know, are we limited to the amount of data we have because the discussions were antithetical to uh flat slab or something, something along those lines?
• 1:11:26
  SPEAKER_02: Yeah.
• 1:11:27
  SPEAKER_01: So can I teach it?
• 1:11:28
  SPEAKER_01: Yeah.
• 1:11:29
  SPEAKER_01: No, you can't possibly teach Rockies in and out.
• 1:11:33
  SPEAKER_01: Okay, fair.
• 1:11:34
  SPEAKER_03: Okay.
• 1:11:36
  SPEAKER_01: Would it be in some ways it's easier?
• 1:11:40
  SPEAKER_01: It's like the there's something called ancestral Rockies, and that's because Africa hit Texas and it went way far in.
• 1:11:47
  SPEAKER_01: And then there's something called the Rockies, and that's because the insular terrain hit North America and it went way far in.
• 1:11:53
  SPEAKER_01: And sometimes they reactivate the same thing.
• 1:11:55
  SPEAKER_01: And so in some ways, it's a much simpler solution.
• 1:11:59
  SPEAKER_01: The other things that makes way I mean, there's other things that make way more sense.
• 1:12:02
  SPEAKER_01: Like the Franciscan.
• 1:12:03
  SPEAKER_01: The Franciscan is the only example on the planet where there's blue shists being exhumed in a subduction zone.
• 1:12:09
  SPEAKER_01: Everywhere else on the planet, they're exhumed in a collisional zone.
• 1:12:13
  SPEAKER_01: And it's like, well, wait a minute, right?
• 1:12:16
  SPEAKER_01: So the like the first order problem that we don't even talk about anymore is why the Franciscan ever got to the surface.
• 1:12:22
  SPEAKER_01: And the answer is you squeezed it up, just like in every other origin.
• 1:12:25
  SPEAKER_01: Your mind just changes, and what be what was hard before is easy, but then raises other questions.
• 1:12:30
  SPEAKER_04: I kind of want to know what it's like for you, Basil, to be kind of this renegade bucking the norm.
• 1:12:38
  SPEAKER_04: You started doing this really early in your career.
• 1:12:41
  SPEAKER_04: You're a young PhD student, you know, trying to figure things out.
• 1:12:45
  SPEAKER_04: That journey been like, I'm just really interested in that.
• 1:12:48
  SPEAKER_01: That's an interesting question.
• 1:12:50
  SPEAKER_01: Um, I I think I don't mind being on the outside.
• 1:12:55
  SPEAKER_01: And I see myself as an outsider, and so it's fine.
• 1:13:00
  SPEAKER_01: I am not a mainstream California geologist in that sense.
• 1:13:04
  SPEAKER_01: So, like I worked with David Green.
• 1:13:06
  SPEAKER_01: David's awesome.
• 1:13:07
  SPEAKER_01: All right, I just enjoy working with him.
• 1:13:09
  SPEAKER_01: But he's always had more of sort of the inside track with those, and again, his dad was USGS or or whatever.
• 1:13:16
  SPEAKER_01: And so you just have to have a little bit of a thick skin about it.
• 1:13:21
  SPEAKER_01: But what's cool about it is you get to meet all the weirdos, right?
• 1:13:24
  SPEAKER_01: Because they're like, oh, this is your crazy idea.
• 1:13:26
  SPEAKER_01: Let me tell you my crazy idea.
• 1:13:28
  SPEAKER_01: It's like, all right, yeah, that's great.
• 1:13:30
  SPEAKER_01: So so it's been okay.
• 1:13:31
  SPEAKER_01: It's I think it takes a particular personality that doesn't mind.
• 1:13:37
  SPEAKER_01: And the other thing is I don't mind being wrong.
• 1:13:39
  SPEAKER_01: If I'm wrong, I'm happy to admit it.
• 1:13:41
  SPEAKER_01: And I've been wrong.
• 1:13:42
  SPEAKER_01: Like the idea of why I went to Idaho, I was just wrong about it.
• 1:13:46
  SPEAKER_01: I thought that the Western Idaho shear zone might have been the fault that moved the insular terrain, and that's just completely wrong.
• 1:13:51
  SPEAKER_01: And what's interesting to me about science is as soon as I gave that up, I found out it was way more interesting that that was wrong.
• 1:13:59
  SPEAKER_01: And then the what the reality was behind it is far more interesting.
• 1:14:04
  SPEAKER_02: I think it's a really important point.
• 1:14:05
  SPEAKER_02: You know, this willingness to be wrong.
• 1:14:06
  SPEAKER_02: We could society could use a little bit more of that uh willingness to be and uh ability to change your opinion without having repercussions.
• 1:14:16
  SPEAKER_02: Like, you know, we we we expect that people are right all the time and need to be able to change our mind on these things when new data comes in.
• 1:14:23
  SPEAKER_02: Question about education.
• 1:14:23
  SPEAKER_02: You've worked on the education stuff a lot in like spatial thinking.
• 1:14:27
  SPEAKER_02: I'm very curious why it's taken so long to think about a big orogenic event in three dimensions as opposed to two dimensions.
• 1:14:34
  SPEAKER_02: But I guess my question, I'm gonna phrase that as a little bit of a different question.
• 1:14:38
  SPEAKER_02: What is the value of a geology or geoscience degree?
• 1:14:42
  SPEAKER_02: And what do you tell students is the value of this degree that we offer all three of us kind of offer our inroads into?
• 1:14:52
  SPEAKER_01: Yeah.
• 1:14:52
  SPEAKER_01: Um what's great about geology is it lets you see the world in a totally different way.
• 1:15:00
  SPEAKER_01: So like you can live on the present walking around, but then you get the oh, why is this like this?
• 1:15:07
  SPEAKER_01: And then you get the it wasn't like this then, right?
• 1:15:10
  SPEAKER_01: And it's different now from when it was, but there's some similarities.
• 1:15:16
  SPEAKER_01: And oh, when this happened in Wisconsin, we were at the equator and North America was basically on its side, right?
• 1:15:23
  SPEAKER_01: And it's just like it's just an un things that are just like crazy just start to make complete sense.
• 1:15:29
  SPEAKER_01: And it's just like this this sort of world view.
• 1:15:32
  SPEAKER_01: I also think deep time in that sense is part of that.
• 1:15:36
  SPEAKER_01: It's not only that.
• 1:15:39
  SPEAKER_01: The older I get, the more I realize I've just enjoyed hanging out with geologists.
• 1:15:44
  SPEAKER_01: Um, right, and they're they're nice, but they're like they're not straight jacketed.
• 1:15:52
  SPEAKER_01: There's they're free to be a little bit outside the norm, and they're just great people.
• 1:15:57
  SPEAKER_01: They're good storytellers.
• 1:15:58
  SPEAKER_02: Yeah.
• 1:15:58
  SPEAKER_02: I find geologists to be the appropriate balance of like hardworking and you know, kind of willing to get their hands dirty, and also, as you're saying, like not overly pretentious about it, not too straight-laced, like you know, we're we're hardworking types that are the work hard, play hard mentality is alive and well amongst the geologists, which I think is really funny.
• 1:16:18
  SPEAKER_00: Exactly.
• 1:16:18
  SPEAKER_01: Yeah right.
• 1:16:19
  SPEAKER_01: And you know, is it that I got attracted to the field because that was the mentality, and I, you know, that's what I like, or you know, or is there something about the field that attracts that?
• 1:16:29
  SPEAKER_01: I don't know.
• 1:16:30
  SPEAKER_01: But I just I happily accept that.
• 1:16:31
  SPEAKER_01: That's just it's been one of the pleasures.
• 1:16:34
  SPEAKER_02: Yeah, I mean so cool.
• 1:16:35
  SPEAKER_02: Wow.
• 1:16:35
  SPEAKER_02: Anyway, thanks.
• 1:16:36
  SPEAKER_02: That was a great answer.
• 1:16:37
  SPEAKER_02: I appreciate that.
• 1:16:38
  SPEAKER_02: Chris, do you want to take us out with the last question here?
• 1:16:40
  SPEAKER_04: Yeah, so Basil, we always ask this as our last question.
• 1:16:44
  SPEAKER_04: What has been or what is what was the best day for you as a geoscientist?
• 1:16:51
  SPEAKER_00: Oh boy.
• 1:16:53
  SPEAKER_00: Um I'm gonna expand that to a week.
• 1:16:58
  SPEAKER_02: Okay.
• 1:16:58
  SPEAKER_02: Oh, okay.
• 1:16:59
  SPEAKER_02: Oh, interesting.
• 1:17:00
  SPEAKER_02: This is the first time we've had this as a as an answer.
• 1:17:02
  SPEAKER_02: I like this.
• 1:17:03
  SPEAKER_01: So in Idaho, we got this bit of data, and it made absolutely no sense.
• 1:17:11
  SPEAKER_01: And it was paleomagnetic data, and it said that that Idaho, that this area that I've been working had been rotated 30 degrees.
• 1:17:20
  SPEAKER_01: And I just I ignored it.
• 1:17:21
  SPEAKER_01: I just basically was like, I can't deal with this.
• 1:17:24
  SPEAKER_01: Like, I'm just there's too much going on.
• 1:17:25
  SPEAKER_01: And then there was one week where I was like, wait a minute.
• 1:17:28
  SPEAKER_01: If that happens, then this would happen.
• 1:17:31
  SPEAKER_01: And then like two days later, I was like, Well, wait a minute, that would explain this, which I've never understood.
• 1:17:37
  SPEAKER_01: And then eight hours later, I was like, wait a minute, if that's true, and like over the course of this week, it all fell into place.
• 1:17:43
  SPEAKER_01: It's just like at the end of the week, I was like, this is obviously right.
• 1:17:47
  SPEAKER_01: I mean, there's too much about it that just makes sense.
• 1:17:51
  SPEAKER_01: And that idea of sort of thinking through something that nobody's thought through, and just seeing that connection and seeing how that all those puzzle pieces fit together.
• 1:18:01
  SPEAKER_01: And it wasn't like it wasn't like, oh, this is gonna be great, you know, people are gonna love it.
• 1:18:05
  SPEAKER_01: It's like it's I don't, no one's gonna care.
• 1:18:07
  SPEAKER_01: But this is awesome, right?
• 1:18:08
  SPEAKER_01: Just the idea, this that fun of just seeing everything just kind of like pull together, like these weird things that you've never really kind of got, and how how that all comes together, that it's it's kind of a high.
• 1:18:22
  SPEAKER_01: I'm sure there's no meat involved actually.
• 1:18:24
  SPEAKER_01: Um, so so that's the kind of thing, and you get little bursts of it in different places, but I would say overall that that type of thing is pretty great.
• 1:18:33
  SPEAKER_02: Were you in the field, or were you you know back in the office looking at data, or where were you when this week was happening?
• 1:18:40
  SPEAKER_01: Yeah, no, that was in the office.
• 1:18:41
  SPEAKER_01: That was basically just thinking about things.
• 1:18:43
  SPEAKER_02: That's so cool though.
• 1:18:44
  SPEAKER_02: Yeah, that sense of discovery is that's a really good way to put it.
• 1:18:48
  SPEAKER_02: It's a high.
• 1:18:48
  SPEAKER_02: Yeah, and I think you can't keep chasing that high.
• 1:18:51
  SPEAKER_02: Yeah, for sure.
• 1:18:51
  SPEAKER_01: It's like and I needed colleagues to push me into that.
• 1:18:54
  SPEAKER_01: Like I remember Rich Gasting said, You just blew my mind.
• 1:18:57
  SPEAKER_01: I was like, wait a minute, how did I blow your mind?
• 1:18:59
  SPEAKER_01: And I was like, Oh, yeah, that is really weird, right?
• 1:19:01
  SPEAKER_01: And then, like to say, and then that stuck with me, you know.
• 1:19:04
  SPEAKER_01: Like, why was that such a problem?
• 1:19:06
  SPEAKER_01: And then it's just like, oh, wait a minute.
• 1:19:08
  SPEAKER_01: Yeah, this makes sense.
• 1:19:09
  SPEAKER_02: That's so cool.
• 1:19:09
  SPEAKER_04: Uh that's a cool personal journey, too, right?
• 1:19:12
  SPEAKER_04: I mean, you you didn't want you didn't understand the data when you first got it.
• 1:19:16
  SPEAKER_04: You didn't you wanted to reject it, and you brought yourself along.
• 1:19:19
  SPEAKER_04: I mean, that's a that's a really cool story.
• 1:19:21
  SPEAKER_01: Yeah, because yeah, I had to be wrong about things, like a lot of things before, and you just have to be like, okay.
• 1:19:27
  SPEAKER_02: That's very cool.
• 1:19:28
  SPEAKER_02: Well, okay, we're over time, Basil.
• 1:19:29
  SPEAKER_02: Thank you.
• 1:19:30
  SPEAKER_02: This has been so fun.
• 1:19:31
  SPEAKER_02: I uh I I really this is giving me a much higher level view and uh or more broader view of the Rocky Mountains, and I think your model is really cool, not knowing much else about the Rockies, frankly, but I've always kind of you know, these things that we hear in the petrology world and and that you hear explained in textbooks, you have a potentially better explanation, and it's really good to hear that there's multiple models that people are testing and working on.
• 1:19:52
  SPEAKER_02: So uh, you need to get a really good job describing it in audio-only format, which is not easy with these things.
• 1:19:59
  SPEAKER_02: So, um, yeah, thanks for joining us.
• 1:20:01
  SPEAKER_02: It's been super fun.
• 1:20:03
  SPEAKER_04: It's been my pleasure.
• 1:20:04
  SPEAKER_04: Absolutely.
• 1:20:04
  SPEAKER_04: Thanks so much, Basil.
• 1:20:06
  SPEAKER_02: Yeah, totally cool.
• 1:20:07
  SPEAKER_02: I love this stuff.
• 1:20:07
  SPEAKER_02: So thanks a lot.
• 1:20:08
  SPEAKER_02: Appreciate it, appreciate the time.
• 1:20:11
  SPEAKER_02: Hey, that's a wrap.
• 1:20:12
  SPEAKER_02: Thanks for listening.
• 1:20:13
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• 1:20:14
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• 1:20:16
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• 1:20:17
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• 1:20:23
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• 1:20:28
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• 1:20:31
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