Paleomagnetism in the Pacific Northwest

foreign thank you for coming tonight this is a geology lecture given here in Ellensburg Washington USA let's look at the title okay wow all right paleomagnetism in the Pacific Northwest looks like that's what's on the menu that sounds hard uh I don't know am I the guy to give a lecture on paleomagnetism I'm not a geophysicist I'm a guy that teaches geology 101 at Central Washington University like right over there I've been teaching for a long time am I the person to give a full hour lecture on paleomagnetism and how the Earth's magnetic field works and how the polarity flips and how there's polar wander and everything else no I'm not the person but yet I'm standing up here giving this talk so so why do I feel like I'm qualified well I teach for a living I know Washington geology quite well now I've lived here for 35 years so that's great and this past winter I did a YouTube series of 26 interviews with geologists from around the country and in a few cases in other countries and many of them were paleomagnetic specialists and so I read their papers I talked to them directly I the live crowd that was watching on the internet was inter asking them questions I feel like I got to know them and so before I forget it all I'm getting older now before I forget it all I feel like this is the time to take some of the beautiful paleomagnetic field data that's been compiled for the last 50 years and place it into some sort of context and I can't hold it I got to say it this paleomag data that we're talking about tonight has been essentially ignored by the geologic Community for 50 years 50 years and it's not just a couple people doing the paleomag work there's a lot of work that's been done and so the context of this and maybe why you're confused possibly why would all this work be not really valued or read or referred to on a regular basis I think there's two answers for that the first one is you don't learn paleomag when you get a geology degree I didn't learn paleomagnetism when I got a geology degree I haven't taught about paleomagnetism in my classes it's kind of a fringe topic among the mainstream geology community so that's one reason but I think a more interesting reason is if you look carefully and read all the paleomagnetic work that's been done uncrushed from Alaska down to California and west of the Rocky Mountains that paleomagnetic data disagrees with the conventional answer for why the Rocky Mountains exist and that old model which I refer to maybe you've seen it on YouTube I did a lecture this spring on how did the Rocky Mountains form and I'm going to do it very quickly right now the old conventional model of how the Rocky mountains formed is you take a big oceanic plate called the Farallon plate you move it east I'm talking about how we're forming the Rocky Mountains you do that subduction starting 180 million years ago you have this big ocean plate diving beneath you make the geology of California you change the angle of the subducting pherlon plate you shallow it out in other words so that you can actually get that Farallon plate underneath the Rocky Mountains and you create these thrust faults of the severe style Rocky Mountain uplift and you form these laramide Block uplifts in Colorado and Wyoming that is the conventional majority opinion the majority rule for how the Rocky mountains formed within Eastward moving oceanic plate that idea was proposed in the early 1970s and it is still 50 years later the conventional wisdom well that model in that lecture I gave earlier this spring is under some doubt because we have found subducted ocean slabs underneath North America and that old Farallon plate isn't there the Fairlawn plate that's supposed to be subducting shallow it's not there it's in the wrong depth it's in the wrong place there's nothing that works with that model so that's check mark number one why that model maybe is not what we want anymore but that's new data that we didn't have in 1970 old data that we did have in the 1970s and the 1980s and the 1990s in the 2000s and the 2010s 50 years of paleomagnetic work says that all of this crust between 85 and 55 million years ago moved North more than a thousand miles I'll give you some specific numbers in a second now if you're a person who wants the Farallon plate moving East to make the Rockies and most do then are you truly going to be enthusiastically reading and supporting other papers on paleomagnetism that show everything moving North I don't think you are it doesn't agree with the model but I think it's time to look at that paleo mag work carefully and again question or maybe just view the Rocky Mountains with a new set of eyes that's the goal tonight okay that was the hook I don't know if it worked that's the hook that was that we're ready like we want to look at it now thank you so I'm going to keep that here I'm going to use a prop believe it or not but the prop is because I don't like this drawing I tried it I don't think I like it it's like a basketball I guess what is this and uh the prop is this old exercise ball from the basement that I brought in here okay so here's my attempt to explain how paleomagnetism Works in less than five minutes oh boy all right so I'll do this so this is our planet planet Earth and there's an invisible magnetic field these red lines the Earth the giant magnet the Earth is like a giant magnet so these invisible magnetic field lines look like this and they flip occasionally that's not a point tonight there's an invisible magnetic field through this Auditorium right now we can't see it there if you're making a list for why people are not accepting paleomagnetism this is invisible data this is this is invisible field and when you look at a rock that's been studied paleomagnetically you can't see anything just holding the rock as you're on your hike so it's an Act of Faith to even get to the point where you're listening to someone doing paleomagnetic research okay but this is our magnetic field these invisible pink lines converging at the poles but the point is that green here is the surface of our planet and I don't know if it's possible here but maybe you can see that at the equator the invisible magnetic field lines are parallel to the surface of the Earth parallel to the surface of the Earth and therefore if you have a ferromagnetic mineral in a rock that's cooling magma that's Cooling at the equator you can measure the orientation of those iron particles and if you're at the equator those iron particles Frozen in your rock during the time of that magma turning to solid rock is going to be parallel to the Earth's surface that's proof that that magma was cooling at the equator conversely if you have a volcanic eruption at the North or South Pole at any time in the past and that magma starts Cooling and if that magma does have iron-rich particles within it then the magma is going to record invisible magnetic field lines vertically intersecting with the surface and so the angle between the orientation of the magnetic field lines and the orientation of the magnetic particle and the Earth's surface the Paleo horizontal is a much higher angle that's a lot of words let me try it with the ball see if it works any better equator North Pole Santa Claus lives up there I'm a magnetic grain at the equator I am going to be Frozen in place parallel to the Earth's surface at the equator now I'm an iron particle being frozen into a rock at the North Pole I'm going to be perpendicular to the Earth's surface those are the two extremes but what if we're at 45 degrees north latitude halfway between the Equator and the North Pole I'm going to have an angle between my finger and the Earth's surface that is 45 degrees I'm not going to be 90 I'm not going to be zero I'm talking about the inclination now the inclination of the grains so inclination is what we want inclination the angle between the orientation of the magnetic grain and the Paleo horizontal the old land surface and so tonight we're going to hear about reports of Bedrock that has shallow inclinations and that means the angle between the iron particle and the Paleo horizontal is a low angle a shallow inclination that means we formed close to the equator if we have a great inclination not a shallow but a great inclination we are closer to the pole so we can determine paleolatitude by carefully measuring the orientation of the iron particles inside of an igneous rock or a sedimentary layer that was my best attempt to explain where these latitudes are coming from and ultimately how we can come up with a way to say that portions of Washington have moved North during the time that the Rocky Mountains were building I feel like I need to cut to something real I don't know I feel like I'm I'm needing to get to a punch line somehow right off the bat I want to give you one right now and then I'll go to the next board so I'm pulling an audible right now okay this says MSB that's Mount Stuart batholith so 50 years ago the 50th Anniversary 50 years ago the first paleomagnetic paper came out and out of all the mountains and all the American West guess which mountain we're talking about that one right over there not sure the mount Stewart batholith was selected to be a case study for determining did the granite of Mount Stewart truly crystallize here in Washington so MSB is on this tiny little map MSB is on this larger map same thing Mount Stuart batholith the mount Stewart batholith today is roughly at 47 degrees north just a touch more but play along 47 degrees north and 90 million years ago 90 million years ago when the magnetic field was locked in to that rock of the mount Stuart granite the mount Stuart batholith was down off the bottom of the chalkboard where's 22 degrees north it's down here 22 degrees north at 90 degrees 22 degrees north 90 million years ago and today Mount Stewart is at 47 degrees north that's 25 degrees of latitude motion between 85 and 55 million years ago based on what based on the shallow inclinations of the magnetite grains in the mount Stewart granite now that was published oh thank you for the reaction that was published to a resounding thought the guy that wrote the paper was Merle Beck a brand new professor oh Round of Applause for Merle back some of you know about him he was a longtime professor at Western Washington University and was a Pioneer in many ways and passed away just a couple months ago but he and his colleagues on the Washington side and a contemporary of Merle Beck Ted Irving over Victoria and Sydney British Columbia in British British Columbia Geological Survey they were doing this paleo mag work back in the 1950s the 1960s and so on and they started coming up with papers that showed this kind of transport my point is they're publishing and nobody's reading these things or they're publishing some geologists are reading those things and saying I'm going to drop that and walk away because that does not agree with what we're trying to talk about here which was the Fairlawn plate model the data continues to be strong and it's not just Mount Stewart so we're now to the portion to talk about why field geologists that I know now who I sit around the campfire with and talk about Baja BC and that's what we're talking about right now those geologists today that I value and respect they go all right I don't think I meant it's from a pluton right the mount Stewart batholith is a Big Blob of magma are you really thinking that that's good data is this somehow this magma just going to like ride beautifully almost 3 000 kilometers without tilting at all or folding or anything that's like impossible think of how much tectonic action has happened in the American West you can see their point so let's address a little bit of that so here's our friend again Mount Stuart baffleth Mount Stuart bath with Mount Stuart bath so Merle Beck and Bernie Hausen his contemporary today at Western Washington University and some others and Ted Irving in the early days were specializing in plutons and we'll focus just on Mount Stuart if you like the mount Stewart bathymet so it was liquid and hot between 96 and 91 million years ago a revelation to me recently is that the age of paleomagnetic signature in the mount Stuart batholith did not precisely happen during the age of crystallization and there's some detailed physics and chemistry to explain that but I'm going to give you those days the mount Stewart batholith between 96 and 91 was Molten it finally solidified and there's ways according to the paleomagnetus people to say that it was 90 million years ago that we lock in the paleomagnetic signature the shallow inclinations to tell us that that mount Stuart baffleth was originally in Mexico I'm drawing a picture of the magma Bean liquid when it was down south of the board and you're like oh I don't quite get that why wouldn't the magnetites lock in at that time that's a detailed question that I'm not equipped to answer but I asked Bernie Hausen on some of these programs this winter and he answered it beautifully I think I tried to follow the point is important though because some people say as field geologists look at Mount Stuart baffleth on a map and we're going to do that in a bit that batholith on a map up by Stevens Pass is folded it makes a horseshoe pattern on a map looking down from heaven you can see it that you're walking the angles ophelitis everybody's folded how can you take this paleomag data to Heart but then you realize that the magnetism is locking in after the folding the folding predates the magnetic setting in that's one example of the detail that we need this magma turns to Stone it stays underground it makes its Journey from 23 degrees north to 47 degrees north and it pops up to the surface less than 10 million years ago okay that maybe doesn't work for a geologist watching this lecture right now and they go ah that still sounds kind of shaky to me well that's one batholith are all the batholiths of the American West agreeing with Mount Stuart batholith with this paleo mag business with moving three thousand color I'll give you the number 2 900 kilometers North that's what the Paleo Meg said in 1972 that's what the Paleo makes still says today with new checks with new data with new paleo poll positions well no not all the plutons do agree if you go to the Snoqualmie batholith it's younger than 55 million years ago there's no paleomag movement at all it didn't move north at all any pluton younger than 55 million years ago is too young for this northward trip and likewise any or any pluton that's older than 100 million years ago doesn't show this movement either so there's a Time window with certain plutons in this time area and before but let's just say 100 to 50 Rocky Mountain Time that these things are moving North okay well maybe it's just one person maybe it's just one lab that's getting these weird numbers no it's a bunch of laps it's a bunch of people there's paleomagnetic people doing work around the world it's not just a couple of schools here in the northwest well let's say you're persistent as some of my buddies are who talk about this and they go well I just I just I gotta I gotta rule out those plutons it's still just kind of a blob I can't I can't make it work for my brain I don't believe it basically well let's go to MT and Mt is another very important paleomagnetic site and my Mt is going to stand for Mount tatlow and this is a famous location and among the Paleo mag people it's Bulletproof it's Bulletproof and what they mean is they're going to look at paleomagnetic indicators not from a pluton not from a blob where it is tough to figure out admittedly where the Paleo horizontal is remember with the with the exercise ball we need that paleo horizontal we need to measure that inclination so Mount tatlow doesn't have plutonic material mount tatlow is a series of layers some of them lava floats with iron particles some of them sedimentary layers with iron particles and it's not like the Grand Canyon of Mount katlow they have been folded but as a paleomag person you drill into these lavas you don't have to guess where paleo horizontal is you can see the betting planes between these layers and even though they're contorted into big McDonald's arches or something like that you can measure the PMAG and you can do what's known as a fold test you can get those tilted layers back to their original position and so therefore you can take your drilled paleomagnetic inclinations and rotate them to get them back to the original paleomag and the Paleo horizontal well that work has been done by Ted Irving and Jane Nguyen and Randy anken and guess what they came up with the same number mount tatlow move 2 900 kilometers roughly the same age 90 million year old material locked in with paleo mag starting down here getting up here and you're like well hold on no Mount tatlo is a little bit farther north shouldn't that number be a little bit higher well it should but there's a big fault called the straight Creek fault that took the crust in western Washington starting 50 million years ago and moved it about a hundred miles north across the border so if we undo the offset on the straight Creek fault which is younger than 50 million years mount tatlow is right over there and so those translation or transport distances work so for some geologists that I know Chris mattinson for instance who didn't know much of this even though he's a very bright guy he's like to me that mount tatlow thing is just like that's it I I get it now I wasn't really understanding why the plutons were that valuable but that field check of these other kinds of layers that's going to work for me loving the energy in the room you're locked in just like the Paleo mag we're going one more place but we're not quite ready I want to do some verbal things quick and I think these visuals are really going to help us so it's almost like we're eating our vegetables right now before it all kind of comes together I think with the magic of the audio visuals mostly visuals not audio okay let's revisit we really are just selecting two sites so far in the American far west west of the Rocky Mountains and that kind of looks like doesn't it that if we ignore this because this is too young this is this is something that's happened after Mount Stewart has made its big Journey that's after both of these guys have come up from Mexico so let's get let's get rid of the straight Creek Falls not that important but what we are kind of looking at is realizing that oh my Lord if there are other places of the right age in Washington Oregon California British Columbia maybe even further Points North does that mean does that mean that all of this stuff moved almost 3 000 kilometers North and if you talk to the paleomagnetus people the answer is yes this is the same stuff if you saw that Rocky Mountain lecture earlier this spring this is the same stuff that was out in the water as a fixed archipelago that North America ran into and so there's a new model called The Hit and Run model where North America hits this fixed Oceanic Island out in the water and then that same thing that we hit which is now on our Hood like we're we're just this big old Buick going down the country road we run into this big deer out in the middle of moose out in the middle of the Rose the Moose slams onto our front grill and then the moon starts sliding off to the right hit and run the Moose hits our windshield and then gets flung off to the right hand side of the windshield up to three thousand kilometers between 85 and 55 million years ago so in the series I was doing this past winter we had an idea about a whale a whale that was migrating to the north and this crust is the stuff that was out in the water it hits North America 100 million years ago and then starting 85 million years ago there's evidence paleomagnetic evidence that this stuff starts moving North these kinds of distances and that feels kind of satisfying and there are some geologists who like that only but that's not everything west of the Rocky Mountains that's like stuff within a day's Drive of the ocean that's a draw a day's Drive Inland from the ocean that's the stuff that's moving North according to many of the paleomagnetic papers and the idea is can I do this quickly the idea is that I'm going to round off some numbers now 3 000 kilometers of northward motion here and then you go a little bit further Inland this is mostly Ted Irving's work 200 2 000 kilometers moving North and then by the time you get this far inland there's no movement North so the general idea is that as you work your way Inland there's less and less northward motion and that all feels pretty good except some of those same paleomagnetic people that I was interviewing this past winter and now we're talking about Randy anken and Jane Nguyen and Stephen Johnston did a very important paleomagnetic study in the Yukon a place called CG the CarMax group I didn't know anything about the CarMax group until this winter I'm now really into the CarMax group the CarMax group are lavas no sediments just a stack of lavas flood basalts way up here in the Yukon but they have the right minerals to do paleomagnetic work on and those three folks Randy Jane and Stephen were up there drilling like crazy multiple parties multiple times in the CarMax and the CarMax group is 70 million years old the lobbys Young compared to mount Stuart and mount and yet there's 1900 kilometers of northward motion of the CarMax group in Yukon based on the shallow inclinations of the magnetic grains I'm pausing for dramatic effect because first of all we're quite a ways inland and we're so young I thought this was 85 to 55. now you're saying this stuff that so far yeah that's so far inland and young is starting to move 70. maybe all of this motion is starting 70 million years ago and not 85s but if you start doing that and start realizing and I think I need to put the karmic I think my maps off a little bit I need to get the CarMax group in here because the idea is now if we have the CarMax group showing this kind of northward motion according to paleo mag we need some sort of a fault sending material North to the east of the CarMax group which suddenly is way the hell over here and geologists since that CarMax work some of them have been looking through do you know the geology here this is like Glacier National Park this is like something called the belt super group and the Purcell super group these are fine-grained shales and silt stones and somewhere in all of that apparently there's some sort of major fault like the San Andreas that's sending everything a mega whale to the north so there's the potential of this paleomagnetic data really blowing things open really changing the way we view much of not only stuff to the west of the Iraqis stuff within the Rockies portions of those thrust faults are now up in Alberta is that an accident did they get moved North with the rest of what was a major fat ribbon continent okay let's add some visuals to this now I think that's what we need so here's tomorrow back who was a real character uh and just lit up on screen when we interviewed him uh for a variety of projects so this is me visiting him in in the hardest part of the lockdown uh in his backyard in Bellingham Washington and I knew Merle at that point because a few years earlier maybe 10 years ago now we drove from Ellensburg up to Bellingham where Merle was working and interviewed him and that's where I first got to know Merle and his story and so here's some screenshots from that PBS program that we did featuring Merle Beck from Western Washington University and right off the bat I mean he wasn't screwing around like this guy has been ignored in the scientific Community for a long time so I mean he was he was like Hey you know these guys don't even know how paleo mag works you know and just you know it it becomes personal in a hurry when you talk to someone who works so hard and does such great work and the work is just not appreciated and that's an understatement here's Merle back in the day in the Stewart range in the early 1970s yeah they still have those samples so this is what these these little drill cores look like so you take a power drill out to some Bedrock you drill into it you take it back you carefully measure the orientation of that little core and then you do your analyzes in the paleomagnetic labs when they get the back these are the little billets that we get the inclination data from don't ask me more than that I barely know this but that's not Stuart Granite right there collected in the early 70s Bernie Housen was hired at Western Washington after Merle retired her he was the hand-picked successor to Merle and Bernie has continued to do some amazing work and there's a brand new scientific paper by Merle Beck Sorry by basil tick off and burning housing that came out this year 2023. so the last interview I got with Merle was just last summer in August and and Merle passed away in January of 2023. a similar vintage Pioneer is Ted Irving so Merle Beck and Ted Irving were the two that were really leading the charge with this paleomagnetic work and so here's Ted Irving up in Sydney British Columbia compiling more paleomagnetic data and Ted Irving had this sweet uh life-size Globe to work with and plot his paleo polls and other paleomagnetic information and this is the series that I put together this past winter which uh perhaps more than anything else just introduced all of these workers to a wider audience and we got a chance to hear them directly learn from them and get to know them so for instance Ted Irving here in the middle we're up in Sydney British Columbia now Ted Irving has retired and his hand-picked successor is Randy Incan from a photo more than 10 years ago now so I hustled and tried to convince all these folks to join me with these interviews and all the interviews exist on online you're welcome to go take a look at any of these each of the interviews I think you might find interesting so Randy from his office and Randy sharing photographs many of these geologists and paleo mag people had selected slides they wanted to share with everybody it was an audience for the first time I don't want to overstate it too much but this beautiful work is finally being absorbed and spread to a an audience that deserves to to hear it and to read it and to see it so here's Randy in the field collecting some of these drills you've got to bust your butt to get up to these some of these spots I think this photo is from the CarMax up in Yukon with Randy Inc and drilling and here are the actual some of the actual drill bits the billets from the CarMax in the Yukon and I see that Jane Nguyen has her name on this drawer so interviewed Jane Nguyen uh and many of these folks are retired now themselves and out of the game here's Merle Beck's first student at Western and the names Linda Nelson and Merle Beck are always together when people bring this up so to get Linda to get on camera was a bit of a chore but I finally talked her into it and she was the first of the series Bernie Houston the guy that I mentioned at Western now Stephen Johnston who mainly wrote the new paper or the paper in the last 15 years on the ribbon continent using the CarMax data so without the CarMax lavas and the Paleo mag results from the CarMax Stephen Johnston wouldn't have gotten this idea of having a major portion basically everything west of the Rocky Mountains was together out in the Pacific as something called a fixed ribbon continent Robert Hildebrand not collecting the Paleo mag himself but writing papers to this day probably writing this evening at his home in Tucson and continuing to make beautiful maps to compile this data so he's been very prolific in the last 10 15 years doing work based on paleomagnetic work basil tick off embracing the Paleo mag so there's there's there's momentum right now who knows how long it will last but there's momentum right now with this paleo mag work dusting this stuff off incorporating some new discussions and that's what's exciting about this this topic in this particular point in time the last show of the series just last month we had multiple heads on camera discussing these things openly and I have to say it the the the the vibe of what we were doing is different than the vibe that's been going on for many decades before the vibe before was I don't like your data I'm not talking to you and back and forth shots fired uh and the the there's the new Penrose conference happening this summer in Idaho and hopefully these kinds of discussions will continue with a collaborative view instead of the opposite there's others who have embraced a Paleo mag without doing them themselves this is Daryl Cowan University of Washington tremendously helpful with this so in these other spring lectures I have not involved people personalities and personal stories necessarily with the geologist but tonight I did feel it was important to include them and introduce those faces to you there are people behind all this very careful work okay well the exercise ball maybe this helps a little bit these are slides from Randy Incan and a slide from a geology 101 textbook not sure if this is helping you or not uh but the idea that you can precisely locate the old latitude of Iraq if you know the age using paleomagnetic inclinations is not a new thing and needs to be incorporated into the tectonic models that we're talking about now and yeah mount Stewart just north of our little town is where it all started this is that original map from that first paper proposing this crazy amount of movement from Mexico up to Northern Washington a map of the Stevens Pass area heading down to this portion which is closer to Leavenworth maybe you can see it's been folded it looks like a big hook here's a more accurate map from burning house and Merle Beck 20 years later 30 years later this Leavenworth down here icicle Canyon and up by Stevens pad at the hook it has been folded but yeah uh the inclination of the magnetic grains is slightly younger than the folding uh the last email I got from Merle right before Christmas a few months ago uh he wanted to get a hold of his 1976 paper and in his words that was his best work so if you only find one paper by Merle Beck uh that he was most proud of it's this American Journal of science June 1976 paper here's another way to plot how unusual some of these rocks are and it's going to be hard to understand these plots let me try it quickly this is North America cratonic North America I mean the old part of North America's continent and these orange circles up here are the paleomagnetic poles so if you drill into a 90 million year old granites in South Dakota and you figure out the inclinations and you do all your measurements you figure out that the magnetic pole at 120 million years ago or 130 million years ago or 110 million years ago all of these kratonic plutons and even lavas are telling you that's where the pole is it makes sense it's what's expected if you do the same thing and find some rocks to drill paleo mag holes into from the Craton at 70 million years 79 66 million years ago again there's a cluster and it makes sense with the position of where North America was at that time but how about you do the drilling in Mount Stuart or Mount tatlow or CarMax or many of these other volcanic sedimentary and plutonic rocks in the Far West that's what they look like they are unexpected they are discordant those plots are gibberish Until you realize that all of these sites have moved they're not in the position that they were formed like the rest of the Craton are you starting to see why this is a paleomagnetic place to work in the far west west of the Rockies so if you have heard of this thing called Baja BC these iconic Maps drawn by Daryl count University of Washington put out in 1997 are showing the proposal this is the whale moving its way North and everything within this whale started down south and moved North and that's based on the paleomagnetic data well is it that crazy to suggest that that's a thing that a sliver of westernmost North America is moving North hell it's happening right now right this is Baja Mexico it hasn't always been like this I'm talking about very recent geology now 10 million years ago this was part of Mainland Mexico so we have current versions of big pieces of North America moving North everything west of the San Andreas Fault in California we have the GPS we know that that's moving North along a strike slip Falls not like this is the only time this has ever happened in the history of the western North American margin and yes we typically visualize strikes look false the most recent major famous motion on the strike slip fault and this section of the San Andreas the great 1906 earthquake in San Francisco which decimated downtown San Francisco I'm just trying to give you a sense that this has been an ongoing thing for 100 million years in Western North America with this motion north of blocks of crust to the west of the Fall in 1906 look at the length in yellow that ruptured not the entire fault but a large portion of the San Andreas fault suddenly moved 10 feet on the West Side compared to the east side well if you get up in a drone and you fly north along the San Andreas fault it's just as fresh as can be is this what we should be visualizing for a Baja bc-like fault coming through Central Washington coming through Spokane or if you're a ribbon continent Mega whale person coming through Glacier Park or maybe we shouldn't visualize a perfectly vertical fault that allows this northward motion is it possible something like the Lewis thrust fault which is a low angle fault between two pizza boxes can you slide a pizza box North on top of the pizza box that's below it does it have to just be an East-West motion these are basic questions but that's where we are right now we're in an open discussion phase at least I hope we are this summer when a bunch of these experts get together at the next Penrose conference I'm still down in San Francisco and Los Angeles and San Francisco's up there Los Angeles is down here there's Bedrock matches that show major amounts of northward motion maybe not 3 000 kilometers but this is motion this just happened in the last 30 million years even in Washington that straight Creek fault which is too young for our Baja BC time but it is a thing we have the same kind of offset Bedrock that can be matched up some of you know Cle Elum Washington that's close to here Burlington Washington that's not close to here but they used to be suburbs of each other 50 million years ago before we started motion on the straight Creek fall so it's almost like you can take your pick which generation of the American West you want to pick and there is dextral or right lateral offset happening on many Falls throughout the American West so you're hearing my point it's not crazy to have paleomag suggesting this kind of northward motion if we go back down to Southern Cal for a second here's Tanya Atwater helping us see that just using the Paleo mag and some other constraints that we have on the ocean floor we can take Santa Barbara and rotate it we can have San Diego moving North hell we got stuff coming from Mexico right on this animation the selenian block is Mexican crust maybe even Central American crust that's made it its way to Southern California so to view this concept of I mean I'm pissed now suddenly I don't know why to view this concept of moving stuff North thousands of kilometers is the more you think about it and the more you think about what you know about basic geology 101 in the American West it fits right in it's not the aberration that it maybe appears at first glance yes vinman's Bakery shout out to them and Jeff at vinman's Bakery making props for the series oh sure and Jeff is here tonight and the idea that these whales are representing portions that have moved North based on the paleomag we probably put a should have put some little magnetic flakes inside of that whale to really show the inclination properly Jeff getting greedy now but the mess that we have the mess that we have up in Yukon up the entire state of Alaska is made out of exotic terrains many of them fragments that depending on who you talk to came from thousands of kilometers to the South isn't this a new way to view the American West even when having discussions with these geologists a couple months ago I would catch myself in the middle of the conversation I'd go let's go up to UConn with Stephen and talk about that geology and I go oh no wait that stuff was almost 2000 that was tough I was almost down here so you have to do all this mental restoration of these puzzle pieces you can see how complicated it is can you imagine doing a puzzle a jigsaw puzzle and the pieces are in seven different rooms in your house and the first step is just to get them all onto one card table and you've got to use the Paleo mag to do it to get them back to the right card table my goodness so it's not a shock probably that we're still trying to figure out much of this material okay I think the last thing I want to say before we quit is that if you pull back as Robert hilderbrand has been doing with his gorgeous Maps and you squint a little bit you can see a significant portion of the crust west of the Rocky Mountains moving North so this greenish tan are the Rocky Mountains and you can see these red blotches and maybe you can even see these liniments that perhaps will restore now even Hildebrand over his last 10 15 years has been ignored or been given the same treatment as the paleomag papers this is too simple this is too outlandish we're not even going to comment on it that's generally The Talk but I think we have so many questions right now it's silly for anybody just to say well that's obviously way out to lunch I'm not going to even talk about that anymore I don't think you can say that with anybody's dead as long as it's good data let's use it let's incorporate it so these kinds of maps that show a lot of crust moving North perhaps in the next decade will become less and less outlandish Mega whale courtesy of Randy anken the last thing I want to show you we're going to skip that we're going to skip that we're going to skip that the last thing I want to show you is an animation I've shown in the two previous lectures this spring this is the same animation I'm going to show again I'm going to drive it but before I play it this time I want to point out a couple of things the orange and the yellow are out in the Pacific Ocean 170 million years ago according to this model and the purple has already been added to North America so there's open ocean between the purple part of North America and orange and yellow out in the water now if you really want the mega whale if you really want everything west of the Rocky Mountains being sent North and you want everything west of the Rocky Mountains being added as one big hunk you want the purple out there with the orange and the yellow you want a major ribbon continent out in the water and one major spladam Kabam whatever Collision and then that thing moves as a unit to the north to me personally that's attractive but among these different models it's not universally accepted I'm showing you this one which doesn't want that Mega whale or that Mega ribbon continent Instead This is the insular in the alacitos out in the water and the Inter-Mountain already added but the reason I'm showing to this again is because this is constant Glock and Mitch mahalinuk's model based on the slabs in the lower mantle this is not a model that's looking carefully at tonight's topic and yet I'm going to play it for you and you're going to see a familiar action let's do it without talking you let me know when you see something familiar pertaining to tonight's topic we're at a hundred million years ago coming right now whoa and I'm gonna play that one more time it's going right now and I feel like I want to emphasize it one more time I specifically asked Karen in the last show in February did you actively use the paleomagnetic data put into this model and she said no the position of the ribbon candy the position of those things that are fixed in the lower mantle if we bring those back up to the surface there's a certain geometry and we need that northward translation to make sense of where the slabs are in the lower mantle to me that alone is a beautiful endorsement from a completely different data set that supports the value of this paleomagnetic work an old cartoon that still kind of makes me happy in its simplicity sometimes the most simple things are the most Pleasant and is that simple I guess it is you take Mount Stewart north of Ellensburg Washington and your snap Mexico on it you feel pretty good about things that's where we're going to leave it tonight thanks everybody for coming thank you very much I love you thank you for coming tonight

Channel: Nick Zentner

Views: 212,216

Keywords: Nick Zentner, paleomagnetism, Baja BC, Myrl Beck, Ted Irving, Rocky Mountain geology

Id: VpGymNvdMmQ

Length: 53min 20sec (3200 seconds)

Published: Sun Apr 16 2023