GEOL 351 - #5 - Long-Lived Yellowstone Hot Spot

well hey everybody how's it going today thank you for joining us welcome to ellensburg washington usa here's to you for joining us who the local time is 12 47 i guess 12 48 possibly and we will begin our session called long-lived yellowstone hot spot long live the yellowstone hot spot at the top of the hour at 1 o'clock local time 1 pm pacific time that's a little more than 10 minutes from now hello matthew good man you doing well i'm glad to hear that let's make sure we're doing okay i've got a couple things to say ahead of class and uh you know the drill by now most of you do most of you are incredibly loyal to what we're trying to do here and uh sure do appreciate you uh jackie's in ireland and uh geneva and tennessee nana she made it today uh michael mckay says it's five by five in beaverton i always love to see that kent is in louisiana kyle 5x5 thanks for that report on audio and visual type stuff milwaukee wisconsin sabres back home in badger land eric is in sylvania ohio phil's in mankato minnesota clear lake california hello rachel oh rachel's on a trip uh jau is in portugal sophie's in zurich switzerland what up homie zazu in uh scrolled too fast but i remember you're over there somewhere edinboro scotland devin uk nicolai is in uh someplace sorry another portugal vicky from marysville washington stefan from ireland bremerton nicole hello indiana bainbridge island vancouver washington a jurica from croatia how's it going uh east of fresno not west of fresno but east of fresno lake city florida manchester uk japanese bow from rotterdam hello uh oakley idaho rent in washington derby uk albany georgia mesa arizona massachusetts lincolnshire uk fresno we've got emma in the room and matthew i just saw the bryce and hayden and a couple others maybe are in class like this isn't the only face-to-face class this quarter in the building so we are slowly getting back towards uh a familiar feel and sound in this building so a few of those guys hi hey gary back country gary's with us from darrington uh hey re uh yeah so you know i'm encouraging people to show up early and kind of visit but some have class right before this i didn't even think of that as a possibility so it's wonderful i have mentioned to you that i'm sharing this lecture room uh with like five other professors this quarter so i have to pack all this stuff up and get it away uh in between our live streams as opposed to just last quarter where i was the only guy here i said had all this stuff just set up the whole quarter nobody else was using the room so we're we're moving in the right direction here and i hope that you are uh in some form where you are madison wisconsin hello dareth yeah a few have been asking um i i this is episode 5 of this 351 series did you catch episode 3 which was a short video from the field so i think our routine will be a tuesday live stream a thursday live stream and then some sort of episode that i will post over the weekend from a field experience and so episode 3 was not a live stream it was a 15 minute video from our time with most of these guys out in the field at the old vantage road it's called hello hayden you do realize i'm looking here i know i know i'm looking at you but i'm talking here you got it okay good but but he's he's waving hello hayden hello hayden hey oh god bryce hi uh i gotta i got a handout for everybody so on cert every time you come in you might just check the back table there and just see if i got something waiting for you i got i got no cookies today but i got a handout that uh will look familiar oh god they are excited oh they are excited for a colored hand out double-sided oh damn colorful totally merry yes colorful oh you're you're you're on fire right now you're off of a high coming out of 203 i can i think you're drunk or something i don't know you're altered in some way what were you doing in that session bryce [Music] yeah you were yeah you were and hayden was now that i think of it hayden was waving at me in there too so hayden's a waiver i got to get used to that okay a couple more hellos to everybody at home hey hayden people are saying hi to you there's people in europe oh he's waving at you hayden's waving at you in portugal yeah bryce is punch drunk yeah hello from sweden hello is bryce the new mason i'm not kidding it says that right here are you there ah all right so greg are you with us again greg from tennessee so um i heard from greg do you remember last time i shared this kind of mystery package with this mystery rock from yellowknife northwest territories and there was no note or anything well uh i think it's you greg right that made this happen and uh things got split up in the mail so yesterday to go along with this mystery rock sample from yellowknife yesterday arrived a separate piece of mail that i think was supposed to arrive with the sample greg i don't know did you call these folks greg or you emailed us somehow so there is a place that can send you the oldest the oldest known thing on the planet from the planet i guess this is a business or something i don't know but this guy up in yellowknife northwest territories uh you can get your own your very own 4.03 billion year old rock everybody's looking at this now they're interested they're not they're no longer interested in the color handout so this is uh the acosta river nice 4.03 billion years in the making this certificate that certifies that your geological specimen case contains the mineral zircon which has been dated uh rock extracted from the site where the world's oldest known intracrustal rock was discovered on an island in the acosta river northwest territories canada so this was signed by mark brown who i guess is the proprietor so mark thank you if you see this but i guess greg is who i really need to thank for i don't know greg is this a gift did you so um so here's a little info on uh i don't know how the focus is anyway thanks greg i will cherish it a piece of the craton from way up north there oh yeah how come there's no chitter chatter how come there's oh i see you're copying down the outline yeah let me get out of your way um and you will hear just a quick request this is a repeat you're going to hear me talking about our field hike tomorrow and townies i again request that you do not join us in the field uh i will film a little bit tomorrow uh with those that come out and hike and uh i will post it over the weekend and derek that will be episode six uh the field the field video will be episode six so that's how we'll roll i'll just keep going so if you're confused still these numbers are the numbers for the geology 351 collection of videos but not all of them will be live streams some of them will i guess every weekend they'll be some kind of posted uh uploaded video from my little gizmo and my iphone nice nice yeah thank you david uh still can't quite read the energy in the room i guess people are pretty businesslike here oh yeah rylynn was in that class too how many were just in that class down the hall mary uh i can't see who you are today ash ashley's in there five of you nice okay this is good this is good jess hello hi uh oh logan's here yeah yeah we'll start in just a couple minutes the holy trinity has not oh there they i just i speak of the devil they travel in packs of three there's tim we have no interlopers oh jess is kind of an interloper actually tim's an interloper now that i'm not i think about it thanks for joining us we will start in a couple of minutes oh yeah where to spread yeah i got so i do have a handout for you wait in the back corner hi yeah how about we do it right now real quick wonderful hey everybody we got a quick announcement from jess in your class here just nice and loud jess oh sure yeah hey everybody jess has got something to say here you guys listen up and in a couple weekends it's uh april 23rd or 25th we're going out to waterville plaza to gtr on some landforms from reporting here in ice sheets so if you want to come camp with us and we basically just need some uh field monkeys if you want to come be on the career and help us survey and learn more about glacial land forms then we'd love to have you just come talk with me after class i'll be hanging out great a question right now uh it's april 23rd to 25th so we'll drive out on a friday come back sunday and just uh camp the whole time nice okay thank you all sorts of opportunities that ain't virtual that sounds pretty damn face to face to me nice oh boy is there oh what what kind of god where are you what's going on is this huh matthew um andrew is wondering if he has a question if he can shoot me a text sure and then i can ask it for him okay yeah just wanted to run that bobby real quick so just in case you see me look at my phone oh i like it okay thank you thank you matthew how does that weird oh nick i got a quick question for you this should just whip right up okay okay is it the jellyfish yeah i'm sure you saw this jellyfish question so usgs posted this oh about yellowstone oh so is this kind of what we're looking at like we've got basalt rhyolite and then basalt coming up from the side this is outside of caldera but that's really creative i don't know i've never seen anything like that uh mid crustal resonates with me so if that's kind of what they're trying to show there but i interesting cartoon i don't know if that's really kind of conventional wisdom at this point but that's an interesting post thanks for catching it usgs would never lie no they wouldn't you know so it is usgs i guess i missed that part sorry uh well yeah let's let's um can you email me that uh or whatever screen grab it or something i we might use it somehow i didn't are you colton what's up luke i got a handout for you call her hand out in the back there you're doing well something's going on you're looking at me i don't know you interwoved on my class and now you're the interlocutor yeah now who who's the interloper now i'm the loper right all right all right well i gotta keep my eye on you bryce something wrong something terribly wrong is going to happen today i can just feel it i cannot be specific no i have like 500 pence oh it's god's we got to get going good afternoon friends and lovers welcome this is geology 351 and we have a good thing going here that's message number one we got a good thing going it's only the end of the second week and i feel great about what we're doing not only our kind of collaborative vibe which is very very strong but also what we've kind of stumbled into as far as science papers as far as working on a narrative and that continues today i am excited to share some of this with you and also listen to you because you know that you're on stage again today and instead of rushing you through that portion i'm guilty of that last time you were all ready to go with all sorts of things to talk about emily cahoon's paper and then i basically kind of gave you lip service and and moved on because i realized they didn't want to do a lot with the cahoon paper i wanted to do more with the aaron steiner work this is different this paper is brand new you caught the date it's january 2021 and i think it does a major job for us and so i do want to slow down today i do want to involve more of you it's probably too forceful to say i want everyone to speak at least once when we go to the your portion of the session and bryce is already looking around but i do want to get a little bit more from you because there's plenty we can chew on here and depending on how this goes today we might even kind of continue with some of this next time on tuesday before we get to all of that and again i'm excited about it and you're still copying down the outline that's great tomorrow is our field day i emailed you the directions i emailed you the meeting time and it's one of my favorite areas i have i guarantee you will be impressed with the area uh it should be very nice out there i know we had snow and wind and all sorts of stuff we probably still have the wind right now but i looked at the forecast supposed to be pretty calm at least tomorrow morning and it's out there towards othello washington it's a little bit more of a drive than we did last time but i i know that you will be impressed i before i forget i want to i said this by email but i want to do it in person too if you really want to join us in the field and you cannot because of you don't have a car or you don't have any money for gas or you don't have a friend in here and you don't know who to ask to carpool with please email me i've got options for you we can make this happen for you i've got options for you if you want to get out in the field then you just cannot due to a variety of reasons if you have a conflict i understand if you're just totally not interested you're oversubscribed to other things i understand but the field things is not required as you know but boy it's it's it's so wonderful to be out there together with all that said how many are planning on being with us tomorrow yeah most of you that's great i i'm so excited for that so i will see you at the designated place in time and send me an email if you're confused about that too um last thing i'll say about that bryce reminded me that you all have been charged a course fee i don't know if you saw it or not it was an 80 fee and that is standard for this class and that 80 course fee pays for the vans hey baby we're not using the vans so how come you were charged a course fee it's my fault our fiscal person said in february you don't want to do the 80 fee i'm sure because we can't use the vans i'm like i'll talk to motor pool we'll be able to use the vans don't you worry well as you know i screwed out i i screwed out what is that i struck out and i screwed up by thinking that i could actually do that so we are in the process which is more work for our fiscal person mariah but we're in the process of getting you refunded for that you just have to take my word for it it's going to be a couple more weeks i think before we can get this but i i promise that you'll get your eighty dollars back and therefore i've saved you eighty dollars what a hero but i don't know if you're keeping track of how much gas costs to get out to these sites if you come each time it's probably more than 80 bucks again i've got options for you you'll let me know okay um anything else before we start i wanted to say one other thing what was it yes i'm emailing you tonight with our first homework assignment you've been expected to do essentially zero so far except show up and i i sent you that grading email and i want to give you the first assignment just a heads up to look for that for me tonight and i'll be very clear about that as well okay here we go all right so you've got it uh first of all i want to set the hook for today second of all i'm coming to you talking about the paper assigned to you today you've got the handout from the paper then my job is to take all that input which will be all over the place i know that your input will be all over the place and you'll you'll see what i mean in just a second and my job is to get us down to being disciplined and thinking about the data that we have and separate that out from the possible ideas that we are still working on models in other words tectonic models to explain this stuff that's my role and we'll see how it goes okay it's going away so we're going the double chalkboard again like we did last time ryan is not required to laugh out loud like he did last time although i really appreciated that whatever i said it was humorous and just what what an amazing guy i am okay uh i'm thinking i'm switching these around though screw it no we're not we're just doing this okay setting the hook what's our magic time window for this class class between 40 and 60 between 40 and 60. look at this it doesn't get more professional than this okay vanilla envelope 40 to 60. so we have not yet gotten to the 40 to 60 window that is the magic time window we're not there yet we're taking the scenic route but my plan has been to start with the yellowstone hot spot in wyoming and work our way back in time and by the end of today we will be in our magic window so what's this this is what we've been doing so far this is the columbia river shock group including emily cahoons 17.2 start with her picture gorge basalts but that's not the start of the story that's not the start of the yellowstone hot spot story what i thought it was according to our chalkboard this is the start of the yellowstone hot spot story and it is the quote-unquote traditional way to teach the yellowstone mantle plume story 16.7 everything starts but we can go back to 17.2 and use cahoons new dates and realize that there's kind of a regional story and i remind you that we had this whole collection of rhyolites even a newly discovered caldera called the castle rock caldera from this area and emma came up afterwards and said did i miss something like why is this up here i don't get it and we're like i guess come on thursday but i'm not sure we'll come up with it then either camp has a model camp has a proposal from his paper to address not only this but some other stuff as well but i'm still setting the hook today we are continuing further to the west in southern oregon dealing with nevada a little bit although i don't want to go that far south and going all the way out to the west coast of what is now oregon you'll see why i'm phrasing it this way but if we go back that far if we go to the coast we can get back into our magic time window let's not screw around 56 million years ago vic camp and others not everybody but others see the yellowstone hot spot out in the pacific ocean i hope you got that at some point as you were reading the paper solezia celecia began to form offshore 56 million years ago so we're going to today go between our columbia basalt group story and going back to celestia time and for the first time in the class we're actually in the magic time window that we need last thing i'll point out we will eventually get into some exotic terrain discussions not much baja bc movement hardly anything that's too old this is a too young situation this is a too old situation for our magic time window so generally by the end of today we will be in our magic time window and i don't think we're leaving i think we are truly going to be in this magic time window for the most for the rest of the quarter okay that was my hook setting the paper you are about to tell me about is vicks camp's paper 2021 and you all have a two-sided collection of beautiful illustrations most famously this guy here which you have and i want now is that now is your time by the way i'm hitting the button on you and i think with the audience i'm just going to try to hold this up here like this the home audience but you've got it in front of you you can see it in real time in real space you can see what i'm pointing at here and even if you're a rookie to geology you're right out of 101 you can contribute here these don't all have to be super high brow statements just new statements to you and this is going to go fast so i just want to fill the air with all of your reports here we go ryan's going to get us started ryan's starting with you know what i'm going to hold you off ryan let's do some some nice simple statements that we understand that we want to report on uh uh uh what is it ariel thank you red and blue so i'm going to just i'm going to keep this going true this is truly going to be lightning i'm not going to just talk for 20 minutes after each contribution so he does have a red star and a blue star and he's realizing that there's two different potential stories here and there's a group of researchers that like the blue star there's another group of researchers that like the red star let's hold off on what that really means let's keep it going uh kyle um so kyle's noticing we have a black dotted line going through the known yellowstone calderas as they get older and older and older and then maybe you're also talking kyle about this dotted gray which is i don't know is that something different let's get off of it right now mary what do you think he means by that there's more stuff there's more stuff going on than we know i love it let's keep going this is not meant to make sense this is meant to just get as many people involved as possible the home viewers can be patient with us here ideally we'll get everybody involved at least a little bit uh rachel umatic rise uh this accumulated bimodal eruptions all right so what the hell sorry patrick slab rupture i'm not sure what a slab is i'm not sure what a rupture is i can guess what those are uh let's keep moving i'm going to come circle back tim slab shielding tim's uh mentioning that he's noticing this timeline down here which goes from brand new back to essentially 42 million years ago and we have two white areas which are times of quiet again slab huh i don't understand rylan um thank you rylynn he's he's plotting there's many reasons i love this paper one of them is he's kind of putting a lot of different uh kinds of studies onto one diagram of course it's very busy that's why i felt like i wanted to actually blow it up for you and give you a hard copy i mean it takes a long time to figure out all these symbols and all these colors and everything else the red are plate reconstruction studies as i understand it by using reference frames so he's got did you catch this these two purple things out in the water are two different ideas using reference frames either the atlantic reference frame or the pacific reference frame don't ask for for details i don't know what i'm talking about that these are two potentially nailed down spots for the yellowstone mantle plume here these dates don't really totally make sense with the rocks as they're plotted correct like look at the distance look at how it looks like north america didn't move very far between these two spots in that 10 million year stretch and the ages of some of these volcanic rocks don't work with this as well so he's not trying to confuse us but he's trying to basically synthesize and uh correlate between these different uh sub-disciplines to show us that there's plenty that still needs to be worked out as as mary said there's lots going on here more especially if you haven't spoken yet we'd love to hear from you this is a safe warm nurturing environment uh oh god it's a vowel help me ashley thank you very much yes we can take our main phase story which is not even really super portrayed here right he doesn't have the main columbia basalt group all over the place but do you recognize this is something that looks familiar to us right what is this what are these things that did we talk about any of this stuff last time the answer is this what in here is recognizable the castle rock caldera he's got it uh cr i didn't use the phrase but we're going to use it today the lake hawaii volcanic field this is our thing emma was asking about like why are we off this is the lake hawaii volcanic field i was kind of talking about it as the strawberry volcanics but if you remember the details of the strawberry volcanics were just one of this whole collection of rhyolites so in case you have not made the connection between the pink blotches and the pink circle on the chalkboard from last time that's one of these yellow blotches including the blue star remember we we ended on the thought that there's an evidence for some sort of if it's not a mantle plume it's some sort of heat source that's feeding that lake oahe volcanic field hayden thank you uh hayden's going way here to the coast of oregon today and looking at the dates of these rocks 40 what was it 42-34 and that's a time of what was the phrase overriding who's overriding who the north american plate is going over the top of the frickin mantle plume and we have rocks from that time this is part of my job is to help us understand these colors if we don't all have it this is beautiful i love you as a group i love you as a group individually i love you as a group jk just kidding that's a sick burn okay anybody else want to say anything re thank you it has not been mentioned yet this green is a belt of i don't even know how to pronounce it is it adakite and and what do you know about or what did you read or what do you know about etiquette what did you just say partial melting of an altered basalt possibly as the source for this attackite i have a little bit about adequite i did email vic camp and heard from him yesterday he just gave a zoom uh lecture in the last hour and so i'll find the recording of that and post it but he mentioned yeah i can't i can't join your live stream i'm going to be finishing up my lecture for eastern washington university so great guy in addition to really interesting work i think a couple more i still saw some hit ryan i pushed you off now i'm gonna come back to you now go ahead yeah yeah yeah how can we tie the laramite orogeny which is the the rocky mountain buildup how can we tie the basin and range to this story uh so ryan's really working he's ryan's working the corners here ryan's not coming down the strike zone all right he wants to go far afield and i'm not willing to go there again you are like a wild horse i'm trying to tame you son i don't want to do that i want to keep that that curiosity going but we're not going to that's too far afield for us last call for a couple more matthew um i know we mentioned the lag um they thought that the the eruptions transitioned from volcanism above the material like the main amount of clean material to above the trail the tail of the plume material so plume head plume tail who wants to spit ball meet with me right now what else besides the plume let's turn this thing over let's turn this puppy over so one of this is also vic camp one of these is from your assigned paper which one the left this one is from the assigned paper today and actually you know what let's just pause do you have anything from this assigned uh uh illustration looking at this do you want to uh spitball with me do you understand anything of what was done here did you get that far in the paper anybody feel like it i can i can do it if you want but anybody want to try go ahead ryan uh if it's literally a tear and we're still talking about a slab some of us don't even know what that means yet that's coming with our interpretations or our models but that's right i just want to point out here it is one more time our strawberry volcanic field from last time including some others that's yellow with the blue star correct that thing freaking lines up with the western snake of her plane the western snake over plane now come on i went to graduate school here andrew in this class not with us today is going to grad school here in pocatello starting this fall this whole area was studied carefully by many of our grad students at idaho state university 30 years ago and nobody then had any idea why the western snake river plane was a thing it's still a bit of a mystery as far as i can understand but as i was reading i think it was kahun she saw some geochemical signatures that were similar does anybody remember this with well maybe it wasn't cahoon maybe it was steiner saying some of the rhyolites here have the same trace elements as some of the volcanic rocks in the western snake river plain and maybe this this story about this isolated volcanic field has something to do there okay i think that's enough i love it of course you can continue to be part of our discussion here i'll try to interrupt as much as you like but i think i want to now take over just a little bit and i mentioned idaho state university for a couple of reasons david rogers was my graduate school advisor you work on a thesis when you get a master's degree and you have an advisor you have a committee but you have a main advisor and my advisor was dave rogers and he was perfect for me this is the late 1980s now before any of you were born before the internet before a lot of things life was simpler back then but this guy was fresh out of stanford he was brand new to the job and he did so many wonderful things for me and he's still there at that school but the main thing he did for me that i have used almost every day of my teaching and those of you that have already had me in 101 or another class you know that i hit this very hard data versus interpretation can we just please start with what we know can we please not put everything in a blender and go right to mantle plume and it's a freaking vortex and we tear it and we do everything else and it's too much and here's why this is important the data is permanent the data in your scientific papers is there for future generations yes the tools and the techniques may improve yes the precision may improve as we just talked about in the last few sessions but the data if it's separated from the interpretations is there to be used in current day but in future generations as well it's valuable data factual information carefully collected that's different than interpretation that's different than ways to explain the data i think you all know this but it's worth i think what we were trying to do here was to get as many people involved than we did but some of that was data and some of that was interpretation and here's the danger ten years from now some idea about the plume or a tear in the slab again whatever that is is proven to be incorrect in other words the idea is proven to be incorrect and what's the tendency we throw the baby out with the bath you know what that idiom means have you ever heard it i'm from wisconsin there's a lot of idioms back there sweating like a butcher you know we'd say that when we were like 16 years old i'm sweating like a butcher throw the baby out with the bath water you don't want to throw out the interpretation bryce is trying to figure it out what does it mean bryce okay okay it's now it's not a baby discussion grandchildren and i'm 50 okay right you don't want to take something valuable some of the data and throw it away along with this idea that was in the paper as well if we separate the data from the interpretation we can throw the old idea away but we can keep the precious data that's my role here so let's do it well now there's a breakout discussion about babies in dirty bath water and why do babies need to be in a bathtub anyway what's that all about hygiene not good i love you i love you i love you all right let's start with the data and camp has done a nice job with that his paper was written differently than many scientific papers he broke it into chapters he was almost telling you a bedtime story wasn't he he was laying it out in individual time chapters and that not only was done in the text but also was done with this so i am going to get your camera right up next to the home viewer's camera because i want of us both to see this so what part of this story is familiar to us what colors work with what we've talked about already in this discussion tim yellow and red correct we started with the yellowstone hotspot in wyoming we've worked our way across southern idaho we're still red-ish and yellow did you catch it yellow is younger let's just say younger than 17. and we're tossing in emily just a little bit but younger than 17. including the rhyolites so what i want to write on the board is focus on the data that we have broken into three main chapters i forget if i said it that way in the outline but that's what i'm going to do right now i'm going to break our data into three main chapters and the three main chapters are separated by white separated by absolute quiet times be very very quiet ain't nothing happened ain't no lavas coming to the surface so let's do it i broke it out i got chicken scratch all over the place can i find what i need to find here it is so three volcanic chapters only one of them that is quasi-familiar to us uh younger than 17. let's do that 17 to 15. let's do that this is the l o v f the m v f and the h r c c i'm using abbreviations because you have the abbreviations on your handout yellow who can help us quickly i guess i can i spent i don't know 20 minutes going through that illustration all those little abbreviations all the little symbols did you catch it the little circles are mapped calderas the little boxes are just a rhyolite location not necessarily a mapped caldera and we have the lake oahe volcanic field i'm reading backwards but hopefully it makes sense to you the mcdermott volcanic field and the high rock caldera complex field all between 17 and 15. let's make some statements i'm not doing the storytelling yet we're just talking about the data that we have and camp is doing a nice job finding all this putting it all in one diagram it's a busy diagram this is a broad regional story is it not this is not all right on the yellowstone hot spot track we have three distinctly different areas with bimodal volcanism i guess but he's emphasizing the fact that most of this is falsic most of this is silicic most of this is rhyolitic in composition i'm talking about the yellow now somebody help me what is the difference then between the blue and the red star did you drill down to that the thank you tim the blue and the red stars are two possible locations for magma magmatic centers doesn't have to be mantle plume necessarily but we have heat sources feeding those volcanics and yes some of the groups like the blue location some of the groups like the red i don't know if there are groups that like both but if we're trying to group data and that's what i'm trying to do here we have a bunch of this bimodal volcanism including a bunch of rhyolites that are not all in a similar trend like this we're doing okay so far then there's a gap on the timeline a noticeable gap 20 to 17. this is data there's no lavas there's no volcanic centers where'd the calderas go like i don't care what kind of lava i just i just need some lava during that time nothing between 12 and a 20 and 17. i'm going to run out of room if i don't use my space a little bit more carefully 30 to 20 is the next of the three volcanic chapters we're going back in time are we not this is also a regional story bark back arc regional volcanism what color are we using for this chapter green teal okay if you don't like green teal so graphically he's doing a nice job right here between 30 and 20. where are we generally in eastern oregon but he's got two different ways to portray this the eye-catching one is this known as the what did you say re attic adakite or ada clay atta atakite is this green area okay so i don't know what an attack is i know bridge i just regis told us but as i mentioned i emailed vic and i want to read the email to you it includes the attackite actually does anybody want to weigh in on this back i'm sorry i want to do one more thing before i read that to you in addition to the attackite belt is there something else that's from this time window in his symbology what else is green on this map we've got a dashed green going all the way around this area this is a wide area of eastern oregon and he labels it area of back arc volcanism now you're taking this class from me i still don't see crazy amounts of evidence that back arcs are significant i still just see back arcs as a place like you're on the you're either in the forearc or the back arc we know a volcanic ark is the arc we're talking about do you know that a line of volcanoes is known as the volcanic ark the cascades are our current volcanic ark a continental volcanic ark and you're either in the four arc or the back arc in washington where's the four arc today it's freaking seattle man you're in the puget lowland that's the four arc that's basically the basin that you cross before you get to the ark get it and then we ellensburg are in the back ark now 30 years ago i was being taught about all this massive amounts of extension in the back arc and all this you know circulation of the mantle beneath the back arc at the time i was confused i think i'm still like okay so where's all this extension today in ellensburg where's all these lavas coming out of the ground in the back arc i don't get it i don't think it's a thing is it you want to say something tim yeah okay partially from the subduction zone i'm going to hold you off i'm going to hold you off yeah yeah i'll i'll steer you away for now we can talk after class if you like so the back arc i'm viewing the back arc as a region truly to the east of the crest of the cascades and there's a bunch more volcanism spread diversely through this area okay now i think i want to pick up the pace just slightly in fact i'm sure of it the attack heights are a big part of this story here's me hey vic i'm really struggling with understanding significance of attackings and their importance in this discussion would you have a few sentences to help me see what everybody agrees on with adakites if anything here we go vic yesterday the original idea is that these rock types form from melting oceanic crust ri was on that of a downgoing oceanic slab okay a slab is an ocean plate that is going down a subduction zone if that's been unclear to you hopefully it's clear now we know what subduction is we know that the juan de fuca plate today subducts beneath washington and creates the ark the volcanic ark well that's the slab that's the slab of ocean floor that continues to go down are you aware that the slab does not go away when it subducts that we can continue to follow the downgoing ocean plate into the mantle we can i don't think we'll throw that into today but that's also part of this story okay what's an adakite they used to think it was just simply melting of ocean crust in a downgoing slab going down the subduction zone downgoing slab but as others have pointed out there are many other possibilities and so there is no consensus at all on their genesis however this is vic we embrace the original definition because we can rule out other possibilities one being the melting of mafic lower crust i'm going to pick up the paste because i don't understand what he's talking about now this is not likely because the crust is too thin in this region and attackites cannot be generated because the base of the crust is within the plagioclase stability zone atakites are defined chemically by their high strontium idi what's why atrium ratios which requires strontium to be an incompatible element in the source rock if plague is present then strontium will always be present as a compatible element in the slab the mafic basaltic crust is converted to amphibolite and then to eclegite where plagioclase cannot exist isn't that nice he gave me all sorts of respect i'm talking to a geologist he'll get it i i was nice and slow in the first two sentences because i understood now i'm going to forward this one to you as well i'm going to forward emily cahoon's email to you because some of you know that background i don't and i'll forward this one to you as well what i do want to say is that my fishing around has helped me understand that an atacite is a very rare andesite it's an endocyte with some unusual isotopic signatures involving that strontium atrium ratio which is way beyond me but i would like at least for now to visualize atakites as a rare igneous rock there's a belt of them between 30 and 20 million years ago in the back arc and because of this weird isotopic ratio signature of the atakites wait for it vic's model i'm cutting to the model i can't help it i'm cutting to the interpretation i can't help it sue me he likes a portion of the slab being melted altered whatever but whether it was re in person or vic by email the thought is the attic heights are somehow the result of melting and getting some of that slab material that has subducted back up to the surface if you have atom if you have an atakite belt which we do between these two ages you have evidence of some sort of slab below eastern oregon that is being altered modified by the plume again i'm doing this out of order now but i just wanted to cut to something with a sexy discussion so the atticuites are related to that slab that's down going i want to keep it moving and then maybe we can open it up a little bit there's another gap by the way i'm sorry um so where did this figure come from uh this is from a paper that you're not responsible for but it's in the list of science papers it's also by vic camp so you were responsible for camp 2021 the long-lived title but i encourage you if you have any interest at all to look at camp 2017 which talks about this story here and really good illustrations talking about the fact of these interpretations we're about to get to probably next time as opposed to today okay the gap he has before the back ark story is here again your model needs to have some way to explain why we just shut off the magma and this is a significant gap this is going 34 to 30. and then we're finally to hayden land thank you sorry and hayden land is between 42 and 34. what color on your illustration thank you blue today the coast range of oregon and there's lots of names there i prefer just to call this one of the kind of regional names that he used i think he called this the tillamook oh you had a phrase i can't remember episode maybe yes the tillamook episode a typical stage yeah either one and so i'll give this to you verbally just to help you kind of see it he's got three different uh collections of rocks there those are the three blue if you can see well there's three little blue circles within the blue region so there are some tillamook volcanics in that age window there's some yakats basalt and some graze river volcanics you see them with the fine-tooth comb there these rocks are mostly basalts if i put this down m-o-r-b or iob those that have had rocks and minerals or mineralogy what do those symbols mean what do those acronyms mean morb does anybody know thank you rachel mid-ocean ridge basalt it's a common acronym m-o-r-b stands for mid-ocean ridge basalt you're like what's that it's a freaking mid-atlantic ridge it's the east pacific rise it's a spreading center it's a divergent plate boundary it's the it's the chemistry of the basalts that come out in those situations what does iob stand for or is it oib is it oh ib oh god ocean island basalt i think yeah it's o.i.b dyslexic much my point is we have basalts in the blue area created in the oceans with the trace elements and the major elements all telling us that that's the story now i'm happy we spent time with this i'm happy we went at kind of a slower pace and less of a pushy pushy pace from me but there's a trade-off we're not as far as i wanted to get today because the fun part is talking about an interpretation and i feel like i want to do in the last two minutes something along those lines so i think i just want to do it verbally i'm going to hold this up in front of the home audience camera maybe yours too and let me just see if you picked up on any of this before we quit and then we're going to come right back to this next time ready go originally i want to do it here i want to do it here [Music] where was the yellowstone hot spot 56 million years ago students it was offshore and it created something we're going to talk about next time called celezia it was a huge oceanic plateau a huge oceanic plateau coming next time oceanic plateaus are monsters out in the pacific ocean built off of the ocean floor the yellowstone hot spot did that according to camp and many others so the yellowstone hot spot was dealing with pure ocean crust oceanic crust uh-oh but north america is drifting to the southwest and the distance between a fixed yellowstone hot spot mantle plume and the continent of north america is getting closer and closer until does anybody have it until how long ago when north america started to drift over this hot spot 42 luke 42 million years ago and the rocks of the tillamook volcanic field tells us this that instead of the yellowstone hot spot burning a hole in oceanic material suddenly now and this is tricky i didn't visualize this till this morning until now the yellowstone hot spot is burning a hole in the thing that it made out in the water this is freaking celezia man this is celestia that was created out of the water but celestia was moved and accreted 51-49 just play along with me celezi is added to north america but now 42 million years ago according to luke north america drifts over the mantle plume and so the thing that was created by celestia is now being penetrated by new lavas pretty sweet didn't have that in my noggin until a few hours ago but we continue the story i promise i'm almost done now as we drift the rest of north america over the stationary mantle plume the mantle plume is now dealing with a third entity the accreted exotic terrains that have different kinds of lithologies involving metamorphic rocks like serpentinite or nice all sorts of things there and then there's a fourth thing that the yellowstone hotspot is going to have to deal with what is that it's going to deal with the crate time it's going to deal with the other side of this strontium 706 line so in my mind and i only really saw it until the way that vic laid that paper out and said a few things that just put off a couple light bulbs in my mind a relatively simple fixed mantle plume which is starting down at the core mantle boundary and coming all the way thousands of kilometers to the surface is dealing with pure ocean floor then it's dealing with the celestia oceanic plateau then it's dealing with exotic terrain material of eastern oregon then it's dealing with the craton of interior north america four distinctly different things to penetrate or to melt through or to invade from below and that's why this signature appears to look so different than this signature which appears to look so different than this signature which appears to look different than what we had out in the ocean floor boy this is cool stuff and the last thing i say i promise is that of course it's not just a mantle plume dealing with north america there is a subducting ocean floor called the farallon plate the slab that not only is trying to subduct during this story but there's evidence that it broke and the slab breaks off and a bunch of extra goodies are coming to the surface with a break off episode and you're like uh we'll have practice thinking about it and looking at it but just a little sneak peek when we get up to central washington there's break off belt magmas up here too it's not just down there along this story fun kind of kind of awkward today it always feels like it's awkward when i'm trying new stuff but we're going to find places where the slab in the subsurface broke off okay i'm going to see most of you tomorrow at the secret spot at the secret time i love you and goodbye i could see us going uh you're not taking offense to that tim when i kind of shut you down sometimes because yeah i don't know yeah good good i'll be with you on a second i'm just going to talk to a couple students hey if you've got questions we'll do some live q a thank you matthew okay we um what the original proposition of the magma the the plume the magmatic body that originally created like did it start with celestia and we don't have any evidence going back and can we use the composition of the basaltic magma of celestia to say that that's what the original yellowstone hot spot composition was or can we not do that i can answer your question this way this is maybe the only way i know how to answer it if you have a mantle plume interacting with a pure ocean plate you're going to create a certain chemistry of lavas and the opposite end of that is if you are having that same mantle plume melting thick continental crust and those are totally different chemistries and you're going to create something totally different the tricky part for me is this transition time in between the two where the mantle plume is dealing with a whole bunch of different kinds of rocks of these exotic terrain mythologies so if you're asking about the original chemistry of the mantle plume i don't i don't know if we can do that but we can we can deal with the result of the heating of the mantle plume of the material over the top because we know okay yeah and then andrew andrew was wondering if the uh hello andrew the rotation of the plate was being represented um oh yeah see that that's part of the email that i was going to add i was going to bring in the crooked river caldera the crooked yes the crooked river caldera in central oregon vic is not talking about clockwise rotation in this paper at all which was a surprise to me and next week we'll try to involve clockwise rotation but for this story um not yet he's not dealing with it okay yeah thank you okay thank you matthew how come i can't come up with your name like immediately i don't know it's okay it's air it's ariel it's like the princess it's like the princess i've gotten on most of my life okay maybe i'll call you a princess do you have a shorter question um yeah so i have like a little car is it going to be fine going out there no problem okay cool i used to drive a blazer but you're not on the transmission okay good question so it's talking about lag time between eruptions yes so obviously it's not going to take as long to burn through here than it is thicker than this yes okay so um it was talking about lag times between eruptions and then when the hotspot was actually there yeah i was wondering yep oh do we see like other numbers that show us like a smaller lag time here than here or like is there a bigger lag time that we can see from when it crosses over from eruption you're doing some heavy lifting here mentally and i'm impressed by that it's a debatable topic and so far with us right now we're just identifying these lag times and not saying not trying to explain them well it makes sense because especially with here with how thick it is it's releasing all of this magma that's like working its way through the crust but the plate's still moving so the hot spot's moving but the magma doesn't it moves with the plate if i can tell you're on this and so if you wanted to peek at the 2017 camp paper he's talking more about a model where the slab is there and it's causing the mantle plume to pool up underneath so he explains the gap by saying we're just going to like it's almost blocked but it's blocking through the block yes yes and that's where we're headed next is to try to see how his ideas about blocking the mantle plume and then finally then having a jailbreak essentially and have a bunch of this stuff come up since this is oregon in idaho so this is yes this is still over here where it technically should be thinner but it has that extra block yeah so it would almost make it that you couldn't really see when it switches because it almost makes it equal correct i like what you're thinking about relative thickness of the crust but according to him and maybe others that's not a big variable in this is that well it's still crustal stuff but as far as you're kind of working with you know aren't you getting a lot more mantle plume to the surface if you have very thin crushed versus thick as i understand it it's more about how when are we going to be blocking the heat source as opposed to letting it come up easily keep working on it keep working on it good okay i gotta talk to the home audience here thanks you guys okay thanks for your patience um we still have people just visiting it's it's just so wonderful to have that uh let's do some live q a if if you're up for it and uh upper case please i agree david ariel's question is great she's uh i don't know her very well but now she's she's talking to others about her question nice uh death mall how was the hot spot stationary in the ocean ocean crushed also moved slowly well i try not to get fancy unless i'm forced to get fancy obviously look at me so in this case i just visualized those hot spots as being fixed regardless if there's ocean crust moving over the top of them or continental crust moving over the top of them now dave one of the david's here is pretty hot on the idea that a mantle plume is usually tied to some sort of spreading ridge and we'll get into that a little bit here or even a triple junction somewhere but i i can't i can't do that here so you know the hawaiian hot spot is beneath the ocean plate the pacific plate's moving to the northwest we have this beautiful seamount trail so i just think of those mantleplumes as fixed and regardless if it's ocean crust or continental crushed or continental crush composed of accreted terrains i just think of these passing ships going over this stationary blowtorch that's just me a nice try randy gotcha uh more i'll scroll back i'm not saying a lot of uppercase right now douglas could water content of the slab uh or oceanic crust be part of the quiet time i'm not sure so i didn't know how much ground we were going to cover today and i now see that we'll spill this over into tuesday which is our next live stream uh you maybe heard me talking to ariel vic camp really likes i don't think it's just vic one of the main ways that vic and others explain a gap in volcanism is that the slab the farallon plate that is subducted is still there but it's blocking the mantle plume from reaching the crust the continental crust and so you pool this hot mantle i guess is one way to say it and that explains the quiet time and then as soon as you get off of a quiet time and you have this kind of series of volcanic fields all showing up regionally that that's one way to do you eat your way through the slab as i understand but i'm just starting to think about this are why does nick live in washington when he knows the severe dangers of volcanoes earthquakes and tsunami in that area well i live here because it's a very beautiful place it's an exciting place geologically and i know that the risk of those events happening in a human lifetime are quite low it's a risk but it's uh it's not a high enough risk to feel like i'm putting me and my family in danger and uh ellensburg is a long way from the ocean i think jerome what parts of washington and oregon were created by celezi i guess that's going to be coming next week jerome but basically celestia was an oceanic plateau that is now making up pretty much all the real estate in washington and oregon west of the crest of the cascades i would think of it that way and you're like whoa i don't think so i've i've collected rocks in puget sound i don't see any celezia basalt there well most of it's in the subsurface because it's such an old story kent what happened to the spreading ridge that the hot spot was straddling yeah you're way ahead of us here let's wait glenn so the quiet time was pooling leading to the crbg uh that's one way to say it yes um i think that is the way to say it right now glenn thank you i'm gonna scroll back in time adrian iceland is a hot spot as well as the mid-atlantic ridge that's true mgo fire can we deduce size of the hot spot based on transition zones i don't know about based on trend well what is a transition zone in this case i think there continues to be a debate about the width of the mantle plume yeah i don't have much more to say there sorry dogny is the strontium 706 line the same as the whiz uh they do they are the same place yes this is called the western idaho sheer zone where there's evidence of major right lateral offset of oregon against idaho and that also happens to be at the old coastline but we don't have massive amounts of offset uh all along the strontium 706 line but at at that place near grangeville idaho and down to whitebird and riggins you're right same thing pat miller are the chalice volcanics part of this time frame um no but we're getting closer pat so those that have been loyal to us know that that we did this exotic terrain a to z series where i was kind of doing similar things but with a much older time frame and i think i'm going to do an eocene a to z live stream series at some point maybe this fall or winter when i'm when the weather's junky and there's nothing else to do and pat in that case i think we will be heading to the chalice magma system and eventually get into the rockies and do all sorts of things and i thought maybe i would do that here i thought maybe we would head to the chalice here but i think there's enough for us to work on just in central washington that i won't do a full treatment to the chalice volcanics but i'll just say right now that the chalice volcanics are part of our time window our magic time window yes less is the nnr a rift valley i don't know what the nnr is oh i see it yeah well this is a geologic symbol for a graben so there must be a normal fault on either side of that and this is a block in between that fell down but i'm chickened to go into nevada right now i don't know i don't even know geography of nevada let alone understanding vic camp's work down in nevada that's part of this story so we'll conveniently be avoiding that for a number of reasons saber are there any broken slab lavas near ellensburg yes we are heading to that in this series it's no call me pass tiana way formation it's coming so it's almost like i planned this to be honest i i had not looked really carefully at this paper by vic camp 2021 until yesterday and i was like wow this is like perfect to follow up on what we did last time but i i i just lucked out like i didn't know that that was part of this paper so it's almost like this is guiding itself it's at some at some weird level let me scroll down to live we'll do a few more i'm impressed with your uh interest here oh it's john yeah john likes the the mantle plume here he is talking about spreading ridge again okay john are spreading ridge upwellings as deep as their hot spot plume neighbor i don't know john i i get a very strong feeling that you know far more about spreading ridges and triple junctions and mantle plumes than i do and so i may get up to your speed at some point but i i'm definitely not there now uh in fact if you've been with us for other programs in the past i've confessed that i've i've always meant to just learn about the ocean floor and just to learn about what's down there and learn about other hot spots and seamount chains and some very basic things with submarine geology that i don't understand or haven't thought about at all even submarine canyons and i don't know just thinking out loud um what will we do on next time which is tuesday of next week with this group we'll definitely talk about celezia but maybe that's an excuse i don't know maybe maybe third i don't know maybe maybe a week from today maybe i'll just try to do some just general oceanic plateau size of things you know maybe i'll just take a break from the narrative and just spend time with the ocean floor not sure that ronnie does the plume slab interaction generate strata volcanoes or just domes well ronnie thanks for the question this plume slab interaction we only really got as far today as saying that the atakites these these special andesites uh seem to be a direct result of a plume um melting a slab where the slab is is blocking the mantle plume from getting to the surface as i understand it ronnie right now so typically no strata volcanoes are are specifically from ocean plate subduction and since we're talking about a plume interacting with the slab i i don't think we should visualize strata volcanoes uh david when did we realize that yellowstone is a super volcano well you know i i did my master's thesis on the northern edge of the snake river plain and i did not use the phrase super volcano at all in 1989. so that phrase super volcano wasn't even in the literature or public parlance 30 years ago but we knew that there was massive high silica explosive caldera forming events which we now call super volcanoes but if you're asking when did we first realize we had these incredibly explosive volcanoes that dwarf mount rainier or something i i guess the answer is 50 to 80 years ago but that's really i hadn't thought about that before i don't know uh now we're off track with lake tahoe and other things let's try i'll go back i'll just answer a couple more kyle when will 60 to 40 million year take us to ellensburg region are you getting impatient kyle maybe some of our students are like i we're we're taking the scenic route we're basically doing this we started at yellowstone we're working our way back in time today we kind of are working our way through southern oregon and next week we'll be out here with celezia and accreting celezia so i suppose it's not till late this month when we're finally in the target area but the target time zone kyle uh we're there now so i'm sorry that i'm not moving fast enough for you sometimes it's good not to move too fast entertaining myself now richard does the subduction rate influence volcanism yes but i i can't really i don't i don't know how to answer that beyond saying that two more then we'll quit i'm seeing some of you are expressing remorse that you didn't read the paper ahead of time well first of all you know you're not you don't have to do anything i hope that you can enjoy this without reading the papers before or after i hope that you can i mean if i'm doing a decent job you can kind of grasp what we're doing even without seeing the papers but of course we have some who are really really into this stuff which is terrific to see but not a requirement of course so my job is to try to make this worth tuning into even without a bunch of background maybe it works fine you keep showing you all keep showing up so i guess it must be working at some at some level i'll find one more to finish on here jay if the plume burns through the slab wouldn't it bring elements of the slab along with it probably yeah and uh you know i'm weak on the geochem so there's obviously debate on the role of attackites and whether it's truly just melted ocean slab or if it's something a combination of plume and slab and something else uh but there's there's plenty more to be done i can't end on that one i don't know i don't i don't know the answer let me end on something i can feel good about here really scrolling back now bruce does the timing of the breakage of the slab relate to the columbia river basalts that's how we'll finish depends on who you talk to but it does seem like a growing narrative is that there was a gap it's not worth getting the other board is it what was our gap between 20 and 17. nothing was happening between 20 and 17. and then suddenly at 17.2 according to emily cahoon's works we begin uh the quote-unquote columbia river basalt group and friends not just here but regionally not just here but regionally yellow yellow yellow all of this is magmas coming to the surface at the dawn of the columbia river basalt group time and so that is one of the main messages that vic is presenting that we begin the crbs because we're done with the gap and the gap was probably because of a slab blocking the mantle plume from getting to the surface so that's a simple way to initiate the crbs and that's a different story isn't it than just saying the yellowstone mantle plume started here which is the way i've taught it forever like we're kind of needing our cake and eating it too or whatever that idiom is that never made any sense to me like if we've got a long-lived yellowstone hot spot which is the title of today's talk why don't we have a continuous set of lavas from the last 56 million years as you saw ariel was thinking about crushed thicknesses and if you had thick crust then you'd have a quiet time but the mechanism that vic and others are visualizing is is the slab significant enough to block the mental plume to block the hot mantle uh from getting to the base of the crust and therefore are we starting the flood basalt with the last of the ruptures of the downgoing slab here's to you here's to your health on april 8th 2021. sunnheit here's to the health of your parents here's to the health of your grandparents here's to the health of your children here's to the health of your grandchildren and great great grandchildren here's to them here's to the physical and mental health of everyone in your community i continue to help out down at the vaccine clinic and we had another shift yesterday afternoon and with each passing shift we get more people vaccinated here in our valley and um i think there's a well we're still heading in the right direction here's to that the next live stream will be tuesday at 1pm but there will be some sort of field video posted this weekend and that will be episode six probably titled i don't know heller columns or othello columns or something like that where we're going to be looking at a couple of very young columbia basalt lava flows and some beautiful colonnade hope you enjoy that field video this weekend and i hope to see you again tuesday at 1pm thank you i love you and goodbye thank you i love you and goodbye thank you i love you and goodbye thank you i love you goodbye thank you i love you and goodbye you

Channel: Nick Zentner

Views: 45,665

Keywords: Nick Zentner, GEOL 351, Vic Camp, Yellowstone Hot Spot

Id: Z8uybLf-5q0

Length: 92min 57sec (5577 seconds)

Published: Thu Apr 08 2021