GEOL 351 lectures from CWU's Discovery Hall by Nick Zentner during Spring Quarter, 2021. Scientific papers are here: www.geology.cwu.edu/facstaff/... Watch 'Partial Melting Basics' video: • Partial Melting of Ign...
Late March thru mid-April was crazy for me, with my Mom in the hospital and having to go out of town. So, I'm just now catching up with the 351 videos & hope to get up to the live sessions soon. I'm loving these! So glad I watched all the 101 classes because that's helping me not only follow the lectures, but get an idea of where you're going with these Nick. This is great!!! I never thought I'd be interested in geology, but your lecture series, the 101 classes and these 351 classes have fired my geologic imagination!! Thank you!
You're a great teacher Nick. I'm enjoying learning about Western US geology. You remind me of my Geology teacher in high school from way back in 1986-88 with your style and energy.
It seems to me that since the bottom of the Lithosphere is not smooth, the mantle plume being a broad head, it could fill the nooks and crannies with slightly more magma and heat. Thus might explain multiple volcanics from the same heat source as the crust overrides the plume.
Hey Nick love your show thank you. My question is this... why do we focus so much on the last Yellowstone cauldera when the evidence shows that the next eruption will be miles away to the Northeast.... shouldn't we be more focused measuring that area? Keeping that in mind and seeing that if your estimate of 640,000 years since the last eruption shouldn't that area be showing signs of volcanism? Keep up the great work!
Thank you for the interesting lecture! Here's a wild idea... Could the boundaries of the accreted terranes (sutures?) have "diverted" the magmas heated up by the mantle plume north - along the terrane boundary - so they formed a huge deep magma chamber (maybe in a gap between those terranes?) under the Castle Rock area, eventually feeding the CRB and leading to that caldera-forming eruption towards its end (when the chamber was empty-ish, given that there was no further supply of magma to it due to the plate having moved further)? Sorry for the maybe somewhat unscientific wording. ^^
A thought I had about why these YHS rhyolites are so far "north" of the charted position of the hotspot during this 17-15 Ma range is perhaps due to how fluids in general seek the path of least resistance, and maybe even includes the NA craton boundary as part of the reason. So as the mantle plume rises, melting material as it rises, approaches the older, harder craton (with greater silica content too), could it be that the plume branches off towards the accreted terranes due to their lower silica content and younger age, so that you end up getting several locations at the surface affected by the YHS? Hope that makes sense; just spit ballin' here! :-)
I missed it... am sorry, dear nick-- was up wayyyy late, so had to sleep all day... but-- am changing to SPRING and SUMMER hours.... will gladly watch you WONDERFUL pre-class!!!! it is part of the whole gem... 🙂💖
Watching late, funeral for my mother today. The field trip was great, students were exciting. Southern Illinois is 80* and sunny and warm as chocolate chip cookies! Earthquakes everywhere, Iceland increasing, and have you viewed Mars rocks? Look like sandstone and limestone drillings, but NO water.
First time catching you live & I had a great time! Thank you Professor Z for sharing your geology lessons online. I'm looking forward to sitting in on the upcoming lessons.
Your illustration gives me the the thought that Sr 706 boundary was more like a hybrid strike slip fault. That said the face of the NA craton being a plow would make this possible, causing the hotspot remnants shattered and north of the other calderas
Gold and silver deposits East of Vale. Silver City, ID was a big hard rock and placer mining area late 1800's and early 1900's. Some "modern" mining between Vale and Silver City. "Primitive" road between Murphy, ID and Vale, OR.
The hotspot moved too far and changed direction in too short a time in my opinion. All I see is there is a relationship and might give clues about the dynamics of a hot spot and it might be related to the fact that it might not have burned through the crust yet. It could be like a torch burning through an inch of steel, the flame deflects and spreads, gets a large area red hot, once the hole is burned through the deflection ends. As it moves forward slowly you heat and burn away the sides and not the bottom.
I keep wandering back to Nick's podcasts because I find them fascinating. Living in Pittsburgh I have almost no opportunity to actually see the formations he describes, but that's my problem not Nick's. Basin and range was my first exposure to real geology, and Nick's has a gift for making the subject accessible.
You gotta make a trip out here. I am from Michigan and moved to Oregon (not recommended) about 10 years ago. I am still amazed by the geology of the area. Incredible! Just driving around is amazing!
I love the new information. FABULOUS! I have to wonder if La Garita in Colorado (~40 million years old and erupted as ~VEI 8 ~26-28 Ma and additional eruptions dating back to ~2100 BC) as well as Valley Grande / Toledo Caldera and the Valles Caldera in New Mexico which erupted between ~1.7 Ma and 50,000 years ago plus the Long Valley Caldera factor into the big picture.
Do not have time to finish video, I have to go to work. Sounds like my Central Oregon is more important than thought in the CRB flows. How does Smith Rock Calder fit into the PRG? Love your videos. You got my wife excited about geology now. You are reaching out to so many, great work. Off to work now.
There were many ounces of gold pulled out of canyon city by john day. By a greenstone belt. The Humboldt cut. And vale has massive gold in the grassy mountain mines. And vale still has active hot springs. There is a lot of rhyolite by ashwood oregon.
I got my intro to geology from GEOL 101 just finished. When you did the story of the Columbia basalts, I thought it was a bit away from the Yellowstone track you painted. Glad to find that there might have been something in my hunch.
I was scrolling by I’m several daze late. HAHA that’s robot thing was funny . Utah Tooele . Anyway I saw strawberry volcanos. I’ve not heard that term before . So I stopped by to get educated.. thank you
I have recently started watching channels concerning geology of Kansas and New Mexico, both places I have lived. It's all very interesting. I may need an intervention to break me of this "habit". BTW, Kansas is much more fascinating than I expected but you need to go back to the cambrian and precambrian.
Is there possibility that North America was crossing over the hot spot with the craeton basement that I would assume was thicker and denser than previous material it was dealing with. Perhaps the craeton was jagged with dense tongue that the hot spot hit and more difficult to melt and the hot spot split with the majority going on to form Yellowstone and a the minority say 15 to 25% going northeast into Oregon central area. With the siliziea coming up behind and squeeze the minority plume up to the surface to create the flood basalt and the caldereas ?? With the smaller volume of magma it could have played out creating the floods and calderas in Oregon. More or less it had just enough juice per se to create these areas in Eastern Oregon. While the big pocket was fortunate enough not to run into other blocks that it couldn't melt out of the way
Like there are mountains and valley's on the surface, maybe there are the same features on the underside of the crust that could influence the direction of the mantle plume or part of it, to explain the rhyolites and the Castle Rock Caldera? Maybe it had to take kind of a hurdle before it could slip completely beneath the Craton.
I live in prineville oregon we hardly get any earth quakes. As a kid I saw my saint Helen's eruption I still have a coffee can of ash from the eruption. But otherwise quiet around here my hole life . Eastern United states get hit by tornado storms and hurricanes. We don't get those here. My elevation is 3500' above sea level so no flood worrys.
Nick needn't apologize for an unpolished lecture. After giving all us townies the basics and a working knowledge of geology vocabulary, we are now learning to fish (to borrow a biblical parable). Facts aren't nearly as exciting as leaning to think.
Does anyone (~60+ years) remember 'Mister Wizard TV show' (Don Herbert), master teacher/presenter. You got bombarded by information and demonstration as much as was possible in 30 minutes, and if interested you would say, 'wait that's it' ? And if like me, that meant getting my Mother to drive me to the city library (yes, no 'intertube' back in the day). So, if Nicolaus can't generate a spark in a student maybe no one can. Cheers, Mark *********************************************
28:35 Have you read about the Sonomia Terrane of NW Nevada, NE California, SE Oregon and extreme Western Idaho? It's the "native" plate remnant of oceanic lithosphere and the Columbia Embayment (my logical conclusion geographically, geologically and place in time) that was accreted to NA. From there, its timeline becomes unclear, but that doesn't stop me from postulating- Accommodating the mechanics of the regional geologic timeline, I reasonably suspect Sonomia was partially subducted on its East side @the continental margin by the over-riding NA continent while being infiltrated through Western subduction, uplifted by the Siletz Terrane from the West and subsequently surviving as its parent oceanic plate (I'm leaning toward the Kula) was consumed on both ends. Yes, I strongly suspect that the Kula resides as the Sonomia Terrane; but it's stretched to double its former area through extension that occurred when it over-rode its own Kula spreading ridge via the NA front bumper analogy. Since it's shallow oceanic crust, it was vulnerable to compression- Nevada Plano, and extension- Over-riding the diverging mantle upwelling of the subducted Kula spreading ridge.
Hi John F. The China volcano video and one other were posted by Deep Dive. In the About section, the poster says his name is Roman. Here's the link to his channel: ru-vid.com/show-UCFPGKw4jb7CJur6cHmIgI3Q.
The YHS plume “decapitation” theory is valid, but is it more likely than simply the differential effects between thick cohesive high silica Craton -vs- relatively thin anomalous low silica oceanic crustal accretion? Moreover, the YHS plume probably has variable margins of varying effects to the overriding crust, and may just be too weak around its 400 mile wide diameter edges to penetrate the Craton. It may also have plume branches of varying intensities and effects.
HI Nick, There I go again asking a complex question in under 200 characters; hard to get my intent across on live chat, but I don’t know if you read the comments section either. Oh well, this is still fun. When I was asking about the EPR Plume, I was referring to upwelling; I suspect that it’s responsible for the whole YHS, NW Rotation and B&R shabang. If “Oceanic” Ridge upwelling had a system as deep as Hotspot plumes (why not, when they exist side by side? JDF-Cobb/ MAR-Iceland) then Continental overrun subduction would have no affect on them; because of their deep nature, they would continue on (along with their spawned Hotspot) as the Continents- NA and NE Africa for example have overridden them, causing divergent related activities such as the African Rift Zone, our B&R, PNW Fissures, and even the NW Rotation as a theoretical Mendocino upwelling section “pushes” the Siletz Terrane, and extends parts of SE OR. and WA. Since the EPR/ Farallon has a roughly North-South alignment, it’s only logical (NA drift) that it doesn’t continue West with the Salinian/San Andreas Terrane, but North-East-North through the Salton Rift, and Central Nevada to a point at a theoretical subterranean Mendocino Transform Fault under NoCal/Nevada, thus connecting it West to the Gorda sub plate as just another ridge upwelling offset, characteristic of the other JDF sub plates. I look at how complex the MAR and other Spreading Ridges are around the globe with their curves and offsets, and can see how they’re much more substantial than what they’re being given credit for. I suspect that they’re much deeper than science has shown so far. Wouldn’t this be a game changer?
@@Reziac We just don’t know enough to either discredit my hypothesis or support it; but I suspect the Spreading Ridge upwelling is much more substantial, and continues on as a global balance, responding to the deep mantle circulations established over the eons.
@@Reziac there was a recent paleomag study done on Hawaii chain showed minor drifting NE to SW by a non-negligible amount while the Pacific moved much faster SE to NW
As a long ago chemistry major... I find myself weirdly enlightened and intrigued by the geochem references... (and wondering why the basalt/rhyolite continuum isn't named something like "basalt Si-65%" instead of making up intermediate terms)...
@@Reziac Referring to the chemical compound will not identify the rock’s origin, such as Andesite-Extrusive, to Diorite-Plutonic, both have the same chemical compound but with a different size crystalline matrix because of their depth and exposure to pressure or lack thereof.
Good one, Nick! I mean the lecture, of course. And the tookies were good, too. I enjoy the spontaneity of the fresh information as much as the polished lectures. From the perspective of thermodynamics, one would expect the heat plume to have very different behavior as it transitions from under ocean crust to the patchwork of accreted terranes and then to the NA craton. The IRIS channel intimated such lateral flows of subduction arc magma in their video: ru-vid.com/video/%D0%B2%D0%B8%D0%B4%D0%B5%D0%BE-XpWLqlp88Fo.html.
I feel kinda bad, a little guilty for having interfered, if you will, and here’s why: the likes were at 666 and i ‘liked’...and changed the number to 667.
Had a credit/debit card with the security code of 666 for a while. If I was ordering or paying over the phone, and they asked for the number, I'd always answer "it's the card of the Devil"...and they got it every time.
