Watched this when you first released it and didn’t understand most of it. After watching all of your vids I now easily understand what you are representing. Aloha...
That Idaho Arc looks like it follow the Sr 706 line. The Absarokas lie just to the south of some Cretaceous volcanic remains of Slide Rock Mountain south of Big Timber, MT that are 78 - 75 Ma, too old for the Challis Magmas, and ending at the beginning of the Laramide Orogeny.
Nick, I never paid much attention to geology aside from volcanoes and earthquakes. Your downtown lecture series has really made me interested in this science.
Thank you for posting this video ! I have watched all of your videos. I am looking forward to seeing the final product ! Two years ago I made a google search on how the "Cascade Range was formed", your video lectures popped up in the results. My wife and I play on weekends in the Glacier Peak Volcano area, there was a nothing but granite land slide on FS 49, Sloan Peak Road. I had never encountered so much granite in one slide prior to this and wondered how it could be. Down the road two miles from there if you take a walk heading north, they're colossal sized granite boulders as big and bigger as my 1 ton dually. Because of your videos and fine teaching skills, I now understand the "Ghost Volcano" ideology! I cannot thank you enough for explaining the west coast to me and I am sure thousands of other curious people !
I love seeing how you are working to put this together. Complicated stuff and I, and I'm sure the legion of your rock-head fans, am looking forward to seeing the lecture that results. Thanks for sharing your thinking.
Stepping "off reservation", in relation to the standard model, the subduction switch from eastern to western orientation hypothesized by Hildebrand seems a worthy line of pursuit to suggest the unusual transition period in magmatic phenomena between the cessation of the Idaho arc (53Ma) and the eventual onset of the Cascade arc (44Ma). Rationalized against direct observation of regional crustal rotation observed in historic time via CWU's own GPS monitoring grid, and proposed rotation post-Sevier and into the Laramide that Hildebrand modeled to explain the Baja-BC scenario, the 53-44 Ma window matches up rather nicely with the E/W subduction switch post-Rubia and pre-Siletzia. Just a thought.
Hey Nick - Revisiting this. You actually don't need slab windows/tears, especially two of them in 5Ma to explain this. You have the Kula-Farallon ridge subducting under North America. When that ridge gets subducted, the two sides continue to be pushed apart in the mantle, without being able to create new plate in between, so as they subduct deeper into the mantle, you get an 'unzipping' of the plates in the mantle. That 'unzipping' propagates farther west as the North American plate travels west, explaining the age progression of 'Challis' Magmas. Furthermore, ridge subduction is known to be a main cause of arcs 'dying', and foreland basement-cored uplifts as in the Argentinian Andes...and our Central rockies. Except I would have the Kula-Farallon ridge oriented NW-SE. The Kula-Farallon Ridge would have gradually swept up the coast from the south, first during the Laramide orogeny, 70-55Ma from Mexico up into the central rockies, causing flat slab subduction, and strange magmas down there, and as the NA plate moves west over the NW-trending ridge, the point of intersection between the two plates gradually migrates northward. There is a whole record of these kind of slab-tear magmas younging up the BC coast towards Alaska (forgetting the paper(s) right now that show this). Additionally, since ridges are comprised of alternating spreading centers and transform faults, this tectonic picture also provides an explanation for Baja BC, in that the NA plate would alternately override a spreading ridge, creating magmas like this, then when it starts to override a transform fault, the northward motion of the Kula plate north of the ridge would become exactly like the modern Mid-pacifc rise colliding with Mexico/California, creating the San Andreas fault. In the case of the SAF, the transform fault was quite long, such that subduction of it caused long-lived strike-slip movement to propagate northward along much of California. Similarly, a large transform fault in the Kula-Farallon Ridge prior to the Challis event (subduction of spreading ridge) would have caused northward dextral offset along the coast - Baja BC. Depending on how the fault jogged, there would be localized transtension and wrench tectonics, creating the Eocene extensional basins. I actually think most of the story of the Cordillera can be explained by the presence of two subducting ridges with their alternating spreading centers and transform faults. Additionally, farther north in northern BC and Alaska there is similar evidence for another ridge subduction and slab tear (the resurrection plate) that broke off of the Kula, and or was a fragment of the Kula later in the same way that the subduction of the Farallon plate caused it to break into the Juan de Fuca and Cocos plates. The rest of the story involves 1.) the interaction of NA with the yellowstone hotspot - the Yellowstone hotspot generates Siletzia when the Kula-Farallon ridge passes over it, exactly like Iceland was created by the mid Atlantic Ridge. Created on a ridge, like Iceland, Siletzia splits in two parts - NA collides with the southern part, and it gets stuck in the subduction zone. The northern part travels northwards along the paleo Queen Charlotte fault as the Yakutat microplate and collides with Alaska, creating the St. Elias orogeny. 2.) extensional collapse of the Cordillera Nevadaplano combined with the cessation of convergence and slab rollback (due to the formation of the San Andreas fault and the strike slip regime) leading towards Basin and Range Extension in the South, and extension in Oregon and Rotation of the coast counterclockwise in the PNW. The B&R extension and PNW rotation I believe can be modeled as two swinging doors swinging outwards into the Pacific. Rotation of the PNW causes alternate extension in East WA/OR/ID/NV, and convergence in the Yakima Fold Belt. As this is occurring, NA is overriding the YS hotspot. It creates a few random volcanic/magmatic events (later Tillamook magmas, etc), but is largely interrupted by the subducting Farallon Plate. Eventually it eats through the plate, after all the hot magma has ponded under it, and just as the regime is changing to extension, the hotspot finally erupts voluminously as the CRB LIP, Steens, etc. Due to continued rotation of Oregon and slab rollback, lavas are erupted younging westward in SE oregon, just as the Yellowstone hotspot continues now unimpeded, under the future Snake River Plain, as the NA plate marches westward and creates an east-ward younging hotspot track towards Yellowstone. I feel like I have a pretty compelling story so far, but some things I am missing are: Olympic Wallowa Lineament (and why is there a missing Cascades volcano and no ghost volcanoes between Mt. Rainier and Glacier Peak?). My initial theory on this involves the rotation of oregon and the creation of an embayment in the Olympic Mountains, such that the slab there dips shallowly (there is seismic evidence for this). The rest of the lineament could be explained by convergence at the leading edge of the rotation of Oregon - the Yakima fold belt. Then there is another major lineament, the Texas lineament, which is parallel to the olympic-wallowa lineament and lewis and clark line, but offset southwards by 1300km. Hildebrand believes that these two lineaments were once continguous and that Baja BC can be explained by dextral offset of the Cordillera during the Sevier event, effectively moving the whole margin northwards west... but I don't see how that could work because it would be evident as a MAJOR shear zone, and also it would go right through the Belt Basin, which has definitely not been offset. And the last piece of the puzzle for me is the origin of the "mid-tertiary ignimbrite flare-up" in Utah & Colorado. Massive amounts of silicic volcanism and mineralization. I believe though that this can best be explained by hydration of the plate due to prolonged flat slab subduction as mentioned before, followed by eventual sinking of the slab and a sweep of volcanism as the slab sinks and aesthenosphere fills the wedge westward, interacting with a hydrated, thick, archean lithospheric keel. Yet greater mysteries are: the Mid-Tertiary to Neogene Sierra Madre Ignimbrite Province in most of Western and Central Mexico (Silicic Large Igneous Province), rotation of the Colorado Plateau and why it remained so cohesive and relatively undeformed during the Laramide, and the later uplift of the CP, the Rio Grande Rift, and then why there is another Basin and Range province 800km east of the US B&R in Mexico, and also a Laramide-aged fold belt in the Sierra Madre Oriental, all the way as far east as the longitude of Houston? So some progress, but so many mysteries still. I hope one day while I am still alive there is a real concerted effort to unravel this.
BTW: see this image for how the 'unzipping' subducting ridge works: d3i71xaburhd42.cloudfront.net/4d3ed5f5fa964d009249e2a07bab37dd1d5a8476/13-Figure4-1.png Also, if you notice in the picture, there is a region of the margin changing to a strike-slip regime north of the ridge - that's Baja BC.
An interesting tid bit about the challis volcanics. A rancher in the 40's discovered a petrified sequoia near Salmon, ID that measured 24' in diameter that was opalized. It was buried around 25 million yrs ago in a big ash fall event.
For once somebody agrees that plates die. Chunks break off the end rather than melt and sink into the mantle making volcanic activity from a deeper depth. I honestly think this is what happened and am glad to see you run with this. Will be interesting to find out if the Flood Basalts are from this activity or the plate boundary crossing the Yellowstone hotspot. Sorry my terminology is so terrible, its been 30 years since Mrs McNamars High School Geology of Oregon class in North Bend Or. Am so glad to see some new content on RUclips. Thank you for your efforts, wish I could participate more.
As I understand silitzia was a MOR hotspot ( Iceland). The crustal basalts were accreted while the mantle plume was subducted with the kula plate. The hot spot catches one of these breaks and then spews out the ‘cow pie’ then continues on the Yellowstone track to end up where it is today. Lots of gold and copper associated with the challis magmas around the end of the Laramie orogeny in western Idaho Utah Colorado . There are Eocene age porphyry copper deposits puckered all through western Idaho. Roof pendants on the Idaho batholith represent uplift of the batholith where the epithermal /porphyry mineralization has been eroded away and washed down into placer gold like at yankee fork, while the roots of the systems are now left exposed. Whenever Nick mentions a volcanic arc or magma emplacement I think “minerals deposit”. There are some Mesozoic windows in southern Oregon that show the history before 90ma, of similar arc volcanism Terrane accretion and strike slip faulting that translocates terranes across Nevada along the NSZ and up the linear western margin of the Idaho batholith - which has now also been dismembered by the basin and range extension. Fascinating stories to the north and south too ; another rich history of the US
Interesting thing about the Challis Magmas map of yours, Nick. That one spot in NE Montana is near Lewiston, I think, and several years back, saw an article in Science News where someone foundout in that area formations that looked like DIAMOND PIPES. Except the diamond-shaped holes within the formation were filled with graphite (the other carbon crystalline form). I thought that was neat. But also, in the area NW of Yellowstone, there were also gold fields in the Ruby Valley area (Virginia City, Sheridan, etc.), and hikers have also found small lots of diamonds in the Gravelly Range. I had fun learning stuff with a rock-hound mother, so I've crawled about in the Rockies looking for fossil shells (spirifer rockymontanis anyone?), panned for gold and sapphires in various places (and, honest, swallowed a pin--sized sapphire once -- long story, won't go there), and when we lived in Butte, used to use copper ore that had fallen off the ore cars to draw hopscotch patterns on the playground at our school.
The way you draw the Idaho Arc - it extends to the Sacramento Valley of California and the western foothills of the Sierra Nevada where gold was mined in the 1840s. Is it possible that this gold is an extension of your Challis Magmas? Or are the ages significantly different?
The mine shaft out in black diamond, that is safely trespass protected and has a grate on the deal, has fossils near it, and so does the Flaming geyser park near the entrance its like a 9 min walk.
Southeast Idaho a overthrust in SE Idaho. So what is the thought on this. Challis is having micro quakes now. Any relation? Grays Lake has blobs of magma residing any ideas.
Wow. So this is the theory and work of grad-students? Or colleagues? Impressive. Your explanation was nicely read. I majored in music and started to minor in geology too. But during my first lab class identifying minerals and such I lost interest. I only wanted to talk about plate tectonics. I gave up on the idea of minor degree. What a mistake that was to quit. But then again there was my so-so music skills that required time (no pun intended) too! That paid off and I teach music in the public school system. Thanks for keeping my interests in geology peaked.
Fascinating! I know this is to much too soon, but it would be cool to see the position of the Yellowstone Hot Spot superimposed on those hand drawn maps.
This rough draft seems unnecessarily complicated. I see models that don’t take Laurentian Drift into account enough. North-South spreading ridges aren’t necessary with enough space and timing of Continental Drift-Oceanic Migration. Head-on perpendicular Subduction also isn’t necessary when SR offsets are included. The accommodating “Kula” isn’t necessary because the ESE-WNW Farallon-Pacific oriented spreading ridge we have today can work. It’s just the placement of the spreading ridge offsets that need to be understood. Q. Isn’t it logical that the subducting SR had an Easterly continuation before the Clarno Formation? What happened on the over-riding plate Pre-Clarno Formation when it was still over an SR? How Far East did your Pre-subducted SR extend beyond your snap-shot in time? 10 miles, a thousand miles? Do you assume that SR’s migrate in relation to adjacent plates?
Sir, could you make a brief summery of the recent happening of the Mississippi river? If this dramatic flooding will make the river "get to the ocean" (?) Either and/or both would be astounding!
@@acr08807 Hi, I'm not in the region. I am interested in the watersheds of it though and path to the ocean. May you give your take on the dry spots I've heard of?
I'm not aware of any dry spots, and my knowledge of the geology of the Mississippi is limited. It's a large, mature river system and it does the things that large, mature river systems do. I can assure you the the Mississippi drains into the Gulf of Mexico just fine.
Before watching this, I had not known that the Bear Paw and Little Rocky mountains in North-Central Montana were of volcanic origin (although it makes sense that they are). Your mention of this in the above video motivated me to investigate further and to learn that this in fact the case. Very cool! Speaking of N-C Montana, does the Missouri River predate other geological features found there? And thank you as well for putting up an impassioned and well-informed fight against those who would deride or otherwise abuse scientific investigation and knowledge.
Nick this tied so much together and as a great 30 minute presentation for your Nick at home series. Secondly, do you think that this sort of plate behavior may have happend in California--- explaining gold in CA. Finally, I understand that you have to control the number of your "independent variables" factors as you attempt to explain these geological occurences. You shelved the BC Baja story for clearity...however could the Baja terranes have taken a ride up the coast with the Kula plate and then got pinned to NA by Siletzia and other Pacific Ocean crust terranes and thus contributed to the tearing of the Kula plate?
I can’t help but notice the relative proximity in location of the Yellowstone hotspot at the time and the spreading Kula/Farallon boundary. Could that have helped with some of these break-offs of the subduction plates in the form of a bit of upward pressure?
I can hardly wait for Nick's lecture, but I don't think it's simply andesite- remember he says the Teanaway basalts are part of "greater Challis". And the Challis formation itself is a mixture of both mafic and silicic magmas. The big difference is most andesites are found in stratovolcano magma arcs caused by classic subduction where heat generated by the subducting oceanic plate is upwelling thru the continental plate-- the compression story. Nick is illustrating something entirely different for the greater Challis-- a tension story where the subducting plate has stretched, broken and created a "plate window", allowing mantle rock to punch thru the window and the continental plate. Hopefully he'll describe the differences in chemstry/mineraology. But obviously, there's gold near them there magmas...
In attempts to visualize the movement of plates (i.e. Kula etc), we have a tendency to just see polygonal shapes. In reality, these are rugged, jagged and irregular. They have already experienced millions of years of movement, quakes, erosion etc. I am thinking that a possible explanation for the (Kula) pieces breaking off might be that the Kula plate already had deep major fault(s) and that the added pressures of subduction caused the fault to completely break allowing the broken to continue subducting (but at a slower rate because where it was attached, on the plate, is being held back by the movement of the NA plate.) 2 of these pieces would mean the Kula plate may have had more than 1 fault, which is quite believable (i.e. the vents/volcanos of eastern washington, or the even seeing the faults of present day California). I also think that you can't dismiss the Canada/Baja movements as they seem to be occuring before,during, and continue today. The spreading trench adds another set of variables. Soo many variables! :)
Hi Nick i was wondering where the B.C. Challis magmas are located...by any chance around Princeton BC and Logan lake BC ? There is the Highland Valley copper mine at Logans Lake and a couple of them at Princeton and most of the creeks around either place have gold or platinum in them. The Tranquille in 'Kamloops and the Similkameen near Princeton I hear have gold and platinum. Havent seen any at either place myself but certainly B.C. has its share of precious metals.
Not sure about the Kula plate but the Farallon plate they do have 'imaging' of it through seismic data. www.princeton.edu/~artofsci/2009/one.php%3Fid=1100.html
Nick maybe somebody can straighten out everyone about Machu Picchu Peru where the rock used to build the structure was already on top after the folding of rock layers to form the mountain ranges. I'm tired of seeing the ancient alien astronauts and super engineering moved the rocks up there.
Ok it's late I tried , tanks a tonne ! Yet have you ever wished a gaint ice Berg would plow off this whole mess , start over , a clean slate , ..I got glacieation and I seek metiorites , where did the glaciers first form melt rivers .
@@svalbard01, while you're at it, look at the rest of his lectures. If you had told me, two years ago that I'd get hooked on a bunch of videos of a guy standing in front of a chalk board, talking about rocks, I'd have told you you had rocks in your head. Now I'm seriously considering going back to school to study geomorphology.
@@104thDIVTimberwolf I've watched a bunch of his shorter ones (five minute geology or something like that) after I got sucked into the Graham Hancock stuff about the Younger Dryas floods. There's some great geology profs right up the road at Pierce College actually. I know one of them for sure knows Nick. But yeah, I'll check out the more in depth ones too.
I thought the Kula and/or Farallon remnants came much further inland under the NA plate? Is it already under there in this time frame, we are just seeing the western "edge"? Perhaps the scale in your drawings is just throwing me off. I study the New Madrid fault in my neck of the woods and one of the major theories to explain the seismic activity is ancient plate remnants sinking deep into the mantle from the NA plate going over the older plates on the west coast. It puts a downwards pulling moment on the NA plate and earthquakes can happen anywhere there is a weakness in the NA plate. At any rate, I am looking forward to seeing the final product here. Not enough good geology channels on youtube.
I was under the impression that the New Madrid earthquakes can be attributed to a failed rift zone that pretty much defines the Mississippi Valley. If there is an older plate remnant sinking deep into the mantle under the center of North America I could see that exerting forces on the New Madrid. But then I would think the quakes would be really deep in the mantle
Ooooo yikes...im packing up moving to a California...8 lanes going 90 mph is awesome...NOT...ill stay here in Boring Oregon 25 miles east of I-5 and wait for my toast to get soggy!
Da ta da...tump...da ts da..tump...da ta da....oh backwards 1/4 inch...going in circles a few billion years...yeee haw... I want GOLD...i lived in Grass Valley California...loved going to the Mallikoff digging to go swimming with my friends...i was 14...mid 1960s....YES there's a town named ROUGH and READY....TIMBUCTOO...and Boring Oregon....btw 1.5 yrs studying Geology, John Snively...captivating professor...i got all As..but drunk driver changed everything...sigh... Cow Pies? Fresh or dried...dry they fly high...i mean they really soar high...but they must be very. VERY flat and very very dry.
Growing up in central Mexico you get used to seeing volcanoes arranged all about, in much the same way as you are describing your neck of the woods. The following site explains the insights rendered from the MASE (MesoAmerican Subduction Experiment) array. I hope this is helpful in its apparent similarity with your "Kula, Challis, etc." video thoughts. www.tectonics.caltech.edu/outreach/highlights/mase/
I’m liking your thinking and investigation!
I’m saving this to rematch to digest fully …thanks I was entranced
Watched this when you first released it and didn’t understand most of it. After watching all of your vids I now easily understand what you are representing. Aloha...
Thank you! Very interesting!!!!
Nice to see this pop up on RUclips right after I watched your geology 101 lecture on exotic terranes.
Absolutely fascinating Nick. Thanks for all you do
That Idaho Arc looks like it follow the Sr 706 line. The Absarokas lie just to the south of some Cretaceous volcanic remains of Slide Rock Mountain south of Big Timber, MT that are 78 - 75 Ma, too old for the Challis Magmas, and ending at the beginning of the Laramide Orogeny.
Nick, I never paid much attention to geology aside from volcanoes and earthquakes. Your downtown lecture series has really made me interested in this science.
Great video
This is going to be a GREAT lecture when he puts all the pieces together, can't wait to see it
Just heard from Nick: 8 April, Morgan Center, Ellensburg. Gonna be great!
I hope he does it as a live stream now that he can’t have a live lecture anymore.
Thank you for posting this video ! I have watched all of your videos. I am looking forward to seeing the final product ! Two years ago I made a google search on how the "Cascade Range was formed", your video lectures popped up in the results. My wife and I play on weekends in the Glacier Peak Volcano area, there was a nothing but granite land slide on FS 49, Sloan Peak Road. I had never encountered so much granite in one slide prior to this and wondered how it could be. Down the road two miles from there if you take a walk heading north, they're colossal sized granite boulders as big and bigger as my 1 ton dually. Because of your videos and fine teaching skills, I now understand the "Ghost Volcano" ideology!
I cannot thank you enough for explaining the west coast to me and I am sure thousands of other curious people !
Thank you, Scott!
Great to have this new stuff--- I have watched the old lectures again and again!
What if the drag created by the docking of Seletzia caused the Kula plate to break? Like tug of war where the rope breaks.
The geology of the PNW just gets more and more complicated and fascinating.
I love seeing how you are working to put this together. Complicated stuff and I, and I'm sure the legion of your rock-head fans, am looking forward to seeing the lecture that results. Thanks for sharing your thinking.
Spring will come and journeys will be fun.
Stepping "off reservation", in relation to the standard model, the subduction switch from eastern to western orientation hypothesized by Hildebrand seems a worthy line of pursuit to suggest the unusual transition period in magmatic phenomena between the cessation of the Idaho arc (53Ma) and the eventual onset of the Cascade arc (44Ma). Rationalized against direct observation of regional crustal rotation observed in historic time via CWU's own GPS monitoring grid, and proposed rotation post-Sevier and into the Laramide that Hildebrand modeled to explain the Baja-BC scenario, the 53-44 Ma window matches up rather nicely with the E/W subduction switch post-Rubia and pre-Siletzia. Just a thought.
Hey Nick - Revisiting this. You actually don't need slab windows/tears, especially two of them in 5Ma to explain this. You have the Kula-Farallon ridge subducting under North America. When that ridge gets subducted, the two sides continue to be pushed apart in the mantle, without being able to create new plate in between, so as they subduct deeper into the mantle, you get an 'unzipping' of the plates in the mantle. That 'unzipping' propagates farther west as the North American plate travels west, explaining the age progression of 'Challis' Magmas. Furthermore, ridge subduction is known to be a main cause of arcs 'dying', and foreland basement-cored uplifts as in the Argentinian Andes...and our Central rockies. Except I would have the Kula-Farallon ridge oriented NW-SE. The Kula-Farallon Ridge would have gradually swept up the coast from the south, first during the Laramide orogeny, 70-55Ma from Mexico up into the central rockies, causing flat slab subduction, and strange magmas down there, and as the NA plate moves west over the NW-trending ridge, the point of intersection between the two plates gradually migrates northward. There is a whole record of these kind of slab-tear magmas younging up the BC coast towards Alaska (forgetting the paper(s) right now that show this). Additionally, since ridges are comprised of alternating spreading centers and transform faults, this tectonic picture also provides an explanation for Baja BC, in that the NA plate would alternately override a spreading ridge, creating magmas like this, then when it starts to override a transform fault, the northward motion of the Kula plate north of the ridge would become exactly like the modern Mid-pacifc rise colliding with Mexico/California, creating the San Andreas fault. In the case of the SAF, the transform fault was quite long, such that subduction of it caused long-lived strike-slip movement to propagate northward along much of California. Similarly, a large transform fault in the Kula-Farallon Ridge prior to the Challis event (subduction of spreading ridge) would have caused northward dextral offset along the coast - Baja BC. Depending on how the fault jogged, there would be localized transtension and wrench tectonics, creating the Eocene extensional basins.
I actually think most of the story of the Cordillera can be explained by the presence of two subducting ridges with their alternating spreading centers and transform faults. Additionally, farther north in northern BC and Alaska there is similar evidence for another ridge subduction and slab tear (the resurrection plate) that broke off of the Kula, and or was a fragment of the Kula later in the same way that the subduction of the Farallon plate caused it to break into the Juan de Fuca and Cocos plates. The rest of the story involves 1.) the interaction of NA with the yellowstone hotspot - the Yellowstone hotspot generates Siletzia when the Kula-Farallon ridge passes over it, exactly like Iceland was created by the mid Atlantic Ridge. Created on a ridge, like Iceland, Siletzia splits in two parts - NA collides with the southern part, and it gets stuck in the subduction zone. The northern part travels northwards along the paleo Queen Charlotte fault as the Yakutat microplate and collides with Alaska, creating the St. Elias orogeny. 2.) extensional collapse of the Cordillera Nevadaplano combined with the cessation of convergence and slab rollback (due to the formation of the San Andreas fault and the strike slip regime) leading towards Basin and Range Extension in the South, and extension in Oregon and Rotation of the coast counterclockwise in the PNW. The B&R extension and PNW rotation I believe can be modeled as two swinging doors swinging outwards into the Pacific. Rotation of the PNW causes alternate extension in East WA/OR/ID/NV, and convergence in the Yakima Fold Belt. As this is occurring, NA is overriding the YS hotspot. It creates a few random volcanic/magmatic events (later Tillamook magmas, etc), but is largely interrupted by the subducting Farallon Plate. Eventually it eats through the plate, after all the hot magma has ponded under it, and just as the regime is changing to extension, the hotspot finally erupts voluminously as the CRB LIP, Steens, etc. Due to continued rotation of Oregon and slab rollback, lavas are erupted younging westward in SE oregon, just as the Yellowstone hotspot continues now unimpeded, under the future Snake River Plain, as the NA plate marches westward and creates an east-ward younging hotspot track towards Yellowstone.
I feel like I have a pretty compelling story so far, but some things I am missing are: Olympic Wallowa Lineament (and why is there a missing Cascades volcano and no ghost volcanoes between Mt. Rainier and Glacier Peak?). My initial theory on this involves the rotation of oregon and the creation of an embayment in the Olympic Mountains, such that the slab there dips shallowly (there is seismic evidence for this). The rest of the lineament could be explained by convergence at the leading edge of the rotation of Oregon - the Yakima fold belt. Then there is another major lineament, the Texas lineament, which is parallel to the olympic-wallowa lineament and lewis and clark line, but offset southwards by 1300km. Hildebrand believes that these two lineaments were once continguous and that Baja BC can be explained by dextral offset of the Cordillera during the Sevier event, effectively moving the whole margin northwards west... but I don't see how that could work because it would be evident as a MAJOR shear zone, and also it would go right through the Belt Basin, which has definitely not been offset. And the last piece of the puzzle for me is the origin of the "mid-tertiary ignimbrite flare-up" in Utah & Colorado. Massive amounts of silicic volcanism and mineralization. I believe though that this can best be explained by hydration of the plate due to prolonged flat slab subduction as mentioned before, followed by eventual sinking of the slab and a sweep of volcanism as the slab sinks and aesthenosphere fills the wedge westward, interacting with a hydrated, thick, archean lithospheric keel.
Yet greater mysteries are: the Mid-Tertiary to Neogene Sierra Madre Ignimbrite Province in most of Western and Central Mexico (Silicic Large Igneous Province), rotation of the Colorado Plateau and why it remained so cohesive and relatively undeformed during the Laramide, and the later uplift of the CP, the Rio Grande Rift, and then why there is another Basin and Range province 800km east of the US B&R in Mexico, and also a Laramide-aged fold belt in the Sierra Madre Oriental, all the way as far east as the longitude of Houston?
So some progress, but so many mysteries still. I hope one day while I am still alive there is a real concerted effort to unravel this.
BTW: see this image for how the 'unzipping' subducting ridge works: d3i71xaburhd42.cloudfront.net/4d3ed5f5fa964d009249e2a07bab37dd1d5a8476/13-Figure4-1.png Also, if you notice in the picture, there is a region of the margin changing to a strike-slip regime north of the ridge - that's Baja BC.
Yes, Yes, Yes! puts a lot of the pieces together
Ah yes mountain building forces the gold to be depleted in the lower metamorphic rock and rise to mid rock and deposited into veins in the rock.
An interesting tid bit about the challis volcanics. A rancher in the 40's discovered a petrified sequoia near Salmon, ID that measured 24' in diameter that was opalized. It was buried around 25 million yrs ago in a big ash fall event.
Wow. That makes sense to me, a total novice. I’ve watched your videos and find them enlightening. Thanks so much.
For once somebody agrees that plates die. Chunks break off the end rather than melt and sink into the mantle making volcanic activity from a deeper depth. I honestly think this is what happened and am glad to see you run with this. Will be interesting to find out if the Flood Basalts are from this activity or the plate boundary crossing the Yellowstone hotspot.
Sorry my terminology is so terrible, its been 30 years since Mrs McNamars High School Geology of Oregon class in North Bend Or.
Am so glad to see some new content on RUclips. Thank you for your efforts, wish I could participate more.
As I understand silitzia was a MOR hotspot ( Iceland). The crustal basalts were accreted while the mantle plume was subducted with the kula plate. The hot spot catches one of these breaks and then spews out the ‘cow pie’ then continues on the Yellowstone track to end up where it is today.
Lots of gold and copper associated with the challis magmas around the end of the Laramie orogeny in western Idaho Utah Colorado . There are Eocene age porphyry copper deposits puckered all through western Idaho. Roof pendants on the Idaho batholith represent uplift of the batholith where the epithermal /porphyry mineralization has been eroded away and washed down into placer gold like at yankee fork, while the roots of the systems are now left exposed. Whenever Nick mentions a volcanic arc or magma emplacement I think “minerals deposit”.
There are some Mesozoic windows in southern Oregon that show the history before 90ma, of similar arc volcanism Terrane accretion and strike slip faulting that translocates terranes across Nevada along the NSZ and up the linear western margin of the Idaho batholith - which has now also been dismembered by the basin and range extension. Fascinating stories to the north and south too ; another rich history of the US
Interesting thing about the Challis Magmas map of yours, Nick. That one spot in NE Montana is near Lewiston, I think, and several years back, saw an article in Science News where someone foundout in that area formations that looked like DIAMOND PIPES. Except the diamond-shaped holes within the formation were filled with graphite (the other carbon crystalline form). I thought that was neat.
But also, in the area NW of Yellowstone, there were also gold fields in the Ruby Valley area (Virginia City, Sheridan, etc.), and hikers have also found small lots of diamonds in the Gravelly Range. I had fun learning stuff with a rock-hound mother, so I've crawled about in the Rockies looking for fossil shells (spirifer rockymontanis anyone?), panned for gold and sapphires in various places (and, honest, swallowed a pin--sized sapphire once -- long story, won't go there), and when we lived in Butte, used to use copper ore that had fallen off the ore cars to draw hopscotch patterns on the playground at our school.
Really looking forward to this lecture. I hope you do another one on Mount Saint Helens being the 40 year anniversary of the 1980 eruption
Oh, I can't wait for this lecture!!!
Just heard from Nick: 8 April, Morgan Center, Ellensburg. Gonna be great!
All due respect to Central Washington, but why the Hell isn't this man a full professor? I hope this work earns him a well-deserved PhD.
Simply because he doesn't do original research. He works with the research of others. He is happy doing this and we benefit.
As my mother the chemist said: BS bull shit. MS more shit. PHD piled higher and deeper. No offense to my son with a PHD
Honorary degree doctorate
The way you draw the Idaho Arc - it extends to the Sacramento Valley of California and the western foothills of the Sierra Nevada where gold was mined in the 1840s. Is it possible that this gold is an extension of your Challis Magmas? Or are the ages significantly different?
The mine shaft out in black diamond, that is safely trespass protected and has a grate on the deal, has fossils near it, and so does the Flaming geyser park near the entrance its like a 9 min walk.
Southeast Idaho a overthrust in SE Idaho. So what is the thought on this.
Challis is having micro quakes now. Any relation?
Grays Lake has blobs of magma residing any ideas.
What causes a plate to break? In particular, what caused the Farallon Plate to break?
Wow. So this is the theory and work of grad-students? Or colleagues? Impressive. Your explanation was nicely read. I majored in music and started to minor in geology too. But during my first lab class identifying minerals and such I lost interest. I only wanted to talk about plate tectonics. I gave up on the idea of minor degree. What a mistake that was to quit. But then again there was my so-so music skills that required time (no pun intended) too! That paid off and I teach music in the public school system. Thanks for keeping my interests in geology peaked.
Fascinating! I know this is to much too soon, but it would be cool to see the position of the Yellowstone Hot Spot superimposed on those hand drawn maps.
Interesting information. I've always wondered what would happen when a mid-oceanic ridge subducts under a continent.
Yellowstone would have to be added to this story in some way. Some very interesting research opportunities in the future. Great job Nick!
I 👀 a chalkboard lecture in the making💛📚
This rough draft seems unnecessarily complicated. I see models that don’t take Laurentian Drift into account enough. North-South spreading ridges aren’t necessary with enough space and timing of Continental Drift-Oceanic Migration. Head-on perpendicular Subduction also isn’t necessary when SR offsets are included.
The accommodating “Kula” isn’t necessary because the ESE-WNW Farallon-Pacific oriented spreading ridge we have today can work. It’s just the placement of the spreading ridge offsets that need to be understood.
Q.
Isn’t it logical that the subducting SR had an Easterly continuation before the Clarno Formation?
What happened on the over-riding plate Pre-Clarno Formation when it was still over an SR?
How Far East did your Pre-subducted SR extend beyond your snap-shot in time? 10 miles, a thousand miles?
Do you assume that SR’s migrate in relation to adjacent plates?
Sir, could you make a brief summery of the recent happening of the Mississippi river? If this dramatic flooding will make the river "get to the ocean" (?) Either and/or both would be astounding!
You think the Mississippi doesn't reach the ocean now?
@@acr08807 Hi, I'm not in the region. I am interested in the watersheds of it though and path to the ocean. May you give your take on the dry spots I've heard of?
@@acr08807 please tell me more.
@@acr08807 Yes. I am under the impression that at times the worlds 4th largest basin doesn't get there and to type it out does seem incorrect.
I'm not aware of any dry spots, and my knowledge of the geology of the Mississippi is limited. It's a large, mature river system and it does the things that large, mature river systems do. I can assure you the the Mississippi drains into the Gulf of Mexico just fine.
My eyes are now crossed.......
Before watching this, I had not known that the Bear Paw and Little Rocky mountains in North-Central Montana were of volcanic origin (although it makes sense that they are). Your mention of this in the above video motivated me to investigate further and to learn that this in fact the case. Very cool!
Speaking of N-C Montana, does the Missouri River predate other geological features found there?
And thank you as well for putting up an impassioned and well-informed fight against those who would deride or otherwise abuse scientific investigation and knowledge.
Nick this tied so much together and as a great 30 minute presentation for your Nick at home series. Secondly, do you think that this sort of plate behavior may have happend in California--- explaining gold in CA. Finally, I understand that you have to control the number of your "independent variables" factors as you attempt to explain these geological occurences. You shelved the BC Baja story for clearity...however could the Baja terranes have taken a ride up the coast with the Kula plate and then got pinned to NA by Siletzia and other Pacific Ocean crust terranes and thus contributed to the tearing of the Kula plate?
I can’t help but notice the relative proximity in location of the Yellowstone hotspot at the time and the spreading Kula/Farallon boundary. Could that have helped with some of these break-offs of the subduction plates in the form of a bit of upward pressure?
11:11 Ha ha! He said "shit". I love this guy! I really miss his town lectures. Please do more!
Sorry Patrick lol
So, what is the chemistry of the "weird" Challis volcanic rock? I'm guessing andesite?
I can hardly wait for Nick's lecture, but I don't think it's simply andesite- remember he says the Teanaway basalts are part of "greater Challis". And the Challis formation itself is a mixture of both mafic and silicic magmas. The big difference is most andesites are found in stratovolcano magma arcs caused by classic subduction where heat generated by the subducting oceanic plate is upwelling thru the continental plate-- the compression story. Nick is illustrating something entirely different for the greater Challis-- a tension story where the subducting plate has stretched, broken and created a "plate window", allowing mantle rock to punch thru the window and the continental plate. Hopefully he'll describe the differences in chemstry/mineraology. But obviously, there's gold near them there magmas...
He described it as bimodal in his podcast today.
@Brett327 Thanks! I'll go listen.
In attempts to visualize the movement of plates (i.e. Kula etc), we have a tendency to just see polygonal shapes. In reality, these are rugged, jagged and irregular. They have already experienced millions of years of movement, quakes, erosion etc. I am thinking that a possible explanation for the (Kula) pieces breaking off might be that the Kula plate already had deep major fault(s) and that the added pressures of subduction caused the fault to completely break allowing the broken to continue subducting (but at a slower rate because where it was attached, on the plate, is being held back by the movement of the NA plate.) 2 of these pieces would mean the Kula plate may have had more than 1 fault, which is quite believable (i.e. the vents/volcanos of eastern washington, or the even seeing the faults of present day California). I also think that you can't dismiss the Canada/Baja movements as they seem to be occuring before,during, and continue today. The spreading trench adds another set of variables. Soo many variables! :)
Revisiting........
More town lectures. I watch them a lot. We need more Nick. I hope your university realizes what an asset you are!
Is it likely the recent earthquake swarm 10km under Challis, Id is another emerging magma chamber?
Wow, this is so fascinating! Is this going to be a lecture at some point?
Hi Nick i was wondering where the B.C. Challis magmas are located...by any chance around Princeton BC and Logan lake BC ? There is the Highland Valley copper mine at Logans Lake and a couple of them at Princeton and most of the creeks around either place have gold or platinum in them. The Tranquille in 'Kamloops and the Similkameen near Princeton I hear have gold and platinum. Havent seen any at either place myself but certainly B.C. has its share of precious metals.
Thank you Nick, that was fascinating. Can I ask how that track matches up with the Yellowstone volcano track?
And I thunk that Electronics was confosing.
You mentioned "modeling of tectonic plates showing that pieces of the Kula plate have broken apart". Are there any videos of that online?
Not sure about the Kula plate but the Farallon plate they do have 'imaging' of it through seismic data.
www.princeton.edu/~artofsci/2009/one.php%3Fid=1100.html
Nick maybe somebody can straighten out everyone about Machu Picchu Peru where the rock used to build the structure was already on top after the folding of rock layers to form the mountain ranges. I'm tired of seeing the ancient alien astronauts and super engineering moved the rocks up there.
Now that you mention it, an attack by ancient aliens would explain why the Kula plate broke.
@@acr08807 Also explains where the many Greek gods of wind went instead of hanging around the sadistic gods of Romans and the middle east.
Ok it's late I tried , tanks a tonne ! Yet have you ever wished a gaint ice Berg would plow off this whole mess , start over , a clean slate , ..I got glacieation and I seek metiorites , where did the glaciers first form melt rivers .
What's Baja BC and why are we ignoring it?
Look up Nick's video on Exotic Terranes of the Pacific Northwest. Set aside an hour and I promise it will be well-spent.
@@104thDIVTimberwolf Will do. Thanks!
@@svalbard01, while you're at it, look at the rest of his lectures. If you had told me, two years ago that I'd get hooked on a bunch of videos of a guy standing in front of a chalk board, talking about rocks, I'd have told you you had rocks in your head. Now I'm seriously considering going back to school to study geomorphology.
@@104thDIVTimberwolf I've watched a bunch of his shorter ones (five minute geology or something like that) after I got sucked into the Graham Hancock stuff about the Younger Dryas floods. There's some great geology profs right up the road at Pierce College actually. I know one of them for sure knows Nick. But yeah, I'll check out the more in depth ones too.
@@svalbard01, you can get rid of Netflix and just binge watch
Nick Zentner videos for weeks :-)
I concur!!!!
I thought the Kula and/or Farallon remnants came much further inland under the NA plate? Is it already under there in this time frame, we are just seeing the western "edge"? Perhaps the scale in your drawings is just throwing me off.
I study the New Madrid fault in my neck of the woods and one of the major theories to explain the seismic activity is ancient plate remnants sinking deep into the mantle from the NA plate going over the older plates on the west coast. It puts a downwards pulling moment on the NA plate and earthquakes can happen anywhere there is a weakness in the NA plate.
At any rate, I am looking forward to seeing the final product here. Not enough good geology channels on youtube.
I was under the impression that the New Madrid earthquakes can be attributed to a failed rift zone that pretty much defines the Mississippi Valley. If there is an older plate remnant sinking deep into the mantle under the center of North America I could see that exerting forces on the New Madrid. But then I would think the quakes would be really deep in the mantle
Ooooo yikes...im packing up moving to a California...8 lanes going 90 mph is awesome...NOT...ill stay here in Boring Oregon 25 miles east of I-5 and wait for my toast to get soggy!
Da ta da...tump...da ts da..tump...da ta da....oh backwards 1/4 inch...going in circles a few billion years...yeee haw...
I want GOLD...i lived in Grass Valley California...loved going to the Mallikoff digging to go swimming with my friends...i was 14...mid 1960s....YES there's a town named ROUGH and READY....TIMBUCTOO...and Boring Oregon....btw 1.5 yrs studying Geology, John Snively...captivating professor...i got all As..but drunk driver changed everything...sigh...
Cow Pies? Fresh or dried...dry they fly high...i mean they really soar high...but they must be very. VERY flat and very very dry.
Growing up in central Mexico you get used to seeing volcanoes arranged all about, in much the same way as you are describing your neck of the woods. The following site explains the insights rendered from the MASE (MesoAmerican Subduction Experiment) array. I hope this is helpful in its apparent similarity with your "Kula, Challis, etc." video thoughts.
www.tectonics.caltech.edu/outreach/highlights/mase/
Geology is a crusty subject.