Mind officially blown! I love the effort to view both models, not as competing, but as exploration. On opening these recent episodes, I feel like a kid at Christmas getting ready to open some endlessly fascinating presents under the tree
"Celebration" was the perfect word for your approach to the content of these A to Z series videos. From the world-wide greetings at the beginning to the Toast to You at the end -- and all the learning in between -- it's been a real pleasure watching your creation evolve. I'm a bit slow with the science, but I know a thing of goodness when I see it. Thanks, Nick.
Your excitement is contagious, Nick! It is great to see you having a blast at this! I also love that you emphasise that this is not a race or even a fight. It is just science happening. New insights, multiple possibilities. Love it!
Wow, we know most of those yellow triangle places and have driven by many times..., cool!!😃✨💞💛 Wow wow, Near Trench Magmas, Triple Junctions migration, the spreading ridge migrations, the Yo-yo, many ways to be more less clear in our minds, thank you to your talent, Nick!!😃✨ I'm loving this episode yet again!!!😘💞🩷✨
This is such fun! Seeing your excitement, years of data from Mike and Jeff, and their teams' thoughts and careful considerations just blows me away. Our family has been all over this area. It's not only fascinating but really sentimental. I can't wait for Saturday.👏🏼😄❣️
I don't mind the confusion.... confusion on uncertainties makes sense 🤪 It seems that Jeff's map(s) at 24:24 and Mike's map(s) at 1:20:20 both show the same thing as far as the the triple junction being in Oregon with subduction of the Farallon to the south post Siletzia accretion. 💖 It seems the difference in timing is that Jeff has the northern edge of the Farallon to present north WA (WA/BC border) though the straight creek fault still was active and the northern edge would/should have still been further south. Mike's 35 Ma works/correlates with the end of SCF movement. The map at 1:27:29 shows the triple junction still further south and/but puts the Granite Falls pluton north of the triple junction (and east of Siletzia but west of the breakoff belt area) ..which would be Kula subducting north of the triple junction (to make the Granite Falls pluton (if) via subduction) ....right? Would Straight Creek fault movement also contribute to or account for northward migration of the triple junction? 💖💞
Would the greater Juan de Fuca plate (the Explorer portion to the north and the Gorda portion to the south) make a good analogy for the visual of the 50-ish Ma spreading ridge? The northern part of the Explorer a triple junction and the southern part of the Gorda the other triple junction. 💭Then to visualize a Siletzia / Yakuletzia scenario occurring on the Pacific & Explorer segment of the spreading ridge with the 'modern' (visualized) Siletzia on Explorer and accreting to eliminate the Explorer portion of the greater Juan de Fuca plate, and jump the northern part of Juan de Fuca (proper) to the new triple junction. ...making the new triple junction closer to the middle of Vancouver Island vs north of it as it is now. 💭🤔 Given the Kula was captured by Pacific, and the Farallon became (greater) Juan de Fuca and the modern segments of the ridge look similar to what Mike has (and the angles similar too) it seems similar enough for a visualization based the modern look ... (perhaps a difference in being transform segments or spreading segments). 🤔 Are the transform segments transpression or transtension or neither? 🥧💖💞
Started watching live, but had to leave and caught the rest on replay. Tough to get my head around all of it, but I love looking at the big picture. Have a better understanding of Jeff Tepper’s model, than Mike Eddy’s. Still trying to digest it all. I noticed you suggested a few times that the Yellowstone hotspot maybe be much bigger than originally imagined. I always remember your advice to not make interpretations without first having the data. Do we have data that would suggest a much larger hot spot? Are there any hotspots in the world today that are as large as you are proposing the Yellowstone hotspot was at one time? Love your videos and livestreams. So glad to hear you and Liz took a hike with her developing the cherry pie analogy.
As you were talking about mafic enclaves in the pluton, the one you picked up at Granite Falls was visible right behind you. I wanted you to show it . I keep finding them lately everywhere I am hiking.
Regarding maps of the spreading ridge .. how detailed vs how vague/fuzzy are our images of the broken off "garage door"? Can we see specific notches that might have represented the faults perpendicular to the ridge or is that beyond the resolution we can achieve now? If we CAN see those still along the edge of the sinking slab, then we should be able to infer what the plate and spreading ridge geometry looked like as well. If it's just a blob down there, indistinct, then the best we have is a guess.
There could be a thin wedge of Resurrection inboard of Kula that is making the Alaska & northern BC near-trench magmas at a Kula-Resurrection triple junction pre-50 Mya. That southern sweep prior to 50 Mya could be Resurrection, not Kula, with Resurrection disappearing under BC about 50 Mya. The yo-yo in the 40s in the Pacific Northwest would be the Kula-Farallon triple junction. I think Wells & Camp have the Yellowstone hot spot track south of the OR-CA border at ~42 Mya, but it occurs to me that if there is a slab window to the north of the plume head, the plume head will naturally want to flow toward it and through it, meaning that the heat would spread northward from the hot spot towards the triple junction.
YES. Yes. Saturday's M is going to be titanic tectonically for me when you explain the bend in the Hawaiian seamounts. Even if the bend has nothing to do with the Pacific Northwest, it will be a very satisfying thing to understand how and why that bend is there.
59:33 - look at the jagged boundary along the Kula plate off shore of the NA plate. If that jagged boundary gets subducted, the triple junction will “appear” to move north & south over time following the jags in the boundary. That helps explain Mike’s position.
Those jagged plate boundaries are probably all expanding plate boundaries. That supports the notion of magmas showing up you discuss a few minutes later.
Thank you so much for explaining these things in the way you do. It's so helpful! I really like Mike Eddy's idea, but I have a problem with the times. If the triple junction was at the Oregon coast like 45-ish Ma ago, and then it was "back" at Vancouver Island like 41 Ma ago, why don't we have NTMs in Washington between 45 and 41 Ma ago? Wouldn't that be a logical consequence? And if he assumes that the plate reorganization was like 48 Ma ago, why did the southward migration last until 45 (or after) Ma ago and changed the direction then? I'm confused, but in a good way, I think. :) Thank you all for making me think about these things, it's fun!
You are showing some of the complexities of the involved processes. I believe they are infinitely more complex than what you and yours have uncovered, but you have to start somewhere. This is how science works and what will trigger human minds to ask questions and seek answers.
Petrologists seek to understanding which melts formed in which tectonic environments. If I pick up a rock, its petrology should tell me where it came from. Near-trench magmas are "weird" in that they have a chemical fingerprint that is "not arc". But like arc magmas, the composition of near-trench magmas are variable within a range - their own range - and form their own distinctive cluster on plots. Not a weird cluster, just one slightly offset from the "typical" cluster for arcs.
Another idea. I think the age of the subducting ocean floor matters. Ocean floor near the spreading ridge is younger, hotter and chemically different (less modified by water). The speed of the spreading effects how quickly it ages. This could affect how it subducts and potentially creates the near trench magmas, or at least the chemistry of them. I seem to remember this is related to ophiolite production and could also be a factor in flat slab subduction Note: because you are subducting a spreading ridge each side of the triple junction has different and mirrored effects from this, if it exists
If the spreading ridge was leaving a trail of magmas on the way south, then reversed, why would it not be leaving a trail of magmas on the reverse trip?
I got some major oceanic fundamentals from Jeff’s concurrence with my chat questions. The first is it takes up to 10 My for freshly upwelled spreading ridge slab to cool to the point that it’s subductible; too warm makes it too plasticized in the trench, causing it to stretch like taffy and snap off the descending slab- “slab break-off.” Second: Spreading Ridge derived mantle upwelling stays active for “millions of years” -Jeff Tepper after it has been overridden by continental crust. My example to Jeff was the rifting of the Baja Peninsula with the EPR Spreading Ridge (thus mantle upwelling) in its center. He either avoided or didn’t see my third question: “Jeff Tepper” With the Franciscan Assemblage in Southern Oregon and with evidence of California Terrane beach cobble evidence on Merchants, Agate and Sacci beaches, just a few miles from the South end of the Siletz Terrane; is it possible that there is solid contact with the Terranes, and since the California Terranes are conveying NNWesterly, could their contact with the Siletz Terrane be causing the NW rotation of Siletzia?
Nick, I suggest you take Liz on a long weekend to Yachats (pronounced Ya-hots). You will both love the scenery and they will correct your pronounciation. Battery Fully Charged
Could the yo-yo instead be explained by two different spreading ridges (the m&ms). One going south and one up by vancouver island? Maybe one is farallon triple, and the other is resurrection?
I like the elegance of subducting spreading ridge/NTMs, but… I also like using contemporary examples as the baseline. What better example source than Google Earth and its oceanic imagery of the subducting Explorer plate North of Vancouver Island and Immediately South of the Queen Charlotte fault; it’s a Triple Junction of the Pacific, Explorer and North American (NA) plates; this is also the location where the Explorer spreading ridge is subducting under NA.; but there is nothing especially active there as far as NTMs, why?
The Nazca ridge isn't a spreading ridge, so I don't think it deserves a green M&M triple junction. It's a hotspot LIP, more like Siletzia. The Juan Fernández and Carnegie Ridges are probably similar, but both are new to me. The one that deserves a green M&M doesn't have one - the Patagonian volcanic gap. It seems the closest present day parallel to Washington 50MYA but I couldn't find any good academic research when I looked (there is some great research into the Nazca Ridge region, though)
If Mike Eddy’s triple junction moves south then back north depositing younger lavas on Vancouver Island why don’t we see both older and younger deposits side by side as the junction moved north. Older deposits as the junction moved south and younger as it moved back north
I'm glad you ended with your question regarding this possibly being a global story. My brain often wonders along these lines any tim we start talking about plates diving under or bumping into each other or spreading, etc, It makes my brain want to back way out and see all of the plate activity at that time. My sense is there are non-local factors contributing to what we're looking at, but I have zero proof of that sense being accurate.
Hey, Ned Zinger! As I am trying to grasp the multiple moving parts, I am reminded of my favorite pastime, square dancing. It looks and feels like befuddling chaos at first, but once you break down the moves, learn to connect them and keep track of the direction you need to go while everyone else does their thing, the patterns become clear and even an observer can track what the simultaneous movements are. For this L episode, the move called Scoot Back may have resonance. There are lots of moves where dancers go all over the place, but miraculously end up back home. This teacher has many short videos you may find interesting to browse. ua-cam.com/video/ACJVQJQ_VKc/v-deo.htmlsi=n5XmmFQSFodHbZnV
IN YO-YO, WHAT IS THE FORCE DRIVING THE TRIPLE JUNCTION MIGRATION SOUTH AGAINST THE LOCAL DEXTRAL FORCES DRIVING KULA, YAKATAT, & FARALLON NORTH. IF GLOBAL PLATE REALIGNMENT IS THE REASON, WHY NO IMPACT ON KULA, YAKATAT, FARALLON NORTHWARD MIGRATION? TP IS A SALMON WHILE ALL ELSE ARE WHALES?
despite the blocking of UA-cam in Russia...
I still watch from it, Veliky Novgorod...
health to everyone...
Mind officially blown! I love the effort to view both models, not as competing, but as exploration. On opening these recent episodes, I feel like a kid at Christmas getting ready to open some endlessly fascinating presents under the tree
I am watching in replay… this is spectacular news about Liz!!!
Thanks for all the hard work on these videos and live streams Nick!
"Celebration" was the perfect word for your approach to the content of these A to Z series videos. From the world-wide greetings at the beginning to the Toast to You at the end -- and all the learning in between -- it's been a real pleasure watching your creation evolve. I'm a bit slow with the science, but I know a thing of goodness when I see it. Thanks, Nick.
Your excitement is contagious, Nick! It is great to see you having a blast at this! I also love that you emphasise that this is not a race or even a fight. It is just science happening. New insights, multiple possibilities. Love it!
So glad to hear of Liz’ recovery!
Wow, we know most of those yellow triangle places and have driven by many times..., cool!!😃✨💞💛 Wow wow, Near Trench Magmas, Triple Junctions migration, the spreading ridge migrations, the Yo-yo, many ways to be more less clear in our minds, thank you to your talent, Nick!!😃✨ I'm loving this episode yet again!!!😘💞🩷✨
Wonderful, Nick!! Now I understand the triple junction migration. You really are a God Given teacher
Quarter has started, thus have office hours at noon and teach at one, so going to have to catch Thursdays stream in the evening. Thank you Nick!
So happy for you and your family Nick. 🎉
This is such fun! Seeing your excitement, years of data from Mike and Jeff, and their teams' thoughts and careful considerations just blows me away. Our family has been all over this area. It's not only fascinating but really sentimental. I can't wait for Saturday.👏🏼😄❣️
I don't mind the confusion.... confusion on uncertainties makes sense 🤪
It seems that Jeff's map(s) at 24:24 and Mike's map(s) at 1:20:20 both show the same thing as far as the the triple junction being in Oregon with subduction of the Farallon to the south post Siletzia accretion. 💖 It seems the difference in timing is that Jeff has the northern edge of the Farallon to present north WA (WA/BC border) though the straight creek fault still was active and the northern edge would/should have still been further south. Mike's 35 Ma works/correlates with the end of SCF movement. The map at 1:27:29 shows the triple junction still further south and/but puts the Granite Falls pluton north of the triple junction (and east of Siletzia but west of the breakoff belt area) ..which would be Kula subducting north of the triple junction (to make the Granite Falls pluton (if) via subduction) ....right?
Would Straight Creek fault movement also contribute to or account for northward migration of the triple junction?
💖💞
Thanks for another great episode Nick, Mike and Jeff! Looking forward to Saturday, and a new decade. Cheers!
Would the greater Juan de Fuca plate (the Explorer portion to the north and the Gorda portion to the south) make a good analogy for the visual of the 50-ish Ma spreading ridge? The northern part of the Explorer a triple junction and the southern part of the Gorda the other triple junction. 💭Then to visualize a Siletzia / Yakuletzia scenario occurring on the Pacific & Explorer segment of the spreading ridge with the 'modern' (visualized) Siletzia on Explorer and accreting to eliminate the Explorer portion of the greater Juan de Fuca plate, and jump the northern part of Juan de Fuca (proper) to the new triple junction. ...making the new triple junction closer to the middle of Vancouver Island vs north of it as it is now. 💭🤔
Given the Kula was captured by Pacific, and the Farallon became (greater) Juan de Fuca and the modern segments of the ridge look similar to what Mike has (and the angles similar too) it seems similar enough for a visualization based the modern look ... (perhaps a difference in being transform segments or spreading segments).
🤔 Are the transform segments transpression or transtension or neither?
🥧💖💞
Awesome news Nick! We love Liz.
Good to hear all your spectacular news about your family ❤❤❤
Started watching live, but had to leave and caught the rest on replay. Tough to get my head around all of it, but I love looking at the big picture. Have a better understanding of Jeff Tepper’s model, than Mike Eddy’s. Still trying to digest it all. I noticed you suggested a few times that the Yellowstone hotspot maybe be much bigger than originally imagined. I always remember your advice to not make interpretations without first having the data. Do we have data that would suggest a much larger hot spot? Are there any hotspots in the world today that are as large as you are proposing the Yellowstone hotspot was at one time? Love your videos and livestreams. So glad to hear you and Liz took a hike with her developing the cherry pie analogy.
As you were talking about mafic enclaves in the pluton, the one you picked up at Granite Falls was visible right behind you. I wanted you to show it . I keep finding them lately everywhere I am hiking.
Regarding maps of the spreading ridge .. how detailed vs how vague/fuzzy are our images of the broken off "garage door"? Can we see specific notches that might have represented the faults perpendicular to the ridge or is that beyond the resolution we can achieve now? If we CAN see those still along the edge of the sinking slab, then we should be able to infer what the plate and spreading ridge geometry looked like as well. If it's just a blob down there, indistinct, then the best we have is a guess.
It's cool that they can do mini time warps. Mad skills.
There could be a thin wedge of Resurrection inboard of Kula that is making the Alaska & northern BC near-trench magmas at a Kula-Resurrection triple junction pre-50 Mya. That southern sweep prior to 50 Mya could be Resurrection, not Kula, with Resurrection disappearing under BC about 50 Mya. The yo-yo in the 40s in the Pacific Northwest would be the Kula-Farallon triple junction.
I think Wells & Camp have the Yellowstone hot spot track south of the OR-CA border at ~42 Mya, but it occurs to me that if there is a slab window to the north of the plume head, the plume head will naturally want to flow toward it and through it, meaning that the heat would spread northward from the hot spot towards the triple junction.
interesting that the slide around 1:30 shows all of the near trench magmas associated with exposures of Siletizia
YES. Yes. Saturday's M is going to be titanic tectonically for me when you explain the bend in the Hawaiian seamounts. Even if the bend has nothing to do with the Pacific Northwest, it will be a very satisfying thing to understand how and why that bend is there.
59:33 - look at the jagged boundary along the Kula plate off shore of the NA plate. If that jagged boundary gets subducted, the triple junction will “appear” to move north & south over time following the jags in the boundary. That helps explain Mike’s position.
Those jagged plate boundaries are probably all expanding plate boundaries. That supports the notion of magmas showing up you discuss a few minutes later.
All caught up!!
that is a lot! I do see some, but not all. thank you!
Thank you so much for explaining these things in the way you do. It's so helpful! I really like Mike Eddy's idea, but I have a problem with the times. If the triple junction was at the Oregon coast like 45-ish Ma ago, and then it was "back" at Vancouver Island like 41 Ma ago, why don't we have NTMs in Washington between 45 and 41 Ma ago? Wouldn't that be a logical consequence? And if he assumes that the plate reorganization was like 48 Ma ago, why did the southward migration last until 45 (or after) Ma ago and changed the direction then? I'm confused, but in a good way, I think. :) Thank you all for making me think about these things, it's fun!
You are showing some of the complexities of the involved processes. I believe they are infinitely more complex than what you and yours have uncovered, but you have to start somewhere. This is how science works and what will trigger human minds to ask questions and seek answers.
Liz is back online!
Petrologists seek to understanding which melts formed in which tectonic environments. If I pick up a rock, its petrology should tell me where it came from. Near-trench magmas are "weird" in that they have a chemical fingerprint that is "not arc". But like arc magmas, the composition of near-trench magmas are variable within a range - their own range - and form their own distinctive cluster on plots. Not a weird cluster, just one slightly offset from the "typical" cluster for arcs.
My AC guy showed up late, then my internet was done. Almost made a live show.
FUN STUFF…… to be continued.
keeping it fresh :)
Cherry pie is a great description.
Another idea. I think the age of the subducting ocean floor matters. Ocean floor near the spreading ridge is younger, hotter and chemically different (less modified by water). The speed of the spreading effects how quickly it ages. This could affect how it subducts and potentially creates the near trench magmas, or at least the chemistry of them. I seem to remember this is related to ophiolite production and could also be a factor in flat slab subduction
Note: because you are subducting a spreading ridge each side of the triple junction has different and mirrored effects from this, if it exists
If the spreading ridge was leaving a trail of magmas on the way south, then reversed, why would it not be leaving a trail of magmas on the reverse trip?
I got some major oceanic fundamentals from Jeff’s concurrence with my chat questions.
The first is it takes up to 10 My for freshly upwelled spreading ridge slab to cool to the point that it’s subductible; too warm makes it too plasticized in the trench, causing it to stretch like taffy and snap off the descending slab- “slab break-off.”
Second: Spreading Ridge derived mantle upwelling stays active for “millions of years” -Jeff Tepper after it has been overridden by continental crust. My example to Jeff was the rifting of the Baja Peninsula with the EPR Spreading Ridge (thus mantle upwelling) in its center.
He either avoided or didn’t see my third question: “Jeff Tepper” With the Franciscan Assemblage in Southern Oregon and with evidence of California Terrane beach cobble evidence on Merchants, Agate and Sacci beaches, just a few miles from the South end of the Siletz Terrane; is it possible that there is solid contact with the Terranes, and since the California Terranes are conveying NNWesterly, could their contact with the Siletz Terrane be causing the NW rotation of Siletzia?
Nick, I suggest you take Liz on a long weekend to Yachats (pronounced Ya-hots). You will both love the scenery and they will correct your pronounciation. Battery Fully Charged
Nick, how do the BajaBC dates work with todays yo-yo topic?
I’ve been interested in learning how all the different movements happened, how they traveled to their destinations and when :-)
Could the yo-yo instead be explained by two different spreading ridges (the m&ms). One going south and one up by vancouver island? Maybe one is farallon triple, and the other is resurrection?
I like the elegance of subducting spreading ridge/NTMs, but… I also like using contemporary examples as the baseline. What better example source than Google Earth and its oceanic imagery of the subducting Explorer plate North of Vancouver Island and Immediately South of the Queen Charlotte fault; it’s a Triple Junction of the Pacific, Explorer and North American (NA) plates; this is also the location where the Explorer spreading ridge is subducting under NA.; but there is nothing especially active there as far as NTMs, why?
The Nazca ridge isn't a spreading ridge, so I don't think it deserves a green M&M triple junction. It's a hotspot LIP, more like Siletzia. The Juan Fernández and Carnegie Ridges are probably similar, but both are new to me. The one that deserves a green M&M doesn't have one - the Patagonian volcanic gap. It seems the closest present day parallel to Washington 50MYA but I couldn't find any good academic research when I looked (there is some great research into the Nazca Ridge region, though)
If Mike Eddy’s triple junction moves south then back north depositing younger lavas on Vancouver Island why don’t we see both older and younger deposits side by side as the junction moved north. Older deposits as the junction moved south and younger as it moved back north
If yhs started going under north america, and seletzia docked earlier, then what is thr connection? I thought seletzia was very much related to yhs
I'm glad you ended with your question regarding this possibly being a global story. My brain often wonders along these lines any tim we start talking about plates diving under or bumping into each other or spreading, etc, It makes my brain want to back way out and see all of the plate activity at that time. My sense is there are non-local factors contributing to what we're looking at, but I have zero proof of that sense being accurate.
There could be more than one green m and m at any one time and all sorts of things happening in the 50 million or so years since.
Hey, Ned Zinger! As I am trying to grasp the multiple moving parts, I am reminded of my favorite pastime, square dancing. It looks and feels like befuddling chaos at first, but once you break down the moves, learn to connect them and keep track of the direction you need to go while everyone else does their thing, the patterns become clear and even an observer can track what the simultaneous movements are. For this L episode, the move called Scoot Back may have resonance. There are lots of moves where dancers go all over the place, but miraculously end up back home. This teacher has many short videos you may find interesting to browse.
ua-cam.com/video/ACJVQJQ_VKc/v-deo.htmlsi=n5XmmFQSFodHbZnV
The way the spreading ridges are depicted, it looks like you may have two green M&Ms at different points on the continent at the same time.
Yachats is pronounced Ya-HOTS.
IN YO-YO, WHAT IS THE FORCE DRIVING THE TRIPLE JUNCTION MIGRATION SOUTH AGAINST THE LOCAL DEXTRAL FORCES DRIVING KULA, YAKATAT, & FARALLON NORTH. IF GLOBAL PLATE REALIGNMENT IS THE REASON, WHY NO IMPACT ON KULA, YAKATAT, FARALLON NORTHWARD MIGRATION? TP IS A SALMON WHILE ALL ELSE ARE WHALES?