Slab Window Demonstration w/ Chris Mattinson

Nick Zentner & Chris Mattinson | January 27, 2025
Central Washington University geology professor Chris Mattinson shares an inspired demonstration of slab window development in the Pacific Northwest.

[@bearbait49]

Nick, I suspect you know it but this has just demonstrated to me that you have created a new form of dynamic symposium with your A-Z series. You bring together the major players and give them the opportunity to arm wave and free think together on a week by week basis. What a wonderful addition to the science.

[@pmgn8444]

Wow! Wow! Wow! I got how the triple junction could 'jump', but this really show how things fit with near-trench magmas, arc volcanoes, and the slab window! Love the arts-and-crafts and how this illustrates this! Thank you Chris and Nick!

[@Vickie-Bligh]

OMG, I finally understand how the m&m moved from N to S. Thank you, Nick, and thank you, Chris. I enjoyed some of my profs in school, but I did not have anyone like you two. I might have stuck to graduate studies had I had people like you.

[@seanthorntonmd3908]

This demonstration made my brain happy.

[@doncook3584]

I want my money back (actually was an athlete on full ride) because we never NEVER had professors 1. Who had a personality 2.sense of humor let alone 3. Used ordinary everyday props to teach. At age 73 we can’t turn the clock back but we can appreciate great instructors. I feel almost obligated to drive to Ellensburg and pass out a flyer begging geology students to treasure these two. As a youngster we were talked “at” not spoken to. Thank you two.

[@leestamm3187]

I'm past 75 but was fortunate to have had excellent professors when I studied geology at Indiana University in the 1970's. They employed diagrams, displays, photos, dynamic models, and field work, while always encouraging questions and discussion. The videos done by Nick and his cohorts at CWU, which offers an excellent degree program in Geology, remind me of those days. They also give viewers hints about the other, more complex geochemical and petrological aspects of geology that are covered in higher level classes, areas of study that clarify the processes involved in forming and altering rocks and minerals.

[@kingswayguitar]

and the goatee

[@KathyChiles]

I am glad we vacated your office in time for you to get this outstanding video out to the community. This really helped to explain a lot of the things you have been teaching us. Thanks Chris and Nick for this fantastic video and simple explanation for a complicated topic. Thanks for your kindness and hospitality.

[@charlesward8196]

2:01 “Not necessarily any relation to plates living or dead” Is PURE GOLD that had me not just laughing out loud, but actually “guffawing.” Great demonstration. I would love to see how the triple point jumped around on the oblique convergence.

[@judischarns4509]

Wow! Chris! This is such a clear picture of slab window. Yes brilliant minds. Chris you have made clear to a great extent how all this fits together. Thank you.

[@craigmccue2841]

This is awesome. The visual helps me 1000%. At the end of the demonstration you can clearly see the zipper that has been mentioned and shown in slides in the past and to see the triple junction move around like that now makes more sense. Great great job Chris and Nick! Oh how I wish I had professors like both of you when I was in college.

[@Dave-from-Mercer-Island-WA-USA]

"I thought your were Tepper all the way and then you gave the old Eddy shuffel." Priceless.

[@wiregold8930]

I've been trying to imagine oblique subduction and it's been tough. Presenting a perpendicular model that I can then begin to rotate in my mind is masterful. The individual steps work for me. Thank you for this presentation, Chris and Nick.

[@solarwizzo8667]

Awesome!!! I have been waiting for this kind of visualization! Chris Mattinson does it in a simple and handy-man like way! Great Teacher! Nick, now you just need ask a computer savvy person in our community, who can show this concept in 3D on the screen with the slabs sinking while going under the continent. Surely easily doable for a person who knows how to work with 3D rendering computer apps. Just a thought. Keep on!

[@jjensen551]

I was thinking the same - a 3D model would be great.

[@pcbg01207]

​@@jjensen551any volunteer graphic artist/ computer graphic animators out there? It may not be the final answer but would help to move forward the story .

[@szaboaz]

I know this is taking this too far, but in the future... someone could add fluid (or solid) dynamics to and under the slabs and plates, and tinker with the directions according to the small artifacts found today driving back the clock. And being a maximalist, you could start this model to go into the future as well! Just imagine the predictive power of scientific theory in Geology!

[@jjensen551]

@ I don't think that is taking it too far. That could be a PHD project for someone. Difficult but so cool.

[@cynthiaberman3798]

Brilliant. Wonderful. Extremely helpful. I agree with Vickie-Bligh: this type of teaching would have changed my trajectory in university. It's too late for me career-wise; but the timing is just right for the joy of learning, sharing, and stretching the imagination. Thank you so very much!

[@jimmarshall1708]

This visual makes everything so much easier to visualize and understand, thanks!

[@jacotacomorocco]

Thanks for this! Its incredibly valuable to many!

[@davidbarrass]

Thank you so much, Chris, for providing such a clear demonstration of what could be happening. I have to confess that I was imagining something very different and nothing was making sense

[@David-kd1gd]

Wow, thank you, Professor Mattinson, for finally helping me visualize this concept that I struggled with throughout the entire series. I had a hard time grasping it as we progressed, but now, thanks to your scrap paper model, I fully understand and can clearly picture it. If he is willing, you should engage Professor Mattinson more often. Finally, Nick, I send my prayers to Liz, you, and the rest of your family. You have been a part of my life since 2020, and I truly enjoy your presentations.

[@WilliamReinhart-z1t]

Thanks Chris. This is an excellent visual. I’ve been trying to envision this but you brought it to life. Cheers.

[@stefanovolponi8546]

I always find Nick's videos really interesting, but this is right up my alley. Clear, full of info but not overwhelming, really helpful. Thanks a bunch Professors Nick and Chris! You gotta love it!

[@billstronk4321]

Wonderful! Watching this in replay, l have to say this is absolute genius. A marvelously simple sequential animation of the complicated movements of the plates. (Why didn't I think of this myself?!?) It's obvious you gentlemen work well together, with complimentary thinking and senses of humor. Please, do more!

[@williamp2359]

I have to say that this was an excellent demonstration of the migration of the triple junction. Congratulations to Chris for creating a great visual representation of the actions involved.

[@hardrockgirl5844]

Brilliant! I was jumping up and down in my seat watching this, whilst having breakfast, here in the UK! 🎉😁

[@jodyfairchild5446]

Another great teacher at CWU.

[@MarkRenn]

This is absolutely brilliant.

[@jefferyherdrich3043]

FANTASTIC!!!! Very good visual. I agree that somebody in computer illustrations could possibly make a 3D rendition. Thank you Steve, I could see it in my mind but couldn't put it on paper. You were able to, fantastic.

[@SingersMom-rx8wt]

Love it also! Dry humor from a brilliant mind pointing out a non important controversial point!

[@briane173]

This is an EXQUISITE demonstration and is the first time I was able to visualize Mike Eddy’s jump of near-trench magmas down to the south. Absolutely brilliant presentation, Chris you’re a DAWG!

[@marymactavish]

I absolutely love this, especially being that I am old and appreciate a good construction paper model instead of a computer animation. I didn't know about the scientific term "subduction juice" but I am happy to add it to my vocabulary.

[@dalehagglund]

Wow, really instructive video. Thank you, Dr Mattinson.

[@raenbow66]

Ha! The green dot. It jumped! OK. Your discussion was really helpful. I appreciate all the prep work Chris. I love this subject so much. Thank you.

[@bevintx5440]

This was such an informative demonstration, that even newbies, such as myself, could understand.

[@theooidgirl]

This is awesome! Visuals always help understanding. Thank you :)

[@briane173]

These are the sorts of visuals in which I wish some brilliant graphic artists could synthesize the entire process in 3 dimensions, from the docking of Siletzia to the present - showing both what’s happening beneath the continental crust as well as at the surface.

[@sharonseal9150]

What a brilliant demonstration of this complex process! Momma is excited, LOL. Thanks so much for this video.Chris and Nick.

[@jetblast1212]

Bravo! An amazingly simple visualization of such a complex concept, great work. I have always felt that there was a way to reconcile Jeff Tepper’s model with Mike Eddy’s so that they both are “correct”, and in my opinion, this demonstrates that. Thank you, Chris Mattinson.

[@oscarmedina1303]

Absolutely brilliant demonstration. Let's us clearly see how the slab window forms and the green m&m moves. Loved this video !!!

[@mikegerbman8141]

This is awesome! I can see Mike's "yoyo" of the green M&M.

[@yukigatlin9358]

Oh wow, wow!! 😘💞💗Chris, thank you SO much for your visual and your demonstration!! It leaves me a much clearer understanding of the Slab Windows and the possible coexistence with Green M&M the Triple Junction mechanism!! Wonderfully colorful!!😃✨🌈

[@redlester7349]

Mind blown!!! What a fantastic visual representation that suddenly opens up an entirely new perspective. The how, why and where of the changes in vulcanism across time. Hats off for Professor Mattinson!

[@jerrylitzza8842]

Two Thumbs UP! I knew where he was headed immediately. I have been screaming my couch for a month; "Nick You Nut!! Look at the off shore transform fault on the Juan De Fuca, it almost straddles the entire state of Oregon!! Of couse a triple junction can jump from one end of Washington to Middle Oregon!" Excellent visual arts Chris, excellent!

[@SShellbee]

After watching I applied this to the current triple junction in CA off Mendocino Ca, what a brilliantly executed/explained tool. Kudos gentlemen

[@Mistydazzle]

Wow! What excellent teachers you are! Thank you, Chris Mattinson, for the wonderful model. The north-south-north green dot - Mind blowing! Thank you, Nick, for asking your questions and showing us Chris' fantastic work!

[@kristihazen3388]

Thank you!!! Love the visual!!!

[@JackMorningstar001]

Good visual for understanding the discussion. No computer, no AI, just hard work and ingenuity. Good stuff!

[@HannumNeil]

For the model maybe if the N. American Crust had a transition going from clear to black on the right side when you push the Farallon plate under it the fade will kinda make it look like it subducts by making the colors less brilliant. I love all the great episodes, and I am learning more about my local region of Southwest Colorado because of them.

[@graham2105]

Great visual....love it!!

[@timroar9188]

Thank you for such a clear demonstration. It really helps see how the green m&m jumps south.

[@jacotacomorocco]

Chris should definitely do more content!!

[@johnnash5118]

Nick, Thank you for this episode, it made my day! I was hyperventilating throughout Chris' elegant YHS-spreading ridge-Yakutat/Siletz Terrane source demonstration; oceanic tectonics has always been my favorite subject to opine in the comment sections, for six frikin' (sorry Patrick) years! Chris, Imho, presuming that the JDF is one of the Farallon remnants, the JDF’s offsets are 650-700 miles West of the YHS override point, now in Yellowstone, Wyoming- The 50 Ma. Northern California coastline prior to its continental conveyance. I remember a YHS episode with Nick and Basil Tikoff about the nature of spreading ridge offsets, Basil said that they're rigid structures that do not change positions; therefore, the Farallon offsets cannot be repositioned 650 miles to the East to accomodate a certain theory, which leaves only two other YHS possibilities that I can see. 1: YHS was a solo Farallon mid-oceanic LIP perhaps associated with oceanic subduction but no associated spreading ridge. 2: The Farallon plate was relatively narrow, but growing and overriding two other oceanic plates to the East that was showcasing the YHS-spreading ridge-LIP. I predict that the plates would've been subducted on both sides- Farallon from the West-NW and NA from the East-NE= Northerly Resurrection-Southerly Kula perhaps. I like this model because it doesn't require a magical Kula to Pacific plate switcharoo, it includes a classic oceanic-oceanic shallow subduction zone combined with a plume LIP and it can have as many spreading ridge offsets as you would want.

[@ccarter5257]

That was simply brilliant!!!

[@veratrabold964]

Brilliant explanation and a great visualisation! Thank you so much for sharing. This demo is helpful.

[@susanwymer6912]

Chris is an amazing teacher!

[@xwiick]

Thanks for all the hard work on these video's Nick and Chris!

[@jscottmaclean226]

That was so cool! Imagine this in 3d... Thank you Chris!

[@vinmansbakery]

Very helpful! Top notch visual of the slab movement, and I think Chris has the better view from up there!

[@daniel-bertrand]

Done using a '70s Sears tape dispenser and 10 fingers!

[@vanessabrackfield5435]

This is a brilliant demonstration, Chris. Thanks Nick for all the information and learning we do.

[@charlesflorian1758]

Started to watch last evening but was getting late. Finished up today (28th). Grateful explanation for an old dense head like me. Great work! Thanks!😊

[@ellenperrin629]

Genius! So easy to finally understand. Thanks!

[@steveneiffel8227]

Brilliant teaching. Like the footnotes on the fluid dynamics amd temperature that you need, this presemtation went fast deep.

[@daltongrowley5280]

This was super freaking helpful!

[@gerardmurf]

Thank you. Really helpful visualisation.

[@jenniferlevine5406]

Brilliant! So much easier to understand when shown like this. Thank you both for sharing this information through your amazing teaching skills!

[@LaihlyaKersteter]

Thank you Professor Mattenson for the detailed answer to my confusion. It now makes more sense with your demonstration. I wish I were a student at CWU but I’m too old to start a new career path at my age (64 years young).

[@lordorion5776]

OK. Simplified, but still not simple. It is not 2 dimensional, it is three dimensional; x:y:time and not x:y:z. Time being represented by the opening of the rift and moving of the NA plexiglass. This went from, I see what he is doing to: I SEE what he is DOING!!! Very nicely done Professor Mattinson.

[@reginebellefontaine4936]

Impressive and helpful demonstration ! Thank you Professor Mattinson for this very welcomed initiative.

[@edcapp7654]

Great presentation. Goes to show there is more to rocks than dirt.

[@cdineaglecollapsecenter4672]

This was great! The manual addition of the new lithosphere really helped slow it down enough to make it absorbable.

[@66kbm]

I can not fault that. Understood it all. Thanks gents.

[@complimentary_voucher]

That was dope Chris, thanks. I can see the problem with getting an animation- how do you describe all these simultaneous processes to someone with no geo background?

[@ssgtmole8610]

I am appreciating that someone had more fun in art classes than I did as a kid. 😅

[@PlayNowWorkLater]

This was great! I’d love to see this into a stop animation. Follow the movement with each step

[@scottowens1535]

That's spectacular! Loud and clear 👍 (croud applause)!!!!

[@wendygerrish4964]

A good time to introduce hershies kisses to represent volcanics. What fun.

[@debc4865]

Wonderful demonstration! I think I've got it. Thanks Chris!

[@alanrobbo6980]

Fantastic Graphic 👍👍 Explains Much, Thank you Chris.

[@StewartSmith-g4f]

Thanks, Chris, that model works for me to explain the migrating triple junction. I can certainly see the correlative geometry of an obliqueaccretion adding complexity.

[@johngregor6743]

Even better the 2nd time through 24 hrs later; there's so much going on!

[@michaelpaeschke168]

Great job clarification complete

[@stevew5212]

That made it so much easier to understand.

[@briankepner7569]

I think I'm obsessing about the slab window idea! I wake up in the middle of night with epiphanies about flood assaults and their relationship with the rollback

[@slowlife2158]

I dream about geology nowadays. Last night I dreamt I was in a mountainside town when the mountain erupted. As I watched the volcanic events heading my way I thought about how cool it is to see a real lahar and real lava and then wondered how fast I have to run to survive the pyroclastic flow. ‘Twas a nighmare but also kind of fun.

[@markpaanakker9655]

What an amazing awesome way to visualise the story. Great! Thank you very much.

[@diblust53]

Excellent visual demo! Bravo to Dr Mattenson!

[@KevinFournier-xd3ub]

That was so cool. Great visual thank you guys.

[@dancooper8551]

Excellent demonstration! Thanks Chris!

[@TheDevice9]

That was great. And as a bonus, that little tidbit about the Sutter Buttes was interesting. I spent a number of childhood years living with those Buttes in sight and never knew that about them.

[@wildwolfwind6557]

Pertaining to what Chris was talking about near the end with flat slab vs Basil's model.... Even though Basil has the Sierra ending at 85 and becoming transform (inboard of INS), Basil still has subduction outboard of INS. It seems reasonable to have both given the timing of the Straight Creek Fault & subduction for initiating the Cascades overlapped in time. In the Idaho series video with Basil, he says flat slab is very difficult north of California, but south ...and Chris says yes in the south, but north of California ....seems reasonable that both could be accurate. The CMB / CPC seems a good indicator that there was subduction beneath INS. As INS moved north, subduction would still be occurring, but under INS where it was during a specific time. In the Basil / Idaho series video, Basil also has Resurrection under INS from 85-55 Ma (which would put Farallon to the south and subducting). If the bulk of INS has Kula offshore by ~55 to 52 Ma, in time for the accretion of Siletzia to be a Kula (or Resurrection) & Farallon configuration; and the accretion occurring at about the CA/OR border and the green M&M jumping south with Farallon subducting to the south, it seems reasonable that Farallon was still able to be subducting to the south (for the eclogites) (given INS had passed) with Basil's model. 🌈⚡🌈⚡🌈

[@maxinee1267]

Wow oh Wowza that shows it so well, Thank you Chris Mattinson, what a brilliant demonstration.

[@pacargile]

Great demo, thanks Chris! It would be super interesting to see what happens if the ridge comes in at an oblique angle.

[@jeffreyogden7191]

Freakin killer demo!

[@sabrnooh7519]

Brilliant demonstration, I suspect most of us overlooked the fact that spreading ridges means the plates are still growing.

[@AvanaVana]

They aren’t still growing after they are subducted-that is what creates the window. Otherwise, for the part of the slab that is un-subducted, it behaves just like any other spreading ridge, meaning crust is being formed there along the spreading axis.

[@Poppageno]

Thanks, Chris well planned and executed! Why doesn't, or did the NAC slough into the slab window?

[@leslie3832]

Brilliant! Thank you Chris and Nick! I’d like a repeat right where the transform jump is. Tell me that again! That is the hard thing to visualize. This helps explain so many things in a simple manner. Thank you.

[@canadianentropy]

This demonstration could be (relatively) easily made into an animation. A series of still pictures taken of each stage could be stitched together in stop-gap like fashion.

[@scottward999]

Thank you Nick & Chris! Very very interesting + understandable.

[@atomdent]

That is sooo much fun!!!! Great teaching device Chris might be a genius at his job Love it, thank you! BTW I think you maybe a genius at your job as well, what a lucky school and student body!!!

[@thirstfast1025]

Excellent! Thanks Chris & Nick!

[@treborg777]

Note that his model also shows (or at least suggested) the clockwise rotation, the angled arrow to the NE

[@wildwolfwind6557]

This is SUPER-AWESOME❣❣ Chris did SOOOOO great❣❣❣❣

[@ms_khoff]

I get it! This was epic. Give this man a 🏆

[@AvanaVana]

I suggest drawing a toothed overriding plate/thrust fault/subduction line on the edge of that clear sheet representing continental NA

[@churlburt8485]

do it and post it asap.

[@Kevin-Tice]

This is awesome! Learning and science in action!