I’ve really been enjoying Professor Zentner’s series. Most geology programs are just too general, covering a broad topic like “Plate Tectonics”, “Volcanism”, “Earthquakes”, etc., but viewing his videos I really learn more. I’m a geologist, I don’t want to just rehash my first “Introduction to Geology” course!
Yeah, I tried sharing some of Nick's videos with family, they acted like they were gonna die of boredom. Not everybody likes rocks, I guess. I'll watch the videos with you!
Around the 18 minute mark, Nick asks, "Am I wasting your time?" To which, I say, "NO!" I can see how a person could spend an entire day there, making notes and taking pictures (and samples) and just marveling at the scene. Thank you, Nick, for taking the time to go there, and allowing us to go along. Many, if not most of us, understand that just because you're a geologist, doesn't mean you have all the answers, no matter where you are in the world. But, because you are, you're able to help bridge the gap between the viewer and the rocks. To me, "it's time well spent."
This is exactly where I went after hearing you talk about Lake Chelan. It’s five minutes from my house. I’m thrilled to hear you talk about it. I can’t wait for more information to come out. 😍
Nick. You are correct. Most migmatites are generally avoided like the plague. At least there's more on it than the ones in Ontario. We got no one studying the migmatites in Ontario. We can't even decide on how to classify them. I divide them into 2 main types. 1) Migmatites where melting has obviously occurred and penetrates the host rock and present within the unmelted part (arterite migmatite). The second is like what you are looking at, where any melting is hard to see but the migmatite was right at or really close the melting point. I call that venite migmatite.
This is, perhaps, one of the most tantalizing videos I’ve seen. It reminded me of what I observed when I went on a motorcycle ride through Kings Canyon National Park.
I discovered these migmatites in roadcuts on a drive from Spokane to Chelan. I think they are the most beautiful and interesting rocks I’ve ever seen, and as a retired geologist, I’ve seen lots. I spent 11 years, off and on, working on a project in Spokane and on the weekends, me and my colleagues would take day or one-overnight trips to see as much of the area’s geology as possible. (We only got to fly home to SF every other weekend).
Some of the roadcuts where these rocks are exposed with fresh surfaces have that wonderful, characteristic, swirling-band migmatite texture. That’s how I spotted them, just driving by at highway speed. This texture captures the exact temperature and pressure conditions where these old gneisses were partially melting to form new plutonic magmas. It’s not something we get to see very often, most migmatites are now deeply buried in the roots of our mountains. These rocks are special!
Yay you remembered your Pick Nick!! Not going hungry on this video!! Ross lake and Pasayten faults might be like the green beans and they got folded in half once they got docked with North America 🇺🇸. A train of terranes crashing in behind them capped by the Still Champion can’t be beat the Large and In Charge Igneous Province that got tore in half and is Still docking in Alaska today! Started the Crazy Eocene fireworks 💥 The one ☝️ the Only SILETZIA!!!
Awesome two videos in two days. Keep cranking them out Nick. Need everyone to like, comment, and subscribe so we can make his channel grow and reach more people.
I have never seen an outcrop like this from my travels from permian sediments in Kansas, through canyons in Colorado rockies, up over the rockies into Wyoming and Utah; can hardly wait for the Chelan Migmatite explanation; get it Nick.
I remember when Nick did his tour of the CWU campus and showed the various rocks of Washington state that were on the grounds, I immediately fell in love with the beauty of the migmatite and I asked where I could find some. As soon as Nick entered the area where he sat down I recognized it as the place where I first saw the migmatite and I just assumed the leucocratic veins were quartzite(I assumed every white vein was quartzite back then) so it was really awesome to see that Nick was in the same place I was at a couple years ago when I first explored the Chelan migmatite. still one of the most amazing and beautiful rocks I've ever seen and it makes me want to go back to Chelan.
Thanks again for another great video Nick. Really connect with your chat on your style as I too need those toned down views from the heavily loaded factual views that are important in science, but can cause over load. When I have more of a basic view, it makes it easier to add the factual layers on top of the basic layers. That why I love your classes so much. Thank you Nick
The colors are lost when you zoom, but after a few seconds they come back. Maybe by iPhone 85 they'll have it fixed! LoL Because of your classes the last couple of years, I just got back from a 14 state trip, with a bag of rock samples! Now I get to try to figure out what I all have. By-the-way, my new hammer is not new anymore! Ha. I even had an opportunity to pick up a Megladon (sp?) Tooth! I'll be my grandsons favorite grandpa for awhile! (Not near any rocks! - around Chesapeake Bay area). There were outcrops that I've never seen you deal with, until possibly today! It was in New York, New Hampshire and Vermont hills. Really great looking stuff. And to quote you, " I could not stop" taking samples and pictures! Thanks Nick, I'm ruined, taking pictures is just not good enough anymore!! LoL
Thanks again, Nick, for another fun geohike! Yeah, I can see why geologists like to overlook this section. Can't wait for the Baja-BC series where we hopefully find out where this leetle terrane pops up south of Washington. Looks like it all went through a mix master of layering, squashing, heating, uplift, and sideways squishing with intermittent faulting and traveling just for fun. Oh, the poor kids who could have this on a test! Glad to hear they are collecting zircons and some are trying to map it at least!
OMG!! Those rocks are so amazing!! If we were there I would give my poor husband a double hernia lugging some of that stuff home. Thank you for sharing another amazing place Nick.💕
Camera colors going crazy! Awesome site!! 100Ma is like yesterday for us here in NYS! Good luck from a Union College Geology Grad. and 20yr ES teacher.
Those Chelan migmatite rocks look very much like the rocks my son and I were seeing on our hike up Phelps Creek to Spider Gap above Lyman Lake in the Glacier Peak Wilderness this summer.
Great video and questions Nick! I am also excited about the direction your teaching sessions will go this fall. I am a retired math teacher and my son is a research materials engineer. We have watched all your videos since March 2020, and when he visits we take out the Roadside Geology guide and head out to explore the places you talk about. All this information connects, and the more I hear about the geology of Washington and the North Cascades, the more it makes sense to me. In fact, I have learned so much from you and your guests that on my own I have started reading "Earth Materials: Introduction to Mineralogy and Petrology," by Klein and Philpotts. Thanks!! Keep it coming. Mary
Okay, I just finished the video, and I'm also officially excited about what's to come. Your excitement is sure contagious, and folks who haven't seen the Exotic Terranes A-Z series, might want to watch them before the beginning of the Baha-BC series. Besides being a good series to watch on its own, I am sure there will be many references this winter.
I have been stopping and looking at the migmatite there. I live in Chelan ❤. I’ve watched your Lake Chelan video 3 or 4 times! That spot boggles my mind. Plus a great big feeder dike there.
The picture that I am getting watching these summer field videos is a vision of how north amercia(like a snow plow) ran into several island arcs and the accretionary material kinda sloughed off to the side, or maybe sides, as the continent kept drifting southwest.
Your enthusiasm and excitement inspire us! It's so fun to see examples of fractures and timelines, and to just be with you. Very much appreciated. I just watched again, on laptop (vs cell phone) and that's just crazy stuff, mixed and blended. Wow!
We have some pretty cool formations in Connecticut too. I can spend hours coming through rocks like the ones in this video. Everyone I know thinks I'm weird. Thank you, Nick. I don't feel like such an outcast anymore.😁
I have so many hypotheses running around in my head and so many questions about where the major faults are in relation to the CMC. Thanks again for another great video Mr Zentner!
Love these Stunning Chelan Migmatites! 😍♥️ Great ramble Nick I appreciate you are learning with us & are willing & humble to express that. Note at the end of this vid you have a perfect heart 💙in the CM resting against your right shoulder!
Prof. Zentner, hello and it's amazing how much "Geology" is to be found within such short distances of each other in your area alone! Yes, recognized the Crystalline Core drawing immediately (27:24) and my head is still spinning with all the information you captured within it:? Let's keep on learning!
What a complex rock. Nick as I found out I have to wonder was the Chelan going up and down or was the sea level and possibly the knappes folding over? It would seem the whole West Coast was doing the elevator ride, Westward subduction? What an amazing set of plates and bowl that would make!
Could it be that the Ross lake is the oldest and the others are newer? I do think that they all play a roll during their time and that the two newest are connected but not far apart in time
Nick, from reading about migmatite on Wikipedia, the light a dark striping comes from "exsolution" of two components that were formerly a *single* melted composite material (presumably, of much older origin than the exsolution event), which then separates into the two main components, forming the bands. According to this, we are *not* looking at leucosome (light) intruding into melanosome(dark), but rather it is the result of leucosome and melanosome materials formerly dissolved within each other, becoming separate macro components with the swirling or banded appearance that you (and I) were marveling at. If the above is correct, does the exsolution event occur during the elevation process? Start as buried granite 30 km down (?) and ends up at the surface, as migmatite?
I don't think so. Migmatites are the result of partial melting, the melanosome never melts and you therefore don't get exsolution. The felsic minerals which will melt as their fusion temperature is lower will form the leucosome in the rocks. Most of what Nick has shown us is in fact in-situ melt, but some large bands are, as he says, coming from the squeezing of partially melted rocks underneath, especially at the last spot he was on. Partial melting is quite simple: It needs to happen deeply and some hydratation is usually involved to lower the fusion point. I don't think it happened during the elevation process, no reason why. Now, I've only worked with 2,7 Ga migmatites, it's interesting to look at in far younger rocks!
Nick, for Baja BC can we keep a RUNNING TALLY of proposed fault offset distance on a physical chart on the wall that is compiled incrementally during the winter session? Would love to see each session reinforcing these thoughts of proposed movement, but individually emphasized and even Challenged, to then reveal both a "conservative" estimate and a "plausible" estimate of proposed translation over a specific time window. Keep following your instincts, absolutely love this channel! And don't be so hard on awestruck Nick , sometimes the lack of the right words can convey the significance just as well if not better.
@19:20 use a laser scanner to map the rock surface geometry. Take multiple camera angle shots all along that surface (drones, maybe?) apply the surface texture image to the rock geometry earlier captured, then model the color contrast boundaries as semi-rigid sheets extending into the volume behind the surface. Well, that's what I'd try, to start.
The past few videos i thought...I need the white board....I saw it through and hopefully i am understanding all the previews for what's coming later in the fall.
There's something that looks similar to this migmatite in the mountains south of San Joaquin Valley, in the mountains on the south side of a valley called Mil Potrero the SW side of the San Andreas Fault. The SAF runs along the north side of Mil Potrero. My parents used to have a vacation house in the area so I used to hike up to the waterfall where the migmatite is. Higher on the mountain the rock is more like granite. I find myself imagining that this came up from the west coast of Baja California and I wish I knew more about the geology of that place. There's a big hook on the west coast of Baja CA called Punta Eugenia, which I imagine as the place from which the south end of the block moving north along the coastal right hand faults of Southern CA came, and another on the mainland of Mexico at Puerto Vallarta which has to be the former home of Cabo San Lucas.
Thanks for the video. This video reminds me of making fudge. When you start adding the marshmallow cream you get all kinds of weird swirls. Maybe as it was forming it just didn't get mixed as well in all places. What did the area look like back then? Were the rocks going up, was the land going down exposing the rocks, was the land going down and the rocks going at the same time? Did the rocks come up because of the fault and change the fault? Was this area weakend because of all the faults?
Thanks for another exciting glimpse into our fascinating geological past. So many questions, so much more to discover! And also thanks for the tip for a new book to hunt down and acquire, lol.
Did you perhaps find your conveyor belt. from Baja? What is the orientation of the leveche veins, in the Chelan, vertical or horizontal? thank you It is all complicated, but that was even more so. ALL stay safe
