Wow! Lookit all that Fireweed you are passing through Nick! That's the tall stalks with the purple flowers. Those tell us when summer is ending. They bloom from the bottom up. When the last little flower at the top falls off - Summer's over.
FINALLY MY MOUNTAINS I Grew up on skied on Played on both side of the border as did my family before me!!!!THANK YOU THANK YOU THANK YOU♥️♥️♥️♥️♥️♥️♥️♥️♥️ and included the twin sisters toooooooo I have died and gone to heaven Thank you Thank you 🙏🏻🫶🏻👵🏻
I don't know if I commented on this the first time I watched this, but this is one of the most fascinating interviews you've done. Gary and Bob are really knowledgeable and enjoy sharing it. This is so amazing that I feel I should show up with a six pack of really good beer as a thank you.
It still blows my mind when I see rock formations from far far away just all welded together like it was all one terrain, just so cool to hear it all broken down into exotic terrains. A huge thank you to you Nick,Darryl, Garry and to Liz ....Scott
Great video. That's what I always loved about college. As an undergrad and years as a grad student, then most of my life working at colleges: listening to people who know what they are talking about. And geology is a fascinating subject. There is so much to learn about rocks and mountains. It's incredible that chunks of mountains can be transported thousands of miles in millions of years. Thanks.
I wish more people would learn to love listening to people who know what they're talking about, instead of falling in love with the sound of their own dumb voices. The world would be a better place, for sure.
Well Professor Nick you really have out done yourself with this video! What spectacular scenery and a big thank you to Gary and Darrel for all their geological knowledge. I have to wonder if Gary doesn't have a little mountain goat blood in him lol. A Big shout out to Liz for being such a trooper. Although I'm sure she loved being in such a beautiful place. THANK YOU ALL SO MUCH.
Great guests and an epic season finale hike! For those of us unable to navigate these trails, what a wonderful chance to be taken along, and see the scene through the eyes of such knowledgeable guests. Thank you for continuing to dazzle us with your videos!
@17:40 In reference to the Bell Pass Melange- I wondered in the previous stop, if the red unconformity toward Mt. Shuksan and a similar unconformity to the far left/@North? were of the same formation and were subsequently separated by erosion. They both appeared to have a dominant oxidized iron constituent that sticks out like a sore thumb. Then we came to the second stop with a close up of the same melange, and Darrel interestingly described its nature, mechanics and inter-relations with the adjacent formations. I love this!
I think that the orange splash on the south side of Shuksan Arm is likely hydrothermal alteration from the 2 million-year-old Lake Ann stock out of sight beneath.
I climbed all those peaks many times, but I'm only just now learning about their past and true natures, thanks to your fantastic channel, Nick. Love it!
Was just at Artist Point on Thursday and I was thinking while taking in the breathtakingly amazing vistas, I wonder what Nick et al could tell me about this area and voila you post a video from last Tuesday! Thank you for what you do!
As an Oregonian we never really cared to learn about Washington. As I am almost 30 now and into prospecting I am 100% blown away by Washington geology! Oregon is great but you guys mountains ohhh my gooooodness!
Enjoyed those men showing their love and knowledge as geologists and a photographer. Lifelong learners about their home area. Your questions let them provide more about previous and to come learning. Thanks!!
Terrific video! So much great information in the field on a great hike. I have been there and it is truly beautiful. Thanks for bringing us along! I don’t think anyone would hit the delete button!
Oh my goodness, this video has so many gems of insights! Love seeing Darrel's copy of Misch 1966 as I keep encountering Tabor et al's references to this report, Fred Beckey's books too. Thank you Nick, Darrel, Gary, and Liz for a beautiful day. P.S. The gentle dome in front and right (north) of Mt. Baker - that one sees from Yellow Aster Butte - is called Keep Kool Butte (2 Ks).
Great video, as usual. Nice to see some places I used to hike in my younger life. Tabor & Crowder were my go-to for decades. Their classic "Routes and Rocks" tomes have graced my bookshelf for over 50 years. Not only informative regarding the geologic knowledge of their day, but a historical record including many backcountry trails that have disappeared from modern maps.
What an epic video. Hanging out on top of the world! So I think what you are looking at with the amphibolite pods there in the serpentinite mélange, is actually what is known as “subduction erosion”, or a “subduction channel”. Essentially, as ocean floor rocks, with their sediments and seamounts, etc subducts at an active margin, this is the “gunk” that gets scraped off of the lower plate and then added in imbricate stages to the bottom of the upper plate, as the thrust through the subduction channel jumps to a lower level. These rocks are subject to high pressure, low temperature metamorphism, generally. Then, with 100s of millions of years of exhumation and unroofing, these rocks are eventually exposed at the surface. Interestingly I was just this morning reading several papers on subduction erosion, regarding the Cordilleran margin of Alaska. To add to what Darrell said re: Ingalls/Josephine-those are coherent, well preserved ophiolite sequences, representing a coherent chunk of oceanic crust, most likely crust formed in the forearc above an ancient subduction zone, or a spreading center between two arcs, like what is seen behind the Tonga and Marianas arcs today, where the actual arc splits in two with intra-arc spreading. The kind of mélange seen in the video, the Bell Pass Mélange, is not a coherent ophiolite sequence, nor any type of sequence. Like I mentioned above, it is just random “gunk” of all ages, scraped off of the bottom plate as it subducts and caked onto the bottom of the upper plate in the subduction channel in layers. The subduction channel is full of devolatilizing sediments and it is theorized that as a consequence of this, pore water pressure fractures the rocks in the channel, combined with physical shearing and deforming of the rocks, combined with serpentinization of the peridotite matrix, and as a result of these processes, the rocks are significantly weakened and acquire that scaly, ductile mélange fabric, as and this weak, fractured, significantly altered, comminuted rock in the subduction channel forms a kind of shear zone that actually contributes to accommodating slip of the lower plate and ultimately subduction itself. One more thing. When I see calc silicates in a mélange, it screams “pieces of subducted seamounts”. Carbonates form on the higher seamounts above the Carbonate Compensation Depth. When subducted, metamorphosed, and deformed in the subduction channel, it becomes foliated.
BTW agree with Darrel’s identification of the Listwaenite. Interestingly, besides Nickel, which is always found in high proportions in ultramafics, there are several known Listwaenite-hosted gold deposits around the world! Very interesting deposits.
Also wanted to add, as I’m watching this video-you know, the Intermontane and Insular superterranes are kind of “first-order” approximations, or a useful diagram of what the tectonic situation may have been, and useful again, as a first-order classification system. But the actual physical reality/geography of the fringing arc systems that became the North American Cordillera must have been much more complicated, more of an archipelago as we see today in the Southwest Pacific/Malay Archipelago. You have your larger arcs (Sumatra, Bali, Java, Malaysia, and then Taiwan-Philippines-Halmhera, and also New Guinea-Solomon Islands-Tonga), but then between those major bounding oceanic arcs you have a whole maze of inner arcs, back-arc basins, microplates, arcs that have been rifted in two, as well as accretionary wedges in the forearc that form subaerial islands. So basically what I’m getting at is, to me there is no doubt that the true geographic situation of the Cordilleran archipelago that accreted to North America was not as simple as the Intermontane+Insular equation, though that simplification is a useful diagram and conceptual framework. And there is geochemical and geological evidence supporting this-I already mentioned that the modern consensus on the Ingalls/Josephine/Smartville Ophiolites is that those rocks represent crust generated by some kind of suprasubduction zone spreading center, for example, the kind of infra/intra-arc spreading center that we see today behind the Tonga and Marianas arcs.
@@AvanaVana Gary and i walked Wednesday from Twin Lakes, east of YA Meadows, to look down at the Lone Jack gold mine: operating in very orange rocks I guess are liswaenite.
@@darrelscowan1537 my (elementary) understanding of the gold ore forming processes in Listwaenites is that the gold is initially accumulated in sulfides through normal magmatic processes, ie in stockworks somewhere under the oceanic crust, perhaps at seamounts or mid-ocean ridges. When the peridotite that surrounds and/or underlays these sulfides undergoes routine serpentinization, which accumulates with age and is also accelerated with fracturing associated with plate bending stresses near the subduction zone, the Au is preferentially incorporated into magnetite and secondary sulfides. Magnetite is a common byproduct of serpentinization, from the oxidation of fayalite in the peridotite, releasing h2 gas as a byproduct. (These serpentinization reactions and the elemental hydrogen they produce is a source of energy for the deep biosphere too!). Then, when this serpentinization oceanic crust is finally subducted and enters the subduction channel, mylonitic shear zones are created and the peridotite is ground into mélange, and deeply and thoroughly fractured. Deeper down the subduction channel, peridotites and sediments, including carbonate sediments, especially associated with subducted seamounts, and fragments thereof, are dehydrated when higher temperatures are reached, causing CO2 and H2O volatiles (carrying with them dissolved silica and other minerals as well) to migrate and hydrothermally metamorphose and carbonatize the deeply permeable serpentinite mylonites and mélanges of the subduction channel, forming listwaenite lenses, as well as calcite and quartz veins. Finally, the magnetite and sulfide lenses hosted in this carbonitized serpentinite mylonite and mélange are dissolved by these hydrothermal fluids associated with carbonitization, and the gold leeched out at high concentrations, to be later preferentially deposited above the brittle-ductile transition zone in quartz and carbonate veins within the listwaenite. Another interesting mineral associated with these processes is Mariposite, which sometimes can also host gold-California was famous for that in an earlier age. And associated with that is the rock “Josephinite”, consisting of almost exclusively the nickel-iron minerals awaruite, taenite, with additional intergrown andradite garnet. Really fascinating rock as well-early on people thought it was a relic from the earth’s core, but since then it’s been shown to be related to hydrothermal metamorphism of serpentinites of the Josephine Ophiolite. Most likely formed in highly reducing circumstances (like the earth’s core) due to H2 production from serpentinization reactions, similar to the way that the magnetite mentioned above forms. I’ve always wondered if there are Josephinite analogs to be found in the Ingalls Complex, since it’s thought to be essentially the same genetic unit.
Since I had to break this viewing session up into multiple segments due to the (wonderful) length, I’m adding another comment: I don’t want to give the impression based on my comments about mélange earlier that all mélanges are products of subduction erosion/subduction channels. In fact, many mélanges don’t show much evidence of being subducted to much depth at all. These types of mélanges might be formed more in an accretionary prism setting, and not deep in the subduction channel. Serpentine diapirism is more common here. But with these rocks you were looking at, you have amphibolite facies metamorphism, blueschists, and a mylonite-ductile shear zone fabric, with a distinct imbricate structure. To me all of those things are a strong indication that the Bell Pass Mélange was part of an ancient subduction channel. Re: Eastern/Western Mélange belts. These are more like the shallow accretionary wedge type of mélange I described. They are broadly correlative with the Franciscan Rocks of CA and OR, and the Chugach Accretionary Complex that is now located in Alaska. The early Tertiary detrital zircons make sense in this characterization-parts of the Fransiscan and Chugach are just as young. Edit: Misch’s marvelous miscellany couldn’t have been meted out to a more deserving man. They are as close to holy relics as you get in PNW structural geology and the way you’ve kept them is wonderful, and your sharing them with all of us is very generous. Thank you!
Thank you for such a wonderful video Nick. I can't say that I can follow everything that Darrel, Gary, and you are talking about, but I sure loved the scenery! More please! And I do continue to learn.
This amazing location shows or rather defines the crossroads of nature and geology. It makes a wonderful display of both. Milions of years in the making and years taken in understanding how it is and not just what it is.
For your next trip I highly recommend driving up to Hart's Pass and Slate Peak (highest maintained road in the state). Do the hike from there to Grasshopper Pass via the PCT for the most amazing geology on display!
I must commend the audio in these videos. Most youtubers have awful audio quality and they are recording in controlled conditions. You are usually on the top of a mountain and I can still hear everything you and your guests are saying.
Hi Nick, I'm in Aldergrove BC this week, just over the border and can see Mount Baker from here. I've always wondered how much material came our way from the Mt. Baker volcano. Were there lahars, lava? I enjoy thinking about that kind of thing. Anyway Hi from the other side of Mt. Baker!
24:00 We got , here on Vancouver Island, one really old formation, 420mya, called Nitnat tuff, but that's not a limestone, but volcanic ash , but similar age.
I wonder how far a glacier could push these isolated blocks, and a series of glaciations pushing them a few or a hundred miles each time. If you have a bunch of them together, at some point they stop being seen as erratics.
I had a question about Shuksan. I thought Shuksan is non volcanic, but there is a strong sulfur smell on the upper Curtis glacier. Has there been volcanic activity on shuksan in the past?
Yes, they are "little" pizza boxes. However, the imbricate zone or Bell Pass melange that we were in, including Tomihoy, separate "big" pizza boxes that each extend over hundreds of square kilometers, e.g the Shuksan nappe.
If ice age sheets can be several kilometres high - higher than local peaks - then a slowly southward moving glacier could have carried erratics and glacial till over these peaks. Just my guess.
Cordillera ice coming south was not thick enough to bulldoze over the tallest peaks, hence their rugged nature carved by local alpine glaciers was preserved.
Three gifted teachers (plus hiking machine Liz) whose skills and fascination and verbal dexterity just kept me glued to a screen immersed in scenic perfection, also gave me sadness at the inevitable end, that it could not continue longer yet. Such a vital gift this was!
We are so fortunate. Thank you Nick, Darrel and Gary for sharing your experience and knowledge. I'm glad to see Liz. I appreciate learning about accessibility as well.
Nick, thank you for having Darrel on!! I went to UW and he was one of my favorite professors. I’m glad to see he is still doing well. He is very knowledgeable and well respected. Your videos are usually killer but well done 👍🏽 - Brady
Thank you lady and gentlemen, sincerely. Your affable nature makes these quite involved subjects so easy to grasp. The videography is wonderful too, Mr. Zentner. Thanks again.
Nick, you FINALLY got to the Yellow Aster. And now our collective minds are blown into tiny little bits. Something comes to mind. Isn't this the crumple zone of clockwise rotation? And also in the Cascade volcanic arc? Is it any wonder that all kinds of bits from all kinds of terranes get barfed up to the surface? I can't imagine how you're going to reference this in your Baja-BC series. Good luck.
Wow, nothing else is like hearing from the experts in these beautiful places..... Above and beyond Nick! Greatest thanks to Backcountry Gary Paull and Professor Darrel Cowan, your contribution to our understanding of these places is immeasurable. Nick and Liz, you two carry the day.
FYI (took me awhile to figure it out)They start at Table Mtn. Then at about 12:00 in the video they move almost seven miles north to below the east side of Yellow Astor Butte :, Lat. 48.952124 Deg., Lon. 121.677527, alt 5,255 ft.. Then at about 37:00 they move west a half mile along the west side of Yellow Astor Butte. At 1:06 they continue discussion in a back yard.
Yes, first day Table Mountain. Second day amazing geology and scenery to yellow Aster meadows. In 1992, the trail we used was not built, so we did the "Keep Kool" trail, a real haul, up, up...The morning shots were after a quick breakfast at Wake 'n Bakery in Glacier. I recommend it.
Those areas have ridiculous views. I need to get up to Mt Baker. Thanks for making new videos i have watched many over the years. We live in such an incredible diverse state!
We are so lucky to live in this area. I was just up to Artist Point myself for the umpteeth time. I can also vouch for the description of the Nooksack Cirque. A spectacular place to visit if you have the chance. Headwaters of the Nooksack river’s north fork, it is a wild, glaciated valley with Mt. Shuksan and the hanging East Nooksack Glacier at the upper end. My first backpack trip 45 years ago and it was my only visit but it will never be forgotten. Although we were camped elsewhere in the cirque, while exploring the 2nd day we were forced to wait out a two hour, very cold, rain-in-your-ear storm under the protection of the “Great Trog.”
Wow; getting my Geo-fix from the best today, maybe just a little behind on the hikes. However, that's a good thing with field trips you can do most of the work in any order... I am a slightly disabled walking vet of seventy-three years of age so you guys are my legs so to say... Thanks for doing all the climbing, don't have much wear & tear left... LOL
Let's see; (timeline) Baja-BC, Siletzia erupts, slab break (cut) off, elevator rise east of Straight Creek Fault, lots of erosion,.... It seems to me that the slab break was like a diving board when the diver departs, it must have had a great deal of recoil energy to push up whatever was above it, even the old deep stuff.
What a great episode! I can really relate to this; as I'm over in the Bozeman MT area and basically an amateur geologist/ paleo botanist, thanks to some classes I took at MSU back in the 90's...
I read a lot of comments. Seems like many people are too busy or just hikes like this are too risky (older age, health issues, etc.) well I am working on an idea to bring the experience into your home. One day :) for now we are blessed to live through this channel!
Spectacular guests... continuing works in progress... Search: DS Cowan - Geologic tests of hypotheses for large coastwise displacements-A critique illustrated by the Baja British Columbia controversy
What an amazing video. The scenery is absolutely beautiful and the wealth of knowledge and information from Darrel, Gary, and Nick. This hike and trails are a most do.
Wow! Lookit all that Fireweed you are passing through Nick! That's the tall stalks with the purple flowers. Those tell us when summer is ending. They bloom from the bottom up. When the last little flower at the top falls off - Summer's over.
It's so important to watch and listen carefully to folks who are "experts, spending the majority of their adult lives on this topic, ask questions
FINALLY MY MOUNTAINS I Grew up on skied on Played on both side of the border as did my family before me!!!!THANK YOU THANK YOU THANK YOU♥️♥️♥️♥️♥️♥️♥️♥️♥️ and included the twin sisters toooooooo I have died and gone to heaven Thank you Thank you 🙏🏻🫶🏻👵🏻
Thank you Nick. beautiful hike without leaving the house.
Thanks, guys. Wish I could have been on the bike. Myrl
Hike, that is.
@@myrlbeck1931 You were there: it all rests on Mt Stuart.
Well your name kept popping up as if you were with us! I thoroughly enjoyed your recent interview with Nick.
I miss you, Myrl.
Gary Paull= Impressive competence.
I don't know if I commented on this the first time I watched this, but this is one of the most fascinating interviews you've done. Gary and Bob are really knowledgeable and enjoy sharing it. This is so amazing that I feel I should show up with a six pack of really good beer as a thank you.
It’s so wonderful to come along on this hike with great conversation. Such a complicated story. And Liz wasn’t too camera shy.
It still blows my mind when I see rock formations from far far away just all welded together like it was all one terrain, just so cool to hear it all broken down into exotic terrains. A huge thank you to you Nick,Darryl, Garry and to Liz
....Scott
Great video. That's what I always loved about college. As an undergrad and years as a grad student, then most of my life working at colleges: listening to people who know what they are talking about. And geology is a fascinating subject. There is so much to learn about rocks and mountains. It's incredible that chunks of mountains can be transported thousands of miles in millions of years. Thanks.
I wish more people would learn to love listening to people who know what they're talking about, instead of falling in love with the sound of their own dumb voices. The world would be a better place, for sure.
Fun as always Nick! Fantastic views! Thank your friends and take Liz out to dinner for putting up with you old rock hounds! 🤣😁✌️
Well Professor Nick you really have out done yourself with this video! What spectacular scenery and a big thank you to Gary and Darrel for all their geological knowledge. I have to wonder if Gary doesn't have a little mountain goat blood in him lol. A Big shout out to Liz for being such a trooper. Although I'm sure she loved being in such a beautiful place. THANK YOU ALL SO MUCH.
Ah love these guys! Really love all the guest geologists! So fun getting to tour this beauty w such knowledgeable fun guys!! Thanks Gary and Darrel!!
Great guests and an epic season finale hike! For those of us unable to navigate these trails, what a wonderful chance to be taken along, and see the scene through the eyes of such knowledgeable guests. Thank you for continuing to dazzle us with your videos!
@17:40 In reference to the Bell Pass Melange- I wondered in the previous stop, if the red unconformity toward Mt. Shuksan and a similar unconformity to the far left/@North? were of the same formation and were subsequently separated by erosion. They both appeared to have a dominant oxidized iron constituent that sticks out like a sore thumb.
Then we came to the second stop with a close up of the same melange, and Darrel interestingly described its nature, mechanics and inter-relations with the adjacent formations. I love this!
I think that the orange splash on the south side of Shuksan Arm is likely hydrothermal alteration from the 2 million-year-old Lake Ann stock out of sight beneath.
@@darrelscowan1537 Thank you for the clarification, Darrel.
I climbed all those peaks many times, but I'm only just now learning about their past and true natures, thanks to your fantastic channel, Nick. Love it!
So much knowledge, so many unknowns, so much beauty! So enjoyable. That WAS a treat!
It’s such a blessing to (spiritual) to go out on these field trips I can’t do anymore. Thanks Nick and company.
From a fellow Wisconson-ian , thanks for the vacation.
Was just at Artist Point on Thursday and I was thinking while taking in the breathtakingly amazing vistas, I wonder what Nick et al could tell me about this area and voila you post a video from last Tuesday! Thank you for what you do!
What word to describe… do not have one! Thanks a lot to the four of you!!! Awesome Episode ❣️❣️❣️
Thank you guys for taking us along. Just beautifull. Love the discussion even if some is over my head.
Darrel Cowan is a gem. Thanks so much for getting him on video!
As an Oregonian we never really cared to learn about Washington. As I am almost 30 now and into prospecting I am 100% blown away by Washington geology! Oregon is great but you guys mountains ohhh my gooooodness!
Enjoyed those men showing their love and knowledge as geologists and a photographer. Lifelong learners about their home area. Your questions let them provide more about previous and to come learning. Thanks!!
Another Top-Shelf production. Thanks Nick, Darrel and Gary!
I retired in B'ham and hike this area all season. What a treat it must be to hike with people so knowledgable. Thank you!
Gorgeous scenery, and a fascinating topic.
Thank all of you so much for this excellent tour, video and discussion of the geology-a real treasure
Beautiful hike and interesting conversation
Terrific video! So much great information in the field on a great hike. I have been there and it is truly beautiful. Thanks for bringing us along! I don’t think anyone would hit the delete button!
Oh my goodness, this video has so many gems of insights! Love seeing Darrel's copy of Misch 1966 as I keep encountering Tabor et al's references to this report, Fred Beckey's books too. Thank you Nick, Darrel, Gary, and Liz for a beautiful day. P.S. The gentle dome in front and right (north) of Mt. Baker - that one sees from Yellow Aster Butte - is called Keep Kool Butte (2 Ks).
Another masterpiece with an All Star 🌟 🌟 🌟 cast
Great video, as usual. Nice to see some places I used to hike in my younger life. Tabor & Crowder were my go-to for decades. Their classic "Routes and Rocks" tomes have graced my bookshelf for over 50 years. Not only informative regarding the geologic knowledge of their day, but a historical record including many backcountry trails that have disappeared from modern maps.
@lee stamm much of the information in those books is still accurate today. The geology notes are very well selected and written
I first moved out to Pac Beach in 75,, the Cascades/ Olympics, are the most incredible places on the planet.
What an epic video. Hanging out on top of the world!
So I think what you are looking at with the amphibolite pods there in the serpentinite mélange, is actually what is known as “subduction erosion”, or a “subduction channel”. Essentially, as ocean floor rocks, with their sediments and seamounts, etc subducts at an active margin, this is the “gunk” that gets scraped off of the lower plate and then added in imbricate stages to the bottom of the upper plate, as the thrust through the subduction channel jumps to a lower level. These rocks are subject to high pressure, low temperature metamorphism, generally. Then, with 100s of millions of years of exhumation and unroofing, these rocks are eventually exposed at the surface.
Interestingly I was just this morning reading several papers on subduction erosion, regarding the Cordilleran margin of Alaska.
To add to what Darrell said re: Ingalls/Josephine-those are coherent, well preserved ophiolite sequences, representing a coherent chunk of oceanic crust, most likely crust formed in the forearc above an ancient subduction zone, or a spreading center between two arcs, like what is seen behind the Tonga and Marianas arcs today, where the actual arc splits in two with intra-arc spreading. The kind of mélange seen in the video, the Bell Pass Mélange, is not a coherent ophiolite sequence, nor any type of sequence. Like I mentioned above, it is just random “gunk” of all ages, scraped off of the bottom plate as it subducts and caked onto the bottom of the upper plate in the subduction channel in layers. The subduction channel is full of devolatilizing sediments and it is theorized that as a consequence of this, pore water pressure fractures the rocks in the channel, combined with physical shearing and deforming of the rocks, combined with serpentinization of the peridotite matrix, and as a result of these processes, the rocks are significantly weakened and acquire that scaly, ductile mélange fabric, as and this weak, fractured, significantly altered, comminuted rock in the subduction channel forms a kind of shear zone that actually contributes to accommodating slip of the lower plate and ultimately subduction itself.
One more thing. When I see calc silicates in a mélange, it screams “pieces of subducted seamounts”. Carbonates form on the higher seamounts above the Carbonate Compensation Depth. When subducted, metamorphosed, and deformed in the subduction channel, it becomes foliated.
BTW agree with Darrel’s identification of the Listwaenite. Interestingly, besides Nickel, which is always found in high proportions in ultramafics, there are several known Listwaenite-hosted gold deposits around the world! Very interesting deposits.
Also wanted to add, as I’m watching this video-you know, the Intermontane and Insular superterranes are kind of “first-order” approximations, or a useful diagram of what the tectonic situation may have been, and useful again, as a first-order classification system. But the actual physical reality/geography of the fringing arc systems that became the North American Cordillera must have been much more complicated, more of an archipelago as we see today in the Southwest Pacific/Malay Archipelago. You have your larger arcs (Sumatra, Bali, Java, Malaysia, and then Taiwan-Philippines-Halmhera, and also New Guinea-Solomon Islands-Tonga), but then between those major bounding oceanic arcs you have a whole maze of inner arcs, back-arc basins, microplates, arcs that have been rifted in two, as well as accretionary wedges in the forearc that form subaerial islands. So basically what I’m getting at is, to me there is no doubt that the true geographic situation of the Cordilleran archipelago that accreted to North America was not as simple as the Intermontane+Insular equation, though that simplification is a useful diagram and conceptual framework. And there is geochemical and geological evidence supporting this-I already mentioned that the modern consensus on the Ingalls/Josephine/Smartville Ophiolites is that those rocks represent crust generated by some kind of suprasubduction zone spreading center, for example, the kind of infra/intra-arc spreading center that we see today behind the Tonga and Marianas arcs.
@@AvanaVana Gary and i walked Wednesday from Twin Lakes, east of YA Meadows, to look down at the Lone Jack gold mine: operating in very orange rocks I guess are liswaenite.
@@darrelscowan1537 my (elementary) understanding of the gold ore forming processes in Listwaenites is that the gold is initially accumulated in sulfides through normal magmatic processes, ie in stockworks somewhere under the oceanic crust, perhaps at seamounts or mid-ocean ridges. When the peridotite that surrounds and/or underlays these sulfides undergoes routine serpentinization, which accumulates with age and is also accelerated with fracturing associated with plate bending stresses near the subduction zone, the Au is preferentially incorporated into magnetite and secondary sulfides. Magnetite is a common byproduct of serpentinization, from the oxidation of fayalite in the peridotite, releasing h2 gas as a byproduct. (These serpentinization reactions and the elemental hydrogen they produce is a source of energy for the deep biosphere too!). Then, when this serpentinization oceanic crust is finally subducted and enters the subduction channel, mylonitic shear zones are created and the peridotite is ground into mélange, and deeply and thoroughly fractured. Deeper down the subduction channel, peridotites and sediments, including carbonate sediments, especially associated with subducted seamounts, and fragments thereof, are dehydrated when higher temperatures are reached, causing CO2 and H2O volatiles (carrying with them dissolved silica and other minerals as well) to migrate and hydrothermally metamorphose and carbonatize the deeply permeable serpentinite mylonites and mélanges of the subduction channel, forming listwaenite lenses, as well as calcite and quartz veins. Finally, the magnetite and sulfide lenses hosted in this carbonitized serpentinite mylonite and mélange are dissolved by these hydrothermal fluids associated with carbonitization, and the gold leeched out at high concentrations, to be later preferentially deposited above the brittle-ductile transition zone in quartz and carbonate veins within the listwaenite.
Another interesting mineral associated with these processes is Mariposite, which sometimes can also host gold-California was famous for that in an earlier age. And associated with that is the rock “Josephinite”, consisting of almost exclusively the nickel-iron minerals awaruite, taenite, with additional intergrown andradite garnet. Really fascinating rock as well-early on people thought it was a relic from the earth’s core, but since then it’s been shown to be related to hydrothermal metamorphism of serpentinites of the Josephine Ophiolite. Most likely formed in highly reducing circumstances (like the earth’s core) due to H2 production from serpentinization reactions, similar to the way that the magnetite mentioned above forms. I’ve always wondered if there are Josephinite analogs to be found in the Ingalls Complex, since it’s thought to be essentially the same genetic unit.
Since I had to break this viewing session up into multiple segments due to the (wonderful) length, I’m adding another comment: I don’t want to give the impression based on my comments about mélange earlier that all mélanges are products of subduction erosion/subduction channels. In fact, many mélanges don’t show much evidence of being subducted to much depth at all. These types of mélanges might be formed more in an accretionary prism setting, and not deep in the subduction channel. Serpentine diapirism is more common here.
But with these rocks you were looking at, you have amphibolite facies metamorphism, blueschists, and a mylonite-ductile shear zone fabric, with a distinct imbricate structure. To me all of those things are a strong indication that the Bell Pass Mélange was part of an ancient subduction channel.
Re: Eastern/Western Mélange belts. These are more like the shallow accretionary wedge type of mélange I described. They are broadly correlative with the Franciscan Rocks of CA and OR, and the Chugach Accretionary Complex that is now located in Alaska. The early Tertiary detrital zircons make sense in this characterization-parts of the Fransiscan and Chugach are just as young.
Edit: Misch’s marvelous miscellany couldn’t have been meted out to a more deserving man. They are as close to holy relics as you get in PNW structural geology and the way you’ve kept them is wonderful, and your sharing them with all of us is very generous. Thank you!
I am still making my way through the video - but what a cinematic view and great discussions. Thanks for this one.
Thank you for such a wonderful video Nick. I can't say that I can follow everything that Darrel, Gary, and you are talking about, but I sure loved the scenery! More please! And I do continue to learn.
What spectacular mountain views. Great filming. Those 2 guys have so much knowledge about the area. Great video Nick.
Back to watch it again😊 being taught from the best thank you
So beautiful!! All of it. OMG.
NICE!
This amazing location shows or rather defines the crossroads of nature and geology. It makes a wonderful display of both.
Milions of years in the making and years taken in understanding how it is and not just what it is.
This video was so informative and the scenery so beautiful I can only say Wow!
For your next trip I highly recommend driving up to Hart's Pass and Slate Peak (highest maintained road in the state). Do the hike from there to Grasshopper Pass via the PCT for the most amazing geology on display!
I must commend the audio in these videos. Most youtubers have awful audio quality and they are recording in controlled conditions. You are usually on the top of a mountain and I can still hear everything you and your guests are saying.
Hi Nick, I'm in Aldergrove BC this week, just over the border and can see Mount Baker from here. I've always wondered how much material came our way from the Mt. Baker volcano. Were there lahars, lava? I enjoy thinking about that kind of thing. Anyway Hi from the other side of Mt. Baker!
Thank you for this. It is so beautiful there!
Stunning scenery. Great geology talk. Thank you! Inspiring me to get back on the trail.
Fantastic Video. Thank you.
Great review.😍
This is pure gold in terms of both geology and scenery! Thanks Nick, Gary and Darrel.
Speechless.................
so fun
24:00 We got , here on Vancouver Island, one really old formation, 420mya, called Nitnat tuff, but that's not a limestone, but volcanic ash , but similar age.
Super views
"That's a big rock!" by Gary Paull
Nick you should enable auto generated captions! I know it wouldn't be perfect but it'd be helpful thanks!
Dude I climbed Sefrit and skied shucksan last winter
I wonder how far a glacier could push these isolated blocks, and a series of glaciations pushing them a few or a hundred miles each time. If you have a bunch of them together, at some point they stop being seen as erratics.
I had a question about Shuksan. I thought Shuksan is non volcanic, but there is a strong sulfur smell on the upper Curtis glacier. Has there been volcanic activity on shuksan in the past?
Are the imbricated layers on Tomihoy some of those thrusted pizza boxes?
Yes, they are "little" pizza boxes. However, the imbricate zone or Bell Pass melange that we were in, including Tomihoy, separate "big" pizza boxes that each extend over hundreds of square kilometers, e.g the Shuksan nappe.
If ice age sheets can be several kilometres high - higher than local peaks - then a slowly southward moving glacier could have carried erratics and glacial till over these peaks. Just my guess.
Cordillera ice coming south was not thick enough to bulldoze over the tallest peaks, hence their rugged nature carved by local alpine glaciers was preserved.
@@garypaull9382 Or perhaps between the rugged peaks...
Geology never get old for me it my cocaine.
What you know is not near as interesting as what you wonder about.
Gorgeous scenery. Incredible geology. Hiking with two absolute experts who explain it all.
Absolutely beautiful place. I could watch this all day. Thanks Nick and gang..
Another learning experience
Evening in paradise! Geology at its finest!
This is when your job is your passion, you can tell how much these guys love geology 🪨 Thank you for sharing this passion with us. Very inspiring! ❤️
What an awesome trail and one incredible view thank you for teaching us what we are looking at
Three gifted teachers (plus hiking machine Liz) whose skills and fascination and verbal dexterity just kept me glued to a screen immersed in scenic perfection, also gave me sadness at the inevitable end, that it could not continue longer yet. Such a vital gift this was!
We are so fortunate. Thank you Nick, Darrel and Gary for sharing your experience and knowledge. I'm glad to see Liz. I appreciate learning about accessibility as well.
Watching again to anchor information recently posted. Wow.
Great video and sound quality.
Oh, I've been waiting for you folks to get up to this part of the state! Fantastic!
so glad to see and hear this discussion and scenery; thanks Darrell and Gary and Nick
Another wowza video, Nick, with another intrepid crew!
Nick, thank you for having Darrel on!! I went to UW and he was one of my favorite professors. I’m glad to see he is still doing well. He is very knowledgeable and well respected. Your videos are usually killer but well done 👍🏽
- Brady
Shuksan Greenschist Blue. Kulshan North Pacific Bride. Sisters Dunite Red.
Thank you lady and gentlemen, sincerely. Your affable nature makes these quite involved subjects so easy to grasp.
The videography is wonderful too, Mr. Zentner.
Thanks again.
Nick, you FINALLY got to the Yellow Aster. And now our collective minds are blown into tiny little bits.
Something comes to mind. Isn't this the crumple zone of clockwise rotation? And also in the Cascade volcanic arc? Is it any wonder that all kinds of bits from all kinds of terranes get barfed up to the surface?
I can't imagine how you're going to reference this in your Baja-BC series. Good luck.
I’ve spent all of my adult life, skiing, climbing and exploring this corner of the North Cascades
How the heck does Nick arrange such Tourism Board weather for his videos?
Wow, nothing else is like hearing from the experts in these beautiful places..... Above and beyond Nick! Greatest thanks to Backcountry Gary Paull and Professor Darrel Cowan, your contribution to our understanding of these places is immeasurable. Nick and Liz, you two carry the day.
FYI (took me awhile to figure it out)They start at Table Mtn. Then at about 12:00 in the video they move almost seven miles north to below the east side of Yellow Astor Butte :, Lat. 48.952124 Deg., Lon. 121.677527, alt 5,255 ft.. Then at about 37:00 they move west a half mile along the west side of Yellow Astor Butte. At 1:06 they continue discussion in a back yard.
Yes, first day Table Mountain. Second day amazing geology and scenery to yellow Aster meadows. In 1992, the trail we used was not built, so we did the "Keep Kool" trail, a real haul, up, up...The morning shots were after a quick breakfast at Wake 'n Bakery in Glacier. I recommend it.
Those areas have ridiculous views. I need to get up to Mt Baker. Thanks for making new videos i have watched many over the years. We live in such an incredible diverse state!
We are so lucky to live in this area. I was just up to Artist Point myself for the umpteeth time. I can also vouch for the description of the Nooksack Cirque. A spectacular place to visit if you have the chance. Headwaters of the Nooksack river’s north fork, it is a wild, glaciated valley with Mt. Shuksan and the hanging East Nooksack Glacier at the upper end. My first backpack trip 45 years ago and it was my only visit but it will never be forgotten. Although we were camped elsewhere in the cirque, while exploring the 2nd day we were forced to wait out a two hour, very cold, rain-in-your-ear storm under the protection of the “Great Trog.”
Wow; getting my Geo-fix from the best today, maybe just a little behind on the hikes. However, that's a good thing with field trips you can do most of the work in any order... I am a slightly disabled walking vet of seventy-three years of age so you guys are my legs so to say... Thanks for doing all the climbing, don't have much wear & tear left... LOL
Let's see; (timeline) Baja-BC, Siletzia erupts, slab break (cut) off, elevator rise east of Straight Creek Fault, lots of erosion,.... It seems to me that the slab break was like a diving board when the diver departs, it must have had a great deal of recoil energy to push up whatever was above it, even the old deep stuff.
What a great episode! I can really relate to this; as I'm over in the Bozeman MT area and basically an amateur geologist/ paleo botanist, thanks to some classes I took at MSU back in the 90's...
Thanks for sharing, Nick!! I've always loved hiking up there on the Nooksack Drainage! Used to have some nice trout in Tomyhoi Lake, too!!
"It Upsets God When You Walk by the Color Purple and Don’t Notice It!" The Color Purple -Alice Walker
I read a lot of comments. Seems like many people are too busy or just hikes like this are too risky (older age, health issues, etc.) well I am working on an idea to bring the experience into your home. One day :) for now we are blessed to live through this channel!
Absolutely stunning views and great information. Thank you so much!
On vacation, on the way to New Hampshire to see the trees turn and stumble over some Rocks!!
As usual great video! Get to talk to Noraly?
Spectacular guests... continuing works in progress... Search: DS Cowan - Geologic tests of hypotheses for large coastwise displacements-A critique illustrated by the Baja British Columbia controversy
Oh Nick, your voice sounds a little hoarse and tired. Maybe you would enjoy a restful week at a peaceful mountain lodge?
What an amazing video. The scenery is absolutely beautiful and the wealth of knowledge and information from Darrel, Gary, and Nick. This hike and trails are a most do.
Three guys looking at cristals(rocks) Liz looking at cells(plants)
Awesome Nick 👍😄
We drive up to Mt Baker Artist point every several years 😁