You can support my field videos by going here. Thanks! www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8 Also, I apologize for mispronouncing "Shoshone" and "Absaroka". I have been properly corrected by several of you. Thank you. To be fair, I live near the iconic "Shoshone Falls" in southern Idaho where it is locally pronounced "show shown" not "Show show knee".
@toughenupfluffy72942 жыл бұрын
Show-show-nee and ABS-roka.
@shawnwillsey2 жыл бұрын
@@toughenupfluffy7294 Yep. See my explanation above.
@kevinrussell11442 жыл бұрын
Don't apologize. All pronunciation is local.....you know, potaytoe, potahtoe. Screw 'em if offended. In Nevaaahda, we say Nuva (as in van) duh. Many watching would question how you know the ages of the various rocks and say what's so great about an unconformity? Didn't any big change happen during the flood, after everything was made on the first or second day (I forget which)? Fossils and radiometric dates would make good separate videos. Your photography is great. Thanks for the show, and yeah, I'm a retired geologist.
@PatrickKQ4HBD Жыл бұрын
@@kevinrussell1144 There was a long period of time between the events of Creation and the destructive/re-creative Great Flood. How long is the big question. The separation of land and water and spreading of land-based plants was on the third day.
@kevinrussell1144 Жыл бұрын
According to your Bible and faith (you quote Genesis), free will allows you to believe in a strict (one day is ONE day) interpretation or you can go with the symbolic view for that first week. You also have to decide if enough time remains after Noah's era for all of human history to make sense (and for deciding what rocks formed after the flood and when it happened). You can look it up. Noah's world-wide flood supposedly happened the same time (~2500 BC) the Great Pyramid was being built. Several young earth creation sites also claim most of the rocks exposed in the Grand Canyon were deposited by THE Flood. Curiously, fossil assemblages from Grand Canyon limestones are OLDER than those of the limestones used to build the Great Pyramid. That sounds like a timing problem to me.@@PatrickKQ4HBD
@crypto44232 жыл бұрын
I have a new appreciation for the scenery on road-trips after your videos
@testbenchdude2 жыл бұрын
Geology is so cool. Just put your hand across a couple billion year gap in the geologic record, nbd. But what's more important to me, at least, is to be able to decipher the rock and then to be able to tell that story to others. Thanks Shawn. This is what the study of geology is all about. So cool.
@richarddavies74192 жыл бұрын
Thanks for the memories! When I was a student at Cody high school in 1952 I peeled back a bit of Flathead Formation to reveal a granite surface that looked almost polished. That made me wonder if glaciation had been involved at some time. (Back then the granite was just termed "Precambrian.") A nearby red granite yielded a 20mm magnetite crystal for my collection.
@TerryBollinger2 жыл бұрын
Your excellent video brought back memories of exploring the 900 million years (myr) Ozark Dome Great Unconformity in a road cut through just west of my hometown of Fredericktown, Missouri. The beginnings of the ~520 myr old Lamotte Sandstone lap up gently against the base of the same re-exposed rhyolite hills that survived the continental and perhaps global Cryogenian ice age of 850 and 635 myr ago. At the base of these hills, you can pick up water-rounded rhyolite pieces of the hills that, by their locations, likely date back to the earliest start of the open-air weathering of the hills. These transitional stones -- igneous stones at the first and roughest stage of becoming sedimentary deposits -- are so weathered you can peel them apart with your bare hands in onion-like layers, despite them being composed of the same granite-hard rhyolite in the hills themselves. The length of open-air and shallow-water weathering required to soften the interior of hand-size and larger rhyolite stones boggles the mind. It must have been a very boring place for a very long time indeed. Looking to the west from the top of that same hill, you can see other small rhyolite hills poking up in the distance. It is a vision of the time shortly after the melting of the glaciers when shallow oceans filled gaps between the hills, and the hills formed an archipelago of islands. It is, quite literally, a fossil landscape of an era nearly a billion and a half years in the past, from a time when no land plants or animals disturbed the immense views of rock, ice, water, and sky.
@toughenupfluffy72942 жыл бұрын
Ah, road cuts. Where would we be without them?
@GeoscienceImaging2 жыл бұрын
Nice! Been there many times with students during field camp trips to WY. Those Cambrian SS show nice onlapping features over by the power plant exposure. There's also that little channel scour in the basement right where you were, which I interpret as a stream channel flowing to the ocean before the beach sands arrived. I think there's a bit of fluivial layering within it, but hard to say for sure.
@hunt4redoctober6282 жыл бұрын
This is absolutely mind-blowing! And I thought that we had some pretty old rocks here in the UK. This has been a really fascinating video and to see the Great Unconfirmity so clearly defined, just incredible.
@kevinrussell11442 жыл бұрын
In Scotland you have another "Great Unconformity", at Siccar Point. In some respects it is more spectacular than the nonconformity shown in this video. At Siccar, I think it is nearly flat-lying Old Red Sandstone resting, in angular unconformity, on older, steeply-dipping "transitional", sedimentary beds, indicating that the older beds were deformed, uplifted, levelled by erosion, then engulfed again by the sea before the upper beds were deposited. Understanding the significance of that outcrop is one of THE signal events in the evolution of geologic thinking.
@sharendonnelly77702 жыл бұрын
Great information, I am learning so much! Love your channel!
@stevewhalen6973 Жыл бұрын
Thanks!
@toughenupfluffy72942 жыл бұрын
In Western Colorado the Great Unconformity is composed of gneisses and schists with granitic intrusions. The metamorphic gneisses are ~1.8 billion years old and the granitic intrusions are ~1.4 billion years old. They are covered by the Triassic Chinle Formation, which is ~215 million years old, with over 1.2 billion years of missing time between them.
@stevehix16562 жыл бұрын
Awesome job,I'm fortunate enough to work with all of these beautiful rocks. It's really interesting to learn more about them from a Professor. Keep up the great work.
@shawnwillsey2 жыл бұрын
What line of work has you dealing with these?
@stevehix16562 жыл бұрын
@@shawnwillsey I have a Stone and Preservation business in Southern California
@a58warrior2 жыл бұрын
I was in Cody this summer for a seasonal job! The landscape is so fascinating from a geologic perspective. The leading theory on how Heart Mountain was formed is mind blowing!!
@brittshepard93173 күн бұрын
Very interesting, I look forward visiting the area. You obviously have no issues with vertigo. I do enjoy your channel. Thank you.
@mizzougrad0012 жыл бұрын
Touching something that's over 2 billion years old could be such a spiritual and humbling experience. That would be something like 40 million human generations before our present time.
@tomgunn80042 жыл бұрын
Some people will believe anything!
@angelcorrea95152 жыл бұрын
Spiritual don’t make people laugh , stop smoking pot
@mawi11722 жыл бұрын
Thomas A. If you really feel that way, touch a Holy Bible. Christ was before there was time. How long ago do you think that was? The Word of God is the oldest thing we know of. And nearly every Earthling has one Bible today. We can read God's word at any time. That's the true miracle. Love you Lord Jesu !!!!! 💋
@mawi11722 жыл бұрын
@@tomgunn8004 while others have NOTHING to hold onto or even hope for. 🙏✝️🙏✝️🙏✝️🇺🇲🇺🇲🇺🇲🇺🇲🇺🇲🇺🇲🇺🇲
@daves.94792 жыл бұрын
@@mawi1172 Speak only for yourself (w/out your religious faith), please.
@Mistydazzle2 жыл бұрын
Enjoyed seeing this, Shawn, thank you! Another highly accessible spot to see this unconformity is along Highway 24, Manitou Springs, west of Colorado Springs. Garden of the Gods Park is just to the north, with beautiful hiking and some rock climbing. The iconic red sandstone of the Fountain Formation, Paleozoic sedimentary rocks, on top of Billion year old Pikes Peak Granite batholith.
@shawnwillsey2 жыл бұрын
Yes, I've seen pictures of this and would like to visit someday. Thanks for the reminder.
@davidmoats6252 жыл бұрын
Manitou Springs is west of Colorado Springs on the way to Pikes Peak.
@Mistydazzle2 жыл бұрын
Dsylexia set in
@davidhenningson47822 жыл бұрын
Canyon walls and road cuts are fascinating windows into what lies beneath the soil we tread and drive over. Great content 👍
@robinday21372 жыл бұрын
There is a really nice visual of the great unconformity on Frenchman mountain in Las Vegas as well. It is on Owens road at a little road cut as you drive up to a new housing development. Worth a view.
@lhv5692 жыл бұрын
Shared with my friends in Wyoming. Very informative. Thanks.
@plabptng92 жыл бұрын
Love it, thanks so much! I majored in geology, and went to grad school, too, only to discover that learning geology is something I’m far more suited to than research. Now I’m an engineer, but I miss it a lot. This takes me back to my undergrad days, going on fiend trips and learning. Thanks for the nostalgia. Also, thanks for representing geology on KZbin! I’ve found great math and physics and astronomy and engineering youtube channels, but geology doesn’t seem to get the love it deserves.
@shawnwillsey Жыл бұрын
Welcome aboard and sorry for the very late reply. Hope you enjoy the geology videos here.
@lionrocklr92172 жыл бұрын
Wonderful Presentation. Thank you.
@granfabrica6 ай бұрын
I find this shit to be fascinating. I'm 71 now, guess I'm too old to become a geologist. Would have dug it though lol
@alanjameson86642 жыл бұрын
There is a place along the Merced River (which flows out of Yosemite) a ways upstream from the town of Mariposa where the granite which makes up most of the Sierra Nevada Mountain Range has been eroded deeply enough to expose older folded and eroded sedimentary rocks.
@xtr3m3852 жыл бұрын
Thank you for sharing your time and knowledge professor Willsey.
@thomasrussell71352 жыл бұрын
thank you for your time
@maryseeker75902 жыл бұрын
Excellent! Great science and enthusiasm!
@jokerace8227 Жыл бұрын
I was recently studying this canyon. Excellent.
@7inrain2 жыл бұрын
Fantastic video which really shows what geology is about. Stumbled upon it only by coincidence. Thanks. You have a new subscriber.
@shawnwillsey2 жыл бұрын
Welcome aboard!
@chrisholcombe1372 жыл бұрын
4:30 the big rock across the Hwy makes me nervous for drivers . To think that people want to stand so close to the edge of the canyon with it wanting to crumble . Looking at the Hwy tunnels , some edges look like they want to fall over ! Great view
@jedibusiness7892 жыл бұрын
Oh…this is exciting. Always learn something from your channel. Great Unconformity.
@RonHei Жыл бұрын
Cody, Wyoming, my home town. Never knew what was in my own back yard. Thank you!
@kimlizotte69410 ай бұрын
Hello from Cheyenne, WY! I know this may sound nuts, but I appreciate what you bring the table even though I've been in the medical field for a career in the last 40 years. I worked for nursing agencies in three states and Wyoming had to be the most fascinating of them all, the other two in Nebraska and Colorado. I eventually settled down in Wyoming because it had so many factors that I was just in love with and one of them was the geology. And that's what's crazy I'm a medical as far as science is concerned but I love geology! I spent some significant time on I-25 going north from Cheyenne to Northern Wyoming and Western Wyoming and I will never forget my time spent up in Thermopolis and the geological factors I saw there, including Chugwater formations like Round Top anybody (who's ever been to Thermopolis knows what I'm talking about) I've driven through the state park at Guernsey and a lot of fascinating geological stuff there, I'm not sure some of the rock samples I took home or petrified wood or agates. So let's see you do a video about some of the geological formations in Guernsey and Thermopolis that would be absolutely incredible! I'm looking forward to it!!
@acebacker12 жыл бұрын
Thank you so much! Absolutely wonderful. 😊
@David-hm9ic2 жыл бұрын
Very cool. I chose to get most of my college science credits in geology courses because it fascinated me. Now as an old guy it still fascinates me.
@valoriel44642 жыл бұрын
Great vid 👌, as always. Thanks 😊
@leslie38322 жыл бұрын
Thank you Shawn! I so enjoy your videos. This one reminded me of the time my husband and I saw this Great Unconformity one mile east of Las Vegas, Nevada. We were following Albert Dickas’ book American Geo-Sites. No 51 was the Great Unconformity that you could see inside the Grand Canyon, but here it was unmarked 1 mile east of the intersection of Lake Mead Blvd and Hollywood Blvd in Las Vegas, at the base of Frenchman Mountain! 1700 mya Tapeats sandstone inclined 50 degrees on top of 1.7 bya Vishnu Schist, “broken exposures of reddish Vishnu Schist”. Really cool and memorable. I have the coordinates from the book of anyone wants to know. And a photo. Thanks for your Cody Wyo video.
@dancooper85512 жыл бұрын
Such a cool area. Stopped there several times over the years traveling to and from YNP. Thanks.
@leechurchill19652 жыл бұрын
Props for navigating that rugged terrain while holding the camera steady and narrating without incident. And all in one clip.
@wchougland12 жыл бұрын
Thank you, well made… wish I had paid more attention in my college geology claas
@susanbone36342 жыл бұрын
Wow, thankyou. It's fascinating to see this; much appreciated.
@brianpeers Жыл бұрын
So cool and so different to what we have here in the North Island of New Zealand. Please keep producing these informative and interesting videos.
@shawnwillsey Жыл бұрын
Thank you! Will do!
@shawnwillsey Жыл бұрын
Hoping to visit your country soon.
@markhall62012 жыл бұрын
Enjoying your channel greatly. As former geologist I’m getting to see cool places I’ve never been. If you want to knock off the great unconformity #4 try Camp Creek east of Melrose and north of Dillon Montana. Not only a great exposure of the unconformity, but of a paleosol, weathered zone, a fault, and pegmatite dike in the Archean rock cut by the unconformity.
@shawnwillsey2 жыл бұрын
Great suggestion. So many areas for me to get to still. I'll add to the long list.
@realityjunky2 жыл бұрын
One is never a former geologist. Geology is for life.
@joycee54932 жыл бұрын
Amazing... Thank you!
@Chas_Reno2 жыл бұрын
Well done, Thanks.
@vudu8ball2 жыл бұрын
I have seen this feature in a road cut just outside Las Vegas many years ago and it blew my mind then. Seeing this video reminded me of the experience. Thank you for posting.
@19stump652 жыл бұрын
Yes it's beautiful, born and raised in Cody
@2flight Жыл бұрын
Thanks. Very interesting.
@muzikhed2 жыл бұрын
Excellent. So interesting to see that time lapse so clearly. Love the pegmatite. Wonder how the beach sandstone got to be sitting directly on top of the old granit , I mean what was originally on top of the granit ?
@shawnwillsey2 жыл бұрын
Other, younger rocks were on top of the sandstone, but they were eroded away before the Cambrian sandstone was deposited. In other locations, we sometimes do see some of the intervening rocks, like the Grand Canyon Supergroup in the Grand Canyon.
@muzikhed2 жыл бұрын
@@shawnwillsey Thanks Shawn
@Michael-rg7mx2 жыл бұрын
@@shawnwillsey So to get the feldspar mixed with the granite there needed to be a mixing pot somewhere, right? Was the granite deposited before the land uplifted out of the sea or after? If after how did it get sediment above it, obviously deposited before the rockies uplifted. So was the granite extruded in an underwater fault? I'm confused
@johnbollenbacher67152 жыл бұрын
Right, how many hundreds of feet of granite had to be removed before this stuff became exposed so that it could be overlayn? In other words, how deep in the earth did this granite form?
@shawnwillsey2 жыл бұрын
@@Michael-rg7mx The feldspar is one of several minerals in the granite. The granite is magma that cooled slowly underground. Much later, it was uplifted and eroded to near sea level, allowing the sandstone to be deposited above it.
@russell_szabados2 жыл бұрын
Awesome video! I was a science nerd growing up, but geology never captured my fancy. But you presented this in a way that really caught my interest. I live close to Red Rock Canyon in Las Vegas, this makes me want to go exploring. Thank you!
@pjford11182 жыл бұрын
In grade school I was really into geology. I've still got a huge collection. I gave it up after talking to geologists, they all said that they never get paid enough for the hard work. In short they felt they were taken for granite!
@jenb.6440 Жыл бұрын
Awesome!! Thank you!
@GB-ew8wc2 жыл бұрын
I accidently found your channel and am now your newest student. Thanks for to days lesson.
@shawnwillsey2 жыл бұрын
Welcome aboard! Enjoy perusing the existing videos while I continue to get out and make new ones.
@holyworrier Жыл бұрын
"What's the cool feature?" It's all cool, Shawn. And fascinating.
@briandwi25042 жыл бұрын
Fantastic spot, great to see it. Thanks!
@cherylwood52022 жыл бұрын
VERY informative. Thanks so much!
@brianmccabe98272 жыл бұрын
Hi Shawn, I loving all your videos and iam learning from you, you are so knowledgeable.Please keep up the good work. Im new to minerology, geology and gemology. Thank you so much.
@ScurvyDog8072 жыл бұрын
Awesome vid! Rocks and Minerals with Wilsey, theory to practice
@PopsMdub2 жыл бұрын
Wow! I did not know there was a place where so much disparity in geologic history existed at one contact point. And to make it even more incredible, you can easily put your hands on it! I am definitely blown away! Thank you so much for documenting this place and sharing it with us. It is now at the top of my list of places to visit. Perhaps I'll post my video of that when I do and link to it here if I can. I best get a check in the mail to you too as I've really enjoyed so many of your highly educating videos.
@shawnwillsey2 жыл бұрын
Hey glad to hear you are enjoying the content Mike. It’s been a fun side project for me. The Great Unconformity is exposed at several locations so maybe there’s a spot closer to where you live. Thanks for your support and subscribing.
@richarddavies74192 жыл бұрын
There are even older (more than 3 billion years) surfaces one can walk on in Canada, Australia, Greenland, etc, many square miles as far as the eye can see.
@georgesheffield15802 жыл бұрын
Wake up ,there are lots of unconformities around in geology.
@PopsMdub2 жыл бұрын
@@georgesheffield1580 Boy, it's too bad we can't all be as woke as you. I'm sure you must know everything by now. I guess I should have seen this and just gone, meh, and moved on.
@davidowen69772 жыл бұрын
Thank you 👍 On the Beach 👌
@friendlyone27062 жыл бұрын
Randall Carlson reawakened my interest in earth's history. So glad KZbin suggested this video.
@DrewWithington2 жыл бұрын
Amazing to see the world through the eyes of a geologist.
@daleeason96872 жыл бұрын
Gosh, a few years ago I drove with my family from Minnesota to Yellowstone and stopped at that dam on the other side of those tunnels. Darn I did not know about those details nor do I ever remember hearing about the great unconformity being there. I think I might have heard of it existing but only in passing. A few years before that we were at the Grand Canyon and then lopped back home through Utah and I wonder if once again near your other great unconformity site. In addition as a child I lived in Worland Wyoming not far from Cody. But never knew all of that geology. I just watched about the worlds largest land slide right near were you are as well. Thanks so much. This is fun to learn about.
@k1j2f302 жыл бұрын
Are you talking about Heart Mountain sliding off the Bear Tooth mountains?
@daleeason96872 жыл бұрын
@@k1j2f30 Yes that is one of the pieces that slid off. Another according to the video I watched is Rattlesnake mountain which I think is what was cut by the highway that Shawn was in. So that could be the reason the unconformity layers got to that location. I had not realize that until now. Did they raise up but then later slide there?
@k1j2f302 жыл бұрын
@@daleeason9687 I'm not sure, but the size of that land slide is mind boggling! Wish I could have seen it happen from a safe distance of course. Can imagine the sound and the earth shaking under my feet!!
@virgo714 Жыл бұрын
Thank you… love this topic
@bobbyadkins8852 жыл бұрын
Another great video, thank you
@deborahriley11662 жыл бұрын
Very cool! Thanks!
@exxzxxe2 жыл бұрын
Very informative- thank you!
@sdmike11412 жыл бұрын
Great stuff Shawn! Way to tie in your other videos…so we have to go back and looksie🤣. Thanks.
@gregorypowell9132 Жыл бұрын
As always. Amazing. Question ? Have ya had a chance to see the folded rocks from the tram ride at snowbird yet?
@shawnwillsey Жыл бұрын
I haven't been up there in several years.
@leesutherland75792 жыл бұрын
Any plans to visit Wind River canyon north of Shoshone reservoir? Your videos are perfect. Thanks.
@shawnwillsey2 жыл бұрын
Eventually. When I get back to that area.
@keithwood6459 Жыл бұрын
Shawn, are there any places where Proterozoic rocks are exposed upon the same Archaean basement? That would fill in some of the lost history in the Archaean-Cambrian Great Unconformity. There is evidence of ice ages down there in the Proterozoic, but I'm not sure if the the GU is exposed under Proterozoic rocks anywhere. It would make a good follow up to this one - closing part of the gap on the GU.
@markvincent5222 жыл бұрын
I live in Riverton, so this is rad and something I can go check out! Look out for the Washakie Needles on your left if you go through Dubois and toward Riverton/Lander.
@shawnwillsey2 жыл бұрын
Didn't make it that far on this trip, but I will be back.
@SCW10602 жыл бұрын
I really enjoyed your videos and just subscribed. Thank you
@Panicagq2 Жыл бұрын
So cool! Here in Oregon our rocky outcrops are less than 50 Mya, barring exotics - my wife's from Wyoming, so I hope to see a trip to Cody in our future lol I'd love to get a nice contact hand sample!
@shawnwillsey Жыл бұрын
I did a video near Cody last fall. kzbin.info/www/bejne/goLVhn6bos93pbs
@tipsyrobot69232 жыл бұрын
What's your opinion on the missing material between the two vastly different time scales in the rock? Where did it go?
@over60withdeb572 жыл бұрын
Outstanding! Thank you!
@richdavis69632 жыл бұрын
I have been a middle school science teacher in Cody for 20 years and just recently found your channel. I am working through your videos and really appreciate the content. I take my 8th graders to this site each year and unfortunately the amazing nature of natural history is mostly lost on them. Their favorite part is throwing rocks at the contact of the unconformity at the end of your video. I guess that’s better than nothing. When you look at the sandstone farther up the stratigraphy you see intermixed beds of shale. I find those almost as fascinating. I’ve always assumed it relays a series of transgression and regression of sea levels. I was wondering if you noticed that or could confirm my suspicions. Again thanks a lot for the excellent videos.
@shawnwillsey2 жыл бұрын
Great work on educating the young folks. You are my hero. Yes, there is some interbeds of sandstone and shale, which indicates rise/fall of sea level at that time.
@doctormix712 жыл бұрын
Thanks so much for this video, as the canyon near the Bill Cody Dam is one of my favorite places to just stare in awe at the splendor of the rocks! 🙏 🤩 Whenever I can, I take loved ones to see Yellowstone, and I always go through Cody. Next time definitely going to stop and place my hands on this geologic marvel 🖐😎
@davidmoats6252 жыл бұрын
I have been to two other places where the Great Unconformity is exposed. One is on Arizona route 87N between Peyson and East Verde Estates, Arizona near mile marker 260. Another is the Black Canyon of the Gunnison, Colorado. This Great Unconformity was supposedly formed in two Snowball Earth episodes during the 850-635 million-The Cryogenian Snowball Earth time period. I have heard that it exposed in the Ozark Mountains somewhere also.
@weatherwatchmore3812 жыл бұрын
Although I’m 17 I actually understand this very well since I study this stuff like crazy as a hobby. I fully understand what’s going on here.
@johnhawk88072 жыл бұрын
I drove that road a dozen times this summer Trout fishing. Too bad I didn't know what I was looking at. Good job on the video.
@itsallspent2 жыл бұрын
On family vacation, with the 1957 Plymoth, dad drove that canyon with the right side headlight out and the the generator kaput. 1962
@michalejones772 жыл бұрын
Another winner! Was there a Big Boy statue in a field off the highway on your way to Cody? Amazing area thanks for the close look!
@shawnwillsey2 жыл бұрын
Thanks. I did not see a Big Boy statue.
@AnkitaYadav-hp9vx8 ай бұрын
"and just like that I walked across the great unconformity" wow what a humbling and surreal experience.
@stevewhalen69732 ай бұрын
Some really old basement rocks 3 billion YO. A really beautiful spot .
@3xHermes7 ай бұрын
beautiful place
@lawrencetaylor4101 Жыл бұрын
Merci beaucoup, I appreciate these videos. I took a geology class at a central Wyoming community college and it was fascinating. My only regret is that I'm colour blind and rock identification was a drawback.
@mountaingirlzstuff43147 ай бұрын
You should go to Kootenai Falls in northwest Montana, the elevation gets deep in the canyon exposing folded belts of rock and ancient algae fossils
@Foxtrap7312 жыл бұрын
Very well presented. That’s a cool unconformity. What happened to all the eroded rocks? Deposited downstream?
@evilcam2 жыл бұрын
Yes they would have been deposited downstream. And who knows, some of the small mineral sediments that were eroded off may have been redeposited as the area filled with water and deposited those sandstones. Some of the sand grains COULD have washed away then made their way back to be deposited as rivers and the like began flowing into the inland sea that eventually covered all of this. Also, yeah that white mark does sorta look like a very small portion of a dried and lithified lahar flow. Though I don't know what it is, and though it resembles an old lahar flow it could be any number of other minerals and deposition schemes.
@Foxtrap7312 жыл бұрын
@@evilcam I’ve been thinking about this. 2B years….igneous rock that was emplaced under an ocean? Or more likely in a shore area to facilitate erosion and movement of the overlying strata? Or a massive flood came along followed by a shore and marine environment. Does the composition of the sandstone tell you anything? I agree, that very well could be what was above, just in an altered state. These questions are why I got into geology. Great video. I’m off to look for some papers on the topic. Btw, I’m not familiar with the lahar deposit. I will look again for that. Perhaps this was a similar environment to current Western Canada. Igneous rocks meet the ocean, some volcanoes around.
@shawnwillsey2 жыл бұрын
@@Foxtrap731 Nice discussion here folks. The jury is out as to why erosion was so extensive just before the Cambrian over such a broad area. One idea is that the late Precambrian glaciation events (sometimes known as "Snowball Earth") were very effective erosional events, scouring the bedrock down. Then, when sea level rose in the Cambrian, the continents were mostly covered, allowing sand and other sediment to be deposited.
@Danika_Nadzan2 жыл бұрын
@@shawnwillsey Thanks to all three of you for the interesting explanations. Such a mind-boggling formation with a number of possibly contributing factors to think about. And thank you, Shawn, for the visuals to go along with the professional description of what we're seeing.
@mike024542 жыл бұрын
If you take age and angle, can you computer simulate/ backtrack in time historic contours? Or do we not have enough data for a large enough area to do so?
@CySteele-Mills-hx9kd Жыл бұрын
Shawn, appreciate your series of educational videos. One question, is there any significant geochemical difference between the Precambrian rocks and the more modern plutonic rocks?
@garyday5299 Жыл бұрын
Re the granite shapes at the beginning of your video, why do they look like individual pillows stacked next to each other. I'm assuming the separations vertically must be water erosion, At Gem Lake, RMNP I noticed similar, where the granite looked like huge pillows stacked on top of each other. But why does the separations between the "pillows happen horizontally? Thanks for answering.
@knightsaberami012 жыл бұрын
So, question: When we're looking at these canyons, cut by rivers, are we talking about a process of uplift, coinciding over time, geologic deep time, or did this occur due to a period of catastrophic flooding and uplift? All you have to do is pull up any sat map, and the alluvial fans, these dry river beds are everywhere in the desert. I realize the bread basket was shallow seas, and now I want to ask if the aquifer came from that, there's a million questions I have in mind. Is there a decent geology textbook out there that you could recommend? Also, I'm on the hunt for one in regards to the geology of New Hamphire. I know at some point we had basalt flooding, I think I've even been able to identify what I believe to be gneiss as well. We have mostly gray granite but I have seen granite with white quartz veins. Thank you, geology is a side hobby and I try to keep to keep engaged with the sciences.
@josephholliman6006 Жыл бұрын
After living in Wyoming and Montana, I recall seeing multiple signs of falling rocks warnings. Could many of these falling rocks or failures be from the result of the road cut into the sand stones atop of the granite basement rocks or the great unconformity such that the sand stones above are less established or seated?
@AKUSUXs2 жыл бұрын
Just Amazing!
@JenniferLupine2 жыл бұрын
Amazing! 👍👍
@lloydspooner2 жыл бұрын
You should check out Fremont Canyon between Alcova and Pathfinder west of Casper.
@plumcrazy98422 жыл бұрын
Check out hwy 141, just south of Grand Junction Co. Uni-weep Canyon.
@THX50002 жыл бұрын
Have you explored Clarks Fork Canyon near Cody? It's pretty amazing.
@pmm10442 жыл бұрын
Put my hand on The Great Unconformity at Red Rock Amphitheater. It was truly awesome. Now wondering how it affects zircon provenance studies assuming that all the host rocks had been eroded away for such a long period. In particular wondering about zircon’s from the Lemhi group in Idaho. Just thinking outload.
@misterguts2 жыл бұрын
Hey Shawn, thanks for the video. There was a story I heard once about a geologist who said she became queasy when looking at golf courses. She said that golf courses were made to resemble glaciated terrain, as in in Scotland where the game originated. Things like small lakes, moraines of sand, undulating ground. She said that seeing a "glaciated" surface where she knew no glaciation had occurred always made her feel disoriented and queasy.
@realityjunky2 жыл бұрын
I'm getting a little vertigo with him waving the camera so much and on the edge of a cliff. I keep thinking he's going to fall over.
@shawnwillsey2 жыл бұрын
@@realityjunky The camera and selfie stick makes it look more dangerous than it actually was.
@realityjunky2 жыл бұрын
@@shawnwillsey Please be very careful. That was some fantastic photography but it's not worth your life or limb. But the video is greatly appreciated. I did the six week University of Michigan field camp course near Jackson Hole decades ago but that roadcut looks awfully familiar. I'm still gonzo for pegmatites.
@petechimney67552 жыл бұрын
Another easy place to see the Great Unconformity is the road up Casper Mountain in Casper, WY. there the billion-year old granites are overlain by Cambrian Deadwood Sandstone. An easy drive and the exposure is right at road level.
@leechild46552 жыл бұрын
9:13 that almost looks like ash from a volcano? anyway, ya! you mentioned a bunch of things I would be asking about. ie: what is the rock composed of, how old is it at time of deposition, and what processes had to happen to make it visible to us today. this video really fascinated me knowing all that basement rock is as old as it is, and to think there was next to no life on land for all that time. wow
@shawnwillsey2 жыл бұрын
9:13 looks like it is some crumbly granite. Granite can weather chemically into granular pieces of minerals, called grus.