The Great Unconformity and Spectacular Geology of Wyoming's Fremont Canyon

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  • čas přidán 28. 12. 2023
  • Journey to central Wyoming with geology professor Shawn Willsey to investigate the scenic geology of Fremont Canyon along the North Platte River. Investigate an amazing roadcut exposing the Great Unconformity and its over two billion year history.
    Stop 1 GPS location: 42.47116, -106.79506; Stop 2 GPS location: 42.46975, -106.77907
    Support the creation of these educational videos! Send support via:
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    Or a good ol' fashioned check to:
    Shawn Willsey
    College of Southern Idaho
    315 Falls Avenue
    Twin Falls, ID 83303
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Komentáře • 92

  • @shawnwillsey
    @shawnwillsey  Před 6 měsíci +9

    You can support my educational videos by clicking on the "Thanks" button just above (right of Like button) or by going here: www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8
    or here: buymeacoffee.com/shawnwillsey

  • @StereoSpace
    @StereoSpace Před 6 měsíci +11

    John Fremont was a 19th century explorer who'd been tasked with discovering if any rivers connected the Mississippi and its tributaries to the Pacific Ocean. His "Memoirs of My Life and Times" is a jaw-dropping account of his group's explorations in the 1840's up the Missouri River to the Platte, along the Oregon Trail, along the Snake River to the Columbia River, then down the eastern Sierra, across them in winter while near starvation, into California, and back. An amazing journey.

  • @Janer-52
    @Janer-52 Před 6 měsíci +17

    Great little trek - I always appreciate your showing us what is in the roadcuts as well as close by. Pointing out the layers helps train the eye to look at the cuts more closely, rather than just whizzing by.

  • @billroberts9182
    @billroberts9182 Před 6 měsíci +8

    Thank you.. 2 billion year unconformity is a bit humbling.

  • @davidk7324
    @davidk7324 Před 6 měsíci +5

    Wyoming, ya gotta love it. Far less traffic, but the hazards of grus.

  • @kevinkoll2420
    @kevinkoll2420 Před 6 měsíci +7

    Thank You for posting this during your "time-off" from teaching. Please be safe and I really appreciate it when you let us know how careful you are being. Rocks are not always as solid as they seem! Says the flat lander to the geologist! 😁

  • @TheEarthMaster
    @TheEarthMaster Před 6 měsíci

    I have always love history and to throw in geology it is my passion!

  • @susanwymer6912
    @susanwymer6912 Před 6 měsíci +9

    This was a beautiful and interesting outcrop! The Great Unconformity is something I need to read more about. Thank you and Happy New Year’s!

  • @kirkvoelcker5272
    @kirkvoelcker5272 Před 6 měsíci +4

    I've seen the Great Unconformity in the Grand Canyon on a raft and on Frenchman Mountain in Las Vegas after taking a small somewhat rugged hike. In Wyoming I can just drive up to it.

  • @polyrhythmia
    @polyrhythmia Před 6 měsíci +9

    As I understand it, it is the Great Unconformity that led to the Snowball Earth hypothesis. Grus, don't bring me down...

    • @brucethomas471
      @brucethomas471 Před 3 měsíci

      I believe you're correct. According to Don Brownlee, a Snowball Earth event happened about 2.1 billion years ago, which I think Shawn said is about the age of this unconformity. Check out Rare Earth and also The Life And Death of Planet Earth (I think it should have been The History and Future of Planet Earth) for more info on this, Ward and Brownlee, 2001.

  • @jaykirschenman
    @jaykirschenman Před 6 měsíci +3

    Grus. New geo word day for me.

  • @charleymitchell5461
    @charleymitchell5461 Před 6 měsíci +2

    I grew up in Montana, Utah, and Wyoming. As a scout and then a USFS firefighter and Geography major,I got to see so much of what you have shown us. Only wish I knew then what I now know, thanks to you. Antelope Island, I've seen the sign a million times, this time I stopped and knew what a special place it is. Thank you.

  • @KnucklebarkRanch
    @KnucklebarkRanch Před 6 měsíci +2

    Thanks again Shawn.

  • @jimjackson1087
    @jimjackson1087 Před 6 měsíci +3

    The river is diverted through a tunnel to a power plant. 1958 OR SO. I fished it with my dad before it was Opened. Amazing place.

  • @jackprier7727
    @jackprier7727 Před 6 měsíci +1

    Nice narrow canyon, & it's always a thrill to encounter the ancient basement. Then- the drama of a 2billion year gap/juxtapositon makes the mind swirl-

  • @edwardlulofs444
    @edwardlulofs444 Před 6 měsíci +2

    I sure hope so visit Wyoming this summer. I haven’t been there for a couple of decades and only to YNP and the migmatite of the Wind River Range. Wonderful glaciers there.

  • @Rachel.4644
    @Rachel.4644 Před 6 měsíci +3

    A strikingly pretty area and I'm glad you're describing it. That would have been hard to figure out otherwise. Gruce is a new word. 👍🏻
    Again, your mineral and rock identification series is SO helpful! Thank you!

  • @stevew5212
    @stevew5212 Před 6 měsíci +2

    thanks Shawn

  • @maggiekelso997
    @maggiekelso997 Před 6 měsíci +2

    Oh wow. I've been waiting for this one for a while and I didn't even know it.

  • @alanharwood1636
    @alanharwood1636 Před 6 měsíci +2

    Another excellent roadcut. I was expecting you to say the overlying strata was Cambrian age so it was interesting to hear it was Devonian.

  • @nitawynn9538
    @nitawynn9538 Před 6 měsíci +1

    Thank you for this road cut lesson. I need to learn more about the unconformity.

  • @toughenupfluffy7294
    @toughenupfluffy7294 Před 6 měsíci +3

    "Don't bring me down...grus!"

    • @briane173
      @briane173 Před 6 měsíci +1

      🤣🤣

    • @briane173
      @briane173 Před 6 měsíci +1

      We've found the excuse Jeff Lynne can use for what he said was just a made-up word to fill a hole in the song (it appears grus can indeed "bring you down"). Beats singing "Bruce" just because the audience does. "Bruce" makes zero sense whatsoever within the context of the rest of the lyrics.

    • @kymkauffman5000
      @kymkauffman5000 Před 6 měsíci

      This was so interesting! I have always enjoyed looking at cutouts driving by and wondering about the different layers. I will stop more often now!

  • @birdwatcher7522
    @birdwatcher7522 Před 5 měsíci

    My dad was a soft rock geologist and turned to crystallography in his retirement (a lot of stuff on MinDat), so watching your stuff gives a bit of nostalgia. Thanks for doing these videos. Sandy (get it? Sandy...soft rock, he did his PhD on some sort of clam) in VA.

  • @brucedymock6635
    @brucedymock6635 Před 6 měsíci

    A great little excursion thanks very interesting

  • @rucadulu
    @rucadulu Před 6 měsíci +1

    Shawn, I spend most of my summers on my boat at Alcova and Pathfinder Reservoirs. To really appreciate the canyon, you need to take a boat trip up the 2 1/2 mile canyon to the power plant from the main body of Alcova Reservoir. There is also a smaller but very unusual canyon on the North Platte River arm of Pathfinder Reservoir. During your next trip that you plan to the Casper Area you have to try and see both of these canyons. I am not a geologist but there appears to be some rather large lava dikes in the rose granite that run through the canyon all the way up to the Marina area and Sweetwater River arm area of Pathfinder Reservoir.

  • @valoriel4464
    @valoriel4464 Před 6 měsíci

    Thx Prof ✌🏻 Happy New Year everyone

  • @Reziac
    @Reziac Před 6 měsíci

    Oooh! this canyon was exactly what I needed to see for a project I'm working on (not geology) ... now I have to drive down there and take pictures. :)

  • @bearbait49
    @bearbait49 Před 6 měsíci +3

    I had never considered looking for the great unconformity here. Would be interesting to map other good exposures in Wyoming and further your observations of the nature of the contact.

    • @edwardlulofs444
      @edwardlulofs444 Před 6 měsíci +1

      Wikipedia has a short, non specific list. Nothing definite enough for me to find on the ground.
      Roadside geology books might have it. But it seems small exposures only and widely dispersed across our continent.
      Unless a real geologist like Willsey corrects me as I’m an amateur.

  • @dianespears6057
    @dianespears6057 Před 6 měsíci

    Another road cut and an exquisite canyon (loved that phrase for some reason). Thank you.

  • @notrub82
    @notrub82 Před 6 měsíci

    I love you man! So cool

  • @gsmith9531
    @gsmith9531 Před 6 měsíci

    Hi, Shawn. We just had an earthquake here in NYC. I'd be so grateful if you do a piece about the splitting up of Pangea and how that created different fault lines throughout the NYC/east coast. NYC geology is very exciting but also VERY confusing at times. From the eastcoast - Happy New Year!

  • @hestheMaster
    @hestheMaster Před 6 měsíci

    That is a really eye-opener of a roadcut professor. There are different unconformities around but it really takes a geologist
    to decern the area of the Great Unconformity. Check out any videos that mention Snowball Earth for more on that.

  • @RWBHere
    @RWBHere Před 6 měsíci +2

    Thanks Shawn. That really is spectacular. 🙂👍
    It would be interesting to take a Geiger counter or other radiation detector, and to see how radioactive that pink granite is. I'm in the U.K., and red or pink granite here is known for its radioactivity, from Radon gas which is a fission product of Uranium and other unstable elements.
    Interestingly, the Precambrian, then the Cambrian and Devonian eras / rocks are named after parts of Great Britain (the correct name of the main island of the U.K.). Devon is a county in the Southwest of England and Cambria is the Latin name of Cymru, or in English, the principality of Wales, which lies to the West of Central England. Both regions are where rocks of the appropriate ages are found.

  • @runninonempty820
    @runninonempty820 Před 6 měsíci +1

    I see the Great Unconformity often referred to and I pretty much know what it is, but I would really like an in depth look into it, like where it is all seen and the age differences between the rocks and more.

    • @TheEarthMaster
      @TheEarthMaster Před 6 měsíci

      the Great Unconformity is found nearly everywhere across the globe. It's a gap in the geologic record that represents a long span of time, ranging from 100 million to 1 billion years. The Great Unconformity is marked by a massive surface of erosion that appears all over the world at about the same time. There is so much info found on google with this.

  • @brucethomas471
    @brucethomas471 Před 3 měsíci

    Anyone remember Ernie Shirley who had a rockshop in Hanksville? Shirley's Rocks and Indian Artifacts. I got some great Fremont pottery from him, and a few points. He passed about 2009, I think. He had some huge dino bones in the back, too, he showed me.

  • @fire_n_ice1984
    @fire_n_ice1984 Před 6 měsíci

    Looks like a fun little crag.

  • @TonyWeesner-ok2pp
    @TonyWeesner-ok2pp Před 6 měsíci

    Layers and waves , big part of a large part of a big picture

  • @QuaaludeCharlie
    @QuaaludeCharlie Před 6 měsíci +1

    It's so Pretty Shawn , One day it's all going to Blow .

  • @jackbelk8527
    @jackbelk8527 Před 6 měsíci

    Another good 'un, Shawn! I think the great unconformity is seen in the western half of Glenwood Canyon on I-70, also.

  • @jonviol
    @jonviol Před 2 měsíci +1

    The river did not cut the canyon as no erosional features are present . The land itself split open and separated which created a natural channel for the water.

  • @charlesward8196
    @charlesward8196 Před 6 měsíci

    Reminds me of the contact between the granitic core rocks of the Black Hills and the Cambrian Deadwood Sandstone in Reaves Gulch in Wind Cave National Park southeast of the “Pigtail Bridge” on Highway 87. Very coarse and pebbly bottom beds of weathered quartz unconformably on the pegmatites and schists.

  • @escapo6895
    @escapo6895 Před 6 měsíci

    One fun thing to think about is that in places like this where the Great Unconformity is exposed at the surface: presumably in time the top layers will be completely lost to erosion and we will end up with an even greater unconformity when the surface is buried again.

  • @richardwest9054
    @richardwest9054 Před 6 měsíci

    Shawn, have you ever been to the Sideling Hill road cut on I-70 in Maryland? It is huge for a road cut. Richard West

  • @paultodd3497
    @paultodd3497 Před 6 měsíci

    You can tell that the limestone and the material underneath with pebbles, was the river banks, before the uplift had accorded, did you dig up any samples of the pebbles, for gold ??

  • @ThePzrLdr
    @ThePzrLdr Před 6 měsíci

    The color banding, lighter/darker sedimentary layers remind me of soil cores taken to survey local ancient climates. Is that the same for the sedimentary layers, light = drier climate, dark = warmer climate?

  • @Mark_in_Boulder
    @Mark_in_Boulder Před 6 měsíci

    Nice video, brings back old memories. did you get to climb there? there are some 4-500 ft walls about 1/2 mile downstream, 2-3 pitches, which are really cool, but you can't go wrong climbing near the bridge.
    A question: Is the pink granite the same as you find in Vedauvoo, south-east of Lararmie off of I-80? it has really big crystals.
    Have a happy new year!

    • @shawnwillsey
      @shawnwillsey  Před 6 měsíci

      Yes, similar age and composition to Vedauvoo.

  • @2Goiz_1ShanDA
    @2Goiz_1ShanDA Před 6 měsíci

    ❤ sounds like you're doing unconformity.... I'll come back and watch this in a little bit, I bet it's good!

  • @candui-7
    @candui-7 Před 6 měsíci +1

    Love it Shawn! Can you tell from drill cores whether heavies are of natural erosional source vs artificial source? Nile delta cores 8-14 kya show a significant spike which, to my untrained eye, don't appear to be natural black sand deposits. Also. the population density along the Nile Valley goes from "normal" to zero at 14 kya. Repopulation happens after 7.5 kya at 5,500 years ago with the predynastics. My research is leading me toward looking at core samples from the mouth of the following rivers: Mississippi, Amazon, Boyne (Ireland), Thames, Seine, all of which have large complexes of neolithic architecture. Looks like they may have had a little more than copper and iron.

    • @candui-7
      @candui-7 Před 6 měsíci +1

      Let's not ignore the Tigris and Euphrates, Yangtze, Mekong etc.

    • @candui-7
      @candui-7 Před 6 měsíci

      Ps I flunked out of math and am a hammer swingin' carpenter.

    • @candui-7
      @candui-7 Před 6 měsíci

      On a here and now note, a multi-year gps chart for the Reykjanes Peninsula shows the dramatic tectonic shift that just happened over the past few months with the prior twelve years having a smooth and steady progression. More lava coming?

  • @geoffgeoff143
    @geoffgeoff143 Před 6 měsíci

    It was already gone when I got there.

  • @lauram9478
    @lauram9478 Před 6 měsíci

    ❤❤

  • @galenhaugh3158
    @galenhaugh3158 Před 26 dny

    Time passes with or without rocks.

  • @bobf.8403
    @bobf.8403 Před 6 měsíci

    Shawn, Very interesting video. I assumed the strata at stop 2 was Cambrian Flathead Fm. I would like to read the reference you mentioned where they think it is now Devonian. The white rocks are Madison Formation Limestones. They are across the road and up a little like you mentioned. The mapping does not show Precambrian rocks at Stop #2, so you might be on to something. I was hoping you were going to throw your climbing rope over the edge and then film from above so we can watch you execute your 5.9 moves.

    • @shawnwillsey
      @shawnwillsey  Před 6 měsíci

      Ha. I wish. This was a solo trip so no climbing at this spot (sadly).

    • @maryshouf3166
      @maryshouf3166 Před 6 měsíci

      The rocks at stop 2 look very much like the Cambrian Flathead Formation in the Teton Range. Basal layer of pebbly conglomerate and a purple layer.

  • @user-wk1mw9nj3i76
    @user-wk1mw9nj3i76 Před 6 měsíci

    I’m going to have to look up the Great Unconformity in some sources. “Grus” = be careful out there! TX!

  • @secularsunshine9036
    @secularsunshine9036 Před 6 měsíci

    So is this "Great unconformity" the floor of the inland sea? I'm also curious about the Red desert, where does it lay in comparison to the Great unconformity?

  • @gailgreen5012
    @gailgreen5012 Před 6 měsíci

    So interesting. Do you ever come upon snakes? And if so, which ones. Greetings from South Africa

    • @shawnwillsey
      @shawnwillsey  Před 6 měsíci

      Very rarely. I am often out in cooler weather.

  • @danoberste8146
    @danoberste8146 Před 6 měsíci

    The GREATER Unconformity!!!

  • @jimlebo5642
    @jimlebo5642 Před 6 měsíci

    just wondering when granite is considered basement rock, even though it must have intruded older rock

  • @stephenhudson8739
    @stephenhudson8739 Před 6 měsíci

    Is that part of the flaming gorge complex?

  • @larsblomberg4985
    @larsblomberg4985 Před 6 měsíci

    Gravel is called "grus" in Swedish, any connection?

  • @georgepeck9288
    @georgepeck9288 Před 6 měsíci

    Wouldn’t Free ont canyon’s steep sides In resistant rock imply it was formed by tectonic forces rather than erosion?

  • @3xHermes
    @3xHermes Před 2 měsíci

    👍

  • @raffyzoo2130
    @raffyzoo2130 Před 6 měsíci

    quarter inch pellets seem to be from a ball mill. expand on this please.

    • @jackbelk8527
      @jackbelk8527 Před 6 měsíci +1

      "Pea gravel" from stream erosion.

  • @wanttopreach
    @wanttopreach Před 6 měsíci

    This canyon was probably an old earthquake falt line!

  • @cliffterrell4876
    @cliffterrell4876 Před 6 měsíci

    Did the river actually cut this canyon or is the canyon a fault that a river utilized with the path of least resistance? The vertical walls without the common U or V erosion that occurs with water. With the fracturing, or possible faulting in the granite, could this be indicative for the presence of a fault? Looking at the strata layers, some shows possible uplifting.

  • @renicostareni2313
    @renicostareni2313 Před 6 měsíci

    🇺🇸🖍📗🔨Dear teacher Sham I've been watching many video from you where you give us so much pleaser to know more about Geology study out of classroom. You are very good MD. I do enjoy to hear from you❤; any time, everyday I can.🔨💚🖍📗🇺🇸

  • @Er-sv5tn
    @Er-sv5tn Před 6 měsíci

    You need a head/shoulder mount camera

  • @kadourimdou43
    @kadourimdou43 Před 6 měsíci

    Parts of that canyon, look like it could collapse at any moment.

  • @daleolson3506
    @daleolson3506 Před 6 měsíci

    I don’t think the water cut that. Maybe a fault line?

  • @cyndikarp3368
    @cyndikarp3368 Před 6 měsíci +1

    Some say Great Unconformity is from Snow Ball Earth. Do you agree? Nice pink granite at contact with unconformity.

    • @candui-7
      @candui-7 Před 6 měsíci +3

      Glacial till found at the GU around the world strongly supports the hypothesis.

  • @katz4dancing
    @katz4dancing Před 6 měsíci

    First shot on second stop looks like face in lower frame.
    6:28 looks like giant feet

  • @Tugela60
    @Tugela60 Před 6 měsíci

    Have they cracked the case and arrested the thieves yet?

  • @RealLifeProduct
    @RealLifeProduct Před 6 měsíci

    Get ready for another Iceland update.

  • @CSGATI
    @CSGATI Před 6 měsíci

    Something hit and formed the moon maybe that erased some history.

  • @surters
    @surters Před 6 měsíci

    Now don't fall down while filming :)

  • @Riverguide33
    @Riverguide33 Před 6 měsíci

    👍