CWU's Nick Zentner returns to Marengo with author/geologist Bruce Bjornstad to learn more about pre-Wisconsin Ice Age Floods. Marengo exposure: goo.gl/maps/pJsA5wbmJrkvRvRJ7 Skye Cooley video from Marengo: • Pre-Missoula Ice Age L...
love this stuff...I'm a Chicago native that moved to Idaho in 2019 and have fallen in love with this country and the Pacific Northwest as a whole...Nick has taught me so much about this whole area and I just can't get enough of it. Thank you Nick for enriching my life
Zactly same here, still in Chicago. Nick if you ever visit, i would love to host you at a fabulous chicago steak house and a trip to the Field Museum of Natural history rock collection and display. I know you’ve seen a lot but i believe you would be impressed by this cow towns collection from all over the world.
Thanks for the virtual field trip. As a retired geologist I don't get out as much as I used to. Thanks too for pointing out just how complex earth processes can be and why our knowledge is so incomplete. There's always more questions than answers and too few people working in these various fields of quaternary geology and climate change. Jokingly we always ended our field excursions by saying, "more work needs to be done." ☺ Glad to see more work being done.
I am speechless on being able to describe what my mind is trying to picture. I want more of the story and you are giving it every time I tune in. I have never been more interested in something all of my life. You’ve got all my attention, Professor thank you again.
Awesome! Geology is being a detective investigating the scene, collecting evidence samples, interpreting the test results and piecing together what happened.
Glad to see Bruce on the channel. I've been a fan for years. His books on the Ice Age Floods clear up much of the mystery and are indispensable to anyone interested in this topic.
The milwaukee Rail Road western expansion was completed in 1909. That cut would have been done between 1906 and 1909 unless a regional RR was already going through there.
SO excited to watch this video, but I must write this first! Bruce's work on Ice Age Flood geology, along with his tribute to Tom Foster, are wonderful. I've been working on my own presentation, combining the I.A. Floods with my field of work, and I return to Bruce's videos over and over again. While I intended for my first presentation to happen in Miami last month...I had to put that on hold while I travel this Spokane flood work with you (and Bretz), Nick. So maybe next August in Miami, lol. It's all good because this adventure and this work has brought me such purpose. I owe much to you and Bruce - thank you!
Love this. I have all three books, but the field guides were useful when I was out there in 2022, and Bruce's drone videos are gorgeous. Almost as much as Nick himself, Bruce's videos are what hooked me on this stuff. Then, after seeing much of the country from ground level in 2022, the aerial viewpoint makes a huge difference in appreciating the overall story. I've gone back to watch several of the videos multiple times after seeing things from ground level.
Amazing!! All the years of my growing up I just wondered at those layers and assumed the top was “recent”. I love that country❤ Thank you, both for all the stories and knowledge.
Thank you, Bruce Bjorstad and Nick Zentner for the excellent job of bringing these great flood stories to the public eye, in an interesting and engaging manner! Rip up class of Loess in the 780,000 year old deposit? If I’m understanding this correctly, probably not from very far away? Violently tearing through the loess layer creating the many nearby loess islands. In a very ancient huge flood!
There is a cut just south of this one, 1911 a year after the line was completed there was a fatal crash. The curve is very tight and was relocated to its present location…I would imagine it was done soon after that wreck. Love the videos!!
Well, that was surprising, and I'm glad you spoke for us, Nick, wondering how loess could give paleomagnetic data. And Bruce, for explaining differences from basalt paleo findings. Reverse polarity, even. We go ever finer in our understandings. This is great. Plus, it's really fun to see you out together. 😁
Excellent outing and truly valuable information. It’s remarkable, too, how much Bruce sounds like Steve Smith on “The Red Green Show”. I keep waiting for the punchlines! (Red Green Show episodes are available on RU-vid if you haven’t already experienced Bruce’s alter ego at The Possum Lodge).
Excellent video! The age and magnetic reversals just blew me away. Bruce is a nice guy, too. Y'all make a good pair, or add Skye and y'all would make a good trio. 😀
We have used both of Bruce’s excellent Guides to find and hike the trails of the Ice Age Floods over the last three years. Highly recommend his books including the Floodscapes photo book. So much knowledge packed into all of these. Thank you for this video exploring the older ages with Bruce. As Bruce said, no one was much interested in the older deposits until recently…..that’s you Nick. Thank you.
This is so interesting. Looking at recent glacial outburst flooding I can see where glaciers would leave their mark on the landscape far beyond their borders. With ice sheets that are miles thick the scablands would seem to be natural drainage from those ice sheets. Probably they channeled the outburst floods from the retreating ice sheets. It’s pretty cool that the loess preserved the flood evidence beneath them.
I was a pre-internet geology student at the University of Oklahoma and pretty much had to trust their 'twang' as the way it was pronounced. This worked fairly well for a few common terms. I learned "loess" being pronounced "less", which had its share of memes, or "lōs" which generated its own, but I don't remember having heard of it pronounced as "loss." Not complaining -- I'd bet the competition to decide who is pronouncing it correctly is as controversial and heated as downgrading Pluto. But the one that they CAN'T take away ... "Geologists are gneiss people."
I think we need a topographical map of the surface of what old flood deposits we have. How much lower was the landscape for ~million-year-old floods versus the later ones?
Greatly informative visit guys along the former Milwaukee Road railroad now the state owned public John Wayne Pioneer Trail. I've read that the railroad completed this line in 1909 well before Bretz came here. On that note however there may have been areas that were improved later ( via cuts and fills) to make some elevation changes to improve speed and travel time . I got to get that third book!
..another great video, part of an entirely fine bit of natural history lessons online; with captions, and gifts of knowledge, too!🌞 ~ from Kenai Mts Alaska
Good to hear the talk and see the subject. Could do with seeing the spelling of and some explantion of the words used. Did find things to do in Luss Loch Lomand which was a new experience. Eventually found loess and pleistocene 2.5 million - 12000 yrs ago. Is 12000 yrs ago the Younger Dryas? Younger Dryas seems to be a period from warm to cold and back to warm. Dryas. Rosaceae is a plant. Thanks for making and showing the video with Mr Bjornstad.
Wow! Thanks Nick and Bruce. So those Marengo gravels as 1 million or more years old and are older than the "recent" ice age floods that Bretz was thinking about. And I have some new books to order.
Gravel at base of exposure grades upward into silt-pebble diamict, then into wind-deposited silt. The overlying calcrete ledge is developed into the silt. I disagree with my friend Bruce's 'bioturbation' interpretation for the diamict. There are cobbles in there too large for beetles, ants, and gophers to move. Gradational contact with gravel below. Clear, abrupt contact with loess at top. Clearly a water-transported unit. Diamict is a thing, especially in pre-Wisconsin deposits. Great video!
Delighted to see you are right back on the old-flood story, how do you differentiate between unsorted flood deposits and unsorted glacial till? The ripped-up clod of loess is a genius method, Mr. Bjornstad can really read a road cut and make it tell a story! Does Bretz make those kinds of distinctions way back then? Utterly fascinating, thank you!
Bruce I think you left your trowel at the site. I left it standing next to a bioturbated tube that appeared to have ash inside. Also crazy as this sounds I found what looks like Ringold formation/sand hills deposits over the top on the SW side of the hill on private property.
So, hmm; the magnetite PM can be effectively measured from single magnetite grains 1-10-µm after they’ve been liberated from their previous igneous rock source? Like a compass needle always pointing to magnetic North. How loose does the matrix have to be to enable the grain adjustment before it gets locked in?
I don’t understand how the wind or water borne magnetite grains in loess can be constrained upon deposition to indicate ANYTHING magnetic. Loess should be magnetically amorphous.
Same way you can sprinkle or toss handfuls of powdered magnetite or just plain iron filings , close by a magnet , and , the majority of them would align with the magnetic field lines of the magnet . Try it with a mix of sand and iron particles , and see if that changes , in any fundamental way , how the iron reacts to the magnetic fields . Many processes are easy to study and to reproduce experimentally , and , humans have been studying magnetism for a very long time , even before we had the common language of mathematics to describe and quantify the phenomenon . you could then do the same with a wet powder or slurry , to see if the same mechanism is affected by water .
Hmmm. Okay. I was stuck on the magnetic alignment created upon cooling of the magma source. Upon further thought, the mag signature sought is for the earth’s polarity at the time the loess matrix set, not paleomag orientation. Thanks for the help.
Wow - that was fascinating! Thank you Nick and Bruce for the awesome field trip. Now I want to know if Bruce (or others) have done paleomag samples for any other Columbia Plateau areas. I find myself wondering, for instance, about the potential loess deposits that were on elevations untouched by either glaciation or flooding on the upper Grande Ronde basalts above Malaga on top of Jumpoff ridge and then going south along the west side of the Columbia towards Vantage. Also I am wondering how much testing and what type of testing was done on the deposits at the Horse Lake road site in back of Wenatchee. I can see there will be a LOT more reading in my future this fall, LOL!!!
Nerd alert, Bruce is wearing the Ray-Ban 2016 Daddy-O sunglasses. I am a former optician and literally sold 2-3 hundred of them. Great frame for prescription eyewear.
The line "nobody questioned the work we did" has me sort of concerned. Its been decades since my last college science course, but I'm pretty sure questioning everything is part of the process.
Yes. I was impressed. Glad he explained it’s the magnetite particles in the silt. As it settles in still water, they must tend to orient with the earth’s magnetic field. I understand the particle alignment with the inclination of the local magnetic field (just like happens with non-magnetized iron filings dropping on a sheet of paper with a magnet underneath, but in 3 dimensions), but I thought some residual magnetism of the particles would make it easy to detect which direction is magnetic north vs south. Maybe inclination reveals it by different inclination depending on which pole is magnetic north
I stayed at a Holiday Inn once. But how does an ice age end or melt? A word you used long ago uniformitarianism (WOW), we are seeing glaciers melt all over the world. I once watched at video on an ice dam break, during spring melt the power to move so much mass was there in a smaller scale. Also watched a glacier melt in Ice land from volcanic activity. What we need is an expert on hydrology from melting ice. Pictures of run off from glaciers in Alaska rivers that ebb and flow change channels and erode new channels, Uniformitarianism? thank you stay safe ALL
Railroads often needed a relative distance for mileposts marking their right of way. Chicago was the starting point in the very beginning of the Milwaukee Road's start. The mainline originally ended at Mobridge , SD at the Missouri River but other railroads they were in competition with demanded the railroad expand west too.
