Flash flood deposits and other geologic treats in Death Valley: Mosaic and Stretched Pebble Canyons

[@shawnwillsey]

You can support my field videos by going here. Thanks! www.paypal.com/donate/?hosted_button_id=EWUSLG3GBS5W8

[@channarosenblatt8197]

Stunning video. You take us to stone that is 750 million years old. I have never, knowingly, touched anything that old. Your knowledge is fantastic. Thank you for sharing it with us.

[@piotrrajmundkoprowski4732]

Sir, this one as well your previously posted movies have such a beautifull narrative. Storytelling about rocks. Amazing.

[@mjinba07]

Just want to say how much I enjoy and learn from your videos. I've been fascinated with rocks and geology since I was a kid but made my career in another field. Your presentations, so clear and accessible for a lay person, have answered so many of my questions and taught me a boatload. The channel is one of my best subscriptions.

[@shawnwillsey]

Wow, thanks! I appreciate your kind remarks. Thanks for watching and learning with me.

[@jayprice4543]

I camped with my wife (also a geologist and a fan of yours) at Stove Pipe Wells and Furnace Creek over the holiday (2023). Among other things, we hiked the entire Mosaic Canyon. It's our third visit there. We are fellow Idahoans (Rexb). We really appreciate your videos.

[@shawnwillsey]

Awesome. DV is amazing. I did a video or two in mosaic canyon back when I started this stuff in 2020.

[@AvanaVana]

Another awesome locale and story. When I saw the Noonday Dolomite early in the video I was hoping you’d also get into the Kingston Peak Diamictite and mention snowball earth, and you did not disappoint. One interesting thing to mention regarding the Noonday dolomite, however, is that it represents a classic example of a Snowball Earth terminal “cap carbonate”, which is a layer of carbonate found all around the world that “caps” or rests on top of each snowball earth episode’s last glacial deposits. The reason they form and their peculiarities are fascinating-the idea is that preceding each snowball earth event, carbon dioxide levels collapsed, and the thick ice sheets covered the world either completely, or at least to near-equatorial, sub-30° latitude levels, including thick amounts of sea ice. World sea levels dropped precipitously, far, far more than the 100m or so associated with our last glacial maximum, due to the amount of ice and water locked up therein. Volcanism around the world, including submarine volcanism at arcs and spreading ridges, was covered by this ice. Prior to the Cambrian explosion (and of course humans and their exploitation of fossil fuels), volcanism was the major source of carbon dioxide. These volcanoes continued to pump out carbon dioxide, and it gradually built up in the atmosphere. Because of the ice sheets ubiquity and thickness, continental weathering, sediment input, and global weather patterns would have been essentially shut down at the height of the snowball earth, and the atmospheric CO2 reservoir separated from the ocean. Freshwater melt from the warm base of congenital glaciers meeting the sea (the weight of thick continental glaciers alone is thought to generate heat at their bases) seeped into the oceans with a minimum of sediment bedload. As a result, the oceans became severely stratified, with the top 800m or so consisting of freshwater, floating on denser salt water. As the atmospheric CO2, with no way to cycle back into the ocean, due to a lack of weather patterns caused by the homogenous ice cover and lack of available moisture, continued to collect in the atmosphere, the greenhouse effect started to become very pronounced, causing extremely rapid deglaciation, and along with it, rapid weathering of the continents, overturn of the stratified ocean, massive sediment influx (including dissolved calcium, magnesium, and other salts), and extremely severe weather patterns, and a drawdown of atmospheric CO2 surplus in the form of carbonic acid from the resulting storms, washed into the global ocean, which would have rapidly flooded the continents once again after deglaciation. All of these things created the perfect conditions for the rapid deposition of carbonates on top of the last snowball-era glacial deposits, the cap carbonates. And the wild weather patterns and peculiarities of the situation result in some very characteristic depositional features in the carbonates, including giant amplitude wave ripples from storms that were more severe than we have ever known. There are also microbial structures associated with them, and the end-snowball conditions of high levels of CO2 and nutrient influx from weathering during initial deglaciation would have been a boon to surviving Cyanobacteria, who found virgin habitat with little competition in the shallowly-flooded, nutrient-rich warm seas of the post snowball world. So that is the fantastic and interesting story behind cap carbonates, like the Noonday dolomite. These are found worldwide directly above nearly every last snowball glacial deposit, for each snowball event, and are considered diagnostic as to whether a specific record of glaciation was “snowball” in its extent, because cap carbonates are not associated with the other more regional glaciations of the Precambrian and Paleozoic. Regarding the cemented debris flows…they are truly stunning. I’ve read that in some conditions they can become cemented like that I just a few years after deposition, and at most it takes only 10-20 years. Crazy. It makes me wonder what paleo debris flows in the geologic record are a result of such continual scour and fill processes, cross cutting from different channel directions and filling with slightly differently-sourced clasts. I can’t personally think of a paleo deposit like this. Perhaps none of them last long enough to be preserved, although an extensional environment, of such low elevation, and relative proximity to the ocean could easily become inundated with epicontinental/pericontinental seas… What I don’t understand at all are those vertical beds. First of all, debris flows rarely show bedding of any kind. Secondly, I don’t understand how that bed could become so tilted as a single mass and then have a perfectly smooth contact with the surround rock. It’s one thing if a big chunk of rock falls off and turns 90°, but such a giant boulder doesn’t remain contiguous with the rest of the outcrop. Have the interstitial spaces been subsequently filled with additional debris flows/flood deposits that I just didn’t notice as lacking the (sub)vertical bedding? Because to me it looked like the bedding went all the way to the contacts on either side. Truly confounding. When I first saw it my thought was that the whole block underwent rotation, with the dolomite, due to listric fault movement. But if that were the case it would have to be much older than it probably is. Still don’t understand where the bedding comes from, unless it was just a collection of several more minor flood deposits. It looks very different from the chaotic rubble of the debris flows shown earlier. Glazner’s Geology Underfoot guide also says they were moved as coherent blocks during flooding events. I didn’t notice whether the dolomite had original bedding, will have to watch again. And again, I wasn’t able to make out if the “gaps” that would have been created by such megabreccia lodged in an irregular slot canyon, which should have then be filled later by sub-horizontal flood and debris flow deposits. Again, great video, iconic outcrop, and thanks for taking the walk to the Kingston Peak snowball earth diamictite!

[@nisawallace5903]

Wow! A mini geology story inside another geology story! It is fascinating how geologists can look at the earth and read these events but they still find mysterious things they can't explain.

[@JoeZorzin]

@@nisawallace5903 These brilliant explanations add greatly to my aesthetic appreciation of land forms- kinda like looking at a great sculpture and learning how the sculptor made it.

[@nisawallace5903]

@@JoeZorzin Oh,yes,I agree,so beautiful and fascinating.

[@nicknichols3810]

Great video, Shawn. Mosaic canyon is one of my favorite spots in DV. Have been several times and always wondered about the geologic story behind it.

[@edwardhanson3664]

I hiked down Mosaic Canyon in 1970 as part of a geology field trip from Chaffey College. It was a fantastic trip.

[@ronjlwhite8058]

Cool story indeed...natural fault shifts and flood layering...EPIC!!!

[@granitfog]

The laying and patchwork like adhesions display such drama from the floods. Nice.

[@voixdelaraison593]

Love your channel

[@shawnwillsey]

Thank you.

[@billrey8221]

Great video! I would like to hear someone put our "Global warming event" into a perspective history of Earths climate over 4600 million years. LIPs, Celestial events, when oxygen was a poisonous gas and we just hit 8 billion people on earth. Thanks for posting!!

[@davedavis5809]

Don't make this man get black balled LOL if you've studied geology you know what the textbooks say and they may have been upgraded since then I don't know but or or (taken liberties with) I should say. Haaaa

[@AvanaVana]

If you have any knowledge of paleoclimate, you would recognize that our current “global warming event” is absolutely unparalleled in earth history, in terms of timescale. Yes, the earth has undergone many, many climate changes and disasters of all kinds, but none so rapid as post industrial anthropogenic climate change.

[@craigf2696]

@@AvanaVana If you had any knowledge of paleoclimatology you would know Co2 rises FOLLOWING warming periods. Furthermore, volcanism releases a minimum of 15 times that of human activity.

[@AvanaVana]

@@craigf2696 That’s right, volcanic events in geologic history have had terrible effects on global climate and have caused mass extinctions. Not typical background volcanism, which has had billions of years to equilibrate with the earth system and the biosphere, but events like the eruption of LIPs/SLIPs and VEI 8+ Plinian eruptions, which distribute aerosolized sulfur dioxide around the world by penetrating the stratosphere. The reason such events have this negative effect on the earth system is because of the high rate at which volatiles are released. As I mentioned, it is the high rate of change in anthropogenic emissions which likewise is having an adverse effect upon the earth system today. The rate is important because the earth system does not have time to equilibrate-diffusion and cycling in the world ocean, for example occurs at timescales that are too slow. For an introduction to paleoclimatology, I’d recommend Michael Bender’s fantastic “Paleoclimate” (Princeton University Press Primers in Climate #10). It’s fairly easy to follow. You may also be interested in thousands of videos, including hundreds on paleoclimate, that I have collected and curated on The Earth Science Online Database (esovdb [dot] org).

[@AvanaVana]

@@craigf2696 I should add that the biggest problem with climate change isn’t even necessarily whether it’s anthropogenic or not (spoiler: it is, in large part). It is actually that human civilization has shot itself in the foot by yoking itself to systems which are inherently unstable, regions and ecological zones which put human civilization directly in danger, and it relies on resources that are equally capable of collapsing under stress. For example: greening the desert, the agricultural intake of water resources, building large amounts of populated cities near the coast, inhabiting lowland areas, hundreds of millions of people inhabiting the immediate vicinity of the 16 USGS-designated “decade volcanoes”, which have high likelihood of erupting in the next 10 years and causing mass casualty events and economic carnage, overfishing, ocean acidification, etc. It does matter that climate change is made much worse by anthropogenic effects, but the real problem is man-made brittleness in the backbone of its civilization,e dependency on global supply chains, overpopulation, and lack of self sufficiency. These are the things that will decimate human civilization, regardless of what causes climate change in the future.

[@akowboyshippielife7405]

Much love to everyone and their families from Quartzsite Arizona USA currently!🤠🌻

[@jonadams8841]

Love the contrast of the dolostone against the mud/siltstone.

[@hunt4redoctober628]

Another really fascinating video again. Thanks Shawn.

[@robmcelwee389]

Love your vids. I live in geological boring Louisiana and ypur vids show me what I'm missing. Hope you do one on Florissant Colorado Leaf and trees fossils and the extinct volcanos there.

[@toughenupfluffy7294]

No, Louisiana has the Mississippi and the Atchafalaya, which are two of the most interesting rivers in the world, as they form the classic bird's foot delta. The Army Corps of Engineers has essentially made the Mississippi Delta an ongoing experiment in alluvial sedimentation, by building dams and levees which have altered the course of both the Atchafalaya and the Mississippi over the past 90 or so years. If you're a fluvial morphologist, Louisiana is the place to study big aggrading river movements.

[@stevewhalen6973]

Beautiful mineralogy in Death Valley.

[@richardcarter7643]

Thanks!

[@dennisdye7270]

Very interesting! Thanks for putting these stories together.

[@briandwi2504]

Amazing landscape, thanks for sharing.

[@MarcoPollo77]

Very nice find! Thanks for sharing this with fellow rock hounds.

[@shawnwillsey]

You bet!

[@3xHermes]

Great story and video! Thx!

[@GregInEastTennessee]

I hope you had a great Thanksgiving. I, and I'm sure all your viewers, are thankful for what you do. Be safe and be well.

[@shawnwillsey]

Thanks Greg. We had a great day. Hope you did as well. Thanks to you and all the viewers who like my chaotic videos.

[@gaames]

Fascinating and nicely presented.

[@Yojimbonh]

Very interesting again. Thanks for posting.

[@Rachel.4644]

They are really excellent examples, the layers of flows full of interesting materials in Mosaic canyon. Beautiful. As well as the diamictite (new word). Love these! ❤️

[@jdean1851]

GREAT VIDEO" Thanks" 4 Posting!

[@toughenupfluffy7294]

At the very end Dr. Willsey shows a conjugate fault, which is essentially two faults crossing each other at angles of ~120° and ~60° (two of these make a total of 360°). The earlier fault at 6:04 is also a set of conjugate faults, even better delineated.

[@bravendyer9529]

Thanks 😊

[@ryder6070]

Really nice work, excellent.

[@justjay4412]

Really cool. Thank you.

[@MountainFisher]

I used to go to Death Valley in the 1970s quite a bit. Interesting place. What is remarkable is that the valley floor keeps sinking to keep up with the sediments that get washed off into it. So it doesn't fill up with sediments. Devil's Golf Course is a few thousand meters of salt from years of salt deposition and it sinks and if I recall is several thousands of feet deep.

[@toughenupfluffy7294]

Death Valley is also sinking due to the extension of the North American plate where it crossed the East Pacific rise starting about 30 million years ago. The East Pacific rise is a place where two plates are spreading apart, and when North America plowed over it, it continued to spread, although now underneath the continental plate. This spreading also caused the Pacific Northwest to rotate about 13° clockwise, which is why the ancient calderas that used to be Yellowstone are farther north than when they erupted. Nick Zentner at Central Washington University is a great source for geologic info on the PNW.

[@hunglo666]

well done on the 10K sir , i learn allot from your vids , thanks

[@austynross]

It just struck me that now would probably be indeed the best time to visit Death Valley

[@leechild4655]

Its funny now you can look for some really remote place, go there and find someones youtube address spray painted to a rock on the ground.

[@MountainFisher]

@@leechild4655 If you drive down old Route 66 in the desert people spell their names out with rocks. Some have lasted a few decades.

[@STHFGDBY]

In Ireland scientists / geologists, examined granite rocks found in coastal areas around Ireland, some big, some the size of a closed fist. They discovered that these rocks did not originate in Ireland but came from Scotland where they originate , and they came here during the ice age carried by glaciers and were eventually deposited in Ireland, hundreds of miles from Scotland.

[@jonadams8841]

Mostly mudstones and siltstones, lots of alluvial stuff, I did canyoneering there in November. Would love to see some flash flooding (from a distance) just to see erosion in action. I was over in the northern end of the Black range, about halfway between Furnace Creek and Dante’s View. Mosaic is over west of telescope peak, so the dolostone would help with supporting the mass of the 11k mountain!😀

[@Helix-ge1ld]

Cool

[@Qingeaton]

We own 11 acres of land in mid Missouri. During projects like digging a small pond and when walking the mud bottom run off creeks, we find some widely varying rock. Is there a general way to maybe "look north" at the stone types and see if we can find the source of them?

[@mawi1172]

❤️❤️❤️❤️

[@jonadams8841]

Is most of that faulting extensional? Seems like small displacements dip-slip stuff.

[@shawnwillsey]

Yes, nearly all extensional (some high angle, some low angle).

[@jonadams8841]

So is a diamictite (new term to me) a rock that has been completely or nearly completely altered only via pressure and minor heating?

[@shawnwillsey]

Diamictite is a very poorly sorted clastic sedimentary rock. Think of the rock equivalent of glacial till.

[@jonadams8841]

@@shawnwillsey didn’t you point out that rocks were deformed in the diamictite? If so, wouldn’t that require pressure or temp?

[@tihspidtherekciltilc5469]

The creek behind my childhood house has clumps of what I thought was concrete with creek gravel from someone upstream but now I know it isn't. I've seen this type of stone was up after storms along the coast of North Carolina where I lived for 30 years which locals call "reef stone" or something else I've forgotten but I collected a bunch of it and made a walkway and a dry stone wall meaning no cement which black widow spiders seemed to love.

[@markclark4154]

Well done on reaching 10 K. 22/12/22

[@shawnwillsey]

Thanks! Crazy how quick this has grown. Thanks for being part of it.

[@toughenupfluffy7294]

Shawn, your videos are great. Just a viewer's suggestion: I'd use a lavalier microphone so the volume of your voice doesn't change when you look away from the camera.

[@shawnwillsey]

Good idea. Working on improving.

[@lauram9478]

❤

[@Yetibiker67]

👏👏🙏🏼

[@hfdole]

Were you just there? I heard all the roads were destroyed by flash floods.

[@shawnwillsey]

No this was fall 2020

[@hime273]

Why did they put gravel on the bottom?

[@JoeZorzin]

to make it easy for hikers 😃

[@mikeashely8198]

I don't know if you've been to titus canyon there

[@shawnwillsey]

kzbin.info/www/bejne/hZ6XpIavbpuXd5I

[@neilrusling3438]

I am just green with envy! You are so lucky to live in a country that has great warm dry weather that keeps that nasty horrible green growing plant stuff in check making sure the beautiful geology gets to be seen. Round my way I cant ever see the geology for the trees and other awful plants, even road cuttings are buried under feet of despicable green spreading nastiness.

[@johnknapp952]

So at ~3:44 in the video no one saw what to me looks like a giant Mole face?

[@toughenupfluffy7294]

Kangaroo rat.

[@channarosenblatt8197]

It IS a mole face. Awesome. Thank you for noticing and for posting it here.

[@jt21419]

Drawing a stratigraphic column of such a convoluted geology must be very frustrating.

[@kmacdowe]

kzbin.info/www/bejne/eIrblpuiltOYp7s would those beds represent periods of great dryness, a time when those sediments could lithify? Great vids, great work, thank you.

[@shawnwillsey]

Thanks for your kind comments and question. The main control on lithification is the calcite and dolomite cement which is soluble. So when the debris flows occurs, the water dissolves calcite and dolomite from the surrounding rocks. When the debris flow comes to rest, the water evaporates and these minerals form the cement that binds the particles together, forming rock. The aridity of the climate probably plays a small role.

[@kman7169]

So wait a moment , what your saying is the washing out actually adds to the debris of the canyon ? Kinda makes the term washout irrelevent . If any one knew how water behaves it it more or less has a covalent bond that wants to flow , not bog down scouring . Floats around objects , except for the initial rush of water carrying the finer debris has a potentiaal for erosion . But as for water itself does not erode unless highly acidic . Have a nice day !

[@arionerron4273]

any water mass can both erode and deposit, depending on the ammount and the speed it moves at. flash floods are short lived. once they run out of energy they deposit the material they carried with them on the canyon floor, so the debris *is* being washed out, it just happens over the course of multiple floods

[@toughenupfluffy7294]

Viewing any long profile of any significant river system will show you that water is trying to flatten everything out due to gravity, making the high spots lower by erosion and making the low spots higher by aggradation.

[@channarosenblatt8197]

Thanks!

[@shawnwillsey]

Thank you!

[@stevewhalen6973]

Thanks!

[@stevewhalen6973]

Thanks!

[@bravendyer9529]

Thanks!

[@shawnwillsey]

Many thanks!