Snowball Earth

Through many posts we have talked about the Great Unconformity (yes, you must capitalize it) and how it occurs worldwide in different rock sections. Why? Scientists believe that at several times in Earth’s history the planet was buried in a blanket of ice. Oceans were nearly frozen. This is what scientists call Snowball Earth, or sometimes Slushball Earth.

The last occurred sometime before 650 million years ago, during the aptly named Cryogenian period. In 200 million years, uplift and the giant erosive conveyor belts of ice eroded continents down to the roots of the ancient mountains and left the land at sea level. Think the Canadian Shield. This scraped bare land is the base of the Great Unconformity. As the glaciers melted, sea level rose and covered the land and deposition of sedimentary layers began. Variations of this happened worldwide. We can focus on the North American continent which looked much different at that time. Forget anything west of Idaho or so. It wasn’t there yet.

Wyoming Geologist Myron Cook does a much better job than I could of explaining Snowball Earth, the Great Unconformity, and why different gaps, between hundreds of millions to billions of years of time, exist across what was North America at the time in his great video published only 11 days ago. Throw in a master-class in Deep Time, and you have it all put together as only a master story teller can. And there are lots of rocks, yay! Watch this wonderful video. Yes, it’s long, but you’ll absolutely hate yourself if you don’t get to see the Mineral Fork Tillite and how the story ends. Trust me.

https://youtu.be/LXzDfQyUlLg

Follow it up with further findings on Snowball earth using thermochronology by Kalin T. McDannell, et. al. including our own @brenhinkeller as they work to help determine if glaciation or the recent hypotheses of tectonic influence had more impact on denudation of the continent. Spoiler alert: read the title of this post again.

https://www.pnas.org/doi/full/10.1073/pnas.2118682119

Another version here: https://eos.org/articles/erasing-a-billion-years-of-geologic-time-across-the-globe

Pinging @BoxcarMurphy who probably knows all about this already :)

#SnowballEarth #SlushballEarth #Glaciation #Cryogenian #TheGreatUnconformity #NorthAmericanContinent #DeepTime #MyronCook #HowSnowballEarthLeveledTheContinentsAndCreatedTheGreatUnconformity #WatchTheDamnVideo #geology #ScienceMastodon @geology

Heart Mountain, Wyoming Revisited

Heart Mountain, a 8,123 feet high peak, is composed of dolomite,limestone and volcanic rocks formed several hundred million years ago, and is lying atop, and surrounded by, younger rocks formed around 55 million years ago. Older rocks atop younger rocks rarely happen, but do occur in geologic features such as igneous intrusions into older rock, recumbent folds, thrust faults, detachment faults, and -spoiler alert- landslides.

But how exactly this mass of older rocks, part of a much larger mass of rocks, managed to overcome gravity and slide 28 miles in under 30 minutes became the controversy of its day. Turns out, Wyoming geologist Myron Cook has the answer due to tons of work by hundreds of geologists, and it is a much larger story than just Heart Mountain. The link below is to his fascinating, but very long video on the Heart Mountain Detachment fault and landslide. I encourage you to watch it, but have recapped it below.

The first image, a Google Earth map below, shows the area of Wyoming near Cody where the landslide occurred. The arrows point to two volcanic systems, even larger than Yellowstone, that lay northwest (map looking to the southeast towards Heart Mountain, small green dot) that existed around 50 million years ago. These stratovolcanoes were 20,000 feet high above the Bighorn basin, and the magma fed up dikes through the hundreds of millions year-old sedimentary rocks.

These volcanoes were explosive and the earthquakes they generated were enough to “rattle things around” and crack open a detachment fault along a bedding plane of the Bighorn Dolomite. Recent research suggests the detachment was caused by collapse of one of the volcanic flanks. Nevertheless, the red outline shows the area of the Heart Mountain detachment/ landslide zone along which about 20 miles by 30 miles of 800 + feet of sedimentary rock topped with (maybe) thousands of feet of volcanic deposits that slid catastrophically, very quickly, and all at once.

The second image shows the detachment fault, a hairline thin contact in the dolomite (carbonate rock) with a very shallow dip of only 2%, just feet above a shale horizon. Once movement was initiated, the mass began to slide. The heat from the friction extracted and superheated CO2 gases buoying the rock. The shallow slope became “frictionless” and in areas there is no deformation of the underlying base.

The slide caused the mass of rock to break into blocks, some have estimated over 100 blocks slid during the slide at a speed well over 100mph. The directions of the sliding bifurcated, (image 3) and some blocks slid towards where Heart Mountain stands now, and some slid more southerly where other blocks now lie.

The last image (4) shows something startling - if you drilled through Heart Mountain down into Bighorn Basin, you would reach Bighorn dolomite again 15,000 feet down, and mirroring the stratigraphy of Heart mountain. This is because between 75 and 50 million years ago, a period of mountain-building called the Laramide Orogeny caused uplift of the area the detachment formed in, and subsidence of the Bighorn basin. The Bighorn basin filled with thousands of feet of newer sedimentary rock including the 55 millon year-old Willwood formation on which Heart Mountain lies.

Learn how Supervolcanoes caused the World’s Largest Landslide in Wyoming by Myron Cook: https://youtu.be/CYS3r3tk2GI

Here is some more technical information for those so inclined: http://faculty.mnsu.edu/stevenlosh/research/block-sliding-heart-mountain-detachment-wyoming/

And more recent info here: https://www.researchgate.net/publication/254617445_Recent_Contributions_to_the_Understanding_of_the_Heart_Mountain_Detachment

Pinging @BoxcarMurphy again. Sorry Boxcar!

#HeartMountainDetachment #HeartMountainLandslide #DetachmentFault #Landslide #BighornBasin #BighornDolomite #WyomingGeology #RecommendWatchingTheVideo #LearnHowSupervolcanoesCausedTheWorldsLargestLandslideInWyoming #MyronCook #Geology #ScienceMastodon @geology

As Southwest CEO Bob Jordan pretends to apologize—remember—SW got a $7B federal bailout, spent $5.6B of that on Stock Buybacks, gave their CEO a raise to $9.1M, & forced frontline workers into 16 hour shifts under threat of termination—while spending $0 updating SW software😳

Southwest’s debacle isn’t an accident. It’s the predictable result of billionaire & corporate corruption & greed—& thousands of workers & travelers are paying the price.

In a just world SW execs will face criminal charges.

He talked about electric cars. I don't know anything about cars, so when people said he was a genius I figured he must be a genius.

Then he talked about rockets. I don't know anything about rockets, so when people said he was a genius I figured he must be a genius.

Now he talks about software. I happen to know a lot about software & Elon Musk is saying the stupidest shit I've ever heard anyone say, so when people say he's a genius I figure I should stay the hell away from his cars and rockets.

I cannot say this more clearly: Clarence Thomas should not be trusted to rule impartially on any cases involving Trump's attempted coup.

His wife Ginni Thomas was directly involved in efforts to overturn the 2020 election.

Conflict of interest much???

Guess how many Ford Pintos caught fire before they were recalled?

38 (27 deaths)

https://washingtonpost.com/archive/business/1978/05/09/fire-hazard-seen-in-2-million-pintos/98828a08-62e1-4847-a0f8-ffb5d4f4e34d/

Guess how many Teslas have caught fire? 144 (44 deaths)
https://tesla-fire.com

#Tesla

No mention of the DNC & RNC pipe bombs in the Jan 6 panel’s final report

No mention of disabled panic buttons

No mention of Pence’s disabled access cards

No ethics referral for Greene, Boebert, Gaetz

No criminal referral for Ginni Thomas

Jack Smith, America is counting on you