Best evidence yet that "Snowball Earth" saw ice cover the entire globe

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</span><a href="/history/palaeontology/">Palaeontology</a></p></nav> <section class="article-container cols-4 md-cols-1 cols-gap-1 padding-bottom-4"> <article class="col col-span-3 post-315846 post type-post status-publish format-standard has-post-thumbnail hentry category-palaeontology category-chemistry category-earth category-earth-sciences category-focus category-history category-news category-our-planet tag-geology tag-ice-age tag-palaeontology tag-snowball-earth"> <header class="rows rows-gap"> <h1 class="entry-title row">Best evidence yet that “Snowball Earth” saw ice cover the entire globe</h1> <div class="row primary-image has-featured-image " data-featured-image="caption_view_of_arapaho_pass_in_colorado_where_a_dark_red_band_of_tava_rock_cuts_through_the_mountain_side._credit_christine_s_siddoway_1.jpeg"> </div> </header> <div class="entry-content cols-6 md-cols-1 cols-gap-1 margin-top-1"> <div class="content-left-sidebar cols-1 col"> <section class="contributors md-cols-1 rows-gap"> <div class="row post-date"> <span class="published-date">November 13, 2024</span> </div> <a href="https://cosmosmagazine.com/contributor/evrim-yazgin/" class="author row md-hide"> <img src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCA0MDAgNDAwIiB3aWR0aD0iNDAwIiBoZWlnaHQ9IjQwMCIgZGF0YS11PSIlMkZ3cC1jb250ZW50JTJGdXBsb2FkcyUyRjIwMjIlMkYwOCUyRlRoZS1TY2llbmNlLUV4Y2hhbmdlLTI0LmpwZyIgZGF0YS13PSI0MDAiIGRhdGEtaD0iNDAwIiBkYXRhLWJpcD0iIj48L3N2Zz4=" data-spai="1" alt="Evrim Yazgin" width="200" /><noscript data-spai="1"><img src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2022/08/The-Science-Exchange-24.jpg" data-spai-egr="1" alt="Evrim Yazgin" width="200" /></noscript> <div class="bio"> <h3>Evrim Yazgin</h3> <p>Cosmos science journalist</p> </div> </a> <div id="author-name" class="hide"> <a href="https://cosmosmagazine.com/contributor/evrim-yazgin/" class="bio"> By Evrim Yazgin </a> </div> <div class="favourite__wrapper row cols"> <button class="showDialog simplefavorite-button" aria-label="Favourite button"> </button> </div> </section> </div> <div class="primary-content cols-1 col-span-5 col"> <div class="flexible-content "> <div class="copy"> <p>More than 700 million years ago, the entire globe was covered in ice in a period called “Snowball Earth”. At least, that’s what scientists think. Now geologists believe they’ve found the best evidence that the “Snowball Earth” was really a global event.</p> <p>For <a href="https://cosmosmagazine.com/earth/earth-sciences/scientists-discover-what-caused-earths-57-million-year-long-ice-age/">reasons which remain unclear</a>, a runaway chain of events caused a massive shift in Earth’s climate about 720 million years ago. Global temperatures plunged and ice sheets kilometres thick are believed to have covered the planet from the poles to the equator.</p> <p>Called the <a href="https://cosmosmagazine.com/earth/earth-sciences/snowball-earth-scotland-rocks/">Sturtian glaciation</a>, Snowball Earth lasted about 60 million years. This was quickly followed by another global ice age called the <a href="https://cosmosmagazine.com/earth/earth-sciences/rapid-melt-after-last-global-ice-age-turned-snowball-earth-into-a-giant-slushy/">Marinoan glaciation</a>. Together, these big freezes made up the geological period called the Cryogenian (720–635 million years ago).</p> <p>Evidence of the extent of ice cover during the Sturtian can be seen in rocks as far apart as Namibia, North America and Australia.</p> <div class="wp-block-image"> <figure class="alignleft size-full is-resized"><img decoding="async" fetchpriority="high" width="800" height="1060" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCA4MDAgMTA2MCIgd2lkdGg9IjgwMCIgaGVpZ2h0PSIxMDYwIiBkYXRhLXU9IiUyRndwLWNvbnRlbnQlMkZ1cGxvYWRzJTJGMjAyNCUyRjExJTJGd2FzLXNub3diYWxsLWVhcnRoLWEtZy5qcGciIGRhdGEtdz0iODAwIiBkYXRhLWg9IjEwNjAiIGRhdGEtYmlwPSIiPjwvc3ZnPg==" data-spai="1" alt="Reddish-brown bands of sandstone in hand" class="wp-image-315855" style="aspect-ratio:0.7547169811320755;width:363px;height:auto" title="best evidence yet that "snowball earth" saw ice cover the entire globe 1"><noscript data-spai="1"><img decoding="async" fetchpriority="high" width="800" height="1060" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/was-snowball-earth-a-g.jpg" data-spai-egr="1" alt="Reddish-brown bands of sandstone in hand" class="wp-image-315855" style="aspect-ratio:0.7547169811320755;width:363px;height:auto" srcset="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/was-snowball-earth-a-g.jpg 800w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/was-snowball-earth-a-g-453x600.jpg 453w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/was-snowball-earth-a-g-768x1018.jpg 768w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/was-snowball-earth-a-g-300x398.jpg 300w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/was-snowball-earth-a-g-600x795.jpg 600w" sizes="(max-width: 800px) 100vw, 800px" title="best evidence yet that "snowball earth" saw ice cover the entire globe 1"></noscript><figcaption class="wp-element-caption">Reddish-brown bands of Tava sandstone cut through other rocks. Credit: Liam Courtney-Davies.</figcaption></figure></div> <p>A new study published in the <em>Proceedings of the National Academy of Sciences</em> presents new evidence that these massive glaciers covered the entire globe.</p> <p>“This study presents the first physical evidence that Snowball Earth reached the heart of continents at the equator,” says lead author Liam Courtney-Davies, a postdoctoral researcher at the University of Colorado Boulder (UCB).</p> <div class="advert ad-in-content ad-mobile auh-250"><div id="adn-00000000001fc2ca-i0p0" style="display: none"></div></div> <p>The researchers examined a series of rocks nicknamed Tavakaiv, or “Tava” – sandstones found on the Front Range of Colorado’s Rocky Mountains which hold clues to Snowball Earth.</p> <p>A technique called laser ablation mass spectrometry was used to date the rocks. The Tava had been forced underground between about 690 to 660 million years ago – likely from the weight of huge glaciers pressing down above them.</p> <a href="https://link.cosmosmagazine.com/OP59" class="newsletter-cta" data-device="mobile"> <img decoding="async" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAzMDAgMjUwIiB3aWR0aD0iMzAwIiBoZWlnaHQ9IjI1MCIgZGF0YS11PSIlMkZ3cC1jb250ZW50JTJGdXBsb2FkcyUyRjIwMjQlMkYwMyUyRldlZWtseS1DYXRjaHVwLTMwMHgyNTAtMS5wbmciIGRhdGEtdz0iMzAwIiBkYXRhLWg9IjI1MCIgZGF0YS1iaXA9IiI+PC9zdmc+" data-spai="1" alt="Newsletter" title="best evidence yet that "snowball earth" saw ice cover the entire globe 2"><noscript data-spai="1"><img decoding="async" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/03/Weekly-Catchup-300x250-1.png" data-spai-egr="1" alt="Newsletter" title="best evidence yet that "snowball earth" saw ice cover the entire globe 2"></noscript> </a> <div class="in-content-area related-box-wrapper content-third content-right margin-bottom-1"> <div class="gradient-title">Read More</div> <ul class="related-box article-listing"> <li class="cols"> <div class="article article-post"> <a href="https://cosmosmagazine.com/earth/earth-sciences/rapid-melt-after-last-global-ice-age-turned-snowball-earth-into-a-giant-slushy/" class="thumbnail ar-16-9" aria-label="Article link"> <span data-spai-bg-on="1" class="image" style="background-image: url(data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAxMjAwIDY3NCIgd2lkdGg9IjEyMDAiIGhlaWdodD0iNjc0IiBkYXRhLXU9Imh0dHBzJTNBJTJGJTJGY29zbW9zbWFnYXppbmUuY29tJTJGd3AtY29udGVudCUyRnVwbG9hZHMlMkYyMDI0JTJGMTElMkZHZXR0eUltYWdlcy0xMzI0MzQxMjY1LmpwZyIgZGF0YS13PSIxMjAwIiBkYXRhLWg9IjY3NCIgZGF0YS1iaXA9IiI+PC9zdmc+)"></span> </a> <div class="article-content has-very-light-grey-background-color"> <a href="/earth/earth-sciences/"> <span class="category earth-color"> Earth Sciences </span> </a> <a href="https://cosmosmagazine.com/earth/earth-sciences/rapid-melt-after-last-global-ice-age-turned-snowball-earth-into-a-giant-slushy/"> <h3>Rapid melt after last global ice age turned snowball Earth into a giant slushy</h3> </a> </div> </div> </li> </ul> </div> <p>“These are classic geological features called injectites that often form below some ice sheets, including in modern-day Antarctica,” Courtney-Davies says.</p> <p>These date to the Sturtian glaciation, showing they were pushed down during Snowball Earth.</p> <p>“We’re excited that we had the opportunity to unravel the story of the only Snowball Earth deposits that have so far been identified in Colorado,” says Rebecca Flowers, also from UCB.</p> <div class="advert ad-in-content ad-mobile auh-250"><div id="adn-00000000001fc2ca-i1p0" style="display: none"></div></div> <p>Before the Cryogenian period, life on Earth was dominated by single-celled organisms.</p> <p>After Snowball Earth thawed are the earliest examples of large organisms during the Ediacaran period (635–541 million years ago).</p> <p>Scientists still don’t understand the processes which led to this explosion in life, after which our planet was changed forever.</p> <figure class="wp-block-image size-full"><img decoding="async" width="1200" height="675" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCAxMjAwIDY3NSIgd2lkdGg9IjEyMDAiIGhlaWdodD0iNjc1IiBkYXRhLXU9IiUyRndwLWNvbnRlbnQlMkZ1cGxvYWRzJTJGMjAyNCUyRjExJTJGY2FwdGlvbl92aWV3X29mX2FyYXBhaG9fcGFzc19pbl9jb2xvcmFkb193aGVyZV9hX2RhcmtfcmVkX2JhbmRfb2ZfdGF2YV9yb2NrX2N1dHNfdGhyb3VnaF90aGVfbW91bnRhaW5fc2lkZS5fY3JlZGl0X2NocmlzdGluZV9zX3NpZGRvd2F5XzEuanBlZyIgZGF0YS13PSIxMjAwIiBkYXRhLWg9IjY3NSIgZGF0YS1iaXA9IiI+PC9zdmc+" data-spai="1" alt="Snowy rocky mountain slope blue sky" class="wp-image-315854" title="best evidence yet that "snowball earth" saw ice cover the entire globe 3"><noscript data-spai="1"><img decoding="async" width="1200" height="675" src="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/caption_view_of_arapaho_pass_in_colorado_where_a_dark_red_band_of_tava_rock_cuts_through_the_mountain_side._credit_christine_s_siddoway_1.jpeg" data-spai-egr="1" alt="Snowy rocky mountain slope blue sky" class="wp-image-315854" srcset="https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/caption_view_of_arapaho_pass_in_colorado_where_a_dark_red_band_of_tava_rock_cuts_through_the_mountain_side._credit_christine_s_siddoway_1.jpeg 1200w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/caption_view_of_arapaho_pass_in_colorado_where_a_dark_red_band_of_tava_rock_cuts_through_the_mountain_side._credit_christine_s_siddoway_1-600x338.jpeg 600w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/caption_view_of_arapaho_pass_in_colorado_where_a_dark_red_band_of_tava_rock_cuts_through_the_mountain_side._credit_christine_s_siddoway_1-768x432.jpeg 768w, https://cdn.shortpixel.ai/spai/q_lossy+ret_img+to_auto/cosmosmagazine.com/wp-content/uploads/2024/11/caption_view_of_arapaho_pass_in_colorado_where_a_dark_red_band_of_tava_rock_cuts_through_the_mountain_side._credit_christine_s_siddoway_1-300x169.jpeg 300w" sizes="(max-width: 1200px) 100vw, 1200px" title="best evidence yet that "snowball earth" saw ice cover the entire globe 3"></noscript><figcaption class="wp-element-caption">A slope along Arapaho Pass in Colorado’s Front Range where orangish Tava sandstone pokes up to the surface. Credit: Christine Siddoway.</figcaption></figure> <p>“You have the climate evolving, and you have life evolving with it,” Courtney-Davies says. “All of these things happened during Snowball Earth upheaval. We have to better characterise this entire time period to understand how we and the planet evolved together.”</p> <div style><a href="https://link.cosmosmagazine.com/Q0f2"><p align="center"><img decoding="async" class="aligncenter size-full wp-image-198773" src="data:image/svg+xml;base64,PHN2ZyB4bWxucz0iaHR0cDovL3d3dy53My5vcmcvMjAwMC9zdmciIHZpZXdCb3g9IjAgMCA4MzcgMjU5IiB3aWR0aD0iODM3IiBoZWlnaHQ9IjI1OSIgZGF0YS11PSJodHRwcyUzQSUyRiUyRmNvc21vc21hZ2F6aW5lLmNvbSUyRndwLWNvbnRlbnQlMkZ1cGxvYWRzJTJGMjAyNCUyRjA5JTJGVHJhdmVsLXdpdGgtc2NpZW50aXN0cy1lbWJlZF83Mjh4MjI1LXYxLmpwZyIgZGF0YS13PSI4MzciIGRhdGEtaD0iMjU5IiBkYXRhLWJpcD0iIj48L3N2Zz4=" data-spai="1" alt="Buy the cosmos emag now" width="600" height="154" title="best evidence yet that "snowball earth" saw ice cover the entire globe 4"><noscript data-spai="1"><img decoding="async" class="aligncenter size-full wp-image-198773" 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Best evidence yet that "Snowball Earth" saw ice cover the entire globe