\n<\/p>\n
March 19, 2026<\/p>\n
4 min read<\/p>\n
Add Us On Google<\/span>Add SciAm<\/span><\/span><\/p>\n When did plate tectonics on Earth begin? New research finds some of the earliest clues<\/p>\n Scientists have found the oldest direct evidence for tectonic motion on Earth by more than half a billion years<\/p>\n By Marissa Grunes edited by Sarah Lewin Frasier<\/span><\/p>\n Outcrop of a 3.5-billion-year-old \u201dpillow basalt\u201c lava flow.<\/p>\n Alec Brenner, Harvard University\/Yale University<\/p>\n The colossal movements of tectonic plates shape our world, influencing the composition of Earth\u2019s atmosphere, the planet\u2019s protective magnetic field and perhaps even the flourishing of life. Now researchers have compelling evidence that some form of plate tectonics may have started as early as 3.48 billion years ago, according to a new study appearing today in Science.<\/p>\n Using magnetic traces from ancient pieces of Earth\u2019s crust, researchers found that a chunk of what is now Western Australia drifted toward the magnetic north pole over a few million years, as part of South Africa remained stationary. It\u2019s the earliest documented instance of relative plate motion by more than half a billion years, and it has implications for understanding early life on Earth and how the planet\u2019s tectonic activity began. (Disclosure: The author of this article embedded with the research team in last year\u2019s field season.)<\/p>\n Earth today is a jigsaw of giant chunks of crust that travel across the planet, smashing together like huge bumper cars, pushing up mountain ranges and melting back into magma along their edges. All this activity, called plate tectonics, seems to be unique in our solar system. It\u2019s believed that our rocky planet neighbors instead have a continuous, solid shell.<\/p>\n If you’re enjoying this article, consider supporting our award-winning journalism by subscribing. By purchasing a subscription you are helping to ensure the future of impactful stories about the discoveries and ideas shaping our world today.<\/p>\n No one knows, however, how or when plate tectonics got started on Earth in the first place. \u201cIt\u2019s one of the most fundamental questions in Earth science,\u201d says study co-author Roger Fu, a Harvard University paleomagnetist. Geologists use various tools to investigate the state of Earth\u2019s crust over the eons, but the gold standard is evidence of relative motion: one piece of Earth\u2019s crust moving away from, or toward, another piece. For that, Earth\u2019s magnetic field\u2014powered by the motion of its core\u2014holds the key.<\/p>\n This illustrated cross-section of Earth 3.5 billion years ago shows the core generating a magnetic field as well as subducting tectonic plates.<\/p>\n Alec Brenner, Harvard University\/Yale University<\/p>\n Like any magnet, Earth has a north and south magnetic pole, aligning roughly with the globe\u2019s geographic poles. These poles flip at irregular intervals; the last such reversal was about 780,000 years ago. (Right now Earth\u2019s magnetic north is technically in the Southern Hemisphere.) The direction and angle of lines of force curving between the poles become imprinted in molten rock as it solidifies at the planet\u2019s surface, providing clues to where ancient rocks have been.<\/p>\n To find such traces, the team analyzed rock samples from remote parts of Western Australia and South Africa. These regions contain some of the planet\u2019s oldest chunks of crust, called cratons, which have survived billions of years of grinding and melting processes and form the building blocks of continents.<\/p>\n The rock layers\u2019 magnetic record shows that a chunk of the craton in Australia shifted northward over the course of a few million years, while part of the craton in South Africa stayed stationary. Such motion is exciting because it \u201csuggests there\u2019s likely to be a plate boundary between the two [cratons],\u201d says Michael Brown, a University of Maryland emeritus geologist who was not involved in the study.<\/p>\n Multiple researchers agreed that this study is about the earliest we will be able to see such results, as so few rocks remain intact from Earth\u2019s first billion years. \u201cIt\u2019s like having a thousand-piece jigsaw, but you only have 35 pieces,\u201d Brown says. The relative motion doesn\u2019t tell us exactly what was going on in this period, Brown adds, but it can put new limits on the mathematical models that researchers use to recreate ancient Earth.<\/p>\n The Pilbara Craton, Western Australia, holds 3.5-billion-year-old rocks.<\/p>\n Alec Brenner, Harvard University\/Yale University<\/p>\n The findings may support another recent study, which uses ancient crystals of the mineral zircon\u2014found in a different part of Western Australia\u2014to suggest that pieces of Earth\u2019s crust may have been melting back into the mantle around 3.35 billion years ago. Evidence from zircon crystals is notoriously difficult to interpret, and the cycling of Earth\u2019s crust into the mantle may happen under many different circumstances. The process is necessary, however, to any form of plate tectonics. In that sense, the two studies reinforce one another.<\/p>\n Fu\u2019s team also found evidence of the earliest known reversal of Earth\u2019s magnetic poles, around 3.46 billion years ago. In concert with the evidence of relative tectonic motion, the study\u2019s results \u201cdemonstrate that Earth was behaving very similar to today,\u201d according to Jun Korenaga, a Yale University geologist who was not involved in the study.<\/p>\n The Western Australian craton that the team studied is home to the world\u2019s oldest confirmed fossils of single-celled organisms, which date back to roughly 3.48 billion years ago. Knowing the latitude of those rocks at the time could help researchers learn more about life\u2019s origins. And understanding what kind of tectonics operated back then may set limits on ways in which Earth\u2019s modern plate tectonics got started. If we know what Earth\u2019s early tectonics looked like, we can start to hunt for similar behavior on other planets, which may in turn guide the search for life. \u201cWhat kind of planet did life first appear on?\u201d Fu wonders. The answer, he says, \u201chas implications for how abundant life is likely to be in the universe.\u201d<\/p>\n If you enjoyed this article, I\u2019d like to ask for your support. Scientific American<\/span> has served as an advocate for science and industry for 180 years, and right now may be the most critical moment in that two-century history.<\/p>\n I\u2019ve been a Scientific American<\/span> subscriber since I was 12 years old, and it helped shape the way I look at the world. SciAm <\/span>always educates and delights me, and inspires a sense of awe for our vast, beautiful universe. I hope it does that for you, too.<\/p>\n If you subscribe to Scientific American<\/span>, you help ensure that our coverage is centered on meaningful research and discovery; that we have the resources to report on the decisions that threaten labs across the U.S.; and that we support both budding and working scientists at a time when the value of science itself too often goes unrecognized.<\/p>\n In return, you get essential news, captivating podcasts, brilliant infographics, can’t-miss newsletters, must-watch videos, challenging games, and the science world’s best writing and reporting. You can even gift someone a subscription.<\/p>\n There has never been a more important time for us to stand up and show why science matters. I hope you\u2019ll support us in that mission.<\/p>\n","protected":false},"excerpt":{"rendered":" March 19, 2026 4 min read Add Us On GoogleAdd SciAm When did plate tectonics on Earth begin? New research finds some of the earliest clues Scientists have found the oldest direct evidence for tectonic motion on Earth by more than half a billion years By Marissa Grunes edited by Sarah Lewin Frasier Outcrop of<\/p>\n","protected":false},"author":1,"featured_media":47140,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[50],"tags":[9639,19650,589,189,13241,3141,23478],"class_list":{"0":"post-47139","1":"post","2":"type-post","3":"status-publish","4":"format-standard","5":"has-post-thumbnail","7":"category-environment","8":"tag-clues","9":"tag-earliest","10":"tag-earth","11":"tag-finds","12":"tag-plate","13":"tag-research","14":"tag-tectonics"},"_links":{"self":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/47139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=47139"}],"version-history":[{"count":0,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/posts\/47139\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=\/wp\/v2\/media\/47140"}],"wp:attachment":[{"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=47139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=47139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/naijaglobalnews.org\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=47139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}On supporting science journalism<\/h2>\n
It\u2019s Time to Stand Up for Science<\/h2>\n