Earth’s core may have segregated at low pressure

Earth’s core may have segregated at low pressure | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Physical Sciences - Article Earth’s core may have segregated at low pressure Jon Wade, Bernard Wood This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5246069/v1 This work is licensed under a CC BY 4.0 License Status: Posted Version 1 posted You are reading this latest preprint version Abstract The current, widely accepted model of terrestrial accretion is that proto-Earth began as a small reduced inner solar system body and grew by adding a mixture of reduced, metal-rich and oxidised (outer solar system) metal-poor bodies with overall oxidation state increasing during planetary growth(1,2). Core segregation took place simultaneously with accretion at pressures which increased as the planet grew, reaching values of 40 GPa, equivalent to >800 km depth (e.g.,1; 2). These extreme pressures are required to explain the estimated partitioning of siderophile (iron-loving) elements between core and mantle. Here we challenge this model and present an alternative based on low pressure core segregation (0-3GPa) in the presence of the most abundant mantle mineral, olivine. Olivine is a major mantle reservoir for Ni, the element whose core-mantle partitioning behaviour best constrains the pressures of core segregation. We construct our model Earth from a mixture of oxidised and reduced bodies all of which segregate their cores at low pressure and show that, with the addition of olivine we can explain the current core-mantle partitioning of Ni, Co, V, Cr, W, Mo and Nb. Importantly we propose tests which would show that pressures were much higher than in our model. Earth and environmental sciences/Planetary science/Geochemistry Earth and environmental sciences/Planetary science/Core processes Full Text Additional Declarations There is NO Competing Interest. Cite Share Download PDF Status: Posted Version 1 posted You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-5246069","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Physical Sciences - Article","associatedPublications":[],"authors":[{"id":376785555,"identity":"ec38f597-27a7-41c0-891b-8a1d2bd32923","order_by":0,"name":"Jon Wade","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA8UlEQVRIiWNgGAWjYBACxgYwxczAj8QDgQTCWiRBjIPEaIECZgaDA8RqYW7vPcDMU2MtZ3y8+dnnjzsY5AwOMD/8wNiWhtthPecSmHmOpRubnTlmPOPgGQZjyQY2YwnGthzcWmbkGDDnsB1O3HYjwZjhYBtDYj8DgxkDY1sFAS3/Dtdvnv/8M1hLGwP7N8JactsOJxhI8MBs4QHZgsdhPWcMDv/tSzeccSanmOFsm4SxZDNPsUTCOdzeN2zvMXw445u1PH/78c0MlW02cgbH2zd++FCWjFtLAwPDASS+BCiO8EekPB65UTAKRsEoGAUQAAC7i1AxJAnZOAAAAABJRU5ErkJggg==","orcid":"https://orcid.org/0000-0002-6998-236X","institution":"University of Oxford","correspondingAuthor":true,"prefix":"","firstName":"Jon","middleName":"","lastName":"Wade","suffix":""},{"id":376785556,"identity":"67118577-16a5-4233-ab79-b0c535dd6d3d","order_by":1,"name":"Bernard Wood","email":"","orcid":"","institution":"University of Oxford","correspondingAuthor":false,"prefix":"","firstName":"Bernard","middleName":"","lastName":"Wood","suffix":""}],"badges":[],"createdAt":"2024-10-11 12:25:21","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5246069/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5246069/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":73792276,"identity":"d6899fb0-45cf-45c8-9e43-40449bdaf5ed","added_by":"auto","created_at":"2025-01-14 17:18:55","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2252588,"visible":true,"origin":"","legend":"Article File","description":"","filename":"LowPpaper.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5246069/v1_covered_689f9477-cc9b-4c85-9c63-a7ada749bf50.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Earth’s core may have segregated at low pressure","fulltext":[],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":false,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":true,"hideJournal":true,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":true,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":true,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"researchsquare","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":true,"externalIdentity":"","sideBox":"","snPcode":"","submissionUrl":"/submission","title":"Research Square","twitterHandle":"researchsquare","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"","reportingPortfolio":"","inReviewEnabled":false,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-5246069/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5246069/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The current, widely accepted model of terrestrial accretion is that proto-Earth began as\r\na small reduced inner solar system body and grew by adding a mixture of reduced,\r\nmetal-rich and oxidised (outer solar system) metal-poor bodies with overall oxidation\r\nstate increasing during planetary growth(1,2). Core segregation took place\r\nsimultaneously with accretion at pressures which increased as the planet grew,\r\nreaching values of 40 GPa, equivalent to \u003e800 km depth (e.g.,1; 2). These extreme\r\npressures are required to explain the estimated partitioning of siderophile (iron-loving)\r\nelements between core and mantle. Here we challenge this model and present an\r\nalternative based on low pressure core segregation (0-3GPa) in the presence of the\r\nmost abundant mantle mineral, olivine. Olivine is a major mantle reservoir for Ni, the\r\nelement whose core-mantle partitioning behaviour best constrains the pressures of\r\ncore segregation. We construct our model Earth from a mixture of oxidised and reduced\r\nbodies all of which segregate their cores at low pressure and show that, with the\r\naddition of olivine we can explain the current core-mantle partitioning of Ni, Co, V, Cr,\r\nW, Mo and Nb. 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