Wetter mantle leads to deeper — not more — decompression melting

Wetter mantle leads to deeper — not more — decompression melting | 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 Article Wetter mantle leads to deeper — not more — decompression melting Jason Morgan, Jia Shao This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-5996693/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 extent to which water content affects mantle melt production during decompression melting beneath mid-ocean ridges and mantle plumes is still debated. Here, we use idealized 1-D numerical experiments to explore the effects of source water content and melt-wallrock interactions on decompression melting of the mantle. The experiments demonstrate that while a wetter mantle indeed begins to melt at a greater depth than a drier mantle, the latent heat consumed by deep melting leads to lower amounts of shallow decompression melting and a similar overall amount of melt production for damp vs. dry decompression melting. This melting behavior is seen for both mid-ocean ridge-like starting mantle temperatures and higher plume-like temperatures. These results challenge previous expectations that melting of a wetter mantle source should be linked to much more melting, as has been observed for batch melting under laboratory conditions of constant pressure and increasing temperature. In addition, we find that diffusion of water from melt into surrounding wallrock can enhance decompression melting of previously melted wallrock. However, for small wallrock/mantle ratios, the net effect on total mantle melt production is relatively small (<2%). Earth and environmental sciences/Solid Earth sciences/Geodynamics Earth and environmental sciences/Solid Earth sciences/Geochemistry Earth and environmental sciences/Solid Earth sciences/Geophysics Earth and environmental sciences/Solid Earth sciences/Petrology Water Decompression melting Mantle melt production Melt-wallrock interaction Full Text Additional Declarations There is NO Competing Interest. Supplementary Files 3SupplementWetterMantleMelt2025.pdf Supplement information 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. 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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-5996693","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":416995372,"identity":"d05e0381-ed0b-46cd-86d5-4da8bdb2b5e1","order_by":0,"name":"Jason Morgan","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA1ElEQVRIiWNgGAWjYBACxgYILccGoSWI12JMvBYYSGwgWinztMPHPn6puZPex346geHHHwt5Bvb2B/gdNjstebbMsWe5bTy5Gxh72yQMG3jOGBDQkmPMLMF2OLdNgncDM2ODRAKDRA5+h0G0/DuczgbSwvAHqEX+OSGH5Rgzfmw7nADRwgayhYGQw9KSmRn7DhuC/HIQ5Jc2nhz8WgxnJx9m/PHtsLx8+9mND378qZPnZz+O32GGDcCA5oFyDoAINrzqgUAe5LgfhFSNglEwCkbByAYAPu8/qP/h92MAAAAASUVORK5CYII=","orcid":"","institution":"ICM-CSIC","correspondingAuthor":true,"prefix":"","firstName":"Jason","middleName":"","lastName":"Morgan","suffix":""},{"id":416995373,"identity":"61eda9f1-65b7-40be-a367-b261a5027336","order_by":1,"name":"Jia Shao","email":"","orcid":"https://orcid.org/0000-0002-5487-7639","institution":"Southern University of Science and Technology","correspondingAuthor":false,"prefix":"","firstName":"Jia","middleName":"","lastName":"Shao","suffix":""}],"badges":[],"createdAt":"2025-02-10 07:35:44","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-5996693/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-5996693/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":92841664,"identity":"76acbc67-06ab-4bd5-8eb9-c8fae2282457","added_by":"auto","created_at":"2025-10-06 09:08:03","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":1120917,"visible":true,"origin":"","legend":"Article File","description":"","filename":"2ManuscriptWetterMantleMelt2025.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5996693/v1_covered_dd0a5ce5-df25-4bd2-8f81-9586e0b9d967.pdf"},{"id":76724560,"identity":"04392e80-e05c-4535-b7bd-52eb85335cb7","added_by":"auto","created_at":"2025-02-20 05:09:25","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"supplement","size":174596,"visible":true,"origin":"","legend":"Supplement information","description":"","filename":"3SupplementWetterMantleMelt2025.pdf","url":"https://assets-eu.researchsquare.com/files/rs-5996693/v1/cb29e485792e69e64fe201d7.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"Wetter mantle leads to deeper — not more — decompression melting","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":"Water, Decompression melting, Mantle melt production, Melt-wallrock interaction","lastPublishedDoi":"10.21203/rs.3.rs-5996693/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-5996693/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"The extent to which water content affects mantle melt production during decompression melting beneath mid-ocean ridges and mantle plumes is still debated. 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