Cosmic Ray Induced Mass-Independent Oxygen Isotope Exchange: A Novel Mechanism for Producing 16O depletions in the Early Solar System

Cosmic Ray Induced Mass-Independent Oxygen Isotope Exchange: A Novel Mechanism for Producing 16O depletions in the Early Solar System | 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 Cosmic Ray Induced Mass-Independent Oxygen Isotope Exchange: A Novel Mechanism for Producing 16 O depletions in the Early Solar System Gerardo Dominguez, Joshua Lucas, Lauren Tafla, Ming-Chang Liu, and 1 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-712743/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 A fundamental puzzle of our solar system’s formation is understanding why the terrestrial bodies including the planets, comets, and asteroids are depleted in 16O compared to the Sun. The most favored mechanism, the selective photodissociation of CO gas to produce 16O depleted water, requires finely tuned mixing timescales to transport 16O depleted water from the cold outer solar system to exchange isotopically with dust grains to produce the 16O depleted planetary bodies observed today. Here we show that energetic particle irradiation of SiO2 (and Al2O3) makes them susceptible to anomalous isotope exchange with H2O ice at temperatures as low as 10 K. The observed magnitude of the anomalous isotope exchange (17O) is sufficient to generate the 16O depletion characteristic of the terrestrial bodies in the solar system. We calculated the cosmic-ray exposure times needed to produce the observed 16O depletions in silicate (SiO2) dust in the interstellar medium and early solar system and find that radiation damage induced oxygen isotope exchange could have rapidly (~101-102 yrs) depleted dust grains of 16O during the Sun’s T-Tauri phase. Our model explains why the oldest and most refractory minerals found in the solar system, the anhydrous Calcium with Aluminum Inclusions (CAIs), are generally 16O enriched compared to chondrules and the bulk terrestrial solids and provides a mechanism for producing 16O depleted grains very early in the solar system’s history. Our findings have broad implications for the distribution of oxygen isotopes in the solar system, the interstellar medium, the formation of the planets and its building blocks as well as the nature of mass-independent isotope effects. 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. 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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-712743","acceptedTermsAndConditions":true,"allowDirectSubmit":true,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":532294402,"identity":"b87c2df2-4a6f-4259-ba15-a60d9f932ff0","order_by":0,"name":"Gerardo Dominguez","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA3klEQVRIiWNgGAWjYFCCBDACAuYDMCEDYrWwJZCgBQJ44Crxa5F3Tz664eGO2sR+/jMfP/5sq4tmYG/eJoFPi+GZZ2k3Es8cT5zZcHazNG/b4dwGnmNl+LXMyDG7kdh2LHHDwd5tzIxtB3IbJHLMiNOy/zDPM0agw3Ib5N/g1yIvAdZSk7iBjYeNgbeNGWgLD34tBjwgv7QdMJ5xhs1Ymufc4dw2nrRiC7y2tCcfuwl0j2x//+GHH3+U1eX2sx/eeAOvLQfA1GGECBs+5WBbGsBUHSF1o2AUjIJRMJIBAAQjUMLFdkstAAAAAElFTkSuQmCC","orcid":"","institution":"California State University, San Marcos","correspondingAuthor":true,"prefix":"","firstName":"Gerardo","middleName":"","lastName":"Dominguez","suffix":""},{"id":532294403,"identity":"4e45e0d7-2257-4433-8e8a-8a71add5cdf3","order_by":1,"name":"Joshua Lucas","email":"","orcid":"","institution":"California State University, San Marcos","correspondingAuthor":false,"prefix":"","firstName":"Joshua","middleName":"","lastName":"Lucas","suffix":""},{"id":532294404,"identity":"66103901-f2b8-447e-a0f9-46c6e4a06898","order_by":2,"name":"Lauren Tafla","email":"","orcid":"","institution":"California State University, San Marcos","correspondingAuthor":false,"prefix":"","firstName":"Lauren","middleName":"","lastName":"Tafla","suffix":""},{"id":532294405,"identity":"2e2e3a9f-ef1a-4c9f-b9ca-3f03e10306dd","order_by":3,"name":"Ming-Chang Liu","email":"","orcid":"","institution":"University of California","correspondingAuthor":false,"prefix":"","firstName":"Ming-Chang","middleName":"","lastName":"Liu","suffix":""},{"id":532294406,"identity":"e9053573-023c-4914-888d-3b69346f2378","order_by":4,"name":"Kevin McKeegan","email":"","orcid":"","institution":"UCLA","correspondingAuthor":false,"prefix":"","firstName":"Kevin","middleName":"","lastName":"McKeegan","suffix":""}],"badges":[],"createdAt":"2021-07-13 22:20:58","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-712743/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-712743/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":101751881,"identity":"a8a1d5c9-aa6f-468f-ac4d-03404670ea08","added_by":"auto","created_at":"2026-02-03 10:24:10","extension":"pdf","order_by":1,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2186687,"visible":true,"origin":"","legend":"Article File","description":"","filename":"CosmicRaysOxygenIsotopesNature2021.pdf","url":"https://assets-eu.researchsquare.com/files/rs-712743/v1_covered_b88b42db-ff0b-4bbd-b75c-c3613447fc63.pdf"}],"financialInterests":"There is \u003cb\u003eNO\u003c/b\u003e Competing Interest.","formattedTitle":"\u003cp\u003eCosmic Ray Induced Mass-Independent Oxygen Isotope Exchange: A Novel Mechanism for Producing \u003csup\u003e16\u003c/sup\u003eO depletions in the Early Solar System\u003c/p\u003e","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-712743/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-712743/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"A fundamental puzzle of our solar system’s formation is understanding why the terrestrial bodies including the planets, comets, and asteroids are depleted in 16O compared to the Sun. The most favored mechanism, the selective photodissociation of CO gas to produce 16O depleted water, requires finely tuned mixing timescales to transport 16O depleted water from the cold outer solar system to exchange isotopically with dust grains to produce the 16O depleted planetary bodies observed today. Here we show that energetic particle irradiation of SiO2 (and Al2O3) makes them susceptible to anomalous isotope exchange with H2O ice at temperatures as low as 10 K. The observed magnitude of the anomalous isotope exchange (17O) is sufficient to generate the 16O depletion characteristic of the terrestrial bodies in the solar system. We calculated the cosmic-ray exposure times needed to produce the observed 16O depletions in silicate (SiO2) dust in the interstellar medium and early solar system and find that radiation damage induced oxygen isotope exchange could have rapidly (~101-102 yrs) depleted dust grains of 16O during the Sun’s T-Tauri phase. 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