Chondrule Fragments in Particles from the Carbonaceous Asteroid (101955) Bennu

Chondrule Fragments in Particles from the Carbonaceous Asteroid (101955) Bennu | 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 Chondrule Fragments in Particles from the Carbonaceous Asteroid (101955) Bennu Kathie Thomas-Keprta, Loan Le, Simon Clemett, Laura Seifert, Lindsay Keller, and 12 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8896456/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted You are reading this latest preprint version Abstract Chondrules are one of the first solid materials that formed during the birth of the Solar System and their study in primitive meteorites has been consequential in understanding the conditions and processes in which the building blocks of the planets, and chondrites, formed. However, chondrules are absent in the most aqueously altered meteorites, the Ivuna-like (CI) carbonaceous chondrites. Samples from the asteroid (101955) Bennu, returned by NASA’s OSIRIS-REx mission, resemble CI chondrites in composition and mineralogy. Here we show that some Bennu particles nevertheless contain numerous chondrule fragments. Although these fragments share many traits of porphyritic and non-porphyritic (barred olivine and radial pyroxene) chondrules observed in non-CI carbonaceous chondrites, they lack any discernible mesostasis or typical secondary phyllosilicate replacement phases. We conclude that aqueous alteration in Bennu’s parent body removed any mesostasis present within the chondrule fragments but did not completely erase or replace their mineralogy. Our findings distinguish the Bennu samples from the CI chondrites and help constrain the reservoir from which Bennu’s parent body formed and the geologic processes that occurred within it. Earth and environmental sciences/Planetary science/Asteroids, comets and Kuiper belt Earth and environmental sciences/Planetary science/Meteoritics Earth and environmental sciences/Planetary science/Mineralogy Earth and environmental sciences/Planetary science/Geochemistry Earth and environmental sciences/Planetary science/Early solar system Full Text Additional Declarations There is NO Competing Interest. Supplementary Files ThomasKeprtaSupplemental.zip Dataset 1 SupplementaryDataVideo1OREX803079241Media.mp4 Supplementary Data Video 1 OREX-803079-241_Media SupplementaryDataVideo2OREX803079241individualfragment.mp4 Supplementary Data Video 2 OREX-803079-241 individual fragment SupplementaryDataVideo3OREX803417103Media.mp4 Supplementary Data Video 3 OREX-803417-103_Media NGSemailattachmentSMC17713492331.pdf SI File Cite Share Download PDF Status: Under Review 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. 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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-8896456","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":601614812,"identity":"7b3f4004-4865-40eb-8714-c7519917ae09","order_by":0,"name":"Kathie 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