Southern Hemisphere Hotspots Traced Back to Distinct Paleo-Subduction Zones

Southern Hemisphere Hotspots Traced Back to Distinct Paleo-Subduction Zones | 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 Southern Hemisphere Hotspots Traced Back to Distinct Paleo-Subduction Zones Gabriel Johnston, Alessandro Forte, Petar Glišović, Catherine Chauvel, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-7827767/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 Mantle plumes beneath the South-Atlantic and Southwest-Indian Ocean hotspots are widely assumed to rise from the margins of the African large low–shear-velocity province (LLSVP). Here we integrate plate reconstructions, joint seismic–geodynamic tomography, and time-reversed particle tracking in a back-and-forth nudged (BFN) mantle convection model to test that premise. Our mantle flow reconstructions trace Tristan–Gough–Discovery and Kerguelen plume particles to paleo-subduction zones along the southern Panthalassa margin of Pangea, whereas trajectories feeding Réunion, Grande Comore and Mayotte converge on slabs that foundered beneath the Paleo-Tethys suture. In both cases the mantle parcels skirt -- rather than penetrate -- the high-density core of the present-day African LLSVP. Pb–Sr–Nd isotope arrays mirror this bifurcation, with DUPAL-rich signatures confined to the Panthalassan lineage and more depleted compositions characterising the Paleo-Tethyan lineage. The results suggest that Indo-Atlantic plume heterogeneity is inherited from Mesozoic subduction zones remote from the African superplume and retained during whole-mantle transport. Our findings call into question a dominant plume–LLSVP origin for isotopic heterogeneity and highlight the need to follow material pathways in time-dependent convective flows to decipher mantle geochemistry. Earth and environmental sciences/Solid Earth sciences/Geodynamics Earth and environmental sciences/Solid Earth sciences/Geochemistry Full Text Additional Declarations There is NO Competing Interest. Supplementary Files supplementarytablefinal.xlsx Data Set 1 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-7827767","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":551335379,"identity":"99c8158d-e57b-407f-9eed-ecfa429b0af6","order_by":0,"name":"Gabriel 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