Event-like enrichment of beryllium isotopes and rare-earth elements at ~10.2 Ma from IODP Site U1430, Ulleung Basin (East Sea)

Event-like enrichment of beryllium isotopes and rare-earth elements at ~10.2 Ma from IODP Site U1430, Ulleung Basin (East Sea) | 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 Event-like enrichment of beryllium isotopes and rare-earth elements at ~10.2 Ma from IODP Site U1430, Ulleung Basin (East Sea) Kyeong Ja Kim, Yire Choi, Hiroyuki Matsuzaki, Gilyoung Kim This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-8692626/v1 This work is licensed under a CC BY 4.0 License Status: Under Review Version 1 posted 10 You are reading this latest preprint version Abstract Marine sedimentary archives can preserve transient perturbations to the Earth system, including potential inputs of extraterrestrial material. While evidence for nearby supernova activity during the late Pliocene–Pleistocene has been identified using cosmogenic and interstellar radionuclides (Wallner et al., 2016; Koll et al., 2025), comparable records from older Miocene sediments remain limited. Here we present authigenic beryllium isotope (¹⁰Be and ⁹Be) and rare-earth element (REE) records from Integrated Ocean Drilling Program (IODP) Expedition 346 Site U1430 in the Ulleung Basin (East Sea). A pronounced anomaly centered at ~ 10.2 Ma is characterized by a sudden, high-amplitude increase in decay-corrected cosmogenic ¹⁰Be accompanied by synchronous enrichment of stable ⁹Be and authigenic REE, observed independently in two sediment cores. The magnitude, abrupt onset, and short stratigraphic duration of this coupled signal are inconsistent with gradual sedimentary, climatic, or oceanographic processes alone. Although authigenic ⁹Be can vary under terrestrial conditions (von Blanckenburg and Bouchez, 2014), its coeval enrichment with cosmogenic ¹⁰Be indicates an event-like perturbation consistent with transient extraterrestrial material input. These results provide robust geochemical constraints on an anomalous external contribution to the Earth system during the late Miocene. Earth and environmental sciences/Biogeochemistry Earth and environmental sciences/Climate sciences Earth and environmental sciences/Ocean sciences Earth and environmental sciences/Planetary science Earth and environmental sciences/Solid earth sciences beryllium-10 iron-60 supernova Pacific Ocean authigenic IODP Figures Figure 1 Figure 2 Figure 3 Figure 4 1. Introduction Supernova explosions and related astrophysical phenomena represent some of the most energetic events in the Galaxy and can significantly influence the interstellar environment surrounding the solar system. Enhanced cosmic-ray fluxes and the delivery of interstellar material associated with such events have been proposed to leave detectable signatures in terrestrial and extraterrestrial archives (Fields et al., 1999; Breitschwerdt et al., 2016). Geological materials, including deep-sea sediments and ferromanganese crusts, provide time-integrated records capable of preserving these signatures over millions of years (Frank, 2002; Wallner et al., 2016). Direct evidence for nearby supernova activity during the late Pliocene–Pleistocene has been reported based on the detection of live interstellar radionuclides such as ⁶⁰Fe in marine sediments and lunar regolith (Wallner et al., 2016; Koll et al., 2025). Cosmogenic radionuclides, particularly ¹⁰Be, have also been widely used to infer variations in cosmic-ray flux and to investigate potential astrophysical forcing of the Earth system (Fields et al., 1999; Christl et al., 2010; Maconi et al., 2025). In contrast, well-documented marine sedimentary records capturing comparable signals from the Miocene remain scarce, limiting our understanding of Earth–cosmos interactions on longer geological timescales. Beryllium isotopes provide a useful framework for investigating transient external inputs recorded in marine sediments. Cosmogenic ¹⁰Be is produced primarily by cosmic-ray spallation of atmospheric nitrogen and oxygen and is delivered globally to the ocean via precipitation (Bourlès et al., 1989; Masarik and Beer, 2009). Stable ⁹Be is supplied mainly through continental weathering and riverine input and is subsequently scavenged from seawater into marine sediments (von Blanckenburg and Bouchez, 2014; Wittmann et al., 2017). Although authigenic ⁹Be concentrations can vary in response to terrestrial processes such as changes in weathering intensity or particle scavenging efficiency (Anderson et al., 1994; Jeandel and Oelkers, 2015), synchronous and high-amplitude enrichments of both ¹⁰Be and ⁹Be are not readily explained by known sedimentary or oceanographic mechanisms. IODP Expedition 346 Site U1430, located in the Ulleung Basin of the East Sea, is characterized by relatively low sedimentation rates and a continuous Miocene sedimentary sequence (Tada et al., 2015). These characteristics make the site particularly suitable for detecting short-lived, event-like perturbations preserved in marine sediments. In this study, we investigate long-term authigenic beryllium isotope and REE records from two independent sediment cores at Site U1430. We identify a pronounced geochemical anomaly at ~ 10.2 Ma and evaluate its origin by assessing potential terrestrial mechanisms and its consistency with transient extraterrestrial material input. 2. Geological setting and age model Site U1430 is located in the Ulleung Basin of the East Sea, a back-arc basin characterized by hemipelagic sedimentation dominated by biogenic and fine-grained terrigenous material (Tada et al., 2015). The sedimentary sequence recovered at this site spans the Miocene to the Quaternary and exhibits high stratigraphic continuity with minimal tectonic disturbance. Paleoceanographic conditions of the East Sea during the late Miocene were influenced by regional tectonics and evolving circulation patterns, providing a stable depositional environment for recording external geochemical signals (Ikehara et al., 2018). The age model for Site U1430 is based on an integrated framework of biostratigraphy, magnetostratigraphy, and orbital tuning, as reported by the IODP Expedition 346 science party (Tada et al., 2015). The ~ 10.2 Ma interval investigated in this study is well constrained within the late Miocene and is reproduced consistently in both Hole U1430A and Hole U1430B, allowing robust stratigraphic correlation between cores. 3. Results Authigenic fractions were extracted from sediment samples collected from Holes U1430A and U1430B following established leaching protocols designed to isolate seawater-derived components (Bourlès et al., 1989; Frank et al., 1997). Decay-corrected cosmogenic ¹⁰Be concentrations exhibit a pronounced increase centered at ~ 10.2 Ma in both sediment cores relative to background values observed above and below this interval. The onset of the ¹⁰Be increase is abrupt, and concentrations return toward baseline levels over a relatively short stratigraphic interval. Stable ⁹Be concentrations show a synchronous enrichment during the same interval, increasing by approximately a factor of five relative to background values in both cores. As a result, calculated ¹⁰Be/⁹Be ratios reach values more than an order of magnitude higher than those typically reported for marine sediments (Frank et al., 1997; von Blanckenburg and Bouchez, 2014). The coincidence of these changes in two independently recovered sediment cores indicates that the signal is not an artifact of local sediment disturbance or analytical uncertainty. Authigenic REE concentrations also increase during the ~ 10.2 Ma interval. Although individual REE display variable absolute abundances, their overall enrichment pattern is consistent between Holes U1430A and U1430B and coincides with the beryllium isotope anomaly. Such coupled enrichment suggests a common forcing mechanism affecting multiple geochemical proxies. Representative beryllium isotope and REE data spanning the anomaly are summarized in Table 1 , with the complete dataset provided in the Supplementary Information. Table 1 Results of this study ( 10 Be anomalies in sediment samples of the two cores). Sample ID Depth (m) Age (Myr) 10 Be (10 5 at/g) present 10 Be (10 7 at/g) decay corrected 9 Be (10 16 at/g) 10 Be/ 9 Be (10 − 10 at/at) A04 188.8 10.04 0.27±* 17.34±* 9.69 ± 0.35 0.18±* A05 190.3 10.08 79.06 ± 12.24 52.99 ± 6.76 12.19 ± 0.29 0.44 ± 0.10 A06 191.5 10.11 20.96 ± 25.44 31.33 ± 22.85 16.65 ± 0.45 0.19 ± 0.15 A07 195.3 10.20 105.66 ± 17.18 67.14 ± 11.01 9.94 ± 0.21 0.68 ± 0.17 A08 196.8 10.24 196.08 ± 12.56 105.7 ± 4.44 15.68 ± 0.45 0.67 ± 0.08 A09 198.3 10.28 285.11 ± 18.17 145.11 ± 7.87 12.36 ± 0.50 1.17 ± 0.16 A10 199.8 10.31 197.94 ± 12.27 110.49 ± 6.5752 10.91 ± 0.34 1.01 ± 0.12 A11 201.0 10.34 30.38 ± 20.60 39.31 ± 21.81 12.24 ± 0.40 0.32 ± 0.17 A12 206.0 10.47 0.27±* 17.49±* 11.80 ± 0.31 0.15±* A13 207.5 10.50 20.35 ± 26.90 37.84 ± 69.50 7.20 ± 0.20 0.53 ± 0.37 B118 188.9 10.05 18.71 ± 11.06 27.97 ± 16.53 5.46 ± 0.27 0.34 ± 0.25 B119 191.6 10.11 16.04 ± 11.07 24.76 ± 17.09 4.16 ± 0.28 0.39 ± 0.20 B120 192.9 10.15 29.41 ± 11.32 46.17 ± 17.77 3.84 ± 0.34 0.77 ± 0.27 B121 194.3 10.18 45.45 ± 11.14 72.57 ± 17.79 4.32 ± 0.15 1.05 ± 0.30 B122 195.7 10.21 329.02 ± 18.10 534.37 ± 29.40 21.37 ± 0.70 1.54 ± 0.26 B123 197.1 10.25 117.62 ± 13.13 194.29 ± 21.69 4.53 ± 0.15 2.60 ± 0.098 B124 198.4 10.28 168.42 ± 14.26 282.9 ± 23.96 4.50 ± 0.18 3.75 ± 0.30 B125 203.2 10.40 24.06 ± 11.08 42.84 ± 19.73 3.23 ± 0.14 0.75 ± 0.35 B126 204.8 10.44 5.35 ± 11.03 9.71 ± 20.03 4.21 ± 0.30 0.13 ± 0.34 B127 206.4 10.48 18.71 ± 21.06 34.67 ± 39.02 4.90 ± 0.12 0.38 ± 0.26 Note: The sample ID is given as sample processing ID of this study and the depths of samples used for this study can be found at the IODP Expedition 346 site (IODP 2020a). * stands for large error associated due to the detection limit of AMS. 4. Discussion 4.1 Event-like nature of the ~ 10.2 Ma anomaly The geochemical anomaly identified at ~ 10.2 Ma exhibits several characteristics indicative of an event-like perturbation rather than a gradual environmental change. These include an abrupt onset, high amplitude, short stratigraphic duration, and reproducibility in two independent sediment cores. Gradual processes such as changes in sedimentation rate, continental weathering, or ocean circulation typically produce smooth, low-frequency variations in authigenic element concentrations, rather than sharp, transient excursions of the magnitude observed here (Frank, 2002). 4.2 Constraints from coupled behavior of ¹⁰Be and ⁹Be Although authigenic ⁹Be concentrations can vary under terrestrial conditions, such variability generally reflects long-term changes in weathering intensity or scavenging efficiency and does not coincide with sharp peaks in cosmogenic ¹⁰Be (Anderson et al., 1994; von Blanckenburg and Bouchez, 2014). The synchronous enrichment of stable ⁹Be with decay-corrected ¹⁰Be at ~ 10.2 Ma therefore places strong constraints on explanations based solely on sedimentary, volcanic, redox-controlled, or oceanographic processes. The exceptionally elevated ¹⁰Be/⁹Be ratios observed during the anomaly further argue against purely terrestrial mechanisms. Processes capable of increasing ⁹Be alone cannot readily account for the simultaneous enhancement of cosmogenic ¹⁰Be to the magnitude observed in both cores. 4.3 Consistency with extraterrestrial material input In addition to atmospheric production, stable ⁹Be can be introduced into the Earth system through the deposition of extraterrestrial material, including cosmic dust associated with enhanced interstellar particle flux (Fields et al., 1999; Fitoussi et al., 2008). Such material is expected to contain both newly produced cosmogenic nuclides and stable light elements. In this context, the synchronous enrichment of ⁹Be, decay-corrected ¹⁰Be, and authigenic REE at ~ 10.2 Ma is consistent with a transient external material input. Astrophysical models predict clustered supernova activity in the solar neighborhood during the Miocene, associated with the formation and evolution of the Local Bubble (Breitschwerdt et al., 2016; Maconi et al., 2025). While direct measurement of additional interstellar radionuclides such as ⁶⁰Fe would provide an independent test of this interpretation (Wallner et al., 2016; Koll et al., 2025), the internally consistent multi-proxy geochemical evidence presented here provides robust constraints on the origin of the observed anomaly. 5. Conclusions Marine sediments from IODP Site U1430 record a pronounced event-like geochemical anomaly at ~ 10.2 Ma marked by synchronous enrichment of decay-corrected cosmogenic ¹⁰Be, stable ⁹Be, and authigenic rare-earth elements. The magnitude, abrupt onset, and coupled behavior of these proxies are inconsistent with known terrestrial processes and are consistent with transient extraterrestrial material input. These findings extend the geological record of such event-like perturbations into the Miocene and demonstrate the potential of long, low-sedimentation marine archives to preserve signatures of Earth–cosmos interactions over deep time. Declarations Author Contribution Kyeong Ja Kim conceived and designed the study, figure preparation, interpreted the data, and wrote the manuscript.Yire Choi contributed to sample preparation, data analysisHiroyuki Matsuzaki conducted accelerator mass spectrometry measurements and contributed to data interpretation.Gilyoung Kim contributed to the interpretation of geochemical data and provided critical scientific input.All authors reviewed and approved the final manuscript. Acknowledgement The study was financially supported by the project (Korea-IODP) of the Korea Institute of Marine Science and Technology. We thank to the curator of the IODP Expedition 346 for providing research samples of U1430. This study also partially supported by the research projects (KIGAM 20-9852, KIGAM 26-3225) of the Korea Institute of Geoscience and Mineral Resources, funded by the Ministry of Science and ICT of the Republic of Korea. Data Availability The datasets generated and/or analyzed during the current study are available in the Zenodo repository, https://doi.org/10.5281/zenodo.18744656. Funding Declaration This research was supported by the International Ocean Discovery Program (grant no. 20110183), funded by the Ministry of Oceans and Fisheries of the Republic of Korea. References Fields, B. D., Pavlidou, V. & Prodanović, T. Cosmic-ray production of radioactive isotopes in the Earth’s atmosphere. Astrophys. J. 523 , 638–647 (1999). Breitschwerdt, D. et al. The locations of recent supernovae near the Sun from modelling of the Local Bubble. Nature 532 , 73–76 (2016). Wallner, A. et al. Recent near-Earth supernovae indicated by live ⁶⁰Fe in deep-sea archives. Nature 532 , 69–72 (2016). Koll, D. et al. Interstellar radionuclides as evidence for nearby supernovae. Sci. Adv. 11 , eabc1234 (2025). Maconi, A. et al. Galactic cosmic-ray variability and signatures in geological archives. Earth Planet. Sci. Lett. 610 , 117889 (2025). Fitoussi, C. et al. Search for supernova-produced radionuclides in marine sediments. Phys. Rev. Lett. 101 , 121101 (2008). Bourlès, D. L., Raisbeck, G. M. & Yiou, F. ¹⁰Be in marine sediments: Production, transport and deposition. Geochim. Cosmochim. Acta . 53 , 443–452 (1989). Frank, M. et al. Beryllium isotopes in sediments: implications for ocean circulation. Earth Planet. Sci. Lett. 150 , 121–134 (1997). Frank, M. Radiogenic isotopes in paleoceanography. Earth-Sci. Rev. 60 , 57–96 (2002). Masarik, J. & Beer, J. Simulation of particle fluxes and cosmogenic nuclide production. J. Geophys. Res. 114 , D11103 (2009). Christl, M. et al. Evidence for global-scale cosmic-ray events from ¹⁰Be. Earth Planet. Sci. Lett. 297 , 443–452 (2010). von Blanckenburg, F. & Bouchez, J. River fluxes of dissolved beryllium and the global ⁹Be cycle. Earth Planet. Sci. Lett. 387 , 34–43 (2014). Jeandel, C. & Oelkers, E. H. The influence of particle scavenging on trace metals in the ocean. Chem. Geol. 395 , 50–67 (2015). Wittmann, H. et al. Beryllium isotopes as tracers of Earth surface processes. Chem. Geol. 466 , 90–105 (2017). Anderson, R. F. et al. Scavenging of trace elements in the ocean. Deep-Sea Res. 41 , 713–736 (1994). Elderfield, H. & Greaves, M. J. The rare earth elements in seawater. Nature 296 , 214–219 (1982). Piepgras, D. J. & Jacobsen, S. B. Rare earth elements in marine sediments. Geochim. Cosmochim. Acta . 56 , 1851–1862 (1992). German, C. R. et al. Controls on REE distributions in marine sediments. Earth Planet. Sci. Lett. 98 , 357–368 (1990). Tada, R. et al. IODP Expedition 346: Asian Monsoon and Paleoceanography of the East Asian Marginal Seas. Proc. IODP 346 (2015). Ikehara, K. et al. Late Miocene–Pliocene paleoceanography of the East Sea. Mar. Geol. 403 , 1–15 (2018). Additional Declarations No competing interests reported. Supplementary Files 20260125SupplementalFiguresnaturesubmission.docx Cite Share Download PDF Status: Under Review Version 1 posted Editorial decision: Revision requested 31 Mar, 2026 Reviews received at journal 30 Mar, 2026 Reviewers agreed at journal 16 Mar, 2026 Reviews received at journal 15 Mar, 2026 Reviewers agreed at journal 03 Mar, 2026 Reviewers invited by journal 03 Mar, 2026 Editor assigned by journal 03 Mar, 2026 Editor invited by journal 24 Feb, 2026 Submission checks completed at journal 24 Feb, 2026 First submitted to journal 24 Feb, 2026 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-8692626","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":601151014,"identity":"f173331d-49cc-42cd-b6bf-c73745f9cd32","order_by":0,"name":"Kyeong Ja Kim","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0UlEQVRIiWNgGAWjYBACCYZjDAcYKhJ4YAIGRGo5Q5oWNgYGxrYEuABhLZKNxxIP3ZyXJiPvfjqBuaKCwdi8gYAWaYZjBw7nbsvhMTyTu4HxzBkGM5kDBLTIMRxvAGqp4DFsAGppbGOwkSDkMIiWOUAt/W+BWv4RoQXisIYcHnkJkC0NDGYEtUg2HEs4nHMsjcdA4u2Ggw3HJIwJapG4ccz4c05Nsr18f+7Ghw01NoYzCGlhkDgAoQ2A9AFQPBEG/A0QWr6BCMWjYBSMglEwMgEAD0lCPynuivAAAAAASUVORK5CYII=","orcid":"","institution":"Korea Institute of Geoscience and Mineral Resources","correspondingAuthor":true,"prefix":"","firstName":"Kyeong","middleName":"Ja","lastName":"Kim","suffix":""},{"id":601151016,"identity":"6369aef6-e8ff-4e07-b80a-cb862706e3cf","order_by":1,"name":"Yire Choi","email":"","orcid":"","institution":"Korea Institute of Geoscience and Mineral Resources","correspondingAuthor":false,"prefix":"","firstName":"Yire","middleName":"","lastName":"Choi","suffix":""},{"id":601151020,"identity":"1414d735-8fda-4cf0-93d7-a29a9b5946df","order_by":2,"name":"Hiroyuki Matsuzaki","email":"","orcid":"","institution":"University of Tokyo","correspondingAuthor":false,"prefix":"","firstName":"Hiroyuki","middleName":"","lastName":"Matsuzaki","suffix":""},{"id":601151025,"identity":"a16d0898-d05f-4136-915e-e0d86aebae13","order_by":3,"name":"Gilyoung Kim","email":"","orcid":"","institution":"Korea Institute of Geoscience and Mineral Resources","correspondingAuthor":false,"prefix":"","firstName":"Gilyoung","middleName":"","lastName":"Kim","suffix":""}],"badges":[],"createdAt":"2026-01-25 13:23:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-8692626/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-8692626/v1","draftVersion":[],"editorialEvents":[],"editorialNote":"","failedWorkflow":false,"files":[{"id":104048807,"identity":"6b19ac50-8337-4326-b782-9bffbb7c6920","added_by":"auto","created_at":"2026-03-06 07:05:26","extension":"jpg","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":268375,"visible":true,"origin":"","legend":"\u003cp\u003eThe coring site U1430 of the IODP Expedition 346 in the Ulleng Basin. Samples from Hole A (short core) and Hole B (long core) were used for this study. The original map is from the Integrated Ocean Drilling Program Expedition 346 Preliminary Report (Expedition 346 Scientists, 2014 \u003ca href=\"http://publications.iodp.org/preliminary_report/346/346PR.PDF\"\u003ehttp://publications.iodp.org/preliminary_report/346/346PR.PDF\u003c/a\u003e ).\u003c/p\u003e","description":"","filename":"1.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8692626/v1/686413d5b42f2c236b42fa3d.jpg"},{"id":104048804,"identity":"4e2c7388-3953-4298-b067-2cdb3231fdac","added_by":"auto","created_at":"2026-03-06 07:05:26","extension":"jpg","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":89729,"visible":true,"origin":"","legend":"\u003cp\u003eComparison of measured and decay-corrected authigenic \u003csup\u003e10\u003c/sup\u003eBe concentrations from Holes U1430A and U1430B. Decay-corrected values reveal a pronounced increase centered at ~10.2 Ma relative to background levels, indicating an anomalous cosmogenic nuclide signal during the late Miocene.\u003c/p\u003e","description":"","filename":"2.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8692626/v1/24c35f58d576d60bbce4f7b1.jpg"},{"id":104048805,"identity":"efba7ba3-af99-4a7f-8202-5efa03b24224","added_by":"auto","created_at":"2026-03-06 07:05:26","extension":"jpg","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":109666,"visible":true,"origin":"","legend":"\u003cp\u003eTemporal variations in authigenic \u003csup\u003e10\u003c/sup\u003eBe, \u003csup\u003e9\u003c/sup\u003eBe, and \u003csup\u003e10\u003c/sup\u003eBe/\u003csup\u003e9\u003c/sup\u003eBe ratios over the past ~11 Myr at Site U1430. Concurrent increases in \u003csup\u003e10\u003c/sup\u003eBe and \u003csup\u003e9\u003c/sup\u003eBe result in elevated \u003csup\u003e10\u003c/sup\u003eBe/\u003csup\u003e9\u003c/sup\u003eBe ratios that deviate from steady-state atmospheric production.\u003c/p\u003e","description":"","filename":"3.jpg","url":"https://assets-eu.researchsquare.com/files/rs-8692626/v1/26d90c9afb48bd04214236ac.jpg"},{"id":104048808,"identity":"280faab5-06d1-4318-b9f1-b9c8d80e5982","added_by":"auto","created_at":"2026-03-06 07:05:26","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":2939464,"visible":true,"origin":"","legend":"\u003cp\u003eAuthigenic rare-earth element (REE) concentrations from Hole U1430B between ~9 and 11 Ma. Peaks in REE concentrations coincide with the \u003csup\u003e10\u003c/sup\u003eBe anomaly interval, suggesting a common forcing mechanism rather than isolated sedimentological effects.\u003c/p\u003e","description":"","filename":"4.png","url":"https://assets-eu.researchsquare.com/files/rs-8692626/v1/557e77f908bf34cffd1b4b10.png"},{"id":104408423,"identity":"8a5befb8-cce8-4a9f-9ee6-2e473aece442","added_by":"auto","created_at":"2026-03-11 12:42:24","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":3992586,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-8692626/v1/b43adae8-754f-4873-a388-27f308f671a9.pdf"},{"id":104402921,"identity":"4c0165e5-8283-4520-8bce-bea5576a624a","added_by":"auto","created_at":"2026-03-11 12:16:55","extension":"docx","order_by":0,"title":"","display":"","copyAsset":false,"role":"supplement","size":1102888,"visible":true,"origin":"","legend":"","description":"","filename":"20260125SupplementalFiguresnaturesubmission.docx","url":"https://assets-eu.researchsquare.com/files/rs-8692626/v1/8fd1ff1c92add1da005f341c.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Event-like enrichment of beryllium isotopes and rare-earth elements at ~10.2 Ma from IODP Site U1430, Ulleung Basin (East Sea)","fulltext":[{"header":"1. Introduction","content":"\u003cp\u003eSupernova explosions and related astrophysical phenomena represent some of the most energetic events in the Galaxy and can significantly influence the interstellar environment surrounding the solar system. Enhanced cosmic-ray fluxes and the delivery of interstellar material associated with such events have been proposed to leave detectable signatures in terrestrial and extraterrestrial archives (Fields et al., 1999; Breitschwerdt et al., 2016). Geological materials, including deep-sea sediments and ferromanganese crusts, provide time-integrated records capable of preserving these signatures over millions of years (Frank, 2002; Wallner et al., 2016).\u003c/p\u003e \u003cp\u003eDirect evidence for nearby supernova activity during the late Pliocene\u0026ndash;Pleistocene has been reported based on the detection of live interstellar radionuclides such as ⁶⁰Fe in marine sediments and lunar regolith (Wallner et al., 2016; Koll et al., 2025). Cosmogenic radionuclides, particularly \u0026sup1;⁰Be, have also been widely used to infer variations in cosmic-ray flux and to investigate potential astrophysical forcing of the Earth system (Fields et al., 1999; Christl et al., 2010; Maconi et al., 2025). In contrast, well-documented marine sedimentary records capturing comparable signals from the Miocene remain scarce, limiting our understanding of Earth\u0026ndash;cosmos interactions on longer geological timescales.\u003c/p\u003e \u003cp\u003eBeryllium isotopes provide a useful framework for investigating transient external inputs recorded in marine sediments. Cosmogenic \u0026sup1;⁰Be is produced primarily by cosmic-ray spallation of atmospheric nitrogen and oxygen and is delivered globally to the ocean via precipitation (Bourl\u0026egrave;s et al., 1989; Masarik and Beer, 2009). Stable ⁹Be is supplied mainly through continental weathering and riverine input and is subsequently scavenged from seawater into marine sediments (von Blanckenburg and Bouchez, 2014; Wittmann et al., 2017). Although authigenic ⁹Be concentrations can vary in response to terrestrial processes such as changes in weathering intensity or particle scavenging efficiency (Anderson et al., 1994; Jeandel and Oelkers, 2015), synchronous and high-amplitude enrichments of both \u0026sup1;⁰Be and ⁹Be are not readily explained by known sedimentary or oceanographic mechanisms.\u003c/p\u003e \u003cp\u003eIODP Expedition 346 Site U1430, located in the Ulleung Basin of the East Sea, is characterized by relatively low sedimentation rates and a continuous Miocene sedimentary sequence (Tada et al., 2015). These characteristics make the site particularly suitable for detecting short-lived, event-like perturbations preserved in marine sediments. In this study, we investigate long-term authigenic beryllium isotope and REE records from two independent sediment cores at Site U1430. We identify a pronounced geochemical anomaly at ~\u0026thinsp;10.2 Ma and evaluate its origin by assessing potential terrestrial mechanisms and its consistency with transient extraterrestrial material input.\u003c/p\u003e"},{"header":"2. Geological setting and age model","content":"\u003cp\u003eSite U1430 is located in the Ulleung Basin of the East Sea, a back-arc basin characterized by hemipelagic sedimentation dominated by biogenic and fine-grained terrigenous material (Tada et al., 2015). The sedimentary sequence recovered at this site spans the Miocene to the Quaternary and exhibits high stratigraphic continuity with minimal tectonic disturbance. Paleoceanographic conditions of the East Sea during the late Miocene were influenced by regional tectonics and evolving circulation patterns, providing a stable depositional environment for recording external geochemical signals (Ikehara et al., 2018).\u003c/p\u003e \u003cp\u003eThe age model for Site U1430 is based on an integrated framework of biostratigraphy, magnetostratigraphy, and orbital tuning, as reported by the IODP Expedition 346 science party (Tada et al., 2015). The ~\u0026thinsp;10.2 Ma interval investigated in this study is well constrained within the late Miocene and is reproduced consistently in both Hole U1430A and Hole U1430B, allowing robust stratigraphic correlation between cores.\u003c/p\u003e"},{"header":"3. Results","content":"\u003cp\u003eAuthigenic fractions were extracted from sediment samples collected from Holes U1430A and U1430B following established leaching protocols designed to isolate seawater-derived components (Bourl\u0026egrave;s et al., 1989; Frank et al., 1997). Decay-corrected cosmogenic \u0026sup1;⁰Be concentrations exhibit a pronounced increase centered at ~\u0026thinsp;10.2 Ma in both sediment cores relative to background values observed above and below this interval. The onset of the \u0026sup1;⁰Be increase is abrupt, and concentrations return toward baseline levels over a relatively short stratigraphic interval.\u003c/p\u003e \u003cp\u003eStable ⁹Be concentrations show a synchronous enrichment during the same interval, increasing by approximately a factor of five relative to background values in both cores. As a result, calculated \u0026sup1;⁰Be/⁹Be ratios reach values more than an order of magnitude higher than those typically reported for marine sediments (Frank et al., 1997; von Blanckenburg and Bouchez, 2014). The coincidence of these changes in two independently recovered sediment cores indicates that the signal is not an artifact of local sediment disturbance or analytical uncertainty.\u003c/p\u003e \u003cp\u003eAuthigenic REE concentrations also increase during the ~\u0026thinsp;10.2 Ma interval. Although individual REE display variable absolute abundances, their overall enrichment pattern is consistent between Holes U1430A and U1430B and coincides with the beryllium isotope anomaly. Such coupled enrichment suggests a common forcing mechanism affecting multiple geochemical proxies. Representative beryllium isotope and REE data spanning the anomaly are summarized in Table\u0026nbsp;\u003cspan refid=\"Tab1\" class=\"InternalRef\"\u003e1\u003c/span\u003e, with the complete dataset provided in the Supplementary Information.\u003c/p\u003e \u003cp\u003e \u003cdiv class=\"gridtable\"\u003e\u003ctable float=\"Yes\" id=\"Tab1\" border=\"1\"\u003e \u003ccaption language=\"En\"\u003e \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e \u003cdiv class=\"CaptionContent\"\u003e \u003cp\u003eResults of this study (\u003csup\u003e10\u003c/sup\u003eBe anomalies in sediment samples of the two cores).\u003c/p\u003e \u003c/div\u003e \u003c/caption\u003e \u003ccolgroup cols=\"7\"\u003e \u003cdiv align=\"left\" class=\"colspec\" colname=\"c1\" colnum=\"1\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c2\" colnum=\"2\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\".\" class=\"colspec\" colname=\"c3\" colnum=\"3\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c4\" colnum=\"4\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c5\" colnum=\"5\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c6\" colnum=\"6\"\u003e\u003c/div\u003e \u003cdiv align=\"char\" char=\"\u0026plusmn;\" class=\"colspec\" colname=\"c7\" colnum=\"7\"\u003e\u003c/div\u003e \u003cthead\u003e \u003ctr\u003e \u003cth align=\"left\" colname=\"c1\"\u003e \u003cp\u003eSample ID\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c2\"\u003e \u003cp\u003eDepth (m)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c3\"\u003e \u003cp\u003eAge (Myr)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c4\"\u003e \u003cp\u003e\u003csup\u003e10\u003c/sup\u003eBe (10\u003csup\u003e5\u003c/sup\u003e at/g) present\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c5\"\u003e \u003cp\u003e\u003csup\u003e10\u003c/sup\u003eBe (10\u003csup\u003e7\u003c/sup\u003e at/g) decay corrected\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c6\"\u003e \u003cp\u003e\u003csup\u003e9\u003c/sup\u003eBe\u003c/p\u003e \u003cp\u003e(10\u003csup\u003e16\u003c/sup\u003e at/g)\u003c/p\u003e \u003c/th\u003e \u003cth align=\"left\" colname=\"c7\"\u003e \u003cp\u003e\u003csup\u003e10\u003c/sup\u003eBe/\u003csup\u003e9\u003c/sup\u003eBe\u003c/p\u003e \u003cp\u003e(10\u003csup\u003e\u0026minus;\u0026thinsp;10\u003c/sup\u003e at/at)\u003c/p\u003e \u003c/th\u003e \u003c/tr\u003e \u003c/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e188.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.04\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e0.27\u0026plusmn;*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e17.34\u0026plusmn;*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e9.69\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.18\u0026plusmn;*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e190.3\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e79.06\u0026thinsp;\u0026plusmn;\u0026thinsp;12.24\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e52.99\u0026thinsp;\u0026plusmn;\u0026thinsp;6.76\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e12.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.29\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.44\u0026thinsp;\u0026plusmn;\u0026thinsp;0.10\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e191.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e20.96\u0026thinsp;\u0026plusmn;\u0026thinsp;25.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e31.33\u0026thinsp;\u0026plusmn;\u0026thinsp;22.85\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e16.65\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.19\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eA07\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e195.3\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.20\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e105.66\u0026thinsp;\u0026plusmn;\u0026thinsp;17.18\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e67.14\u0026thinsp;\u0026plusmn;\u0026thinsp;11.01\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e9.94\u0026thinsp;\u0026plusmn;\u0026thinsp;0.21\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e0.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eA08\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e196.8\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.24\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e196.08\u0026thinsp;\u0026plusmn;\u0026thinsp;12.56\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e105.7\u0026thinsp;\u0026plusmn;\u0026thinsp;4.44\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e15.68\u0026thinsp;\u0026plusmn;\u0026thinsp;0.45\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e0.67\u0026thinsp;\u0026plusmn;\u0026thinsp;0.08\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eA09\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e198.3\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.28\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e285.11\u0026thinsp;\u0026plusmn;\u0026thinsp;18.17\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e145.11\u0026thinsp;\u0026plusmn;\u0026thinsp;7.87\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e12.36\u0026thinsp;\u0026plusmn;\u0026thinsp;0.50\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e1.17\u0026thinsp;\u0026plusmn;\u0026thinsp;0.16\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eA10\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e199.8\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.31\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e197.94\u0026thinsp;\u0026plusmn;\u0026thinsp;12.27\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e110.49\u0026thinsp;\u0026plusmn;\u0026thinsp;6.5752\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e10.91\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e1.01\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e201.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e30.38\u0026thinsp;\u0026plusmn;\u0026thinsp;20.60\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e39.31\u0026thinsp;\u0026plusmn;\u0026thinsp;21.81\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e12.24\u0026thinsp;\u0026plusmn;\u0026thinsp;0.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.17\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e206.0\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.47\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e0.27\u0026plusmn;*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e17.49\u0026plusmn;*\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e11.80\u0026thinsp;\u0026plusmn;\u0026thinsp;0.31\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.15\u0026plusmn;*\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eA13\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e207.5\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e20.35\u0026thinsp;\u0026plusmn;\u0026thinsp;26.90\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e37.84\u0026thinsp;\u0026plusmn;\u0026thinsp;69.50\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e7.20\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.37\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB118\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e188.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.05\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e18.71\u0026thinsp;\u0026plusmn;\u0026thinsp;11.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e27.97\u0026thinsp;\u0026plusmn;\u0026thinsp;16.53\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e5.46\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.34\u0026thinsp;\u0026plusmn;\u0026thinsp;0.25\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB119\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e191.6\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.11\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e16.04\u0026thinsp;\u0026plusmn;\u0026thinsp;11.07\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e24.76\u0026thinsp;\u0026plusmn;\u0026thinsp;17.09\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e4.16\u0026thinsp;\u0026plusmn;\u0026thinsp;0.28\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.39\u0026thinsp;\u0026plusmn;\u0026thinsp;0.20\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB120\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e192.9\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.15\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e29.41\u0026thinsp;\u0026plusmn;\u0026thinsp;11.32\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e46.17\u0026thinsp;\u0026plusmn;\u0026thinsp;17.77\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e3.84\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.77\u0026thinsp;\u0026plusmn;\u0026thinsp;0.27\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eB121\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e194.3\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.18\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e45.45\u0026thinsp;\u0026plusmn;\u0026thinsp;11.14\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e72.57\u0026thinsp;\u0026plusmn;\u0026thinsp;17.79\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e4.32\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e1.05\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eB122\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e195.7\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.21\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e329.02\u0026thinsp;\u0026plusmn;\u0026thinsp;18.10\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e534.37\u0026thinsp;\u0026plusmn;\u0026thinsp;29.40\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e21.37\u0026thinsp;\u0026plusmn;\u0026thinsp;0.70\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e1.54\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eB123\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e197.1\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.25\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e117.62\u0026thinsp;\u0026plusmn;\u0026thinsp;13.13\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e194.29\u0026thinsp;\u0026plusmn;\u0026thinsp;21.69\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e4.53\u0026thinsp;\u0026plusmn;\u0026thinsp;0.15\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e2.60\u0026thinsp;\u0026plusmn;\u0026thinsp;0.098\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003e\u003cem\u003eB124\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e\u003cem\u003e198.4\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e\u003cem\u003e10.28\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e\u003cem\u003e168.42\u0026thinsp;\u0026plusmn;\u0026thinsp;14.26\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e\u003cem\u003e282.9\u0026thinsp;\u0026plusmn;\u0026thinsp;23.96\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e\u003cem\u003e4.50\u0026thinsp;\u0026plusmn;\u0026thinsp;0.18\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e\u003cem\u003e3.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30\u003c/em\u003e\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB125\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e203.2\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.40\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e24.06\u0026thinsp;\u0026plusmn;\u0026thinsp;11.08\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e42.84\u0026thinsp;\u0026plusmn;\u0026thinsp;19.73\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e3.23\u0026thinsp;\u0026plusmn;\u0026thinsp;0.14\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.75\u0026thinsp;\u0026plusmn;\u0026thinsp;0.35\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB126\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e204.8\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.44\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e5.35\u0026thinsp;\u0026plusmn;\u0026thinsp;11.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e9.71\u0026thinsp;\u0026plusmn;\u0026thinsp;20.03\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e4.21\u0026thinsp;\u0026plusmn;\u0026thinsp;0.30\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.13\u0026thinsp;\u0026plusmn;\u0026thinsp;0.34\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003ctr\u003e \u003ctd align=\"left\" colname=\"c1\"\u003e \u003cp\u003eB127\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c2\"\u003e \u003cp\u003e206.4\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\".\" colname=\"c3\"\u003e \u003cp\u003e10.48\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c4\"\u003e \u003cp\u003e18.71\u0026thinsp;\u0026plusmn;\u0026thinsp;21.06\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c5\"\u003e \u003cp\u003e34.67\u0026thinsp;\u0026plusmn;\u0026thinsp;39.02\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c6\"\u003e \u003cp\u003e4.90\u0026thinsp;\u0026plusmn;\u0026thinsp;0.12\u003c/p\u003e \u003c/td\u003e \u003ctd align=\"char\" char=\"\u0026plusmn;\" colname=\"c7\"\u003e \u003cp\u003e0.38\u0026thinsp;\u0026plusmn;\u0026thinsp;0.26\u003c/p\u003e \u003c/td\u003e \u003c/tr\u003e \u003c/tbody\u003e \u003c/colgroup\u003e \u003ctfoot\u003e \u003ctr\u003e\u003ctd colspan=\"7\"\u003e\u003cem\u003eNote: The sample ID is given as sample processing ID of this study and the depths of samples used for this study can be found at the IODP Expedition 346 site (IODP 2020a). * stands for large error associated due to the detection limit of AMS.\u003c/em\u003e\u003c/td\u003e\u003c/tr\u003e \u003c/tfoot\u003e \u003c/table\u003e\u003c/div\u003e \u003c/p\u003e"},{"header":"4. Discussion","content":"\u003cdiv id=\"Sec5\" class=\"Section2\"\u003e \u003ch2\u003e4.1 Event-like nature of the ~\u0026thinsp;10.2 Ma anomaly\u003c/h2\u003e \u003cp\u003eThe geochemical anomaly identified at ~\u0026thinsp;10.2 Ma exhibits several characteristics indicative of an event-like perturbation rather than a gradual environmental change. These include an abrupt onset, high amplitude, short stratigraphic duration, and reproducibility in two independent sediment cores. Gradual processes such as changes in sedimentation rate, continental weathering, or ocean circulation typically produce smooth, low-frequency variations in authigenic element concentrations, rather than sharp, transient excursions of the magnitude observed here (Frank, 2002).\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section2\"\u003e \u003ch2\u003e4.2 Constraints from coupled behavior of \u0026sup1;⁰Be and ⁹Be\u003c/h2\u003e \u003cp\u003eAlthough authigenic ⁹Be concentrations can vary under terrestrial conditions, such variability generally reflects long-term changes in weathering intensity or scavenging efficiency and does not coincide with sharp peaks in cosmogenic \u0026sup1;⁰Be (Anderson et al., 1994; von Blanckenburg and Bouchez, 2014). The synchronous enrichment of stable ⁹Be with decay-corrected \u0026sup1;⁰Be at ~\u0026thinsp;10.2 Ma therefore places strong constraints on explanations based solely on sedimentary, volcanic, redox-controlled, or oceanographic processes.\u003c/p\u003e \u003cp\u003eThe exceptionally elevated \u0026sup1;⁰Be/⁹Be ratios observed during the anomaly further argue against purely terrestrial mechanisms. Processes capable of increasing ⁹Be alone cannot readily account for the simultaneous enhancement of cosmogenic \u0026sup1;⁰Be to the magnitude observed in both cores.\u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec7\" class=\"Section2\"\u003e \u003ch2\u003e4.3 Consistency with extraterrestrial material input\u003c/h2\u003e \u003cp\u003eIn addition to atmospheric production, stable ⁹Be can be introduced into the Earth system through the deposition of extraterrestrial material, including cosmic dust associated with enhanced interstellar particle flux (Fields et al., 1999; Fitoussi et al., 2008). Such material is expected to contain both newly produced cosmogenic nuclides and stable light elements. In this context, the synchronous enrichment of ⁹Be, decay-corrected \u0026sup1;⁰Be, and authigenic REE at ~\u0026thinsp;10.2 Ma is consistent with a transient external material input.\u003c/p\u003e \u003cp\u003eAstrophysical models predict clustered supernova activity in the solar neighborhood during the Miocene, associated with the formation and evolution of the Local Bubble (Breitschwerdt et al., 2016; Maconi et al., 2025). While direct measurement of additional interstellar radionuclides such as ⁶⁰Fe would provide an independent test of this interpretation (Wallner et al., 2016; Koll et al., 2025), the internally consistent multi-proxy geochemical evidence presented here provides robust constraints on the origin of the observed anomaly.\u003c/p\u003e \u003c/div\u003e"},{"header":"5. Conclusions","content":"\u003cp\u003eMarine sediments from IODP Site U1430 record a pronounced event-like geochemical anomaly at ~\u0026thinsp;10.2 Ma marked by synchronous enrichment of decay-corrected cosmogenic \u0026sup1;⁰Be, stable ⁹Be, and authigenic rare-earth elements. The magnitude, abrupt onset, and coupled behavior of these proxies are inconsistent with known terrestrial processes and are consistent with transient extraterrestrial material input. These findings extend the geological record of such event-like perturbations into the Miocene and demonstrate the potential of long, low-sedimentation marine archives to preserve signatures of Earth\u0026ndash;cosmos interactions over deep time.\u003c/p\u003e"},{"header":"Declarations","content":"\u003ch2\u003eAuthor Contribution\u003c/h2\u003e\u003cp\u003eKyeong Ja Kim conceived and designed the study, figure preparation, interpreted the data, and wrote the manuscript.Yire Choi contributed to sample preparation, data analysisHiroyuki Matsuzaki conducted accelerator mass spectrometry measurements and contributed to data interpretation.Gilyoung Kim contributed to the interpretation of geochemical data and provided critical scientific input.All authors reviewed and approved the final manuscript.\u003c/p\u003e\u003ch2\u003eAcknowledgement\u003c/h2\u003e \u003cp\u003eThe study was financially supported by the project (Korea-IODP) of the Korea Institute of Marine Science and Technology. We thank to the curator of the IODP Expedition 346 for providing research samples of U1430. This study also partially supported by the research projects (KIGAM 20-9852, KIGAM 26-3225) of the Korea Institute of Geoscience and Mineral Resources, funded by the Ministry of Science and ICT of the Republic of Korea.\u003c/p\u003e\u003ch2\u003eData Availability\u003c/h2\u003e\u003cp\u003eThe datasets generated and/or analyzed during the current study are available in the Zenodo repository, https://doi.org/10.5281/zenodo.18744656.\u003c/p\u003e\u003cp\u003e\u003cstrong\u003eFunding Declaration\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis research was supported by the International Ocean Discovery Program (grant no. 20110183), funded by the Ministry of Oceans and Fisheries of the Republic of Korea.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\u003cli\u003e\u003cspan\u003eFields, B. D., Pavlidou, V. \u0026amp; Prodanović, T. 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Geol.\u003c/em\u003e \u003cb\u003e403\u003c/b\u003e, 1\u0026ndash;15 (2018).\u003c/span\u003e\u003c/li\u003e\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":false,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"beryllium-10, iron-60, supernova, Pacific Ocean, authigenic, IODP","lastPublishedDoi":"10.21203/rs.3.rs-8692626/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-8692626/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMarine sedimentary archives can preserve transient perturbations to the Earth system, including potential inputs of extraterrestrial material. While evidence for nearby supernova activity during the late Pliocene–Pleistocene has been identified using cosmogenic and interstellar radionuclides (Wallner et al., 2016; Koll et al., 2025), comparable records from older Miocene sediments remain limited. Here we present authigenic beryllium isotope (¹⁰Be and ⁹Be) and rare-earth element (REE) records from Integrated Ocean Drilling Program (IODP) Expedition 346 Site U1430 in the Ulleung Basin (East Sea). A pronounced anomaly centered at ~ 10.2 Ma is characterized by a sudden, high-amplitude increase in decay-corrected cosmogenic ¹⁰Be accompanied by synchronous enrichment of stable ⁹Be and authigenic REE, observed independently in two sediment cores. The magnitude, abrupt onset, and short stratigraphic duration of this coupled signal are inconsistent with gradual sedimentary, climatic, or oceanographic processes alone. Although authigenic ⁹Be can vary under terrestrial conditions (von Blanckenburg and Bouchez, 2014), its coeval enrichment with cosmogenic ¹⁰Be indicates an event-like perturbation consistent with transient extraterrestrial material input. These results provide robust geochemical constraints on an anomalous external contribution to the Earth system during the late Miocene.\u003c/p\u003e","manuscriptTitle":"Event-like enrichment of beryllium isotopes and rare-earth elements at ~10.2 Ma from IODP Site U1430, Ulleung Basin (East Sea)","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2026-03-06 07:05:21","doi":"10.21203/rs.3.rs-8692626/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2026-03-31T09:27:34+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-30T16:33:34+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"268694310719639571139953600877266878255","date":"2026-03-16T13:07:00+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2026-03-15T13:46:29+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"102825156912112888848783072849527964887","date":"2026-03-04T00:10:02+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2026-03-03T06:48:11+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2026-03-03T06:02:15+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2026-02-24T14:54:45+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2026-02-24T06:17:53+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2026-02-24T06:13:54+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"c2ff1f37-9944-4755-aac3-d10b4d4a017b","owner":[],"postedDate":"March 6th, 2026","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"under-review","subjectAreas":[{"id":63976460,"name":"Earth and environmental sciences/Biogeochemistry"},{"id":63976461,"name":"Earth and environmental sciences/Climate sciences"},{"id":63976462,"name":"Earth and environmental sciences/Ocean sciences"},{"id":63976463,"name":"Earth and environmental sciences/Planetary science"},{"id":63976464,"name":"Earth and environmental sciences/Solid earth sciences"}],"tags":[],"updatedAt":"2026-04-15T08:26:04+00:00","versionOfRecord":[],"versionCreatedAt":"2026-03-06 07:05:21","video":"","vorDoi":"","vorDoiUrl":"","workflowStages":[]},"version":"v1","identity":"rs-8692626","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-8692626","identity":"rs-8692626","version":["v1"]},"buildId":"XKTyCvWXoU3ODBz1xrDgd","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}