{
  "abstract": "Submarine petit-spot volcanoes form where oceanic plates bend and flex before sinking into subduction zones, providing a rare opportunity to sample mantle-derived melts before subduction. Here we report results from the first scientific drilling of a sediment-buried petit-spot volcano during International Ocean Drilling Programme Expedition 502, recovering basalts from a previously inaccessible interior of a petit-spot magmatic system. The recovered basalts exhibit a distinctive geochemical signature among oceanic intraplate magmas, combining Ni-rich olivine phenocrysts with unusually low Mg/(Mg + Fe2+), SiO2-rich bulk compositions, pronounced Ba enrichment and Th–U–Nb–Ta depletion, and the most enriched mantle 1 (EM1)-like Sr–Nd isotopic compositions yet recognized in petit-spot basalts. Thermodynamic modelling rules out fractional crystallization of dry or carbonated peridotite-derived parent melts and requires a contribution from enriched SiO2-excess pyroxenite. Fresh glasses further record CO2 depletion and low vesicularity relative to exposed petit-spot basalts. These findings reveal the petrological complexity of known EM1-type mantle heterogeneity, with isotopic signatures that can mask diverse mantle lithologies and melting processes that remain hidden from conventional seafloor sampling.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 44,
  "authors": [
    {
      "name": "Norikatsu Akizawa"
    },
    {
      "name": "Kazuto Mikuni"
    },
    {
      "name": "Jennifer M. Lington"
    },
    {
      "name": "Christopher Yen"
    },
    {
      "name": "Takashi Miyazaki"
    },
    {
      "name": "Francesco Narduzzi"
    },
    {
      "name": "Takanori Kagoshima"
    },
    {
      "name": "Katie Preece"
    },
    {
      "name": "Hayato Ueda"
    },
    {
      "name": "Paola Vannucchi"
    },
    {
      "name": "Lottie Atton"
    },
    {
      "name": "Hirano Naoto"
    },
    {
      "name": "Shiki Machida"
    },
    {
      "name": "Takeshi Hanyu"
    },
    {
      "name": "Tomoki Sato"
    },
    {
      "name": "Bogdan S. Vaglarov"
    },
    {
      "name": "Qing Chang"
    },
    {
      "name": "Yuto Sato"
    },
    {
      "name": "Kenji Shimizu"
    },
    {
      "name": "Takayuki Ushikubo"
    },
    {
      "name": "Asuka Yamaguchi"
    },
    {
      "name": "Hiroko Kitajima"
    },
    {
      "name": "Natsumi Okutsu"
    },
    {
      "name": "Yuya Akamatsu"
    },
    {
      "name": "Olivier Fabbri"
    },
    {
      "name": "Matt J. Ikari"
    },
    {
      "name": "Taro Kido"
    },
    {
      "name": "Rachel Lauer"
    },
    {
      "name": "Kenji M. Matsuzaki"
    },
    {
      "name": "Ayumu Miyakawa"
    },
    {
      "name": "Yasuyuki Nakamura"
    },
    {
      "name": "Hanaya Okuda"
    },
    {
      "name": "Andrew P. Roberts"
    },
    {
      "name": "Louisa H. Stokes"
    },
    {
      "name": "Fuka Takuwa"
    },
    {
      "name": "Taizo Uchida"
    },
    {
      "name": "Edoardo Barbero"
    },
    {
      "name": "Chin-Yeh Chen"
    },
    {
      "name": "Jose-Abel Flores"
    },
    {
      "name": "Mila Huebsch"
    },
    {
      "name": "Yuji Kato"
    },
    {
      "name": "Eun Young Lee"
    },
    {
      "name": "Jason P. Morgan"
    },
    {
      "name": "Sebastien Pilet"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/50x1p05y0vq5s.bib",
  "cited_by": 0,
  "doi": "10.31223/x5db90",
  "fulltext_url": null,
  "id": "50x1p05y0vq5s",
  "issns": [],
  "landing_url": "https://eartharxiv.org/repository/view/15421/",
  "language": null,
  "licence": "CC-BY-NC-SA-4.0",
  "licence_label": "CC BY-NC-SA 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by-nc-sa/4.0/legalcode",
  "metadata_licence": null,
  "native_subjects": [
    [
      "bepress",
      "Basalt"
    ],
    [
      "bepress",
      "Geochemistry"
    ],
    [
      "bepress",
      "Geology"
    ],
    [
      "bepress",
      "IODP3"
    ],
    [
      "bepress",
      "Mantle"
    ],
    [
      "bepress",
      "Nd–Sr isotopes"
    ],
    [
      "bepress",
      "Petit-spot"
    ],
    [
      "openalex",
      "1908|Geological and Geochemical Analysis"
    ]
  ],
  "openalex": "W7221163851",
  "pdf_url": "https://eartharxiv.org/repository/object/15421/download/26737/",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/50x1p05y0vq5s.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:42Z",
      "native_id": "15421",
      "source": "eartharxiv",
      "url": "https://eartharxiv.org/repository/view/15421/"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "bepress:Geochemistry",
      "subfield": "geology-geochemistry"
    }
  ],
  "title": "Drilled petit-spot basalts reveal asthenospheric mantle heterogeneity before subduction",
  "title_text": "Drilled petit-spot basalts reveal asthenospheric mantle heterogeneity before subduction",
  "type": "preprint",
  "updated_at": "2026-10-30T12:17:42Z",
  "url": "https://research.draconitic.com/paper/50x1p05y0vq5s",
  "venue": "EarthArXiv",
  "versions": []
}