{
  "abstract": "The dichotomy between partial melting and metasomatism is a paradigm of mantle geochemistry since the pioneering work of Frey and Prinz (1978) on the occurrence of LREE-enriched harzburgites. However, the thermo-chemical implications of such two-stage scenarios are often poorly considered, and the latter fail to explain why trace-element enrichment and major-element depletion are often proportional. We here re-envisage the petrogenesis of the famous San Carlos peridotites based on new petrographic observations and detailed modal, major- and trace-element compositions. The lherzolites (and pyroxenites) are characterized by homogeneously fertile mineral chemistry and LREE-depleted patterns consistent with low degrees of partial melting of the lherzolitic protolith. Bulk compositions and mineral zoning suggest that opx-rich pyroxenites formed by pressure-solution creep during melt-present deformation, locally accompanied by magmatic segregations of cpx. The harzburgites are characterized by stronger mineral zoning with low-Mg# and Na-, Al- and Cr-rich cpx rims, and can be discriminated in a low-Jd and high-Jd cpx groups. The high-Jd group is interpreted as the result of local elemental redistribution in the presence of a low-degree hydrous melt, in good agreement with their wide range of LREE enrichment. In contrast, the MREE-to-HREE fractionation and increasing Cr# in spinel of the low-Jd group indicate that they experienced higher degrees of melting. Open-system melting simulations of trace-element fractionation during hydrous flux melting suggests that the high-Jd harzburgites are the result of low fluid influx producing poorly extracted melt, while higher influx led to higher melting degrees and efficient melt extraction in the low-Jd harzburgites; the lherzolites mostly remained below or near solidus during that process. The lithological and chemical heterogeneity of San Carlos mantle is thus compatible with a single-stage evolution, which is also supported by the striking consistency between Fe-Mg exchange and REE thermometric estimates (1057 and 1074 °C on average, respectively), indicating that harzburgites and lherzolites probably followed a similar P-T path and relatively little sub-solidus re-equilibration. These interpretations suggest that the development of melt extraction pathways promoted by reactive channeling instability is able to produce complex lithological heterogeneities during hydrous flux melting. This process provides a self-consistent explanation for the systematic enrichment of harzburgites observed in many mantle terranes and xenoliths worldwide. We argue that San Carlos is one of such examples where a ca 1.5-Ga continental lithosphere experienced localized flux melting and deformation during the tectonic reactivation of a Proterozoic subduction zone, providing new constraints on the mantle sources of volcanic activity in the Jemez Lineament.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 5,
  "authors": [
    {
      "name": "Romain Tilhac"
    },
    {
      "name": "Tomoaki Morishita"
    },
    {
      "name": "Natsumi Hanaue"
    },
    {
      "name": "Akihiro Tamura"
    },
    {
      "name": "Juan Miguel Guotana"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/3x7gky049gg13.bib",
  "cited_by": 12,
  "doi": "10.1016/j.lithos.2021.106195",
  "fulltext_url": null,
  "id": "3x7gky049gg13",
  "issns": [
    "0024-4937",
    "1872-6143"
  ],
  "landing_url": "https://hal.science/hal-05784314v1",
  "language": "en",
  "licence": "CC-BY",
  "licence_label": "CC BY",
  "licence_source": "journal",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "hal",
      "0.sdu"
    ],
    [
      "hal",
      "1.sdu.stu"
    ],
    [
      "hal",
      "2.sdu.stu.gc"
    ],
    [
      "openalex",
      "1908|Geological and Geochemical Analysis"
    ]
  ],
  "openalex": "W3159796162",
  "pdf_url": "https://www.sciencedirect.com/science/article/pii/S0024493721002310/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-07",
  "publisher": "Elsevier",
  "ris": "https://research.draconitic.com/paper/3x7gky049gg13.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:50Z",
      "native_id": "hal-05784314",
      "source": "hal",
      "url": "https://hal.science/hal-05784314v1"
    }
  ],
  "subjects": [
    {
      "field": "earth",
      "origin": "hal:2.sdu.stu.gc",
      "subfield": "geology-geochemistry"
    }
  ],
  "title": "Systematic LREE enrichment of mantle harzburgites: The petrogenesis of San Carlos xenoliths revisited",
  "title_text": "Systematic LREE enrichment of mantle harzburgites: The petrogenesis of San Carlos xenoliths revisited",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:50Z",
  "url": "https://research.draconitic.com/paper/3x7gky049gg13",
  "venue": "Lithos",
  "versions": []
}