Hidden Early Clinopyroxene Relicts Record Reactive Porous Flow in Oceanic Plutonic Series.
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| Title: | Hidden Early Clinopyroxene Relicts Record Reactive Porous Flow in Oceanic Plutonic Series. |
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| Authors: | Falc'hun, Cloé1 (AUTHOR), France, Lydéric2 (AUTHOR) |
| Source: | Journal of Petrology. Feb2026, Vol. 67 Issue 2, p1-10. 10p. |
| Subject Terms: | *Pyroxene, *Mid-ocean ridges, *Igneous rocks, *Geochemical modeling |
| Abstract: | Almost two-thirds of the Earth's magmatic budget is concentrated at mid-ocean ridges, with 85% of this being emplaced as intrusive rocks. In these systems, now understood to consist mostly of a crystal-dominated igneous medium (mush), melt differentiation at depth is predominantly governed by melt-mush reactions. These reactions have been well described for primitive lithologies (ranging from troctolite to gabbro) and are characterized by disequilibrium processes between a reactive melt and the crystal framework through which it percolates. This leads to mineral assimilation and crystallization reactions. Although thermodynamic and geochemical models (assimilation and fractional crystallization) consistently indicate the need for clinopyroxene assimilation in the case of a gabbroic mush, petrographic observations have only revealed poikilitic and late interstitial clinopyroxene interpreted as a late crystallizing phase. Here, we present chromium and titanium chemical maps of an apparently interstitial poikilitic clinopyroxene from ODP Hole 735B, Southwest Indian Ridge. We present key evidence for Cr-rich amoeboidal clinopyroxene relicts preserved within the larger poikilitic grains. In this reactive context, these primitive relicts are remnants of earlier clinopyroxene assimilation. Accordingly, clinopyroxene may be present early in oceanic plutonic crystallization, at least at slow- and ultraslow-spreading ridges, and it must participate in assimilation reactions occurring during the reactive porous flow differentiation process. [ABSTRACT FROM AUTHOR] |
| Database: | Energy & Power Source |
| FullText | Text: Availability: 0 |
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| Header | DbId: enr DbLabel: Energy & Power Source An: 192033589 AccessLevel: 6 PubType: Academic Journal PubTypeId: academicJournal PreciseRelevancyScore: 0 |
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| Items | – Name: Title Label: Title Group: Ti Data: Hidden Early Clinopyroxene Relicts Record Reactive Porous Flow in Oceanic Plutonic Series. – Name: Author Label: Authors Group: Au Data: <searchLink fieldCode="AR" term="%22Falc'hun%2C+Cloé%22">Falc'hun, Cloé</searchLink><relatesTo>1</relatesTo> (AUTHOR)<br /><searchLink fieldCode="AR" term="%22France%2C+Lydéric%22">France, Lydéric</searchLink><relatesTo>2</relatesTo> (AUTHOR) – Name: TitleSource Label: Source Group: Src Data: <searchLink fieldCode="JN" term="%22Journal+of+Petrology%22">Journal of Petrology</searchLink>. Feb2026, Vol. 67 Issue 2, p1-10. 10p. – Name: Subject Label: Subject Terms Group: Su Data: *<searchLink fieldCode="DE" term="%22Pyroxene%22">Pyroxene</searchLink><br />*<searchLink fieldCode="DE" term="%22Mid-ocean+ridges%22">Mid-ocean ridges</searchLink><br />*<searchLink fieldCode="DE" term="%22Igneous+rocks%22">Igneous rocks</searchLink><br />*<searchLink fieldCode="DE" term="%22Geochemical+modeling%22">Geochemical modeling</searchLink> – Name: Abstract Label: Abstract Group: Ab Data: Almost two-thirds of the Earth's magmatic budget is concentrated at mid-ocean ridges, with 85% of this being emplaced as intrusive rocks. In these systems, now understood to consist mostly of a crystal-dominated igneous medium (mush), melt differentiation at depth is predominantly governed by melt-mush reactions. These reactions have been well described for primitive lithologies (ranging from troctolite to gabbro) and are characterized by disequilibrium processes between a reactive melt and the crystal framework through which it percolates. This leads to mineral assimilation and crystallization reactions. Although thermodynamic and geochemical models (assimilation and fractional crystallization) consistently indicate the need for clinopyroxene assimilation in the case of a gabbroic mush, petrographic observations have only revealed poikilitic and late interstitial clinopyroxene interpreted as a late crystallizing phase. Here, we present chromium and titanium chemical maps of an apparently interstitial poikilitic clinopyroxene from ODP Hole 735B, Southwest Indian Ridge. We present key evidence for Cr-rich amoeboidal clinopyroxene relicts preserved within the larger poikilitic grains. In this reactive context, these primitive relicts are remnants of earlier clinopyroxene assimilation. Accordingly, clinopyroxene may be present early in oceanic plutonic crystallization, at least at slow- and ultraslow-spreading ridges, and it must participate in assimilation reactions occurring during the reactive porous flow differentiation process. [ABSTRACT FROM AUTHOR] |
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| RecordInfo | BibRecord: BibEntity: Identifiers: – Type: doi Value: 10.1093/petrology/egag004 Languages: – Code: eng Text: English PhysicalDescription: Pagination: PageCount: 10 StartPage: 1 Subjects: – SubjectFull: Pyroxene Type: general – SubjectFull: Mid-ocean ridges Type: general – SubjectFull: Igneous rocks Type: general – SubjectFull: Geochemical modeling Type: general Titles: – TitleFull: Hidden Early Clinopyroxene Relicts Record Reactive Porous Flow in Oceanic Plutonic Series. Type: main BibRelationships: HasContributorRelationships: – PersonEntity: Name: NameFull: Falc'hun, Cloé – PersonEntity: Name: NameFull: France, Lydéric IsPartOfRelationships: – BibEntity: Dates: – D: 01 M: 02 Text: Feb2026 Type: published Y: 2026 Identifiers: – Type: issn-print Value: 00223530 Numbering: – Type: volume Value: 67 – Type: issue Value: 2 Titles: – TitleFull: Journal of Petrology Type: main |
| ResultId | 1 |
