%0 Conference Paper %F Poster %T Melt-rock interactions in south armorican peridotites %+ Bureau de Recherches Géologiques et Minières (BRGM) (BRGM) %+ Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG) %A Aertgeerts, Geoffrey %A Lorand, Jean-Pierre %A Monnier, Christophe %A La, Carole %< avec comité de lecture %B Goldschmidt 2017 %C Paris, France %8 2017-08-13 %D 2017 %K South Armorican Massif %K Peridotites %K Melt-rock interaction %K Champtoceaux %K Audierne %Z Sciences of the Universe [physics]/Earth Sciences/Geochemistry %Z Sciences of the Universe [physics]/Earth Sciences/PetrographyConference poster %X Five occurrences (four from Champtoceaux; one from Audierne) of South Armorican (SA) serpentinized peridotites were studied using optical microscopy, EMP, ICP-OES, solution ICPMS and laser ablation-ICPMS. Their whole-rock major and trace element contents are characteristic of mantle-derived peridotites. All but one Champtoceaux lherzolite occurrence are harzburgites that have experienced 12 to 25% partial melting (0.57900°C with small-volume HIE-enriched melt/fluids that produced 10-15 vol. % of colourless, sometimes twinned, Ti-poor pargasites from clinopyroxene and spinel. The Audierne samples were pervasively refertilized by water-rich alkali-rich melts that precipitated K- and Cr-richer, low-Ti pargasite. Our new data identify SA peridotites as pieces of residual mantle that were processed with slab-derived melt/fluids in supra-subduction zone settings. %G English %2 https://brgm.hal.science/hal-01518861/document %2 https://brgm.hal.science/hal-01518861/file/Goldschmidt_Abstract_Lorand.pdf %L hal-01518861 %U https://brgm.hal.science/hal-01518861 %~ INSU %~ UNIV-NANTES %~ BRGM %~ CNRS %~ UNIV-ANGERS %~ GIP-BE %~ LPG %~ NANTES-UNIVERSITE %~ UNIV-NANTES-AV2022