eprintid: 1462110 rev_number: 31 eprint_status: archive userid: 608 dir: disk0/01/46/21/10 datestamp: 2015-02-16 19:38:43 lastmod: 2021-09-20 22:22:04 status_changed: 2015-02-16 19:38:43 type: article metadata_visibility: show item_issues_count: 0 creators_name: von Strandmann, PAEP creators_name: Dohmen, R creators_name: Marschall, HR creators_name: Schumacher, JC creators_name: Elliott, T title: Extreme Magnesium Isotope Fractionation at Outcrop Scale Records the Mechanism and Rate at which Reaction Fronts Advance ispublished: pub divisions: UCL divisions: B04 divisions: C06 divisions: F57 keywords: diffusion, isotope, metasomatism, monomineralic note: This is a pre-copyedited, author-produced PDF of an article accepted for publication in von Strandmann, PAEP; Dohmen, R; Marschall, HR; Schumacher, JC; Elliott, T; (2015) Extreme Magnesium Isotope Fractionation at Outcrop Scale Records the Mechanism and Rate at which Reaction Fronts Advance. Journal of Petrology, 56 (1) 33 - 58. 10.1093/petrology/egu070, following peer review. The version of record [insert complete citation information here] is available online at: http://dx.doi.org/10.1093/petrology/egu070 abstract: Isotopic fractionation of cationic species during diffusive transport provides a novel means of constraining the style and timing of metamorphic transformations. Here we document a major (∼1‰) decrease in the Mg isotopic composition of the reaction front of an exhumed contact between rocks of subducted crust and serpentinite in the Syros mélange zone. This isotopic perturbation extends over a notable length scale (∼1 m), implicating diffusion of Mg through an intergranular fluid network over a period of ∼100 kyr. These novel observations confirm models of diffusion-controlled growth of reaction zones formed between rocks of contrasting compositions, such as found at the slab–mantle interface in subduction zones. The results also demonstrate that diffusive processes can result in exotic stable isotope compositions of major elements with implications for mantle xenoliths and complex intrusions. date: 2015-01 official_url: http://dx.doi.org/10.1093/petrology/egu070 vfaculties: VMPS oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_source: WoS-Lite elements_id: 1013303 doi: 10.1093/petrology/egu070 lyricists_name: Pogge Von Strandmann, Philip lyricists_id: PPOGG57 full_text_status: public publication: Journal of Petrology volume: 56 number: 1 pagerange: 33 - 58 issn: 0022-3530 citation: von Strandmann, PAEP; Dohmen, R; Marschall, HR; Schumacher, JC; Elliott, T; (2015) Extreme Magnesium Isotope Fractionation at Outcrop Scale Records the Mechanism and Rate at which Reaction Fronts Advance. Journal of Petrology , 56 (1) 33 - 58. 10.1093/petrology/egu070 <https://doi.org/10.1093/petrology%2Fegu070>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/1462110/1/Syros%20Mg%20JPet%20final.pdf