Boninite-like intraplate magmas from Manihiki Plateau require ultra-depleted and enriched source components

Roman Golowin*, Maxim Portnyagin, Kaj Hoernle, Folkmar Hauff, Andrey Gurenko, Dieter Garbe-Schönberg, Reinhard Werner, Simon Turner

*Corresponding author for this work

Research output: Contribution to journalArticle

19 Citations (Scopus)

Abstract

The Ontong Java and Manihiki oceanic plateaus are believed to have formed through high-degree melting of a mantle plume head. Boninite-like, low-Ti basement rocks at Manihiki, however, imply a more complex magma genesis compared with Ontong Java basement lavas that can be generated by ~30% melting of a primitive mantle source. Here we show that the trace element and isotope compositions of low-Ti Manihiki rocks can best be explained by re-melting of an ultra-depleted source (possibly a common mantle component in the Ontong Java and Manihiki plume sources) re-enriched by ≤1% of an ocean-island-basalt-like melt component. Unlike boninites formed via hydrous flux melting of refractory mantle at subduction zones, these boninite-like intraplate rocks formed through adiabatic decompression melting of refractory plume material that has been metasomatized by ocean-island-basalt-like melts. Our results suggest that caution is required before assuming all Archaean boninites were formed in association with subduction processes.

Original languageEnglish
Article number14322
Pages (from-to)1-10
Number of pages10
JournalNature Communications
Volume8
DOIs
Publication statusPublished - 9 Feb 2017

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Copyright the Author(s) 2017. Version archived for private and non-commercial use with the permission of the author/s and according to publisher conditions. For further rights please contact the publisher.

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