Fertile components of the NE Atlantic mantle - Minor elements and O-isotopes in olivine phenocrysts

Abstract

Primitive off-rift basalts in Iceland and Jan Mayen sample subcontinental lithospheric mantle (SCLM) in addition to the Iceland plume with recycled oceanic crust (ROC) and meltdepleted or primitive lower mantle material [1]. The SCLM/ROC-ratios are high at Jan Mayen (high La/Sm and ^(87)/^(86)Sr and low ^(206)/^(204)Pb, ^(187)/^(188)Os and ^(143)/^(144)Nd), intermediate in the Snæfellsnes Flank Zone and low in the Southern Flank Zone, including Surtsey. The fertile components are also present in tholeiites in the Icelandic rift zones and the NE Atlantic and Arctic ridges, despite larger proportions of melts from refractory asthenosphere. The SCLM/ROC-ratios are high where the distances to the nearest continental margin or the continental Jan Mayen Ridge are relatively short.

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