High-silica boninite magma was generated by remelting of recycled, Proterozoic slab: A probe into the upper mantle heterogeneity

Abstract

It is of prime interest to understand how subducted slab circulates and is assimilated to the convecting asthenospheric mantle. The residual mantle comprising the majority of slab is considered to have been fragmented and dispersed within the depleted MORB mantle (DMM), enhancing the heterogeneity of the upper mantle. These residues are highly refractory and are hence uninvolved in most magmas produced in the convecting mantle. Analyses of the genetic conditions of boninite revealed an essential role of Proterozoic slab as the boninite magma source, providing an insight to the heterogeneity of the upper mantle.