Intraplate volcanism: concepts, problems and proofs

Models for the generation of sources for intraplate volcanism include: (i) the plume model involving isolation of subducted oceanic crust at depth in the mantle; (ii) the streaky-mantle model where ocean island basalts are derived from preferential melting of crustal components remixed into the convecting mantle MORB-source; (iii) the hydrous-peridotite model where volatile-bearing sources are generated at convergent margins from the infusion of slab-derived melts or fluids and sediment into the mantle wedge, and are superimposed on streaky-mantle heterogeneity. Only the latter satisfies geochemical constraints and produces a source with lower solidus temperature than average mantle as required by petrological evidence.