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We performed reaction experiments between partial melt of volatile-free MORB-eclogite and volatile-free fertile peridotite at 2.5–3GPa, 1375°C and 1440°C. The fraction of added basaltic andesite melt was varied from ~8 to 50wt.%. Melt was introduced either as a separate layer or mixed homogeneously with peridotite to simulate channelized and porous flow, respectively. Layered experiments produced a zone of orthopyroxene-rich garnet-websterite separating the reacted melt pool from a residual four phase lherzolite while mixed experiments produced a residual assemblage of orthopyroxene±clinopyroxene±olivine±garnet co-existing with reacted melt where residual olivine was absent only in the experiments with 50wt.% added melt. It is observed that the reacted melts display a continuous spectrum from tholeiitic to alkalic melts with increasing extent of wall–rock reaction for the layered runs and decreasing …