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This study investigates the partial melting of variable bulk H 2 O-bearing parcels of mantle-wedge hybridized by partial melt derived from subducted metapelites, at pressure–temperature (P–T) conditions applicable to the hotter core of the mantle beneath volcanic arcs. Experiments are performed on mixtures of 25% sediment-melt and 75% fertile peridotite, from 1200 to 1300° C, at 2 and 3 GPa, with bulk H 2 O concentrations of 4 and 6 wt.%. Combining the results from these experiments with previous experiments containing 2 wt.% bulk H 2 O (Mallik et al., 2015), it is observed that all melt compositions, except those produced in the lowest bulk H 2 O experiments at 3 GPa, are saturated with olivine and orthopyroxene. Also, higher bulk H 2 O concentration increases melt fraction at the same P–T condition, and causes exhaustion of garnet, phlogopite and clinopyroxene at lower temperatures, for a given pressure …