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Siliceous slab-derived partial melts infiltrate the sub-arc mantle and cause rock-melt reactions, which govern the formation of diverse primary arc magmas and lithological heterogeneities. The effect of bulk water content, composition of reactants, and nature of melt infiltration (porous versus channelized) on the rock-melt reactions at sub-arc conditions have been investigated by previous studies. However, the effect of multiple episodes of rock-melt reactions in such scenarios has not been investigated before. Here, we explore mantle wedge modifications through serial additions of hydrous-silicic slab partial melts and whether such a process may ultimately explain the origin of high-Mg# andesites found in arcs worldwide. A series of piston-cylinder experiments simulate a serial addition of silicic slab melts in up to three stages (I through III) at 3 GPa and 800–1050°C, using rock-melt proportions of 75–25 and 50 …