Our measurements of Hf and Nd isotopic compositions for Aleutian lavas from locations from Cold Bay, which is located on the western tip of the Alaska Peninsula, to Piip Volcano, an active seamount near Medny Island in the far western Aleutians, demonstrate that the isotopic compositions of Aleutian lavas is strongly tied to their physical location in the arc, which is tied to the subduction rate and the rate of sedment recycling, which both decrease from east-to-west along the arc.