Complex sentence: In the subduction zone, loss of volatiles from the subducted slab induces partial melting of the overriding mantle and generates low-density, calc-alkaline magma that buoyantly rises to intrude and be extruded through the lithosphere of the overriding plate.
Split into simpler sentences: In the subduction zone, loss of volatiles from the subducted slab induces partial melting of the overriding mantle. This process, called flux melting, generates low-density calc-alkaline magma that buoyantly rises to intrude and be extruded through the lithosphere of the overriding plate.