Serpentinite, formed by low-temperature hydrothermal alteration of mantle peridotite, is distributed in the lithospheric mantle at the bottom of the subduction slab (slab-serpentinite) and forearc mantle wedge above the subduction slab (mantle wedge serpentinite) in the subduction zone.
Click here for original story, Zinc isotopes of arc-related lavas reveal recycling of forearc serpentinites into subarc mantle
Source: Phys.org