Subduction-Related Hydration and Sulfur Metasomatism
in the Mariana forearc mantle wedge:.
Hydration and serpentinization of the mantle wedge during subduction
in the Mariana forearc has resulted in protrusion of serpentintite seamounts
at the surface (Fig 1). At these sites, serpentite formed at depth
is exposed at the surface and fluids derived from the subducting slab,
some 30 km below, vent from these seamounts. Study of the sulfide
and oxide mineralogy and the contents and isotopic compositions of sulfur
in the serpentinites will help constrain the conditions of serpentinization
at depth, and provide important data to understand fluxes of slufr from
the slab to arc volcanics (e.g., Alt et al., 1993).