Uncovering and quantifying the subduction zone sulfur cycle from the slab perspective.

ABSTRACT: Sulfur belongs among H₂O, CO₂, and Cl as one of the key volatiles in Earth's chemical cycles. High oxygen fugacity, sulfur concentration, and δ³⁴S values in volcanic arc rocks have been attributed to significant sulfate addition by slab fluids. However, sulfur speciation, flux, and isotope composition in slab-dehydrated fluids remain unclear. Here, we use high-pressure rocks and enclosed veins to provide direct constraints on subduction zone sulfur recycling for a typical oceanic lithosphere. Textural and thermodynamic evidence indicates the predominance of reduced sulfur species in slab fluids; those derived from metasediments, altered oceanic crust, and serpentinite have δ³⁴S values of approximately -8‰, -1‰, and +8‰, respectively. Mass-balance

SUBMITTER: Li JL 

PROVIDER: S-EPMC6981181 | biostudies-literature | 2020 Jan

REPOSITORIES: biostudies-literature