Origin and evolution of serpentine seamount fluids, Mariana and Izu-Bonin forearcs: Implications for the recycling of subducted material

he objective of this dissertation is to determine the origin and evolution of serpentine seamount fluids. Characterizing and quantifying the chemical fluxes in forearcs have important implications for the chemical evolution of the mantle and crust and mass-balancing of subduction-related geographical cycles. The serpentine seamounts of the Mariana and Izu-Bonin forearcs are interpreted to be the result of fluids generated by the dehydration of subducted material. These fluids interact with the overlying mantle wedge creating fluid charged serpentine diapirs. Thus, these seamounts provide an unique opportunity to study subduction-related fluids in subduction zones if the subducted origin of the fluids can be established.;Samples of serpentine matrix from two serpentine seamounts, Conical Seamount (ODP Sites 779 and 780) and Torishima Forearc Seamounts (ODP Site 784), and marine sediment were analyzed for ;In order to determine the origin of these fluids, the extent and character of fluid evolution must be characterized by back-stripping of the effects of seawater and seafloor interactions, mobilization through the forearc and on-going serpentinization. Seawater and seafloor interaction are evident by aragonite and B enrichment. Mafic material added to the serpentine matrix is evident by strong correlations of major and trace elements with ;Stable isotope compositions of serpentine matrix are consistent with a subducted origin for the serpentine seamount fluids.