Investigation of blueschist and serpentinized harzburgite from the Mariana forearc: Insights into the mechanisms of element mobilization in subduction zones and storage of fluid-mobile elements in the mantle wedge

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The serpentine-mud volcanoes from the forearc of the Izu-Bonin-Mariana (IBM) subduction zone houses the only known samples worldwide that have been transported to the ocean floor from within an active subduction zone from a depth of 20 km (directly from the slab-mantle interface). Many serpentinized harzburgites and blueschist-facies metamafics are found within the serpentine-mud. Using high-resolution, in situ geochemical analysis, this project seeks to study these samples, which offer unique information about the subduction process. In particular, this project includes secondary ion mass spectrometry (SIMS) as well as Time-of-Flight (TOF)-SIMS, in order to ascertain accurate Li and B concentrations, 0 B-measurements at a scale of 10-30//m, as well as element-mapping of the above-mentioned elements with a <\pm resolution, respectively. Combining these techniques with other modern forms of analysis should help to answer how trace elements at the ^m scale are included in particularly fine-grained minerals. It is thought that this strategy will allow the recognition of specific trace element pattern associated with specific textures within these rocks, which reflect specific subduction zone processes.