IEDA
Project Information
The Role of the Forearc in Subduction Zone Chemical Cycles: Elemental and Isotopic Signatures of Forearc Serpentinites, ODP Leg 125
Start Date:
1999-09-01
End Date:
2002-08-31
Description/Abstract
Subduction zones are the one place on Earth where materials from the surface (water, sediments and crustal rocks) can be carried into our planet's deep interior. To quantify this process of subduction-zone recycling, we need to understand both the input of sediments and crust to trenches, and all geochemical outputs related to the subduction process. While the chemical outputs represented by magmatism at volcanic arcs and in back-arc settings have been widely studied, little is known about possible subduction-related outfluxes through the shallow forearc, between the arc and the trench. We are attempting to characterize the "forearc flux" by examining serpentinites which are rising diapirically through the forearc mantle and crust in the Mariana arc-trench system. Our work will complete efforts begun (with NSF support) several years ago, and will characterize these samples (and the slab-derived fluids which helped to create them) for radiogenic isotopes, lithium and oxygen isotopes, and the "fluid-mobile" elements Cs, Rb, U, As, Pb, and Sb. Our work will allow us to characterize both the chemical inventories of species that are released from subducting slabs beneath forearcs, and the magnitude of this flux, for comparison with results for trench inputs (being collected as part of ODP Leg 125), and existing data for arc volcanic outputs in the Mariana system.
Personnel
Person Role
Ryan, Jeffrey Investigator
Funding
Marine Geology and Geophysics Award # 9977306
AMD - DIF Record(s)
Data Management Plan
None in the Database
Datasets
Repository Title (link) Status
USAP-DC B-Be-Li Abundance and Isotope Data: Mt. Erebus-McMurdo Volcanics exist

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