This is an expedition objective research proposal that will use samples from IODP exp. 340 to the Lesser Antilles. This proposal seeks to examine the effect of tephra deposition and diagenesis on sediment chemistry, pore fluids, and ocean chemistry. The specific hypothesis is that tephra sedimentation and diagenesis promotes burial of organic carbon. It does this by consuming oxidizers that would otherwise degrade organic carbon and/or binding carbon to metals. The PI proposes to analyze major and trace elements and Sr isotopes, for all samples and pore waters. The PI also proposes to analyze organic C, carbonate, carbon isotopes, reactive Fe and Al for sediments and pore water solids. The work has the potential to provide an important constraint on the oceanic carbon cycle.
