Evaluation of linkages between climate change and sedimentary biogeochemistry in the glacial/interglacial North Atlantic

Over the past 125,000 years, global climate has varied in lock step with the growth and decay of large continental ice sheets. Concomitant with these large-scale glacial/interglacial climate shifts are marked changes in deep-sea sedimentation in the North Atlantic basin. Warm interglacial climates are generally associated with more CaCO3-rich deep-sea sediments, while cold glacial intervals are typically manifest as more clay-rich intervals. This study examines the impact of these glacial/interglacial sedimentologic changes on benthic (ocean bottom) biogeochemistry, and also investigates potential feedbacks between benthic processes and climate. In addition to documenting the glacial/interglacial response of marine sedimentation in the North Atlantic, with respect to select major, minor and trace elements that can be used to reconstruct changes in lithogenous, biogenic and authigenic processes, this work addresses a number of key biogeochemical interactions that centrally involve iron, which is plentiful in the clay-rich glacial sediments, but scarce in the interglacial sediments.