Building benchmark Pliocene-Pleistocene palaeomagnetic records using sediments cored during IODP Expedition 397 (Iberian Margin Palaeoclimate)

Marine sediments from the Iberian Margin have proven to be remarkable archives for the study of long (hundreds of thousand years) and short (hundreds to thousands of years) timescale changes in Earth's past climate. This archive can be tied to the benchmark polar ice core records and enables the study of detailed marine, ice core, and terrestrial linkages. This marine sediment reference record currently goes back about 1.4 million years. Exp. 397 will extend this reference record back to about 5 million years at multiple sites with varying water depths (sensitive to different water masses).

This unique set of sediment archives will allow us to answer a list of fundamental questions related to millennial and orbital scale climate variabilities, interhemispheric phase relationships, and terrestrial, marine, and ice core linkages. They also provide exciting opportunities to reconstruct past changes in Earth's magnetic field directions and intensity. Essential to these exciting research opportunities are reliable and detailed age models and stratigraphic correlations for the cored sediment sequences, so that the timing of events, rates of change and phase relation of processes can be confidently constrained.

This project will address this by generating high-resolution (every 1-cm interval) geochemical and palaeomagnetic data for selected cores. We will: develop high-resolution records of reversals/excursions, relative paleointensity (RPI), and palaeosecular variation (PSV) to help construct robust integrated stratigraphies and build benchmark records of the dynamics of geomagnetic changes; (ii) create high-resolution environmental magnetic records that are sensitive indicators of paleo-environmental/climate changes including millennial climate variability; and (iii) collect X-ray fluorescence (XRF) data to verify and improve hole-to-hole and site-to-site correlations.