Completing the Eocene cyclostratigraphy - new perspectives from a greenhouse world

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The aim of our project is to establish a for the first time complete cyclostratigraphic framework based on the identification of the stable long eccentricity cycle for the entire Eocene (55 to 34 Ma) for both the Atlantic and Pacific oceans at unprecedented resolution. The accuracy of the intended age model for both oceans will allow very detailed insights into the Eocene greenhouse climate variability in general and the transition to a cooler Late Paleogene climate state. In the here proposed third year we plan to round-off and extend our records based on the right now evolving, very exciting results. These additional analyses are crucial to achieve the scientific objectives of our project. New magnetostratigraphic data covering magnetic polarity Chrons C23 and C24n at Leg 208 sites and additional stable isotope data to determine the exact duration of magnetic polarity Chron C18n are key records for completing the Eocene Atlantic stratigraphic framework. Built on the very promising results from the ongoing first phase of our project we envisage investigating additional selected intervals for two additional, relative short high-resolution benthic isotope records. This is important to test whether Earth´s climate cooled through a series of individual steps rather than gradually at the end of the long-term cooling following the extremely warm world of the Early Eocene Climate Optimum more than 12 million years before the Eocene - Oligocene transition. Ultimately, integrating and synthesizing all magneto-, chemo-, and cyclostratigraphic data of the project will substantially contribute to document the occurrence and frequency of middle to late Eocene hyperthermal events, understanding their relationship to orbital forcing, and their relationship to greenhouse climate dynamics.