New high-resolution compilation of benthic stable isotope data spanning 34 to 75 Ma - for both Atlantic and Pacific Ocean.

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In international collaboration we aim to develop an astronomically calibrated and high-resolution deep-sea benthic isotope reference curve for both Atlantic and Pacific Ocean spanning the Late Cretaceous to Eocene (34 to 75 Ma). The new record will utilize carefully selected deep-sea section at unprecedented resolution (<10kyr) and is envisioned to serve as the next generation benthic stable carbon and oxygen isotope reference curve. Current compilations do not resolve Milankovitch cyclicity and lack an astronomically tuned age model inadequate to study the true climate variability of the warm latest Cretaceous to Eocene global climate. With the recovery of new high-quality, multiple-hole cored sedimentary successions from the Atlantic (ODP Leg 171B, 207, 208, IODP Exp. 342) and the Pacific (ODP Leg 198 and 199, IODP Exp. 320/321) suitable material has been recovered to generate high-resolution (<10kyr) benthic stable isotope records. In our project we seek to compile available benthic stable isotope data, fill gaps by generating new records and increase the resolution of existing records from 34 to 75 Ma. Extensive generation of new benthic data will even allow forming a single continuous record for the South Atlantic on sediments retrieved during Leg 208 (Walvis Ridge). Based on extensive data sets and the detailed knowledge of earlier projects we will update, modify and then establish a fully integrated and consistent astronomically calibrated age model for the Atlantic and Pacific compilation which will consist of the genus Cibicidoides and Nuttallides only. Our synchronized astronomical time scale will provide completely new insight to the Eocene to Late Cretaceous climate dynamics. Having two high-resolution records from two ocean basins we will be able to compare Atlantic and Pacific paleoceanographic changes and characteristics at unprecedented detail in a relatively warm interval of Earths history. The high-resolution records established in this project combined with a very accurate age model will provide new insight to the instability of the climate system during the long-term cooling trend of the latest Campanian and Maastrichtian and the shift from greenhouse to icehouse climate state in the Late Eocene.