Der Eozän/Oligozän Übergang aus zyklostratigraphischer Perspektive

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We plan to establish a fully integrated and astronomically calibrated bio-, chemo-, and magnetostratigraphy at the equatorial Pacific for the Bartonian and Priabonian (41 to 34 Ma) to improve, date, and intercalibrate bio- and magnetostratigraphic datums. An accurate and precise age model is critical to unravel the cause and consequences of events across the Eocene/Oligocene climatic transition. Prerequisite is the correlation and integration of ODP Leg 199 (Sites 1218 through 1220) and IODP Expedition 320 (Sites U1331 through U1334) data (XRF core scanning, physical properties, bio- and magnetostratigraphy) for the middle to late Eocene and earliest Oligocene (magnetic polarity chrons C12n to C20n). The revised composite records will be used to validate and extend the astronomical calibration of the geological timescale into the middle Eocene. We plan to reconstruct the equatorial Pacific Carbonate Compensation Depth (CCD) in detail by using calibrated high-resolution XRF core scanning data with the aim to address how and why the acidity of the oceans changed in association with shifts in the global Eocene climate. We further will explore the characteristics of the Carbonate Accumulation Events (CAE) and evaluate the relationship of the long-period carbonate cycles in the equatorial Pacific sediments to astronomical forcing. Finally, we would like to contribute to a new high-resolution (on orbital time-scales) record of stable isotopes from bulk sediments at four IODP Exp. 320 sites (U1331 through U1334) along a depth transect from the top of magnetic polarity chron C15n through the base of C12r across the Eocene/Oligocene transition (35 to 33 Ma).